MOPOMS —  Poster Session - Matsaman   (13-Jun-22   14:00—16:00)

Paper	Title	Page
MOPOMS001	Progress on Development of AXSIS: A Femtosecond THz-Driven MeV Accelerator and keV X-Ray Source	621
	N.H. Matlis, M. Fakhari, F.X. Kärtner, T. Kroh, M. Pergament, T. Rohwer, M. Vahdani, D. Zhang CFEL, Hamburg, Germany R. Bazrafshan, F.X. Kärtner, T. Rohwer Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany R. Bazrafshan, M. Vahdani University of Hamburg, Hamburg, Germany M. Fakhari, D. Zhang DESY, Hamburg, Germany F.X. Kärtner, T. Kroh The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany
	Funding: This work was supported by KA908-12/1 of the Deutsche Forschungsgemeinschaft and by the ERC under the European Union’s Seventh Framework Program (FP7/2007-2013) through Synergy Grant AXSIS (609920). We re­port on the de­sign and progress in im­ple­ment­ing a THz-dri­ven rel­a­tivis­tic elec­tron ac­cel­er­a­tor and as­so­ci­ated X-ray source, the AXSIS Fa­cil­ity at DESY. We have de­vel­oped a full lay­out of the ma­chine based on a THz gun fol­lowed by a multi-cy­cle di­elec­tric loaded metal wave­guide THz lin­ear ac­cel­er­a­tor to gen­er­ate 20 MeV level, 10 fs elec­tron bunches. The re­quired THz pulse en­er­gies are on the mJ-level for the gun and multi-10-mJ-level for the THz linac. Cus­tomized laser tech­nolo­gies have been de­vel­oped al­low­ing for the gen­er­a­tion of these pulses up to 1 kHz rep­e­ti­tion rate. The gen­er­ated elec­tron bunches are then fo­cused into a counter prop­a­gat­ing op­ti­cal pulse ’op­ti­cal un­du­la­tor’ to gen­er­ate X-rays in the 6-7 keV range. We will dis­cuss the over­all lay­out of the ma­chine, sta­tus of its im­ple­men­ta­tion and tech­ni­cal chal­lenges in the dif­fer­ent com­po­nents as well as di­ag­nos­tics of this new type of ac­cel­er­a­tor and X-ray source.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS001
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 21 June 2022
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MOPOMS003	Single-Sided Pumped Compact Terahertz Driven Booster Accelerator	625
SUSPMF026	use link to see paper's listing under its alternate paper code
	T. Kroh, R. Bazrafshan, F.X. Kärtner, N.H. Matlis Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany M. Fakhari, M. Pergament, T. Rohwer, M. Vahdani, D. Zhang CFEL, Hamburg, Germany F.X. Kärtner The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany K. Kawase JAEA, Kizugawa, Japan
	Funding: European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) through the Synergy Grant ’Frontiers in Attosecond X-ray Science: Imaging and Spectroscopy’ (609920). Scal­ing the RF-ac­cel­er­a­tor con­cept to ter­a­hertz (THz) fre­quen­cies brings sev­eral com­pelling ad­van­tages, in­clud­ing com­pact­ness, in­trin­sic tim­ing be­tween the pho­toe­mis­sion and dri­ving field sources, and high field gra­di­ents as­so­ci­ated with the short THz wave­length and high break­down thresh­old. Re­cent demon­stra­tions of such THz pow­ered ac­cel­er­a­tors re­lied on two counter-prop­a­gat­ing sin­gle-cy­cle THz pulses. How­ever, to achieve high en­ergy gains in the ac­cel­er­a­tion process high en­ergy THz pulses are needed which in turn re­quire com­plex op­ti­cal se­tups. Here, we pre­sent on the de­vel­op­ment of a match­box sized multi-lay­ered ac­cel­er­a­tor de­signed to boost the 50 keV out­put of a DC elec­tron gun to en­er­gies of ~400 keV that only re­quires a sin­gle THz pulse to be pow­ered. An in­te­grated tun­able mir­ror in­side the struc­ture in­ter­feres the front of the dri­ving THz pulse with its rear part such that the field in the in­ter­ac­tion re­gion is op­ti­mized for ef­fi­cient ac­cel­er­a­tion. This re­duces the com­plex­ity of the re­quired op­ti­cal setup. Such a com­pact booster ac­cel­er­a­tor is very promis­ing as elec­tron source in ul­tra­fast elec­tron dif­frac­tion ex­per­i­ments and as booster stage prior to THz based LINACs.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS003
About •	Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 20 June 2022
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MOPOMS004	Optimizing Activation Recipe with Cs, Te, O for GaAs-Based Photocathodes	628
	J. Bae, M.B. Andorf, I.V. Bazarov, A. Galdi, J.M. Maxson Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L. Cultrera BNL, Upton, New York, USA
