THPOPT —  Poster Session - Padthai   (16-Jun-22   16:00—18:00)

Paper	Title	Page
THPOPT001	Online Optimization of the ESRF-EBS Storage Ring Lifetime	2552
	N. Carmignani, L.R. Carver, L. Hoummi, S.M. Liuzzo, T.P. Perron, P. Raimondi, S.M. White ESRF, Grenoble, France
	In the first year of op­er­a­tion of the EBS stor­age ring, on­line non­lin­ear dy­nam­ics op­ti­mi­sa­tions were per­formed to in­crease the Tou­schek life­time. Sev­eral sex­tu­pole, oc­tu­pole and skew quadru­pole knobs have been stud­ied in sim­u­la­tions and tested in the ma­chine. A fast op­ti­mi­sa­tion pro­ce­dure has been de­fined and it is fol­lowed at each ma­chine restart. The knobs and the op­ti­mi­sa­tion pro­ce­dure are de­scribed in the paper. As a re­sult, up to 41 h Tou­schek life­time in nom­i­nal multi-bunch mode have been achieved.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT001
About •	Received ※ 07 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 21 June 2022
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THPOPT002	Beam Power Deposition on the Cryogenic Permanent Magnet Undulator	2556
	L.R. Carver, C. Benabderrahmane, P. Brumund, N. Carmignanipresenter, J. Chavanne, G. Le Bec, R. Versteegen, S.M. White ESRF, Grenoble, France
	X-rays with high bril­liance and low phase er­rors are gen­er­ated in the Cryo­genic Per­ma­nent Mag­net Un­du­la­tor (CPMU) cur­rently in use at the ESRF. In the event of a fail­ure of the cryo­genic cool­ing the beam will con­tinue to de­posit power into the mod­ule, even when the un­du­la­tor jaws are fully opened. This could lead to un­ac­cept­ably high heat­ing of the mag­net blocks which could cause their de­mag­neti­sa­tion. Im­ped­ance sim­u­la­tions were per­formed using IW2D and CST to com­pute the power de­posited by the beam in both the closed and open jaw set­tings. This was fol­lowed by ther­mal sim­u­la­tions to com­pute the ex­pected tem­per­a­ture rise. These re­sults will help ad­vise the op­er­a­tional pro­ce­dure in the event of a cool­ing fail­ure.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT002
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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THPOPT003	A First attempt at implementing TRIBs in BESSY III’s Design Lattice	2560
	M. Arlandoo, P. Goslawski, M. Titzepresenter HZB, Berlin, Germany
	At HZB’s BESSY II and PTB’s Metrol­ogy Light Source (MLS), res­o­nances and is­lands in trans­verse phase space are ex­ploited in a spe­cial op­er­a­tion mode usu­ally re­ferred to as Trans­verse Res­o­nance Is­land Buck­ets (TRIBs). This mode pro­vides a sec­ond sta­ble orbit well sep­a­rated from the main orbit and one of its ap­pli­ca­tions in pho­ton sci­ence is the ul­tra-fast switch­ing of the he­lic­ity of cir­cu­larly po­lar­ized light pulses. In the con­text of the con­cep­tual de­sign study of BESSY III, it is under in­ves­ti­ga­tion how this spe­cial op­tics mode can be im­ple­mented in an MBA struc­ture and how it will im­pact the pho­ton source pa­ra­me­ters. In this paper we pre­sent a pre­lim­i­nary at­tempt at im­ple­ment­ing TRIBs in BESSY III’s de­sign lat­tice, a multi-bend achro­mat, by break­ing the sym­me­try of the lat­tice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT003
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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THPOPT004	Design of a Compact 180-Degree Single-Shot Energy Spectrometer Based on a Halbach Dipole Magnet	2564
	R. Bazrafshan, T. Rohwer Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany M. Fakhari, N.H. Matlis CFEL, Hamburg, Germany F.X. Kaernter DESY, Hamburg, Germany
	In the AXSIS pro­ject at DESY, we de­velop com­pact THz ac­cel­er­at­ing struc­tures for a table-top x-ray source. Ac­cel­er­a­tion is achieved by pass­ing the elec­tron beam through a di­elec­tric-loaded wave­guide pow­ered by multi-cy­cle THz ra­di­a­tion. The final elec­tron en­ergy strongly de­pends on THz-power in­jected into the LINAC and tim­ing. Thus in first ex­per­i­ments we ex­pect large en­ergy fluc­tu­a­tions and a large range of en­er­gies to cover. We de­signed an elec­tron en­ergy spec­trom­e­ter for a wide range of final en­er­gies cov­er­ing 5 to 20 MeV in a sin­gle-shot. Here, we pre­sent the de­sign of an en­ergy spec­trom­e­ter which uses a com­pact di­pole mag­net based on the Hal­bach array con­cept to de­flect the elec­tron beam through a 180° path in­ter­cepted by a Fiber Optic Scin­til­la­tor (FOS) mounted in­side the vac­uum per­pen­dic­u­lar to the beam. The 180-de­gree bend­ing geom­e­try pro­vides the pos­si­bil­ity of hav­ing the focus point of all en­er­gies at the same dis­tance from the mag­net edge which makes the de­sign sim­pler and more com­pact. It also re­moves the ne­ces­sity of in­stalling a safety di­pole at the end of the ac­cel­er­a­tor. A slit sys­tem at the spec­trom­e­ter en­trance in­creases res­o­lu­tion to bet­ter than 0.2%.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT004
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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THPOPT005	Field Enhanced, Compact S-Band Gun Employing a Pin Cathode	2567
SUSPMF020	use link to see paper's listing under its alternate paper code
	R. Bazrafshan, T. Rohwer Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany M. Fakhari, K. Flöttmann, F.X. Kaernter DESY, Hamburg, Germany N.H. Matlis CFEL, Hamburg, Germany
	S-band RF-guns are highly de­vel­oped for pro­duc­tion of low emit­tance rel­a­tivis­tic elec­tron bunches, but need pow­er­ful kly­strons for dri­ving. Here, we pre­sent the de­sign and first ex­per­i­men­tal tests of a com­pact S-band gun, which can ac­cel­er­ate elec­trons up to 180 keV pow­ered by only 10 kW from a com­pact rack-mount­able solid-state am­pli­fier. A pin-cath­ode is used to en­hance the RF elec­tric field on the cath­ode up to 100 MV/m as in large-scale S-band guns. An elec­tron bunch is gen­er­ated through pho­toe­mis­sion off a flat cop­per sur­face on the pin ex­cited by a UV laser pulse fol­lowed by a fo­cus­ing so­le­noid pro­duc­ing a low emit­tance bunch with 0.1 mm mrad trans­verse emit­tance for up to 100 fC bunch charge. We are cur­rently in the con­di­tion­ing phase of the gun and first ex­per­i­ments show good agree­ment with sim­u­la­tions. The com­pact gun will serve three pur­poses: (i) it can be used di­rectly for ul­tra­fast elec­tron dif­frac­tion; (ii) as an in­jec­tor into a THz booster pro­duc­ing 0.3MeV to 2 MeV elec­tron bunches for ul­tra­fast elec­tron dif­frac­tion; (iii) The sys­tem in (ii) serves as an in­jec­tor into a THz lin­ear ac­cel­er­a­tor pro­duc­ing a 20 MeV beam for the AXSIS X-ray source pro­ject.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT005
About •	Received ※ 21 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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THPOPT006	Beam Dynamics Observations at Negative Momentum Compaction Factors at KARA	2570
	P. Schreiber, M. Brosi, B. Härer, A. Mochihashi, A.-S. Müller, A.I. Papash, R. Ruprecht, M. Schuh KIT, Karlsruhe, Germany
	Funding: We are supported by the DFG-funded "Karlsruhe School of Elementary and Astroparticle Physics: Science and Technology" and European Union’s Horizon 2020 research and innovation programme (No 730871) For the de­vel­op­ment of fu­ture syn­chro­tron light sources new op­er­a­tion modes often have to be con­sid­ered. One such mode is the op­er­a­tion with a neg­a­tive mo­men­tum com­paction fac­tor to pro­vide the pos­si­bil­ity of in­creased dy­namic aper­ture. For suc­cess­ful ap­pli­ca­tion in fu­ture light sources, the in­flu­ence of this mode has to be in­ves­ti­gated. At the KIT stor­age ring KARA (Karl­sruhe Re­search Ac­cel­er­a­tor), op­er­a­tion with neg­a­tive mo­men­tum com­paction has been im­ple­mented and the dy­nam­ics can now be in­ves­ti­gated. Using a va­ri­ety of high-per­for­mance beam di­ag­nos­tics de­vices it is pos­si­ble to ob­serve the beam dy­nam­ics under neg­a­tive mo­men­tum com­paction con­di­tions. This con­tri­bu­tion pre­sents dif­fer­ent as­pects of the re­sults of these in­ves­ti­ga­tions in the lon­gi­tu­di­nal and trans­ver­sal plane.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT006
About •	Received ※ 08 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 08 July 2022
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THPOPT007	High Bunch Charges in the Second Injection Beamline of MESA	2574
	A.A. Kalamaiko, K. Aulenbacher, M.A. Dehn, S. Friederich, C.P. Stollpresenter KPH, Mainz, Germany
	MESA (Mainz En­ergy-re­cov­er­ing Su­per­con­duct­ing Ac­cel­er­a­tor) is an ac­cel­er­a­tor with two laser-dri­ven elec­tron sources (po­lar­ized and un­po­lar­ized) op­er­at­ing at 100 kV which is under con­struc­tion at the Jo­hannes Guten­berg Uni­ver­sity in Mainz. The un­po­lar­ized elec­tron source MIST (MESA In­jec­tor Source Two) al­lows to pro­duce high charged elec­tron bunches with charge up to 7.7 pC. This source and a Mott po­larime­ter will be arranged on the same height above the MESA in­jec­tor main beam­line. A par­al­lel shift­ing beam­line was de­vel­oped which al­lows to trans­port high charged beam from the source MIST to the main MESA beam­line. More­over, the de­signed beam­line al­lows to trans­port beam from the elec­tron source STEAM to the Mott po­larime­ter. This re­port is ded­i­cated to the de­sign of the sep­a­ra­tion beam­line which trans­ports and com­presses highly charged elec­tron bunches from the elec­tron source MIST to the first ac­cel­er­a­tion sec­tion of MESA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT007
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 23 June 2022 — Issue date ※ 23 June 2022
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THPOPT008	Beam Orbit Shift Due to BPM Thermal Deformation Using Machine Learning	2577
	K.M. Chen, M. Hosaka, F.Y. Wang, G. Wang, Z. Wang, W. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China L. Guopresenter Nagoya University, Nagoya, Japan