	Funding: Department of Energy (DOE) DE-SC0021039. GaAs-based pho­to­cath­odes are the most pop­u­lar elec­tron sources for pro­duc­ing highly spin-po­lar­ized elec­tron beams in ac­cel­er­a­tor physics and con­densed mat­ter physics. Spin-po­lar­ized pho­toe­mis­sion re­quires ac­ti­va­tion to achieve Neg­a­tive Elec­tron Affin­ity (NEA). Con­ven­tional NEA sur­faces such as CS-O/NF3 are ex­tremely vac­uum sen­si­tive, and this re­sults in rapid QE degra­da­tion. In this work, we ac­ti­vated GaAs with var­i­ous recipes using Cs, Te, and oxy­gen. We demon­strate NEA ac­ti­va­tion on GaAs sur­faces. Among Cs-Te ac­ti­vated sam­ples, the ox­i­dized sam­ple showed the high­est QE and longest life­time at 780 nm.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS004
About •	Received ※ 04 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 24 June 2022
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MOPOMS005	Start-to-End Simulations of a THz-Driven ICS Source	631
	M. Fakhari, Y.-K. Kan DESY, Hamburg, Germany F.X. Kärtner The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany F.X. Kärtner Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany N.H. Matlis, M. Vahdanipresenter CFEL, Hamburg, Germany M. Vahdanipresenter University of Hamburg, Hamburg, Germany
	We pre­sent start-to-end sim­u­la­tions for a fully THz-dri­ven table-top X-ray source. A di­elec­tric-loaded metal­lic cav­ity op­er­at­ing at its Higher Order Mode ac­cel­er­ates 1 PC photo emit­ted elec­tron bunch up to 430 keV ki­netic en­ergy. The out­put beam of the gun is in­jected into a di­elec­tric-loaded wave­guide where phase ve­loc­ity of the trav­el­ing wave is ad­justed in such a way that elec­trons see an ac­cel­er­at­ing field all the way along the tube re­sult­ing to an 18.5-MeV out­put beam which is then trans­ported to an in­verse Comp­ton scat­ter­ing (ICS) stage. The in­jec­tion phase of the elec­trons can be tuned to in­tro­duce a neg­a­tive en­ergy chirp to the elec­tron bunch lead­ing to a bal­lis­tic bunch com­pres­sion after the linac. In ad­di­tion, a set of per­ma­nent mag­net quadrupoles is de­signed to focus the beam at the ICS in­ter­ac­tion point where the elec­tron beam scat­ters off a 250-mJ, 0.5ps, 1-µm laser beam and gen­er­ates an X-ray beam with 2.6x107 pho­tons per shot con­tain­ing pho­ton en­er­gies 2keV< Eph <8keV in a beam with 50 mrad half open­ing angle. The re­quired ter­a­hertz waves to power the gun and linac are 550-ps pulses at 300 GHz con­tain­ing 5 mJ and 23 mJ en­er­gies re­spec­tively with 1 kHz rep­e­ti­tion rate.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS005
About •	Received ※ 08 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 25 June 2022
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MOPOMS007	Optimized Dielectric Loaded Waveguide Terahertz LINACs	634
SUSPMF028	use link to see paper's listing under its alternate paper code
	M. Vahdani University of Hamburg, Hamburg, Germany M. Fakhari DESY, Hamburg, Germany F.X. Kärtner The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany F.X. Kärtner Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany M. Vahdani CFEL, Hamburg, Germany
	Di­elec­tric loaded wave­guides (DLW) pow­ered by mul­ti­cy­cle ter­a­hertz (THz) pulses have shown promis­ing per­for­mance as com­pact lin­ear ac­cel­er­a­tors due to higher break­down fields at THz fre­quen­cies com­pared to con­ven­tional RF com­po­nents. By chang­ing the di­elec­tric di­men­sions one can con­trol phase and group ve­loc­i­ties of the THz pulse in­side the DLW. Since op­ti­mum wave­guide di­men­sions are de­pen­dent on ini­tial elec­tron en­ergy, THz pulse en­ergy, and etc., it is worth­while to de­ter­mine op­ti­mum val­ues for dif­fer­ent con­di­tions to max­i­mize final ki­netic en­ergy. In this work, we pre­sent a com­bined an­a­lyt­i­cal/nu­mer­i­cal guide to de­ter­mine the op­ti­mum DLW pa­ra­me­ters for sin­gle on-axis elec­tron ac­cel­er­a­tion. We also in­tro­duce nor­mal­ized graphic rep­re­sen­ta­tions to vi­su­al­ize op­ti­mum de­signs for dif­fer­ent ini­tial elec­tron and THz pulse en­er­gies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS007
About •	Received ※ 09 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 21 June 2022
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MOPOMS008	Diagnosis of Transverse Emittance in Laser-Driven Ion Beam	637
SUSPMF029	use link to see paper's listing under its alternate paper code