	Sta­bi­liz­ing beam orbit is crit­i­cal for ad­vanced syn­chro­tron ra­di­a­tion light sources. The beam orbit can be af­fected by many sources. To main­tain a good orbit sta­bil­ity, global orbit feed­back sys­tems (OFB) has been widely used. How­ever, the BPM ther­mal de­for­ma­tion would lead to BPM mis­read­ing, which can not be han­dled by OFB. Usu­ally, extra di­ag­nos­tics, such as po­si­tion trans­duc­ers, is needed to mea­sure the de­for­ma­tion de­pen­dency of BPM read­ings. Here, an al­ter­na­tive ap­proach by using the ma­chine op­er­a­tion his­toric data, in­clud­ing BPM tem­per­a­ture, in­ser­tion de­vice (ID) gaps and cor­rec­tor cur­rents, is pre­sented. It is demon­strated at Hefei Light Source (HLS). The av­er­age orbit shift due to BPM ther­mal de­for­ma­tion is about 34.5 mi­crons/de­gree Cel­sius (hor­i­zon­tal) and 20.0 mi­crons/de­gree Cel­sius (ver­ti­cal).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT008
About •	Received ※ 19 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
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THPOPT009	Dependency Measurement of BPM Reading in the HLS-II Storage Ring	2580
	G. Wang, K.M. Chen, G. Feng, M. Hosaka, Z. Wang, W. Xu USTC/NSRL, Hefei, Anhui, People’s Republic of China L. Guopresenter Nagoya University, Nagoya, Japan S.W. Wang DLS, Oxfordshire, United Kingdom
	Beam orbit sta­bil­ity is es­sen­tial for the op­er­a­tion of the stor­age ring based light sources. Orbit feed­back sys­tems are com­monly adopted to main­tain the beam on a ref­er­ence orbit. How­ever, the BPM read­ing could be af­fected by its tem­per­a­ture, beam cur­rent, etc, which leads to shift of the beam ref­er­ence orbit. On­line ex­per­i­ment is car­ried out in the HLS-II stor­age ring to study the de­pen­dence of the beam ref­er­ence orbit on the BPM tem­per­a­ture and beam cur­rent. The re­sult shows that the av­er­age change of BPM read­ings due to BPM tem­per­a­ture is about 37.4 ’m/’C hor­i­zon­tally and 11.5 ’m/’C ver­ti­cally. The av­er­age change of BPM read­ings in­duced by beam cur­rent is about 0.27 ’m/mA hor­i­zon­tally and 0.20 ’m/mA ver­ti­cally.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT009
About •	Received ※ 19 May 2022 — Revised ※ 23 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 28 June 2022
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THPOPT010	Beam Loss Reduction During Energy Ramp-Up at the SAGA-LS	2583
	Y. Iwasaki SAGA, Tosu, Japan
	The ac­cel­er­a­tor of the SAGA Light Source (SAGA-LS) con­sists of a 255 MeV in­jec­tor linac and a 1.4 GeV stor­age ring. The en­ergy of the elec­trons is ramped up to 1.4 GeV in 4 min­utes in the stor­age ring. The elec­tron beam cur­rent stored in the stor­age ring is about 300 mA. At the beg­ging of the en­ergy ramp-up, the elec­tron beam was lost like step func­tion. The lost beam cur­rent was nor­mally about 5 mA to 30 mA. To un­der­stand the beam loss mech­a­nism, we de­vel­oped si­mul­ta­ne­ous image log­ging sys­tem of beam pro­file in ad­di­tion to the beam cur­rent, the mag­nets power sup­plies, and the beam po­si­tions using Na­tional In­stru­ments PXI. It was found that the ver­ti­cal beam size was grow­ing in the step-like beam loss process. The small per­tur­ba­tion of the out­put cur­rents of the quadru­pole power sup­plies caused the ver­ti­cal beam size growth. By op­ti­miz­ing the ramp-up pat­tern of the quadru­pole power sup­plies, sex­tu­pole power sup­plies, and the steer­ing power sup­plies for the orbit con­trol, we have achieved the re­duc­tion of the step-like beam loss and total time of the ramp-up.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT010
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 28 June 2022
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THPOPT013	Emittance Reduction with the Variable Dipole for the ELETTRA 2.0 Ring	2586
	A. Poyet, Y. Papaphilippou CERN, Meyrin, Switzerland M.A. Domínguez, F. Toral CIEMAT, Madrid, Spain R. Geometrante, E. Karantzoulis Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy R. Geometrante KYMA, Trieste, Italy
	ELET­TRA is a 2/2.4 GeV third-gen­er­a­tion elec­tron stor­age ring, lo­cated near Tri­este, Italy. In view of a sub­stan­tial in­crease of the ma­chine per­for­mance in terms of bril­liance, the so-called ELET­TRA 2.0 up­grade is cur­rently on-go­ing. This up­grade is based on a 6-bends achro­mat, four dipoles of which hav­ing a lon­gi­tu­di­nally vari­able field. So far, those dipoles are fore­seen to pro­vide a field with a two step pro­file. The VAri­able Di­pole for the ELET­TRA Ring (VADER) task, dri­ven by the I.​FAST Eu­ro­pean pro­ject, aims at de­vel­op­ing a new di­pole de­sign based on a trape­zoidal shape of the bend­ing ra­dius, which would allow for a fur­ther re­duc­tion of the hor­i­zon­tal emit­tance. A pro­to­type of this mag­net should be de­signed by the CIEMAT lab­o­ra­tory and built by KYMA com­pany. This paper dis­cusses the new di­pole field spec­i­fi­ca­tion and de­scribes the cor­re­spond­ing op­tics op­ti­miza­tion that was per­formed in order to re­duce at best the emit­tance of the ELET­TRA ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT013
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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THPOPT014	Simulation and Optimization of SPS-II Linac	2590
	T. Chanwattana, S. Chunjarean, N. Juntong, S. Klinkhieo, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	Siam Pho­ton Source II (SPS-II), the new 3-GeV syn­chro­tron light source pro­ject in Thai­land, has been de­signed based on an ac­cel­er­a­tor sys­tem con­sist­ing of a 150-MeV in­jec­tor linac, a full-en­ergy booster syn­chro­tron and a stor­age ring based on a Dou­ble Triple Bend Achro­mat (DTBA) lat­tice. A turn-key linac sys­tem has been used in an in­jec­tion sys­tem of many syn­chro­tron fa­cil­i­ties, and thus it is con­sid­ered for the SPS-II pro­ject. Pre­lim­i­nary beam dy­nam­ics sim­u­la­tion and op­ti­miza­tion of the SPS-II linac are nec­es­sary for in­ves­ti­gat­ing achiev­able beam pa­ra­me­ters which can be used for study of beam in­jec­tion through a trans­fer line to the booster. Multi-ob­jec­tive op­ti­miza­tion al­go­rithm (MOGA) has been used in de­sign and op­ti­miza­tion of many ac­cel­er­a­tors in­clud­ing a linac sys­tem for syn­chro­tron light sources, sim­i­lar to the SPS-II linac. In this paper, re­sults of beam dy­nam­ics sim­u­la­tion and MOGA op­ti­miza­tion of the SPS-II linac are dis­cussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT014
About •	Received ※ 19 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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THPOPT015	The Design of the Full Energy Beam Exploitation (FEBE) Beamline on CLARA	2594
	A.R. Bainbridge, D. Angal-Kalinin, J.K. Jones, T.H. Pacey, Y.M. Saveliev, E.W. Snedden STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The CLARA fa­cil­ity at Dares­bury Lab­o­ra­tory was orig-in­ally de­signed for the study of novel FEL physics utilis-ing high-qual­ity elec­tron bunches at up to 250 MeV/c. To max­imise the ex­ploita­tion of the ac­cel­er­a­tor com­plex, a ded­i­cated full en­ergy beam ex­ploita­tion (FEBE) beam-line has been de­signed and is cur­rently being in­stalled in a sep­a­rate vault on the CLARA ac­cel­er­a­tor. FEBE will allow the use of high charge (up to 250 pC), mod­er­ate en­ergy (up to 250 MeV), elec­tron bunches for a wide va­ri­ety of ac­cel­er­a­tor ap­pli­ca­tions crit­i­cal to on­go­ing ac­cel­er­a­tor de­vel­op­ment in the UK and in­ter­na­tional com­mu­ni­ties. The fa­cil­ity con­sists of a shielded en­clo-sure, ac­ces­si­ble dur­ing beam run­ning in CLARA, with two very large ex­per­i­men­tal cham­bers com­pat­i­ble with a wide range of ex­per­i­men­tal pro­pos­als. High-power laser beams (up to 100 TW) will be avail­able for elec­tron-beam in­ter­ac­tions in the first cham­ber, and there are con­crete plans for a wide va­ri­ety of ad­vanced di­ag­nos­tics (in­clud-ing a high-field per­ma­nent mag­net spec­trom­e­ter and di­elec­tric lon­gi­tu­di­nal streaker), es­sen­tial for mul­ti­ple ex­per­i­men­tal par­a­digms, in the sec­ond cham­ber. FEBE will be com­mis­sioned in 2024.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT015
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT016	Commissioning Simulations for the DIAMOND-II Upgrade	2598
	H.C. Chao, R.T. Fielder, J. Kallestrup, I.P.S. Martin, B. Singh DLS, Oxfordshire, United Kingdom
	The Di­a­mond-II stor­age ring, com­pared to Di­a­mond, im­proves the nat­ural beam emit­tance from 2.7 nm to 160 pm and the beam en­ergy from 3 to 3.5 GeV. The num­ber of straight sec­tions is also dou­bled from 24 to 48 thanks to the mod­i­fied hy­brid six-bend-achro­mat lat­tice. To re­duce the im­pact on the ex­ist­ing sci­ence pro­gram, the dark time pe­riod must be min­imised. To as­sist in this aim, stor­age ring com­mis­sion­ing sim­u­la­tions have been car­ried out to pre­dict and re­solve pos­si­ble is­sues. These stud­ies in­clude beam com­mis­sion­ing start­ing from on-axis first-turn beam thread­ing up to beam based align­ment and full lin­ear op­tics cor­rec­tion with stored beam. The lin­ear op­tics cor­rec­tions with in­ser­tion de­vices are also in­cluded. The ma­chine char­ac­ter­i­sa­tions at dif­fer­ent stages are com­pared. Con­sid­er­a­tions on re­al­is­tic cham­ber lim­i­ta­tions, error de­f­i­n­i­tions and some com­mis­sion­ing strate­gies are also dis­cussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT016
About •	Received ※ 19 May 2022 — Accepted ※ 15 June 2022 — Issue date ※ 15 June 2022
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THPOPT017	Orbit Stability Studies for the Diamond-II Storage Ring	2602
	I.P.S. Martin, C.A. Abraham, D. Crivelli, H. Ghasempresenter, B. Nicholson, T. Olsson, P. Sanchez Navarro DLS, Oxfordshire, United Kingdom
	The pho­ton-beam po­si­tional sta­bil­ity rel­a­tive to the beam size is a key per­for­mance pa­ra­me­ter for stor­age ring light sources. The nat­ural emit­tance of the Di­a­mond-II ring will be low­ered by a fac­tor 16.7 com­pared to the ex­ist­ing ring, so the ab­solute sta­bil­ity re­quire­ment for the elec­tron beam must re­duce ac­cord­ingly. In ad­di­tion, ad­vances in de­tec­tor speed and res­o­lu­tion mean the tol­er­ances are tighter com­pared to pre­vi­ous gen­er­a­tions of stor­age rings, with a tar­get of 3 % of beam size up to 1 kHz hav­ing been adopted for Di­a­mond-II. In this paper we pre­sent stud­ies of how the an­tic­i­pated ground vi­bra­tions, girder mo­tion and power sup­ply rip­ple will af­fect the elec­tron beam sta­bil­ity as a func­tion of fre­quency.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT017
About •	Received ※ 08 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022
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THPOPT018	Aperture Sharing Injection for Diamond-II	2606
	J. Kallestrup, H. Ghasempresenter, I.P.S. Martin DLS, Oxfordshire, United Kingdom
	The planned Di­a­mond-II stor­age ring will pro­vide users with an in­crease in bright­ness of up to two or­ders of mag­ni­tude com­pared with the ex­ist­ing Di­a­mond fa­cil­ity. The aim is to main­tain ex­cel­lent pho­ton beam sta­bil­ity in top-up mode, which re­quires fre­quent in­jec­tions. This paper in­tro­duces the aper­ture shar­ing in­jec­tion scheme de­signed for Di­a­mond-II. The scheme promises, through the use of short striplines equipped with high-volt­age nano-sec­ond pulsers, a quasi-trans­par­ent in­jec­tion while main­tain­ing an ap­prox­i­mately 100% in­jec­tion ef­fi­ciency.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT018
About •	Received ※ 31 May 2022 — Accepted ※ 30 June 2022 — Issue date ※ 01 July 2022
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THPOPT019	Multi-Alkali Antimonide Photocathode Development for High Brightness Beams	2610
	S. Mistry, T. Kamps, J. Kühn, C. Wang HZB, Berlin, Germany T. Kamps HU Berlin, Berlin, Germany C. Wang University Siegen, Siegen, Germany
	Funding: This work is funded by the DFG CO 1509/10-1 | MI 2917/1-1 Pho­to­cath­ode R&D at the Helmholtz-Zen­trum Berlin (HZB) is dri­ven by the mo­ti­va­tion to pro­duce high bright­ness elec­tron beams for the SRF pho­toin­jec­tor test fa­cil­ity, Sealab/ bERLinPro. Multi-al­kali an­ti­monides are the choice pho­to­cath­ode ma­te­r­ial due to high quan­tum ef­fi­ciency (QE) and low in­trin­sic emit­tance in the vis­i­ble range. In this work a more ro­bust al­ter­na­tive to the tried and tested Cs-K-Sb is con­sid­ered. Na-K-Sb of­fers sim­i­lar ad­van­tages to Cs-K-Sb in­clud­ing, high QE at green wave­lengths but more­over, it of­fers ex­cel­lent sta­bil­ity at el­e­vated tem­per­a­tures. This prop­erty could lengthen the cath­ode life­time by en­hanc­ing the ro­bust­ness of the pho­to­cath­ode in­side the SRF gun. In this work, a sta­tus re­port show­cas­ing first re­sults to­wards the de­vel­op­ment of a growth pro­ce­dure for Na-K-Sb is pre­sented by means of spec­tral re­sponse and XPS mea­sure­ments con­ducted in the HZB pho­to­cath­ode lab.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT019
About •	Received ※ 03 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 04 July 2022
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THPOPT020	Status and Plans for the New CLS Electron Source Lab	2614
	M.J. Boland, D. Bertwistle, F. Le Pimpec CLS, Saskatoon, Saskatchewan, Canada X.F.D. Stragier TUE, Eindhoven, The Netherlands
	The Cana­dian Light Source (CLS) has re­cently cre­ated a new Elec­tron Source Lab (ESL) that can run in­de­pen­dently from user op­er­a­tions. A sec­tion of the old Saskatchewan Ac­cel­er­a­tor Lab­o­ra­tory ex­per­i­men­tal nu­clear physics tun­nels has been re­built with new shield­ing and a sep­a­rate en­trance. The lab­o­ra­tory will be used to pre­pare an op­er­a­tional spare elec­tron gun for the 250 MeV linac. In ad­di­tion, there are plans to de­velop RF guns for a fu­ture branch line to in­ject into the linac and for pos­si­ble short pulse pro­duc­tion. This paper will give an overview of the ESL space and the first elec­tron guns which plan to be in­stalled.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT020
About •	Received ※ 16 June 2022 — Revised ※ 29 June 2022 — Accepted ※ 04 July 2022 — Issue date ※ 08 July 2022
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THPOPT022	Study on QE Evolution of Cs₂Te Photocathodes in ELBE SRF Gun-II	2617
	R. Xiang, A. Arnold, S. Ma, P. Michelpresenter, P. Murcek, A.A. Ryzhov, J. Schaber, J. Teichert, P.Z. Zwartek HZDR, Dresden, Germany
	The qual­ity of the pho­to­cath­odes is crit­i­cal for the sta-bil­ity and re­li­a­bil­ity of the pho­toin­jec­tor’s op­er­a­tion. Thanks to the ro­bust mag­ne­sium and Cs2Te pho­to­cath­odes, SRF gun-II at HZDR has been proven to be a suc-cess­ful ex­am­ple in CW mode for high cur­rent user op­er­a­tion. In this con­tri­bu­tion, we will pre­sent our ob­ser­va­tion of the QE evo­lu­tion of Cs2Te pho­to­cath­odes dur­ing SRF gun op­er­a­tion. The vari­ables in­clud­ing sub­strate sur­face, film thick­ness, Cs/Te sto­i­chio­met­ric, mul­ti­pact­ing, RF load­ing and charge ex­tract are con­sid­ered in the analy­sis.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT022
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022
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THPOPT023	Flexible Features of the Compact Storage Ring in the cSTART Project at Karlsruhe Institute of Technology	2620
	A.I. Papash, A. Bernhard, E. Bründermann, D. El Khechen, B. Härer, A.-S. Müller, R. Ruprecht, J. Schaeferpresenter, M. Schwarz KIT, Karlsruhe, Germany
	Within the cSTART pro­ject (com­pact stor­age ring for ac­cel­er­a­tor re­search and tech­nol­ogy), a Very Large Ac­cep­tance com­pact Stor­age Ring (VLA-cSR) will be re­al­ized at the In­sti­tute for Beam Physics and Tech­nol­ogy (IBPT) of the Karl­sruhe In­sti­tute of Tech­nol­ogy. (KIT). A mod­i­fied geom­e­try of a com­pact stor­age ring op­er­at­ing at 50 MeV en­ergy range has been stud­ied and main fea­tures of the new model are de­scribed here. The new de­sign, based on 45° bend­ing mag­nets, is suit­able to store a wide mo­men­tum spread beam as well as ul­tra-short elec­tron bunches in the sub-ps range in­jected from the plasma cell as well as from the Fer­n­in­frarot Linac- Und Test Ex­per­i­ment (FLUTE). The DBA lat­tice of the VLA-cSR with dif­fer­ent set­tings and re­laxed pa­ra­me­ters, split el­e­ments and higher order op­tics of tol­er­a­ble strength al­lows to im­prove the dy­namic aper­ture and mo­men­tum ac­cep­tance to an ac­cept­able level. This con­tri­bu­tion dis­cusses the lat­tice fea­tures in de­tail, ex­pected life­time, in­jec­tion, tol­er­ances and dif­fer­ent pos­si­ble op­er­a­tion schemes of the ring.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT023
About •	Received ※ 20 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 02 July 2022
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THPOPT024	MIST - The MESA-Injector Source Two	2624
	M.A. Dehn, P.S. Plattnerpresenter IKP, Mainz, Germany K. Aulenbacher HIM, Mainz, Germany K. Aulenbacher GSI, Darmstadt, Germany K. Aulenbacher KPH, Mainz, Germany
	Funding: Work supported by the German science ministry BMBF through Verbundforschung The new ac­cel­er­a­tor MESA (Mainz En­ergy Re­cov­er­ing Su­per­con­duct­ing Ac­cel­er­a­tor) will pro­vide an av­er­age CW elec­tron beam cur­rent of up to 10 mA. Op­er­at­ing at 1.3 GHz, this cor­re­sponds to a bunch charge of 7.7 pC. The new DC pho­toe­mis­sion source MIST is op­ti­mized for these re­quire­ments. A chal­lenge is heat­ing of the pho­to­cath­ode at high laser power. By a suit­able me­chan­i­cal con­struc­tion and the use of spe­cific ma­te­ri­als, the heat can be dis­si­pated dur­ing op­er­a­tion. Op­tions for fur­ther im­prove­ments are dis­cussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT024
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT025	Photocathode Stress Test Bench at INFN LASA	2627
	D. Sertore, D. Giove, L. Monaco INFN/LASA, Segrate (MI), Italy A. Bacci, F. Canella, S. Cialdi, I. Drebotpresenter, D. Giannotti, L. Serafini INFN-Milano, Milano, Italy D. Cipriani, E. Suerra Università degli Studi di Milano, Milano, Italy G. Galzerano POLIMI, Milano, Italy G. Guerini Rocco Università degli Studi di Milano & INFN, Segrate, Italy
	A UHV test bench based on a 100 kV DC gun and a 100 MHz rep­e­ti­tion rate laser has been setup up at INFN LASA to test Cs2Te pho­to­cath­odes. This op­er­a­tion mode is the base­line of the BriXSinO pro­ject, cur­rently in the de­sign phase in our lab­o­ra­tory, and the qual­i­fi­ca­tion of the Cs2Te pho­to­cath­odes is a key issue. In this paper, we pre­sent the re­cent ad­vances in the dif­fer­ent as­pects of this R&D ac­tiv­ity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT025
About •	Received ※ 10 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 20 June 2022
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THPOPT026	Assembly and Characterization of Low-Energy Electron Transverse Momentum Measurement Device (TRAMM) at INFN LASA	2630
	D. Sertore, M. Bertuccipresenter, A. Bosotti, D. Giove, L. Monaco, R. Paparella INFN/LASA, Segrate (MI), Italy G. Guerini Rocco, C. Pagani Università degli Studi di Milano & INFN, Segrate, Italy
	In the frame­work of high-bright­ness elec­tron beam gen­er­a­tion, ther­mal emit­tance is nowa­days a key pa­ra­me­ter. While al­kali tel­lurides are ex­ten­sively used in ad­vanced elec­tron sources, al­kali an­ti­monides pho­to­cath­odes demon­strated high QE in the vis­i­ble, thus mak­ing fea­si­ble CW op­er­a­tions for RF-based pho­toin­jec­tors. The INFN LASA lab­o­ra­tory in Milan is fully equipped with ded­i­cated pro­duc­tion sys­tems for pho­to­cath­ode prepa­ra­tion and op­ti­cal setup for QE eval­u­a­tion. In this paper, we de­scribe a newly de­signed de­vice ded­i­cated to elec­tron trans­verse mo­men­tum mea­sure­ment (TRAMM). It will be con­nected to the main pro­duc­tion cham­bers and will serve as an "emit­tance mon­i­tor­ing" sys­tem dur­ing pho­to­cath­ode growth. From the de­sign phase, through the pa­ra­me­ter es­ti­mate, as­sem­bly of the com­po­nents, to the in­stal­la­tion and first mea­sure­ments, we de­scribe the sta­tus of this pro­ject and its fu­ture de­vel­op­ments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT026
About •	Received ※ 09 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 07 July 2022
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THPOPT027	R&D on High QE Photocathodes at INFN LASA	2633
	D. Sertore, M. Bertuccipresenter, L. Monaco INFN/LASA, Segrate (MI), Italy G. Guerini Rocco Università degli Studi di Milano & INFN, Segrate, Italy S.K. Mohanty, H.J. Qian, F. Stephan DESY Zeuthen, Zeuthen, Germany
	We pre­sent the re­cent ac­tiv­i­ties on an­ti­monide and tel­luride al­kali based pho­to­cath­odes at INFN LASA. The R&D on Cs2Te ma­te­ri­als is fo­cused on in­ves­ti­gat­ing ef­fects of ma­te­r­ial thick­ness and growth pro­ce­dures on the pho­to­cath­odes per­for­mances dur­ing op­er­a­tion in RF guns. We aim to im­prove ther­mal emit­tance and long term sta­bil­ity of these films. The more re­cent work on al­kali an­ti­monide showed the need for sub­stan­tial im­prove­ments in sta­bil­ity and QE dur­ing op­er­a­tion. We pre­sent here our re­cent achieve­ments and plans for fu­ture ac­tiv­i­ties.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT027