	T. Miyatake, I. Takemoto, Y. Watanabe Kyushu University, Interdisciplinary Graduate School of Engineering Sciences, Kasuga-Shi, Japan T.-H. Dinh, M. Kando, S. Kojima, K. Kondo, K. Kondo, M. Nishikino, M. Nishiuchi, H. Sakaki National Institutes for Quantum Science and Technology, Kyoto, Japan
	Funding: This work was supported by JST-MIRAI R&D Program No. JPMJMI17A1. This work was supported by JSPS KAKENHI Grant Number JP21J22132. Ion beam pro­duced in laser-dri­ven ion ac­cel­er­a­tion by ul­tra-in­tense lasers has char­ac­ter­is­tics of high peak cur-rent and low emit­tance. These char­ac­ter­is­tics be­come an ad­van­tage to op­er­ate the re­quest for the beam ap­plica-tion. There­fore, we study how to con­trol the pa­ra­me­ters with the laser-plasma in­ter­ac­tion. Here, we used 2D Par­ti­cle-in-Cell code to sim­u­late the laser-dri­ven ion ac­cel­er­a­tion and in­ves­ti­gated the re­sults in terms of trans­verse emit­tance, beam cur­rent, and bright­ness. The laser spot size and tar­get thick­ness were changed in the sim­u­la­tion. And, these qual­i­ta­tive re­sults show that in­ter­ac­tion tar­get thick­ness is a major fac­tor in con­trol­ling beam char­ac­ter­is­tics.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS008
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 18 June 2022
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MOPOMS010	Beam Dynamics and Drive Beam Losses Within a Planar Dielectric Wakefield Accelerator	641
SUSPMF030	use link to see paper's listing under its alternate paper code
	T.J. Overton, Y.M. Saveliev Cockcroft Institute, Warrington, Cheshire, United Kingdom T.H. Pacey, Y.M. Saveliev STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G.X. Xia UMAN, Manchester, United Kingdom
	Funding: Science and Technology Funding Council (STFC) Student Grant Beam-dri­ven di­elec­tric wake­field ac­cel­er­a­tors (DWA) have the po­ten­tial to pro­vide ac­cel­er­at­ing gra­di­ents in the GV/m range. The trans­verse dy­nam­ics in such de­vices need to be un­der­stood to avoid in­sta­bil­i­ties over long trans­port dis­tances and fa­cil­i­tate beam match­ing to spe­cific ap­pli­ca­tions (e.g. FELs). This pre­sen­ta­tion de­tails sim­u­la­tion stud­ies of the mag­ni­tude of beam-breakup in­sta­bil­ity (BBU) in pla­nar di­elec­tric lined wave­guides (DLWs). These are for DWA drive beams, with high charge and mo­men­tum that can be pro­duced at cur­rent fa­cil­i­ties. Using a se­ries of per­pen­dic­u­lar DLW seg­ments has been pro­posed to con­trol in­sta­bil­i­ties over larger dis­tances. Using self-de­vel­oped soft­ware, the beam dy­nam­ics of a drive beam within a DLW are sim­u­lated and the mag­ni­tude of beam losses along a DLW of vary­ing lengths cal­cu­lated and beam qual­ity preser­va­tion in­ves­ti­gated. Meth­ods to re­duce trans­verse in­sta­bil­i­ties have been ex­plored, and the im­pact of these on the length of a pos­si­ble DWA ac­cel­er­a­tion stage are in­ves­ti­gated. An ac­cel­er­a­tion stage with m-scale length, con­sist­ing of mul­ti­ple al­ter­nat­ing pla­nar DLWs, is sug­gested and preser­va­tion of beam qual­ity along this dis­tance is shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS010
About •	Received ※ 07 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
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MOPOMS012	Simulation Studies of Drive Beam Instability in a Dielectric Wakefield Accelerator	645
	W.H. Tan, P. Piot Northern Illinois University, DeKalb, Illinois, USA A. Huebl, R. Jambunathan, R. Lehé, A. Myers, T. Rheaume, J.-L. Vay, W. Zhang LBNL, Berkeley, USA P. Piot ANL, Lemont, Illinois, USA
	Funding: This work is supported by the US DOE award DE-SC0018656 with NIU and DE-AC02-06CH11357 with ANL. This work used resources from NERSC, supported by DOE contract DE-AC02-05CH11231. This research used WarpX, which is supported by the US DOE Exascale Computing Project. Primary WarpX contributors are with LBNL, LLNL, CEA-LIDYL, SLAC, DESY, CERN, and Modern Electron. Beam-dri­ven collinear wake­field ac­cel­er­a­tion using struc­ture wake­field ac­cel­er­a­tors promises a high gra­di­ent ac­cel­er­a­tion within a smaller phys­i­cal foot­print. Sus­tain­able ex­trac­tion of en­ergy from the drive beam re­lies on pre­cise un­der­stand­ing of its long term dy­nam­ics and the pos­si­ble onset or mit­i­ga­tion of the beam in­sta­bil­ity. The ad­vance of com­pu­ta­tional power and tools makes it pos­si­ble to model the full physics of beam-dri­ven wake­field ac­cel­er­a­tion. Here we re­port on the long-term beam dy­nam­ics stud­ies of a drive beam con­sid­er­ing the ex­am­ple of a di­elec­tric wave­guide using high fi­delity par­ti­cle-in-cell sim­u­la­tions per­formed with WarpX.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS012