About •	Received ※ 09 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 17 June 2022
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THPOPT028	Dependence of CsK2Sb Photocathode Performance on the Quality of Graphene Substrate Film	2637
	L. Guo, K. Goto, Y. Takashima Nagoya University, Nagoya, Japan H. Yamaguchi LANL, Los Alamos, New Mexico, USA M. Yamamoto KEK, Ibaraki, Japan
	Funding: U.S.-Japan Science and Technology Cooperation Program in High Energy Physics A pho­to­cath­ode that ex­tracts elec­trons by ir­ra­di­at­ing a semi­con­duc­tor or metal with a laser is ap­plied to ad­vanced ac­cel­er­a­tors and elec­tron mi­cro­scopes as a high-per­for­mance cath­ode. In par­tic­u­lar, the CsK2Sb pho­to­cath­ode is of in­ter­est be­cause it has fea­tures such as low emit­tance, ex­citabil­ity with vis­i­ble light, and high quan­tum ef­fi­ciency. Gen­er­ally, the CsK2Sb pho­to­cath­ode is pro­duced by de­posit­ing a cath­ode el­e­ment on a sub­strate, so that the cath­ode per­for­mance strongly de­pends on the sur­face con­di­tion of the sub­strate. We have found graphene as reusable sub­strate, which has the prop­erty of being chem­i­cally in­ac­tive. In this study, graphene film qual­ity de­pen­dence of CsK2Sb photo-cath­ode per­for­mance was eval­u­ated. Specif­i­cally, CsK2Sb cath­ode was de­posited using dif­fer­ent qual­ity graphene film sub­strates and their QE val­ues and uni­for­mity were com­pared. The qual­ity of graphene films was an­a­lyzed using X-ray Pho­to­elec­tron Spec­troscopy (XPS) and X-ray ab­sorp­tion spec­troscopy (XAS). We found that the graphene film can be cleaned by heat­ing at 500 deg. The QE of the cath­ode on a good qual­ity graphene film was higher and more uni­form than that on a poor qual­ity graphene film.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT028
About •	Received ※ 16 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 10 June 2022 — Issue date ※ 24 June 2022
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THPOPT029	Study on the Performance Improvement of Alkali Antimonide Photocathodes for Radio Frequency Electron Guns	2640
	R. Fukuoka, K. Ezawa, Y. Koshiba, M. Washio Waseda University, Tokyo, Japan K. Sakaue The University of Tokyo, Graduate School of Engineering, Bunkyo, Japan
	Semi­con­duc­tor pho­to­cath­odes such as Cs-Te and Cs-K-Sb are used as elec­tron sources in ac­cel­er­a­tors to gen­er­ate high bright­ness beams using radio fre­quency (rf) elec­tron guns. Al­kali an­ti­monide pho­to­cath­odes have a high quan­tum ef­fi­ciency (Q.E.) of ~10%, and their ex­ci­ta­tion wave­length is in the vis­i­ble light re­gion (532 nm), so that they are ex­pected to re­duce the re­quire­ments on the op­ti­cal sys­tem and in­crease the amount of charge com­pared to Cs-Te. How­ever, al­kali an­ti­monide pho­to­cath­odes have a short life­time and de­grade under poor vac­uum con­di­tions, so it is es­sen­tial to im­prove dura­bil­ity by pro­tec­tive film coat­ings. There­fore, we are cur­rently work­ing on the fab­ri­ca­tion of high Q.E. al­kali an­ti­monide pho­to­cath­odes that can with­stand the Q.E. re­duc­tion dur­ing coat­ing. In this pre­sen­ta­tion, we will re­port the re­sults of com­par­i­son be­tween the fab­ri­cated al­kali an­ti­monide pho­to­cath­ode and Cs-Te pho­to­cath­ode, and fu­ture prospects.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT029
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 09 July 2022
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THPOPT030	Design Study of 30 MeV Linac for a Compact THz Radiation Source	2643
	S. Jummunt, S. Chunjarean, N. Juntong, S. Klinkhieo SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	Funding: This work is supported by Science, Research, and Innovation Fund (SRI Fund) A com­pact THz ra­di­a­tion source plays a pos­si­bil­ity to achieve in­tense THz ra­di­a­tion at tun­able fre­quen­cies be­tween 0.5 and 5.0 THz, with a peak power of sev­eral MW and nar­row-band­width. This source re­quires es­sen­tially the re­li­able high gra­di­ent s-band lin­ear ac­cel­er­a­tor (linac) to pro­vide an elec­tron beam en­ergy up to 30 MeV with high bunch charge. In order to ob­tain a high gra­di­ent linac men­tioned, the cav­ity struc­ture has been op­ti­mized and per­formed using the soft­ware CST. The pre­lim­i­nary de­sign of linac and beam dy­nam­ics study are pre­sented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT030
About •	Received ※ 14 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 16 June 2022
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THPOPT031	SUNDAE1: A Liquid Helium Vertical Test-Stand for 2m Long Superconducting Undulator Coils	2646
	B. Marchetti, S. Abeghyan, J.E. Baaderpresenter, S. Casalbuoni, M. Di Felice, U. Englisch, V. Grattoni, D. La Civita, M. Vannoni, M. Yakopov, P. Ziolkowski EuXFEL, Schenefeld, Germany S. Barbanotti, H.-J. Eckoldt, A. Hauberg, K. Jensch, S. Lederer, L. Lilje, R. Ramalingam, T. Schnautz, R. Zimmermann DESY, Hamburg, Germany A.W. Grau KIT, Karlsruhe, Germany
	Su­per­con­duct­ing Un­du­la­tors (SCUs) can pro­duce higher pho­ton flux and cover a wider pho­ton en­ergy range com­pared to per­ma­nent mag­net un­du­la­tors (PMUs) with the same vac­uum gap and pe­riod length. To build the know-how to im­ple­ment su­per­con­duct­ing un­du­la­tors for fu­ture up­grades of the Eu­ro­pean XFEL fa­cil­ity, two mag­netic mea­sure­ment test stands named SUN­DAE 1 and 2 (Su­per­con­duct­ing UN­Du­lA­tor Ex­per­i­ment) are being de­vel­oped. SUN­DAE1 will fa­cil­i­tate re­search and de­vel­op­ment on mag­net de­sign thanks to the pos­si­bil­ity of train­ing new SCU coils and char­ac­ter­iz­ing their mag­netic field. The ex­per­i­men­tal setup will allow the char­ac­ter­i­za­tion of mag­nets up to 2m in length. These mag­nets will be im­mersed in a He­lium bath at 2K or 4K tem­per­a­ture. In this ar­ti­cle, we de­scribe the ex­per­i­men­tal setup and high­light its ex­pected per­for­mances.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT031
About •	Received ※ 03 June 2022 — Revised ※ 17 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 17 June 2022
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THPOPT032	SUNDAE2 at EuXFEL: A Test Stand to Characterize the Magnetic Field of Superconducting Undulators	2649
	J.E. Baader, S. Abeghyan, S. Casalbuoni, D. La Civita, B. Marchetti, M. Yakopov, P. Ziolkowski EuXFEL, Schenefeld, Germany H.-J. Eckoldt, A. Hauberg, S. Lederer, L. Lilje, T. Wohlenberg, R. Zimmermann DESY, Hamburg, Germany A.W. Grau KIT, Eggenstein-Leopoldshafen, Germany
	Eu­ro­pean XFEL fore­sees a su­per­con­duct­ing un­du­la­tor (SCU) af­ter­burner in the SASE2 hard X-ray beam­line. It con­sists of six 5m-long un­du­la­tor mod­ules with a 5mm vac­uum gap, where each mod­ule con­tains two 2m-long coils and one phase shifter. Prior to in­stal­la­tion, the mag­netic field must be mapped ap­pro­pri­ately. Two mag­netic mea­sure­ment test stands named SUN­DAE 1 and 2 (Su­per­con­duct­ing UN­Du­lA­tor Ex­per­i­ment) are being de­vel­oped at Eu­ro­pean XFEL. While SUN­DAE1 will be a ver­ti­cal test stand to mea­sure SCU coils up to two me­ters with Hall probes in a liq­uid or su­per­fluid he­lium bath, SUN­DAE2 will mea­sure the SCU coils as­sem­bled in the final cryo­stat. This con­tri­bu­tion pre­sents the de­vel­op­ment sta­tus of SUN­DAE2 and its main re­quire­ments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT032
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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THPOPT033	Performance Characterisation at Daresbury Laboratory of Cs-Te Photocathodes Grown at CERN	2653
	L.A.J. Soomary, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C. Benjamin, H.M. Churn, L.B. Jonespresenter, T.C.Q. Noakes STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C. Benjamin University of Warwick, Coventry, United Kingdom E. Chevallay, V.N. Fedosseev, E. Granados, M. Himmerlich, H. Panuganti CERN, Meyrin, Switzerland L.B. Jonespresenter, T.C.Q. Noakes, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: STFC Doctoral Training Studentship The search for high-per­for­mance pho­to­cath­odes is a pri­or­ity in the field of par­ti­cle ac­cel­er­a­tors. The sur­face char­ac­ter­is­tics of a pho­to­cath­ode af­fect many im­por­tant fac­tors of the pho­toe­mis­sion process in­clud­ing the pho­toe­mis­sion thresh­old, the in­trin­sic emit­tance and the quan­tum ef­fi­ciency. These fac­tors in turn de­fine the elec­tron beam qual­ity, which is mea­sur­able using fig­ures of merit like beam emit­tance, bright­ness and en­ergy spread. We pre­sent char­ac­ter­i­sa­tion mea­sure­ments for four cae­sium tel­luride pho­to­cath­odes syn­the­sized at CERN. The pho­to­cath­odes were trans­ported under ul­tra-high vac­uum (UHV) and analysed at STFC Dares­bury Lab­o­ra­tory, using ASTeC’s Mul­ti­probe (SAPI)* for sur­face char­ac­ter­i­sa­tion via XPS and STM, and for Mean Trans­verse En­ergy (MTE) mea­sure­ments using the Trans­verse En­ergy Spread Spec­trom­e­ter (TESS)**. The MTE mea­sure­ments were es­ti­mated at cryo­genic and room tem­per­a­tures based on the re­spec­tive trans­verse en­ergy dis­tri­b­u­tion curves. We dis­cuss cor­re­la­tions found be­tween the syn­the­sis pa­ra­me­ters, and the mea­sured sur­face char­ac­ter­is­tics and MTE val­ues. *B.L. Militsyn, 4-th EuCARD2 WP12.5 meeting, Warsaw, 14-15 March 2017 **L.B. Jones et al., Proc. FEL ’13, TUPPS033, 290-293; https://accelconf.web.cern.ch/FEL2013/papers/tupso33.pdf
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT033
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 05 July 2022
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THPOPT034	Controlled Degradation of a Ag Photocathode by Exposure to Multiple Gases	2657
	L.A.J. Soomary, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom L.B. Jonespresenter, T.C.Q. Noakes, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom L.B. Jonespresenter, T.C.Q. Noakes STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	Funding: STFC Doctoral Training Studentship The search for high per­for­mance pho­to­cath­ode elec­tron sources is a pri­or­ity in the ac­cel­er­a­tor sci­ence com­mu­nity. The sur­face char­ac­ter­is­tics of a pho­to­cath­ode de­fine many im­por­tant fac­tors of the pho­toe­mis­sion process in­clud­ing the work func­tion, the in­trin­sic emit­tance and the quan­tum ef­fi­ciency of the pho­to­cath­ode. These fac­tors in turn de­fine the ul­ti­mate elec­tron beam qual­ity, which is mea­sur­able as nor­malised emit­tance, bright­ness and en­ergy spread. Strate­gies for im­prov­ing these pa­ra­me­ters vary, but un­der­stand­ing and in­flu­enc­ing the rel­e­vant cath­ode sur­face physics which un­der­pin these at­trib­utes is a pri­mary focus for the com­mu­nity*. We pre­sent per­for­mance data under il­lu­mi­na­tion at 266 nm for Ag (100) sin­gle-crys­tal cath­ode and a Ag poly­crys­talline cath­ode after pro­gres­sive ex­po­sure to O2, CO2, CO and N2 using our TESS** in­stru­ment both at room and cryo­genic tem­per­a­tures. Cru­cially the data shows the ef­fect of pro­gres­sive degra­da­tion*** in the pho­to­cath­ode per­for­mance as a con­se­quence of ex­po­sure to con­trolled lev­els of O2 and that ex­pos­ing an ox­i­dized Ag sur­face to CO can drive par­tial QE re­cov­ery. *K.L. Jensen; Appl. Phys. Lett. 89, 224103 (2006); **L.B. Jones et al.; Proc. FEL ’13, TUPPS033, 290-293; ***N. Chanlek et al.; J. Phys. D: Appl. Phys. (2014) 47, 055110;
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT034
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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THPOPT035	A Second Generation Light Source Aiming at High Power on the Giant Dipole Resonance	2661
	X. Buffat, L.L. Cuanillon, E.N. Kneubuehler CERN, Meyrin, Switzerland
	We pro­pose an ac­cel­er­a­tor con­cept which could en­able nu­clear waste trans­mu­ta­tion and en­ergy am­pli­fi­ca­tion using a sec­ond gen­er­a­tion light source rather than a high power pro­ton beam. The main pa­ra­me­ters of the ring and in­ser­tion de­vices are es­ti­mated, tar­get­ing a pho­ton beam power of 1 GW with a spec­trum that max­i­mizes the po­ten­tial for nu­clear re­ac­tions via the Giant Di­pole Res­o­nance. The syn­er­gies with tech­nolo­gies de­vel­oped for high en­ergy physics, in par­tic­u­lar within the Fu­ture Cir­cu­lar Col­lider study (FCC), are high­lighted.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT035
About •	Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 25 June 2022
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THPOPT036	New Microwave Thermionic Electron Gun for APS Upgrade: Test Results and Operation Experience	2665
	S.V. Kutsaev, R.B. Agustsson, A.C. Araujo Martinez, R.D. Berry, O. Chimalpopoca, A.Y. Murokh, M. Ruelas, A.Yu. Smirnov, S.U. Thielk RadiaBeam, Santa Monica, California, USA J.E. Hoyt, W.G. Jansma, A. Nassiri, Y. Sun, G.J. Waldschmidt ANL, Lemont, Illinois, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Basic Energy Science, under contracts DE-SC0015191 and DE- AC02-06CH11357 Re­cently, Ra­di­a­Beam has de­signed and built a ro­bust thermionic RF gun with op­ti­mized elec­tro­mag­netic per-for­mance, im­proved ther­mal en­gi­neer­ing, and a ro­bust cath­ode mount­ing tech­nique. This gun al­lows to im­prove the per­for­mance of ex­ist­ing and fu­ture light sources, in­dus­trial ac­cel­er­a­tors, and elec­tron beam dri­ven te-ra­hertz sources. Un­like con­ven­tional elec­tri­cally or side-cou­pled RF guns, this new gun op­er­ates in ’-mode with the help of mag­netic cou­pling holes. Such a de­sign al-lows op­er­a­tion at longer pulses and has neg­li­gi­ble di­pole and quadru­pole com­po­nents. The gun pro­to­type was built, then in­stalled and tested at the Ad­vanced Pho­ton Source (APS) in­jec­tor. This paper pre­sents the re­sults of high power and beam tests of this RF gun, and op­er­a­tion-al ex­pe­ri­ence at APS to this mo­ment.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT036
About •	Received ※ 31 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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THPOPT037	Ceramics Evaluation for MW-Power Coaxial Windows, Operating in UHF Frequency Range	2668
	S.V. Kutsaev, R.B. Agustsson, P.R. Carriere, N.G. Matavalam, A.Yu. Smirnov, S.U. Thielk RadiaBeam, Santa Monica, California, USA A.A. Haase SLAC, Menlo Park, California, USA T.W. Hall, D. Kim, J.T.M. Lyles, K.E. Nichols LANL, Los Alamos, New Mexico, USA
	Funding: This work was supported by the U.S. Department of Energy, Office of Basic Energy Science, under SBIR grant DE- SC0021552 Mod­ern ac­cel­er­a­tor fa­cil­i­ties re­quire re­li­able high-power RF com­po­nents. The RF vac­uum win­dow is a crit­i­cal part of the wave­guide cou­plers to the ac­cel­er­at­ing cav­i­ties. It is the point where the RF feed crosses the vac­uum bound­ary and thus forms part of the con­fine­ment bar­rier. RF win­dows must be de­signed to have low power dis­si­pa­tion in­side their ce­ramic, be re­sis­tant to me­chan­i­cal stresses, and free of dis­charges. In this paper, we re­port on the eval­u­a­tion of three dif­fer­ent ce­ramic can­di­dates for high power RF win­dows. These ma­te­ri­als have low loss tan­gents, low sec­ondary elec­tron yield (SEY), and large ther­mal ex­pan­sion co­ef­fi­cients. The ac­quired ma­te­ri­als were in­spected, coated, and mea­sured to se­lect the op­ti­mal set.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT037
About •	Received ※ 01 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 04 July 2022
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THPOPT038	Sirius Injection Optimization	2672
	X.R. Resende, M.B. Alves, L. Liu, A.C.S. Oliveira, J.V. Quentino, F.H. de Sá LNLS, Campinas, Brazil
	Sir­ius is the new 3 GeV stor­age ring (SR)-based 4th gen­er­a­tion syn­chro­tron light source built and op­er­ated by the Brazil­ian Syn­chro­tron Light Lab­o­ra­tory (LNLS) lo­cated in the CNPEM cam­pus, in Camp­inas. The fore­see­able move to a top-up in­jec­tion scheme de­mands im­prove­ment of in­jec­tion ef­fi­ciency and re­peata­bil­ity lev­els. In this work we re­port on the lat­est ef­forts in op­ti­miz­ing the Sir­ius in­jec­tion sys­tem.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT038
About •	Received ※ 08 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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THPOPT039	Performance Report of the SOLEIL Multipole Injection Kicker	2675
SUSPMF022	use link to see paper's listing under its alternate paper code
	R. Ollier, P. Alexandre, R. Ben El Fekih, A. Gamelin, N. Hubert, M. Labat, A. Nadji, L.S. Nadolski, M.-A. Tordeux SOLEIL, Gif-sur-Yvette, France
	A Mul­ti­pole In­jec­tion Kicker (MIK) was in­stalled in a short straight sec­tion of the SOLEIL stor­age ring and suc­cess­fully com­mis­sioned in 2021. A small hor­i­zon­tal orbit dis­tor­tion in the mi­crom­e­ter range was achieved out­per­form­ing the stan­dard bump-based in­jec­tion scheme in­stalled in a 12-m long straight sec­tion. Re­fined stud­ies have been con­ducted to fully un­der­stand and fur­ther im­prove the per­for­mance of the de­vice. In­deed, a novel gen­er­a­tion of the MIK will be the key el­e­ment for the in­jec­tion scheme of the SOLEIL Up­grade. We re­port sim­u­la­tion stud­ies and the lat­est MIK ex­per­i­men­tal per­for­mance. Both in­jected and stored beam-based mea­sure­ments were per­formed using new types of di­ag­nos­tics with turn-by-turn ca­pa­bil­ity (Lib­era Bril­lance+ BPM, KA­LYPSO: 2x1D imag­ing). The resid­ual per­tur­ba­tions on the beam po­si­tions and sizes were mea­sured; the mag­netic field of the MIK de­vice was re­con­structed. An un­ex­pected kick was de­tected in the ver­ti­cal plane and an ac­tive cor­rec­tion im­ple­mented to can­cel the re­sult­ing per­tur­ba­tion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT039
About •	Received ※ 09 June 2022 — Accepted ※ 29 June 2022 — Issue date ※ 06 July 2022
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THPOPT040	Injection Using a Non-Linear Kicker at the ESRF	2679
	S.M. White, T.P. Perronpresenter ESRF, Grenoble, France
	The ESRF in­jec­tion con­sists in a stan­dard four kick­ers bump off-axis in­jec­tion. Al­though this scheme is very ro­bust and re­li­able it is known to dis­turb users dur­ing in­jec­tions and may rep­re­sent a se­vere lim­i­ta­tion in case fre­quent in­jec­tions are re­quired. The non-lin­ear kicker in­jec­tion scheme pro­vides a pos­si­ble so­lu­tion to this prob­lem by act­ing only on the in­jected beam. This paper re­ports on the po­ten­tial in­te­gra­tion of a non-lin­ear kicker in­jec­tion scheme at the ESRF. A lay­out and spec­i­fi­ca­tions for the kicker are pro­posed and sim­u­la­tions are pro­vided to eval­u­ate the per­for­mance and lim­i­ta­tions of such scheme.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT040
About •	Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT041	Commissioning of New Kicker Power Supplies to Improve Injection Perturbations at the ESRF	2683
	S.M. White, N. Carmignani, L.R. Carver, M. Dubrulle, L. Hoummi, M. Morati, T.P. Perronpresenter, B. Roche ESRF, Grenoble, France
	The ESRF-EBS stor­age ring re­sumed op­er­a­tion in 2020. Due to the re­duced life­time, top-up in­jec­tion is re­quired for all op­er­a­tion modes. Per­tur­ba­tions on the stored beam in­tro­duced by the pulsed in­jec­tion el­e­ments rep­re­sent a sig­nif­i­cant dis­tur­bance to the beam lines that need to run ex­per­i­ments across in­jec­tion. In order to re­duce these per­tur­ba­tion, new kicker power sup­plies with slower ramp­ing times and bet­ter shot-to-shot re­pro­ducibil­ity were de­vel­oped at ESRF to im­prove the ef­fi­ciency of the feed-for­ward com­pen­sa­tion scheme. This paper re­ports on the de­sign, com­mis­sion­ing and first ex­per­i­men­tal val­i­da­tion of these new power sup­plies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT041
About •	Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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THPOPT042	Studies for a Laser Wakefield Driven Injector at ELSA	2686
	K. Kranz, K. Desch, D. Elsner, M.T. Switkapresenter ELSA, Bonn, Germany