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 16 June 2022
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MOPOMS013	Toward Emittance Measurements at 11.7 GHz Short-Pulse High-Gradient RF Gun	649
	S.V. Kuzikov, C.-J. Jing, E.W. Knight Euclid TechLabs, Solon, Ohio, USA G. Chen, C.-J. Jing, P. Piot, E.E. Wisniewski ANL, Lemont, Illinois, USA C.-J. Jing Euclid Beamlabs, Bolingbrook, USA P. Piot Fermilab, Batavia, Illinois, USA P. Piot, W.H. Tanpresenter Northern Illinois University, DeKalb, Illinois, USA
	Funding: This project is supported with DoE SBIR Phase II Grant #DE-SC0018709. A short pulse high gra­di­ent RF gun has been re­cently tested at Ar­gonne Wake­field Ac­cel­er­a­tor (AWA) fa­cil­ity. The car­ried-out test showed that the 1,5-cell gun was able to in­ject 3 MeV, up to 100 pC bunches at room tem-per­a­ture being fed by 9 ns up to 300 MW 11.7 GHz puls-es. The cath­ode field was as high as about 400 MV/m. So high field is aimed to mit­i­gate re­peal­ing Coulomb forces sub­stan­tially. In ac­cor­dance with sim­u­la­tions the emit-tance could be as low as less than 0.2 mcm. To ob­tain so low emit­tance in the ex­per­i­ment, the gun is as­sumed to be equipped with a down­stream linac to be fed from the same power ex­trac­tor as the gun it­self. Here we re­port de­sign of the RF power dis­tri­b­u­tion sys­tem split­ting RF power among the gun and the linac, re­sults of low-power tests, and emit­tance mea­sure­ment plans for up­com­ing new ex­per­i­ment at AWA.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS013
About •	Received ※ 01 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 01 July 2022
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MOPOMS014	Commissioning of a High-Gradient X-Band RF Gun Powered by Short RF Pulses from a Wakefield Accelerator	652
SUSPMF040	use link to see paper's listing under its alternate paper code
	W.H. Tan, X. Lu, P. Piot Northern Illinois University, DeKalb, Illinois, USA S.P. Antipov, C.-J. Jing, E.W. Knight, S.V. Kuzikov Euclid TechLabs, Solon, Ohio, USA D.S. Doran, G. Ha, C.-J. Jing, W. Liu, X. Lu, P. Piot, P. Piot, J.G. Power, J. Shao, C. Whiteford, E.E. Wisniewski ANL, Lemont, Illinois, USA
	Funding: This work is supported by the U.S. DOE, under award No. DE-SC0018656 to NIU, DOE SBIR grant No DE-SC0018709 at Euclid Techlabs LLC, and contract No. DE-AC02-06CH11357 with ANL. A high-gra­di­ent X-band (11.7-GHz) pho­toin­jec­tor de­vel­oped by Eu­clid Tech­labs, was re­cently com­mis­sioned at the Ar­gonne Wake­field Ac­cel­er­a­tor (AWA). The sys­tem com­prises a 1+1/2-cell RF gun pow­ered by short RF pulses gen­er­ated as a train of high-charge bunches from the AWA ac­cel­er­a­tor passes through a slow-wave power ex­trac­tion and trans­fer struc­ture. The RF pho­toin­jec­tor was re­li­ably op­er­at­ing with elec­tric fields in ex­cess of 300 MV/m on the pho­to­cath­ode sur­face free of break­down and with an in­signif­i­cant dark-cur­rent level. We re­port on the RF-gun setup, com­mis­sion­ing, and the as­so­ci­ated beam gen­er­a­tion via pho­toe­mis­sion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS014
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 19 June 2022
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MOPOMS015	Temporal and Spatial Characterization of Ultrafast Terahertz Near-Fields for Particle Acceleration	656
SUSPMF031	use link to see paper's listing under its alternate paper code
	A.E. Gabriel, M.C. Hoffmann, E.A. Nanni, M.A.K. Othman SLAC, Menlo Park, California, USA