	At the Uni­ver­sity of Bonn, Ger­many, the stor­age ring ELSA ex­tracts elec­trons with en­er­gies up to 3.2 GeV to hadron physics and novel de­tec­tor test­ing ex­per­i­ments. We study the fea­si­bil­ity of re­plac­ing the cur­rent 26 MeV LINAC in­jec­tor with a laser wake­field ac­cel­er­a­tor (LWA). For this, con­tem­po­rary pa­ra­me­ters from cur­rent LWA se­tups at other lab­o­ra­to­ries are as­sumed and matched to the ac­cep­tance of the booster syn­chro­tron. More­over, a con­cep­tional draft of a po­ten­tial LWA setup is cre­ated. This takes into con­sid­er­a­tion the in­flu­ence of build­ing con­di­tions such as avail­able floor space and build­ing vi­bra­tions to es­ti­mate a setup and laser beam sta­bil­ity of a plasma gen­er­at­ing high power laser sys­tem and beam­line to the plasma cell. The meth­ods and in­ter­me­di­ate re­sults of this study will be pre­sented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT042
About •	Received ※ 08 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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THPOPT043	Injection Design Options for the Low-Emittance PETRA IV Storage Ring	2689
	M.A. Jebramcik, I.V. Agapov, S.A. Antipov, R. Bartolini, R. Brinkmann, D. Einfeld, T. Hellert, J. Keil, G. Loisch, F. Obier DESY, Hamburg, Germany
	The pro­posed PETRA IV elec­tron stor­age ring that will re­place DESY’s flag­ship syn­chro­tron light source PETRA III will fea­ture a hor­i­zon­tal emit­tance as low as 20 pm based on a hy­brid six-bend achro­mat lat­tice. Such a lat­tice de­sign leads to the dif­fi­culty of in­ject­ing the in­com­ing beam into an ac­cep­tance that is as small as 2.6 um. In con­trast to ear­lier lat­tice it­er­a­tions based on a seven-bend achro­mat lat­tice, the lat­est ver­sion al­lows ac­cu­mu­la­tion, i.e., the off-axis in­jec­tion of the in­com­ing beam. In this con­tri­bu­tion, the ef­fects of de­ploy­ing dif­fer­ent sep­tum types, namely a pulsed or a Lam­bert­son sep­tum, on the in­jec­tion process as well as the in­jec­tion ef­fi­ciency are pre­sented. This analy­sis in­cludes the ef­fects of com­mon ma­nip­u­la­tions to the in­jected beam, e.g., beam ro­ta­tion and aper­ture shar­ing, on the in­jec­tion ef­fi­ciency. Fur­ther­more, the op­tion of a non­lin­ear kicker and its op­ti­miza­tion (wire po­si­tions, wire cur­rent, op­tics func­tions) are pre­sented since a non­lin­ear kicker could pro­vide an al­ter­na­tive to the rather large num­ber of strip-line kick­ers that are nec­es­sary to gen­er­ate the orbit bump at the sep­tum.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT043
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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THPOPT044	The Alkali-Metal Photocathode Preparation Facility at Daresbury Laboratory: First Caesium Telluride Deposition Results	2693
	H.M. Churn, C. Benjamin, L.B. Jones, T.C.Q. Noakes STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C. Benjamin University of Warwick, Coventry, United Kingdom H.M. Churn, L.B. Jones, T.C.Q. Noakes Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Fourth gen­er­a­tion light sources re­quire high bright­ness elec­tron beams. To achieve this a pho­to­cath­ode with a high quan­tum ef­fi­ciency and low in­trin­sic emit­tance is re­quired, which is also ro­bust with a long op­er­a­tional life­time and low dark cur­rent. Al­kali-metal pho­to­cath­odes have the po­ten­tial to ful­fil these re­quire­ments, so are an im­por­tant re­search area for the ac­cel­er­a­tor physics com­mu­nity. STFC Dares­bury Lab­o­ra­tory are cur­rently com­mis­sion­ing the Al­kali-metal Pho­to­cath­ode Prepa­ra­tion Fa­cil­ity (APPF) which will be used to grow al­kali pho­to­cath­odes. Pho­to­cath­odes pro­duced by the APPF will be analysed using Dares­bury Lab­o­ra­tory’s ex­ist­ing Mul­ti­probe sys­tem* and the Trans­verse En­ergy Spread Spec­trom­e­ter (TESS)**. Mul­ti­probe can per­form a va­ri­ety of sur­face analy­sis tech­niques while the TESS can mea­sure the Mean Trans­verse En­ergy of a pho­to­cath­ode from its Trans­verse En­ergy Dis­tri­b­u­tion Curve over a large range of il­lu­mi­na­tion wave­lengths. We pre­sent an overview on our cur­rent progress in the com­mis­sion­ing and test­ing of the APPF, the re­sults from the first Cs-Te de­po­si­tion and de­tail the work planned to fa­cil­i­tate the man­u­fac­ture of Cs2Te pho­to­cath­odes for the CLARA ac­cel­er­a­tor***. *B.L. Militsyn, 4th EuCARD2 WP12.5 meeting, Warsaw, 14-15 Mar. 2017 **L. Jones et al., Proc. FEL ’13, TUPPS033, 290-293 ***D. Angal-Kalinin et al., Phys. Rev. Accel. Beams, Vol. 23, Iss. 4, 2020
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT044
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 23 June 2022
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THPOPT045	OPAL Simulations of the MESA Injection System	2697
	S. Friederich IKP, Mainz, Germany K. Aulenbacher HIM, Mainz, Germany K. Aulenbacher GSI, Darmstadt, Germany K. Aulenbacher, C.P. Stollpresenter KPH, Mainz, Germany
	Funding: This work is supported by the DFG excellence initiative PRISMA+. The MESA in­jec­tion sys­tem will pro­duce the spin-po­lar­ized elec­tron beam for the up­com­ing ac­cel­er­a­tor MESA in Ger­many. The pho­toe­mis­sion elec­tron source (STEAM) will de­liver 150 uA of spin-po­lar­ized elec­trons from GaAs-based pho­to­cath­odes for the P2 ex­per­i­ment. Af­ter­wards the low-en­ergy beam trans­porta­tion sys­tem (MELBA) can ro­tate the spin using two Wien fil­ters and a so­le­noid for po­lar­iza­tion mea­sure­ments and to com­pen­sate for the spin pre­ces­sion in MESA. A chop­per and buncher sys­tem pre­pares the phase space for the first ac­cel­er­a­tion in the nor­mal-con­duct­ing pre-booster MAMBO. First OPAL sim­u­la­tion re­sults of MELBA were pre­sented at IPAC’21. Mean­while these sim­u­la­tions have been ex­tended by a 270-de­gree-bend­ing alpha mag­net as well as the elec­tro­sta­tic and mag­ne­to­sta­tic fieldmaps of the Wien fil­ters. Fur­ther­more the fieldmaps of the 4 mod­ules of the pre-ac­cel­er­a­tor MAMBO have been im­ple­mented. Hence, the com­plete MESA in­jec­tion sys­tem could be sim­u­lated in OPAL and the re­sults will be shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT045
About •	Received ※ 30 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 05 July 2022
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THPOPT047	A Double Dipole Kicker for Off and On-Axis Injection for ALBA-II	2701
	G. Benedetti, M. Carlà, M. Pont ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	In­jec­tion into the ALBA-II stor­age ring will be per­formed off-axis in a 4 me­ters straight sec­tion with a sin­gle mul­ti­pole kicker. We pre­sent a novel topol­ogy for the coils of the in­jec­tion kicker, named dou­ble di­pole kicker (DDK). The re­sult­ing mag­netic field is the su­per­po­si­tion of two op­po­site dipoles, gen­er­ated by four inner and four outer con­duc­tor rods. When the eight rods are pow­ered, the di­pole term can­cels and the re­main­ing mul­ti­pole field is used for off-axis in­jec­tion. Al­ter­na­tively, when the four inner rods are switched off, an al­most pure di­pole is pro­duced, that is use­ful for on-axis in­jec­tion dur­ing the com­mis­sion­ing. A pro­to­type of DDK is presently under de­sign to be in­stalled and tested in the ex­ist­ing ALBA stor­age ring. The po­si­tion­ing of the rods is cal­cu­lated in order to max­imise the kick ef­fi­ciency in mrad/kA and min­imise the dis­tur­bance to the orbit and the emit­tance of the stored beam. A metal­lic coat­ing with op­ti­mised thick­ness along the inner ce­ramic vac­uum cham­ber should pro­vide com­pen­sa­tion for the eddy cur­rents in­duced field in order to min­i­mize the dis­tur­bance to the stored beam while en­sur­ing suf­fi­ciently low heat dis­si­pa­tion by the beam image cur­rents.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT047
About •	Received ※ 16 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 20 June 2022
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THPOPT048	Impact of IDs on the Diamond Storage Ring and Application to Diamond-II	2705
	R.T. Fielder, B. Singhpresenter DLS, Oxfordshire, United Kingdom
	When in­ves­ti­gat­ing the ef­fect of in­ser­tion de­vices (IDs) on stor­age ring op­er­a­tions, it is not pos­si­ble to sim­u­late all of the large num­ber of gap, phase and field set­tings that are avail­able. This can be of par­tic­u­lar con­cern for tran­sient ef­fects in IDs that are moved fre­quently, or AP­PLE-II de­vices which may use many dif­fer­ent po­lar­i­sa­tion states. We there­fore pre­sent mea­sure­ments of the im­pact of se­lected IDs on var­i­ous pa­ra­me­ters in the cur­rent Di­a­mond stor­age ring in­clud­ing orbit dis­tor­tion, tunes, chro­matic­ity and emit­tance, and as­sess the ex­pected im­pact when ap­plied to the Di­a­mond-II lat­tice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT048
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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THPOPT049	Beam Dynamics Studies for the Diamond-II Injector	2708
	I.P.S. Martin, R.T. Fielder, J. Kallestrup, T. Olsson, B. Singhpresenter DLS, Oxfordshire, United Kingdom J.K. Jones, B.D. Muratori STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
	The re­place­ment, low-emit­tance booster for the Di­a­mond-II pro­ject will have a race­track struc­ture of 36 units cells con­structed from al­ter­nat­ing fo­cussing and de­fo­cussing com­bined-func­tion dipoles*. In this paper we re­port on how the de­sign and per­for­mance char­ac­ter­i­sa­tion of the booster has re­cently de­vel­oped; this in­cludes an in­crease in the in­jec­tion en­ergy from 100 to 150 MeV, a mod­i­fied cir­cum­fer­ence to match to the stor­age ring RF fre­quency, and a new nom­i­nal tune-point to im­prove the per­for­mance and en­able emit­tance ex­change. The in­flu­ence of the vac­uum cham­ber im­ped­ance and in­tra-beam scat­ter­ing on the elec­tron bunch pa­ra­me­ters dur­ing the ramp are pre­sented, along with the nec­es­sary changes to the trans­fer line lay­outs. *I.P.S. Martin, et al. "Progress with the Booster Design for the Diamond-II Upgrade", in Proc. IPAC’21, paper ID MOPAB071, Campinas, Brazil, May 2021
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT049
About •	Received ※ 07 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 29 June 2022
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THPOPT050	Development and Construction of Cryogenic Permanent Magnet Undulators for ESRF-EBS	2712
	C. Benabderrahmane, P. Brumund, J. Chavanne, D. Coulon, G. Le Bec, B. Ogier, R. Versteegen ESRF, Grenoble, France
	The ESRF Ex­tremely Bril­liant Source (ESRF-EBS) is on op­er­a­tion for Users since Au­gust 2020 after 20 months of shut­down. This first of a kind fourth gen­er­a­tion high en­ergy syn­chro­tron is based on a Hy­brid Multi-Bend Achro­mat lat­tice. The main goal of the ESRF-EBS is to re­duce the hor­i­zon­tal emit­tance, which leads to a sig­nifi-cant in­crease of the X-ray source bril­liance. To cover the in­ten­sive de­mand of short pe­riod small gap un­du­la­tors at ESRF-EBS, a new de­sign for a 2 m Cryo­genic Per­ma­nent Mag­net Un­du­la­tor (CPMU) has been de­vel­oped. Six CPMUs will be in­stalled in the next years; the first two CPMUs have been con­structed and ac­tu­ally used on ID15 and ID16 beam­line, the third one is under con-struct­ing. An in­ten­sive re­fur­bish­ment work has been done on the ex­ist­ing in­ser­tion de­vices to adapt them to the new ac­cel­er­a­tor which has shorter straight sec­tion and closer dipoles to the IDs than in the old one. This con­tri­bu­tion will re­view the de­vel­op­ment, con­struc-tion and com­mis­sion­ing of the new CPMUs, and the re­fur­bish­ment work done on the ex­ist­ing ones to adapt them to the new ac­cel­er­a­tor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT050
About •	Received ※ 02 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 18 June 2022
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THPOPT052	The Status of the In-Vacuum-APPLE II Undulator IVUE32 at HZB / BESSY II	2716
	J. Bahrdt, J. Bakos, S. Gaebel, S. Gottschlich, S. Grimmer, S. Knaack, C. Kuhn, F. Laube, A. Meseck, C. Rethfeldt, E.C.M. Rial, A. Rogosch-Opolka, M. Scheer, P.I. Volz HZB, Berlin, Germany
	At BESSY II, two new beam­lines for RIXS and for X-Ray-mi­croscopy de­mand a short pe­riod vari­ably po­lar­iz­ing un­du­la­tor. For this pur­pose, the first in-vac­uum APPLE un­du­la­tor world­wide is under con­struc­tion. The pa­ra­me­ters are as fol­lows: pe­riod length=32mm, mag­netic length=2500mm, min­i­mum gap=7mm. The de­sign in­cor­po­rates a force com­pen­sa­tion scheme as pro­posed by two of the au­thors at the SRI2018. All pre­ci­sion parts of the drive chain are lo­cated in air. New trans­verse slides for the trans­ver­sal slit ad­just­ment have been de­vel­oped and tested. Op­ti­cal mi­crom­e­ters mea­sure the gap and shift po­si­tions, sim­i­lar to the sys­tem of the CP­MU17 at BESSY II. They pro­vide the sig­nals for motor feed­back loops. A new UHV-com­pat­i­ble sol­der­ing tech­nique, as de­vel­oped with in­dus­try, re­laxes fab­ri­ca­tion tol­er­ances of mag­nets and mag­net hold­ers and sim­pli­fies the mag­net as­sem­bly. A 10-pe­riod pro­to­type has been setup for life­time tests of the new mag­netic keeper de­sign. The paper de­scribes first re­sults of the pro­to­type and other key-com­po­nents and sum­ma­rizes the sta­tus of the full-scale un­du­la­tor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT052
About •	Received ※ 19 May 2022 — Revised ※ 10 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 22 June 2022
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THPOPT053	Goubau-Line Set Up for Bench Testing Impedance of IVU32 Components	2719
SUSPMF023	use link to see paper's listing under its alternate paper code
	P.I. Volz, A. Meseck HZB, Berlin, Germany A. Meseck KPH, Mainz, Germany
	The world­wide first in-vac­uum el­lip­ti­cal un­du­la­tor, IVUE32, is being de­vel­oped at Helmholtz-Zen­trum Berlin. The 2.5 m long de­vice with a pe­riod length of 3.2 cm and a min­i­mum gap of about 7 mm is to be in­stalled in the BESSY II stor­age ring. It will de­liver ra­di­a­tion in the soft X-ray range to sev­eral beam­lines. The prox­im­ity of the un­du­la­tor struc­ture to the elec­tron beam makes the de­vice sus­cep­ti­ble to wake­field ef­fects which can in­flu­ence beam sta­bil­ity. A com­plete un­der­stand­ing of its im­ped­ance char­ac­ter­is­tics is re­quired prior to in­stal­la­tion and op­er­a­tion, as un­fore­seen heat­ing of com­po­nents could have cat­a­strophic con­se­quences. To un­der­stand and mea­sure the IVU’s im­ped­ance char­ac­ter­is­tics a Goubau-Line test stand is being de­signed. A Goubau-line is a sin­gle wire trans­mis­sion line for high fre­quency sur­face waves with a trans­verse elec­tric field re­sem­bling that of a charged par­ti­cle beam out to a cer­tain ra­dial dis­tance. A con­cept op­ti­mized for bench test­ing IVUE32-com­po­nents will be dis­cussed, mi­crowave sim­u­la­tions will be pre­sented to­gether with first mea­sure­ments from a test stand pro­to­type.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT053
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 16 June 2022
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THPOPT056	Emittance Exchange at Sirius Booster for Storage Ring Injection Improvement	2722
	J.V. Quentino, M.B. Alvespresenter, F.H. de Sá LNLS, Campinas, Brazil
	SIR­IUS is the new 4th gen­er­a­tion stor­age ring based syn­chro­tron light source built and op­er­ated by the Brazil­ian Syn­chro­tron Light Lab­o­ra­tory (LNLS) at the Brazil­ian Cen­ter for Re­search in En­ergy and Ma­te­ri­als (CNPEM). Cur­rently, the ef­fi­ciency of the hor­i­zon­tal off-axis in­jec­tion sys­tem of the stor­age ring is still not suit­able for top-up op­er­a­tion due to a smaller than ex­pected hor­i­zon­tal dy­namic aper­ture. In this work, we re­port the sim­u­la­tions and ex­per­i­men­tal re­sults of trans­verse emit­tance ex­change (TEE) per­formed at SIR­IUS booster by cross­ing a cou­pling dif­fer­ence res­o­nance dur­ing en­ergy ramp, with the goal of de­creas­ing the in­jected hor­i­zon­tal beam size and im­prove the off-axis in­jec­tion ef­fi­ciency.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT056
About •	Received ※ 20 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 09 July 2022
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THPOPT058	Status and Powering Test Results of HTS Undulator Coils at 77 K for Compact FEL Designs	2726
SUSPMF024	use link to see paper's listing under its alternate paper code
	S.C. Richter, A. Bernhard, A.-S. Müller KIT, Karlsruhe, Germany A. Ballarino, T.H. Nes, S.C. Richter, D. Schoerling CERN, Meyrin, Switzerland
	Funding: This work has been supported by the Wolfgang Gentner Program of the German Federal Ministry of Education and Research (grant no. 05E18CHA). The pro­duc­tion of low emit­tance positron beams for fu­ture lin­ear and cir­cu­lar lep­ton col­lid­ers, like CLIC or FCC-ee, re­quires high-field damp­ing wig­glers. Just as com­pact free-elec­tron lasers (FELs) re­quire high-field but as well short-pe­riod un­du­la­tors to emit high en­er­getic, co­her­ent pho­tons. Using high-tem­per­a­ture su­per­con­duc­tors (HTS) in the form of coated ReBCO tape su­per­con­duc­tors al­lows higher mag­netic field am­pli­tudes at 4 K and larger op­er­at­ing mar­gins as com­pared to low-tem­per­a­ture su­per­con­duc­tors, like Nb-Ti. This con­tri­bu­tion dis­cusses the de­vel­op­ment work on su­per­con­duct­ing ver­ti­cal race­track (VR) un­du­la­tor coils, wound from coated ReBCO tape su­per­con­duc­tors. The pre­sented VR coils were mod­u­larly de­signed with a pe­riod length of 13 mm. Pow­er­ing tests in liq­uid ni­tro­gen of mul­ti­ple ver­ti­cal race­track coils were per­formed at CERN. The re­sults from the mea­sure­ments are pre­sented for three VR coils and com­pared with elec­tro­mag­netic sim­u­la­tions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT058
About •	Received ※ 17 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 21 June 2022
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THPOPT059	Development of a Transfer Line for LPA-Generated Electron Bunches to a Compact Storage Ring	2730
	B. Härer, E. Bründermann, D. El Khechen, A.-S. Müller, A.I. Papash, S.C. Richterpresenter, R. Ruprecht, J. Schäfer, M. Schuh, C. Widmann KIT, Karlsruhe, Germany L. Jeppe Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany A.R. Maier, J. Osterhoff, E. Panofski DESY, Hamburg, Germany P. Messner University of Hamburg, Hamburg, Germany
	The in­jec­tion of LPA-gen­er­ated beams into a stor­age ring is con­sid­ered to be one of the most promi­nent ap­pli­ca­tions of laser plasma ac­cel­er­a­tors (LPAs). In a com­bined en­deav­our be­tween Karl­sruhe In­sti­tute of Tech­nol­ogy (KIT) and Deutsches Elek­tro­nen-Syn­chro­tron (DESY) the key chal­lenges will be ad­dressed with the aim to suc­cess­fully demon­strate in­jec­tion of LPA-gen­er­ated beams into a com­pact stor­age ring with large en­ergy ac­cep­tance and dy­namic aper­ture. Such a stor­age ring and the cor­re­spond­ing trans­fer line are cur­rently being de­signed within the cSTART pro­ject at KIT and will be ide­ally suited to ac­cept bunches from a 50 MeV LPA pro­to­type de­vel­oped at DESY. This con­tri­bu­tion pre­sents the fore­seen lay­out of the trans­fer line from the LPA to the in­jec­tion point of the stor­age ring and dis­cusses the sta­tus of beams op­tics cal­cu­la­tions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT059
About •	Received ※ 05 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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THPOPT060	Tolerance Study on the Geometrical Errors for a Planar Superconducting Undulator	2734
	V. Grattoni, S. Casalbuonipresenter, B. Marchetti EuXFEL, Schenefeld, Germany
	At the Eu­ro­pean XFEL, a su­per­con­duct­ing af­ter­burner is con­sid­ered for the SASE2 hard X-ray beam­line. It will con­sist of six un­du­la­tor mod­ules. Within each mod­ule, two su­per­con­duct­ing un­du­la­tors (SCU) 2 m long are pre­sent. Such an af­ter­burner will en­able pho­ton en­er­gies above 30 keV. A high field qual­ity of the SCU is cru­cial to guar­an­tee the qual­ity of the elec­tron beam tra­jec­tory, which is di­rectly re­lated to the spec­tral qual­ity of the emit­ted free-elec­tron laser (FEL) ra­di­a­tion. There­fore, the ef­fects of the SCU’s me­chan­i­cal im­per­fec­tions on the re­sul­tant mag­netic field have to be care­fully char­ac­ter­ized. In this con­tri­bu­tion, we pre­sent pos­si­ble me­chan­i­cal er­rors af­fect­ing the un­du­la­tor struc­ture, and we per­form an an­a­lyt­i­cal study aimed at de­ter­min­ing the tol­er­ances on these er­rors for our SCUs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT060
About •	Received ※ 03 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 27 June 2022
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THPOPT061	European XFEL Undulators - Status and Plans	2737