	Funding: This work was supported by Department of Energy contract DE-AC02-76SF00515. We have mea­sured the THz near-field in order to in­form the de­sign of im­proved THz-fre­quency ac­cel­er­at­ing struc­tures. THz-fre­quency ac­cel­er­at­ing struc­tures could pro­vide the ac­cel­er­at­ing gra­di­ents needed for next gen­er­a­tion par­ti­cle ac­cel­er­a­tors with com­pact, GV/m-scale de­vices. One of the most promis­ing THz gen­er­a­tion tech­niques for ac­cel­er­a­tor ap­pli­ca­tions is op­ti­cal rec­ti­fi­ca­tion in lithium nio­bate using the tilted pulse front method. How­ever, ac­cel­er­a­tor ap­pli­ca­tions are lim­ited by sig­nif­i­cant losses dur­ing trans­port of THz ra­di­a­tion from the gen­er­at­ing non­lin­ear crys­tal to the ac­cel­er­a­tion struc­ture. In ad­di­tion, the spec­tral prop­er­ties of high-field THz sources make it dif­fi­cult to cou­ple THz ra­di­a­tion into ac­cel­er­at­ing struc­tures. A bet­ter un­der­stand­ing of the THz near-field source prop­er­ties is nec­es­sary for the op­ti­miza­tion of THz trans­port and cou­pling. We have de­vel­oped a tech­nique for de­tailed mea­sure­ment of the THz near-fields and used it to re­con­struct the full tem­po­ral 3D THz near-field close to the LN emis­sion face. Analy­sis of the re­sults from this mea­sure­ment will in­form de­signs of novel struc­tures for use in THz par­ti­cle ac­cel­er­a­tion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS015
About •	Received ※ 08 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOMS016	Application of Nanostructures and Metamaterials in Accelerator Physics	659
	J. Resta-López ICMUV, Paterna, Spain Ö. Apsimon, C. Bonțoiu, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom A. Bonatto Universidade Federal de Ciências da Saúde de Porto Alegre, Porto Alegre, Brazil B. Galante CERN, Meyrin, Switzerland C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom G.X. Xia UMAN, Manchester, United Kingdom
	Funding: This work is supported by the Generalitat Valenciana under Grant agreement No. CIDEGENT/2019/058. Car­bon-based nanos­truc­tures and meta­ma­te­ri­als offer ex­tra­or­di­nary me­chan­i­cal and opto-elec­tri­cal prop­er­ties, which make them suit­able for ap­pli­ca­tions in di­verse fields, in­clud­ing, for ex­am­ple, bio­science, en­ergy tech­nol­ogy and quan­tum com­put­ing. In the lat­est years, im­por­tant R&D ef­forts have been made to in­ves­ti­gate the po­ten­tial use of graphene and car­bon-nan­otube (CNT) based struc­tures to ma­nip­u­late and ac­cel­er­ate par­ti­cle beams. In the same way, the spe­cial in­ter­ac­tion of graphene and CNTs with charged par­ti­cles and elec­tro­mag­netic ra­di­a­tion might open in­ter­est­ing pos­si­bil­i­ties for the de­sign of com­pact co­her­ent ra­di­a­tion sources, and novel beam di­ag­nos­tics tech­niques as well. This paper gives an overview of novel con­cepts based on nanos­truc­tures and meta­ma­te­ri­als with po­ten­tial ap­pli­ca­tion in the field of ac­cel­er­a­tor physics. Sev­eral ex­am­ples are shown and fu­ture prospects dis­cussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS016
About •	Received ※ 08 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 13 June 2022
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MOPOMS017	Beam Transport Simulations Through Final Focus High Energy Transport Lines with Implemented Gabor Lenses	663
	A. Sherjan, M. Droba, O. Meusel, S. Reimann, K.I. Thoma IAP, Frankfurt am Main, Germany S. Reimann GSI, Darmstadt, Germany
	First in­ves­ti­ga­tions on Gabor Lens GL2000 at Goethe Uni­ver­sity have shown that it is pos­si­ble to con­fine a 2m long sta­ble Elec­tron Plasma Col­umn and to apply it as a hadron beam fo­cus­ing de­vice. With this knowl­edge the­o­ret­i­cal im­ple­men­ta­tions of GLs in final focus and trans­fer lines have started. The fo­cus­ing with GLs is a weak but smooth fo­cus­ing in ra­dial di­rec­tion. The GL is a suit­able and in­ex­pen­sive choice in ad­di­tion to the ex­ist­ing fo­cus­ing el­e­ments eg. mag­netic quadrupoles. The de­vice helps to im­prove beam qual­ity and min­i­mize losses over long dis­tances. The in­ves­ti­ga­tion of rel­a­tivis­tic hadron beams in GeV range using the ex­am­ple of the pro­posed NA61/SHINE VLE-beam­line at CERN is car­ried out and will be pre­sented. Thin-ma­trix sim­u­la­tions with a gen­er­ated dis­tri­b­u­tion as well as field map sim­u­la­tions with gen­er­ated and re­al­is­tic dis­tri­b­u­tions (Geant4) at 1 - 6 GeV/c have been analysed and com­pared. In ad­di­tion, the H4-beam­line at North Area (CERN) is pro­posed to im­ple­ment GLs for ex­per­i­men­tal tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS017
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 14 June 2022
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MOPOMS018	Tungsten Electron Emitter (TE²) with Direct Heated Cathode by Plasma Stream	667
	K.I. Thoma, M. Droba, T. Dönges, O. Meusel, H. Podlech, K. Schulte-Urlichs IAP, Frankfurt am Main, Germany K. Schulte-Urlichs, K.I. Thoma GSI, Darmstadt, Germany