	S. Casalbuoni, S. Abeghyan, J.E. Baader, U. Englisch, V. Grattoni, S. Karabekyan, B. Marchetti, H. Sinn, F. Wolff-Fabris, M. Yakopov, P. Ziolkowski EuXFEL, Schenefeld, Germany
	Eu­ro­pean XFEL has three un­du­la­tor lines based on per­ma­nent mag­net tech­nol­ogy: two for hard and one for soft X-rays. The pla­nar un­du­la­tors can be tuned to cover the ac­cep­tance in terms of pho­ton beam en­ergy of the re­spec­tive pho­ton beam­lines: 3.6-25 keV (SASE1/2) and 0.25-3 keV (SASE3) by chang­ing the elec­tron en­ergy range be­tween 11.5 GeV and 17.5 GeV and/or the un­du­la­tor gap. In order to ob­tain dif­fer­ent po­lar­iza­tion modes, as re­quired by the soft X-ray beam­lines, a he­li­cal af­ter­burner con­sist­ing of four APPLE X un­du­la­tors de­signed by PSI has been in­stalled at the down­stream end of the pre­sent SASE3 un­du­la­tor sys­tem. The Eu­ro­pean XFEL plans to de­velop the tech­nol­ogy of su­per­con­duct­ing un­du­la­tors, which is of strate­gic im­por­tance for the fa­cil­ity up­grade. In order to ex­tend the en­ergy range above 30 keV a su­per­con­duct­ing un­du­la­tor af­ter­burner is fore­seen to be in­stalled at the end of SASE2. This con­tri­bu­tion pre­sents the cur­rent sta­tus and the planned up­grades of the un­du­la­tor lines at Eu­ro­pean XFEL.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT061
About •	Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 04 July 2022
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THPOPT063	Design of Scilab Xcos Simulation Model for Pulsed Wire Method Data Analyses	2741
	H. Jeevakhan NITTTR, Bhopal, India S.M. Khan, G. Mishra Devi Ahilya University, Indore, India
	Pulsed wire method (PWM)is used for un­du­la­tor char­ac­ter­i­sa­tion. Scilab Xcos sim­u­la­tion model is de­signed for the analy­ses of data ob­tained by PWM. The data ob­tained from PWM is given as input to the model and its out­put gives the mag­netic field of the un­du­la­tor. Scilab Xcos model can also be uti­lized for de­ter­min­ing the phase error of the un­du­la­tor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT063
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 09 July 2022
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THPOPT064	Hall Probe Magnetic Measurement of 50 mm Period PPM Undulator	2744
SUSPMF025	use link to see paper's listing under its alternate paper code
	S.M. Khan, G. Mishra Devi Ahilya University, Indore, India M. Gehlot MAX IV Laboratory, Lund University, Lund, Sweden H. Jeevakhan NITTTR, Bhopal, India
	In this paper, we pre­sent the lat­est upgra­da­tion of Hall Probe mag­netic mea­sure­ment sys­tem. The Hall Probe mea­sure­ment sys­tem is up­graded with po­si­tion mea­sur­ing de­tec­tors and 3D F.W. Bell Tes­lame­ter. The field in­te­grals and the phase er­rors are cal­cu­lated with a new user friendly MAT­LAB code. The in­te­grated mul­ti­poles both nor­mal and skew com­po­nents are mea­sured and dis­cussed in the paper. The pro­posed ac­tiv­i­ties on 300 mm length pro­to­type asym­met­ric un­du­la­tor and 50 mm quasi pe­riod, six pe­riod length at Laser In­stru­men­ta­tion and In­ser­tion De­vice Ap­pli­ca­tion lab­o­ra­tory of Devi Ahilya Vishwa Vidyalaya (DAVV), In­dore, India has been dis­cussed and de­sign com­po­nents are pre­sented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT064
About •	Received ※ 06 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 22 June 2022
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THPOPT065	Operation of X-Ray Beam Position Monitors with Zero Bias Voltage at Alba Front Ends	2747
	J. Marcos, U. Irisopresenter, V. Massana, R. Monge, D. Yépez ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
	Blade-type X-ray Beam Po­si­tion Mon­i­tors (XBPMs) are cus­tom­ar­ily op­er­ated with a neg­a­tive bias volt­age ap­plied to the blades in order to pre­vent the trans­fer­ence of pho­to­elec­trons be­tween the blades, and hence to max­i­mize the sig­nal at each blade and to avoid cross-talk. This was the se­lected ap­proach at ALBA since the start of its op­er­a­tion for users in 2012. How­ever, over the years the in­su­la­tion pro­vided by the ce­ramic pieces sep­a­rat­ing the blades from the sup­port struc­ture has de­graded pro­gres­sively, giv­ing rise to an ever-in­creas­ing leak­age cur­rent not re­lated with the pho­ton beam to be mon­i­tored. On 2020 the level of these leak cur­rents had al­ready be­come com­pa­ra­ble to the pho­tocur­rents gen­er­ated by the pho­ton beam it­self, mak­ing the read­ings from many of the XBPMs un­re­li­able. Fol­low­ing the ex­am­ple from other fa­cil­i­ties, we de­cided to re­move the bias volt­age from the blades and to test the per­for­mance of the XBPMs under these con­di­tions, with such good re­sults that we apply this method also for the new, non de­graded, XBPMs. In this paper we pre­sent the ap­proach used at ALBA to analyse XBPM data, and our ex­pe­ri­ence op­er­at­ing them with zero bias volt­age.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT065
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 29 June 2022
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THPOPT066	Helical Wiggler Design for Optical Stochastic Cooling at CESR	2751
	V. Khachatryan, M.B. Andorf, I.V. Bazarov, J.A. Crittenden, S.J. Levenson, J.M. Maxson, D.L. Rubin, J.P. Shanks, S. Wang Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA W.F. Bergan BNL, Upton, New York, USA
	Funding: The authors thank the Center for Bright Beams, NSF award PHY-1549132; W.F.B. was supported by the NSF Graduate Research Fellowship Program under grant number DGE-1650441. A he­li­cal wig­gler with pa­ra­me­ter kund=4.35 has been de­signed for the Op­ti­cal Sto­chas­tic Cool­ing (OSC) ex­per­i­ment in the Cor­nell Elec­tron Stor­age Ring (CESR). We con­sider four Hal­bach ar­rays, which di­men­sions are op­ti­mized to get the re­quired he­li­cal field pro­file, as well as, to get the best Dy­namic Aper­ture (DA) in sim­u­la­tions. The end poles are de­signed with dif­fer­ent di­men­sions to min­i­mize the first and sec­ond field in­te­grals to avoid the need of ad­di­tional cor­rec­tors for the beam orbit. The de­sign is adopted to min­i­mize the risks for the mag­net blocks de­mag­ne­ti­za­tion. To quan­tify the tol­er­ances, we sim­u­lated the ef­fects of dif­fer­ent types of geo­met­ri­cal and mag­netic field er­rors on the OSC damp­ing rates. In ad­di­tion, to un­der­stand the chal­lenges for the con­struc­tion, as well as, to val­i­date the model field cal­cu­la­tions, we pro­to­typed a small two pe­riod ver­sion. The pro­to­type field is com­pared to the model, and the re­sults are pre­sented in this work.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT066
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 14 June 2022
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THPOPT067	Propagation of Gaussian Wigner Function Through a Matrix-Aperture Beamline	2755
	B. Nash, D.T. Abell, P. Moeller, I.V. Pogorelov RadiaSoft LLC, Boulder, Colorado, USA N.B. Goldring STATE33 Inc., Portland, Oregon, USA
	Funding: This work is supported by the US Department of Energy, Office of Basic Energy Sciences under Award No. DE-SC0020593. We de­velop a sim­pli­fied beam prop­a­ga­tion model for x-ray beam­lines that in­cludes par­tial co­her­ence as well as the im­pact of aper­tures on the beam. In par­tic­u­lar, we con­sider a gen­eral asym­met­ric Gauss­ian Schell model, which also cor­re­sponds to a Gauss­ian Wigner func­tion. The ra­di­a­tion is thus rep­re­sented by a 4x4 sym­met­ric sec­ond mo­ment ma­trix. We ap­prox­i­mate rec­tan­gu­lar aper­tures by Gauss­ian aper­tures, tak­ing care that the loss in flux is the same for the two mod­els. The beam will thus stay Gauss­ian through both lin­ear trans­port and pas­sage through the aper­tures, al­low­ing a self-con­sis­tent pic­ture. We de­rive ex­pres­sions for de­crease in flux and changes in sec­ond mo­ments upon pas­sage through the aper­ture. We also de­rive ex­pres­sions for the co­her­ence lengths and an­a­lyze how these prop­a­gate through lin­ear trans­port and Gauss­ian aper­tures. We apply our for­mal­ism to cases of low emit­tance light source beam­lines and de­velop a bet­ter un­der­stand­ing about trade-offs be­tween co­her­ence length in­crease and flux re­duc­tion while pass­ing through phys­i­cal aper­tures. Our for­mu­lae are im­ple­mented in Ra­di­a­Soft’s Sirepo Shadow ap­pli­ca­tion al­low­ing easy use for re­al­is­tic beam­line mod­els.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT067
About •	Received ※ 09 June 2022 — Accepted ※ 11 June 2022 — Issue date ※ 17 June 2022
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THPOPT068	Linear Canonical Transform Library for Fast Coherent X-Ray Wavefront Propagation	2759
	B. Nash, D.T. Abell, P. Moeller, I.V. Pogorelov RadiaSoft LLC, Boulder, Colorado, USA N.B. Goldring STATE33 Inc., Portland, Oregon, USA
	Funding: This work is supported by the US Department of Energy, Office of Basic Energy Sciences under Award No. DE-SC0020593. X-ray beam­lines are es­sen­tial com­po­nents of all syn­chro­tron light sources, trans­port­ing ra­di­a­tion from the stored elec­tron beam pass­ing from the source to the sam­ple. The lin­ear op­tics of the beam­line can be cap­tured via an ABCD ma­trix com­puted using a ray trac­ing code. Once the trans­port ma­trix is avail­able, one may then in­clude dif­frac­tion ef­fects and ar­bi­trary wave­front struc­ture by using that same in­for­ma­tion in a Lin­ear Canon­i­cal Trans­form (LCT) ap­plied to the ini­tial wave­front. We de­scribe our im­ple­men­ta­tion of a Python-based LCT li­brary for 2D syn­chro­tron ra­di­a­tion wave­fronts. We have thus far im­ple­mented the sep­a­ra­ble case and are in the process of im­ple­ment­ing al­go­rithms for the non-sep­a­ra­ble case. Rec­tan­gu­lar aper­tures are also in­cluded. We have tested our work against cor­re­spond­ing wave­front com­pu­ta­tions using The Syn­chro­tron Ra­di­a­tion Work­shop (SRW) code. LCT vs. SRW tim­ing and bench­mark com­par­isons are given for un­du­la­tor and bend­ing mag­net beam­lines. This al­go­rithm is being in­cluded in the Sirepo im­ple­men­ta­tion of the Shadow ray trac­ing code. Fi­nally, we de­scribe our plans for ap­pli­ca­tion to par­tially co­her­ent ra­di­a­tion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOPT068
About •	Received ※ 15 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 01 July 2022
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