	At Goethe-Uni­ver­sity, a novel con­cept of heat­ing metal­lic cath­odes is cur­rently under in­ves­ti­ga­tion. In the scope of the ARIES col­lab­o­ra­tion WP16, an RF-mod­u­lated elec­tron gun was de­vel­oped and man­u­fac­tured for ap­pli­ca­tion in elec­tron lenses for space charge com­pen­sa­tion. The goal of this pro­ject is to in­crease the in­ten­sity of pri­mary beams, es­pe­cially in low en­ergy booster syn­chro­trons like the SIS18 and SIS100 at GSI/FAIR or the SPS at CERN. The gun was de­signed to pro­duce elec­tron cur­rents of 10 A at ex­trac­tion volt­ages of 30 kV. The tung­sten elec­tron emit­ter (TE²) and the grid elec­trode were de­signed and man­u­fac­tured to be in­te­grated in the ex­trac­tor of the orig­i­nal vol­ume type ion source. Sig­nif­i­cant ef­fort was put into a ro­bust and flex­i­ble de­sign with highly re­li­able key com­po­nents. The cath­ode is heated by a plasma stream gen­er­ated in the plasma cham­ber of the source. Dif­fer­ent heat­ing op­tions of the cath­ode are cur­rently being stud­ied. This con­tri­bu­tion pre­sents the work­ing prin­ci­ples of the elec­tron gun and first mea­sure­ments re­sults of cath­ode heat­ing.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS018
About •	Received ※ 18 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 26 June 2022
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MOPOMS019	The New SPARC_LAB RF Photo-Injector	671
	D. Alesini, M.P. Anania, M. Bellaveglia, A. Biagioni, F. Cardelli, G. Costa, M. Del Franco, G. Di Pirro, L. Faillace, M. Ferrario, G. Franzini, A. Gallo, A. Giribono, L. Piersanti, L. Sabbatini, A. Stella, A. Vannozzi INFN/LNF, Frascati, Italy A. Battisti, E. Chiadroni, G. Di Raddo, A. Liedl, V.L. Lollo, L. Pellegrino, R. Pompili, S. Romeo, V. Shpakov, C. Vaccarezza, F. Villa LNF-INFN, Frascati, Italy M. Carillo, E. Chiadroni Sapienza University of Rome, Rome, Italy A. Cianchi, M. Galletti Università di Roma II Tor Vergata, Roma, Italy
	A new RF photo-in­jec­tor has been de­signed, re­al­ized and suc­cess­fully in­stalled at the SPAR­C_LAB fa­cil­ity (INFN-LNF, Fras­cati, Rome). It is based on a 1.6 cell RF gun fab­ri­cated with the new braz­ing free tech­nol­ogy re­cently de­vel­oped at the Na­tional Lab­o­ra­to­ries of Fras­cati. The elec­tro­mag­netic de­sign has been op­ti­mized to have a full com­pen­sa­tion of the di­pole and quadru­pole field com­po­nents in­tro­duced by the cou­pling hole with an im­prove­ment of the ef­fec­tive pump­ing speed with two added pump­ing ports. The gun is over­cou­pled (\beta=2) to re­duce the fill­ing time and to allow the op­er­a­tion with short RF pulses. The over­all in­jec­tor in­te­grates a new so­le­noid with a re­mote con­trol of the trans­verse po­si­tion and a vari­able skew quadru­pole for the com­pen­sa­tion of resid­ual quadru­pole field com­po­nents. It also al­lows an on axis laser in­jec­tion sys­tem with the last mir­ror in air, and the pos­si­bil­ity of a fu­ture in­te­gra­tion of an X/C band cav­ity lin­earizer. In the paper we re­port the main char­ac­ter­is­tics of the elec­tro­mag­netic and me­chan­i­cal de­sign and the low and high power test re­sults that shows the ex­tremely good per­fo­mances of the new de­vice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS019
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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MOPOMS020	Dark Current Studies for a High Gradient SW C-Band RF Gun	675
	F. Cardelli, D. Alesinipresenter, L. Faillace, A. Giribono, A. Vannozzi INFN/LNF, Frascati, Italy G. Di Raddo LNF-INFN, Frascati, Italy T.G. Lucas PSI, Villigen PSI, Switzerland
	It is now well-es­tab­lished that for the gen­er­a­tion of very high bright­ness beams, re­quired for fourth gen­er­a­tion light sources, it is highly ad­van­ta­geous to use in­jec­tors based on Ra­diofre­quency photo-guns with very high peak elec­tric fields on the cath­ode (>120 MV/m). This very high sur­face elec­tric field leads to the gen­er­a­tion of un­de­sir­able elec­trons due to the field emis­sion ef­fect. The emit­ted elec­trons can be cap­tured and prop­a­gate along the Linac form­ing a dark cur­rent beam, lead­ing to back­ground ra­di­a­tion that can dam­age the in­stru­men­ta­tion and ra­dioac­ti­vate com­po­nents. Con­se­quently, it is im­por­tant that the emis­sion of these elec­trons, and their sub­se­quent trans­porta­tion, is care­fully eval­u­ated. Re­cently, in the frame­work of the I-FAST pro­ject, a high gra­di­ent, stand­ing wave, C-band (5712 MHz) RF pho­to­gun has been de­signed and will be re­al­ized soon. In this paper, the re­sults of dark cur­rent stud­ies and sim­u­la­tions are il­lus­trated. The trans­port ef­fi­ciency and the spec­trum of the dark cur­rent have been eval­u­ated by Par­ti­cle-In-Cell sim­u­la­tions for dif­fer­ent cath­ode peak field val­ues con­sid­er­ing also the ef­fect of the fo­cus­ing so­le­noid on the dark cur­rent beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS020
About •	Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 30 June 2022
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MOPOMS021	The New C Band Gun for the Next Generation RF Photo-Injectors	679
	D. Alesini, M. Ferrario, A. Giribono, A. Gizzi, L. Piersanti, A. Vannozzi INFN/LNF, Frascati, Italy F. Cardelli, G. Di Raddo, L. Faillace, S. Lauciani, A. Liedl, L. Pellegrino, C. Vaccarezza LNF-INFN, Frascati, Italy G. Castorina AVO-ADAM, Meyrin, Switzerland M. Croia ENEA Casaccia, Roma, Italy L. Ficcadenti INFN-Roma, Roma, Italy G. Pedrocchi SBAI, Roma, Italy
	Funding: European Union’s Horizon 2020 Research and Innovation programme under GA No 101004730 and INFN Commission V. RF photo-in­jec­tors are widely used in mod­ern fa­cil­i­ties, es­pe­cially in FEL, as very low-emit­tance and high-bright­ness elec­tron sources. Presently, the RF tech­nol­ogy mostly used for RF guns is the S band (3 GHz) with typ­i­cal cath­ode peak fields of 80-120 MV/m and rep­e­ti­tion rates lower than 120 Hz. There are solid rea­sons to be­lieve that the fre­quency step-up from S band to C band (6 GHz) can pro­vide a strong im­prove­ment of the beam qual­ity due to the po­ten­tial higher achiev­able cath­ode field (>160 MV/m) and higher rep­e­ti­tion rate (that can reach the kHz level). In the con­test of the Eu­ro­pean I.​FAST pro­ject, a new C band gun has been de­signed and will be re­al­ized and tested. It is a 2.5 cell stand­ing wave cav­ity with a four port mode launcher, de­signed to op­er­ate with short RF pulses (<300 ns) and cath­ode peak field larger than 160 MV/m. In the paper we pre­sent the elec­tro­mag­netic and thermo-me­chan­i­cal de­sign and the re­sults of the pro­to­typ­ing ac­tiv­ity and rf mea­sure­ments.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS021
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 28 June 2022
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MOPOMS022	Studies of a Ka-Band High Power Klystron Amplifier at INFN-LNF	683
	M. Behtouei, L. Faillace, A. Mostacci, B. Spataro LNF-INFN, Frascati, Italy F. Bosco, M. Carillopresenter, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy F. Di Paolo, S. Fantauzzi, A. Leggieri, F. Marrese, L. Valletti Università degli Studi di Roma "Tor Vergata", Roma, Italy G. Torrisi INFN/LNS, Catania, Italy
	In the frame­work of the Com­pact Light XLS pro­ject, a Ka-band lin­earizer with elec­tric field rang­ing from 100 to 150 MV/m is re­quested. In order to feed this struc­ture, a proper Ka-band high power kly­stron am­pli­fier with a high ef­fi­ciency is needed. This paper re­ports a pos­si­ble so­lu­tion for a kly­stron am­pli­fier op­er­at­ing on the TM010 mode at 36 GHz, the third har­monic of the 12 GHz linac fre­quency, with an ef­fi­ciency of 44% and 10.6 MW ra­diofre­quency out­put power. We dis­cuss also here the high-power DC gun with the re­lated mag­netic fo­cus­ing sys­tem, the RF beam dy­nam­ics and fi­nally the mul­ti­physics analy­sis of a high- power mi­crowave win­dow for a Ka-band kly­stron pro­vid­ing 16MW of peak power.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS022
About •	Received ※ 18 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 18 June 2022 — Issue date ※ 10 July 2022
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MOPOMS023	Start-to-End Beam-Dynamics Simulations of a Compact C-Band Electron Beam Source for High Spectral Brilliance Applications	687
	L. Faillace, M. Behtouei, B. Spataro, C. Vaccarezza LNF-INFN, Frascati, Italy R.B. Agustsson, I.I. Gadjev, S.V. Kutsaev, A.Y. Murokh RadiaBeam, Santa Monica, California, USA F. Bosco, M. Carillopresenter, L. Giuliano, M. Migliorati, A. Mostacci, L. Palumbo Sapienza University of Rome, Rome, Italy D.L. Bruhwiler RadiaSoft LLC, Boulder, Colorado, USA O. Camacho, A. Fukasawa, N. Majernik, J.B. Rosenzweig, O. Williams UCLA, Los Angeles, USA A. Giribono INFN/LNF, Frascati, Italy S.G. Tantawi SLAC, Menlo Park, California, USA
	Funding: This work is partially supported by DARPA under the Contract No. HR001120C0072, by DOE Contract DE-SC0009914, DOE Contract DE-SC0020409, and by the National Science Foundation Grant No. PHY-1549132. Pro­pos­als for new lin­ear ac­cel­er­a­tor-based fa­cil­i­ties are flour­ish­ing world-wide with the aim of high spec­tral bril­liance ra­di­a­tion sources. Most of these ac­cel­er­a­tors are based on elec­tron beams, with a va­ri­ety of ap­pli­ca­tions in in­dus­try, re­search and med­i­cine such as col­lid­ers, free-elec­tron lasers, wake-field ac­cel­er­a­tors, co­her­ent THz and in­verse Comp­ton scat­ter­ing X/’ sources as well as high-res­o­lu­tion di­ag­nos­tics tools in bio­med­ical sci­ence. In order to ob­tain high-qual­ity elec­tron beams in a small foot­print, we pre­sent the op­ti­miza­tion de­sign of a C-band lin­ear ac­cel­er­a­tor ma­chine. Dri­ven by a novel com­pact C-band hy­brid pho­toin­jec­tor, it will yield ul­tra-short elec­tron bunches of few 100’s pC di­rectly from in­jec­tion with ul­tra-low emit­tance, frac­tion of mm-mrad, and a few hun­dred fs length si­mul­ta­ne­ously, there­fore sat­is­fy­ing full 6D emit­tance com­pen­sa­tion. The nor­mal-con­duct­ing linacs are based on a novel high-ef­fi­ciency de­sign with gra­di­ents up to 50 MV/m. The beam max­i­mum en­ergy can be eas­ily ad­justed in the mid-GeV’s range. In this paper, we dis­cuss the start-to-end beam-dy­nam­ics sim­u­la­tions in de­tails.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS023
About •	Received ※ 07 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 03 July 2022
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MOPOMS025	Photocathode Performance Characterisation of Ultra-Thin MgO Films on Polycrystalline Copper	691
SUSPMF039	use link to see paper's listing under its alternate paper code
	C. Benjamin, H.M. Churn, L.B. Jones, T.C.Q. Noakes STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G.R. Bell, C. Benjamin, T.J. Rehaag University of Warwick, Coventry, United Kingdom H.M. Churn, L.B. Jones, T.C.Q. Noakes Cockcroft Institute, Warrington, Cheshire, United Kingdom
	Funding: Department of Physics, The University of Warwick, Coventry, United Kingdom STFC ASTeC, Daresbury, Warrington, United Kingdom WA4 4AD The per­for­mance ex­pected from the next gen­er­a­tion of elec­tron ac­cel­er­a­tors is dri­ving re­search into pho­to­cath­ode tech­nol­ogy as this fun­da­men­tally lim­its the achiev­able beam qual­ity. The per­for­mance char­ac­ter­is­tics of a pho­to­cath­ode are most no­tably; nor­malised emit­tance, bright­ness and en­ergy spread*. Ultra–thin Oxide films on metal sub­strates have been shown to lower the work func­tion (WF) of the sur­face, en­hanc­ing com­monly utilised metal pho­to­cath­odes, po­ten­tially im­prov­ing life­time and per­for­mance char­ac­ter­is­tics**. We pre­sent the char­ac­ter­i­sa­tion of two MgO/Cu pho­to­cath­odes grown at Dares­bury. The sur­face prop­er­ties such as; sur­face rough­ness, el­e­men­tal com­po­si­tion and WF, have been stud­ied using atomic force mi­croscopy (AFM), X-ray pho­to­elec­tron spec­troscopy (XPS) and ul­tra­vi­o­let pho­to­elec­tron spec­troscopy (UPS). The pho­toe­mis­sive prop­er­ties have been char­ac­terised with quan­tum ef­fi­ciency (QE) mea­sure­ments at 266 nm. Ad­di­tion­ally, we mea­sure the Trans­verse En­ergy Dis­tri­b­u­tion Curves (TEDC) for these pho­to­cath­odes under il­lu­mi­na­tion at var­i­ous wave­lengths using ASTeC’s Trans­verse En­ergy Spread Spec­trom­e­ter (TESS) and ex­tract the Mean Trans­verse En­ergy (MTE)***. *D.H. Dowell, et al, Nucl. Instr. and Meth A (2010), doi:10.1016/j.nima.2010.03.104 **V. Chang, et al, Phys. Rev. B (2018), doi.org/10.1103/PhysRevB.97.155436 ***Proc. FEL ’13, TUPPS033, 290-293
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS025
About •	Received ※ 19 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 21 June 2022
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MOPOMS027	Synthesis of First Caesium Telluride Photocathode at ASTeC Using Sequential and Co-Deposition Method	695
	R. Valizadeh, A.N. Hannah STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom V.R. Dhanak The University of Liverpool, Liverpool, United Kingdom S. Lederer DESY, Hamburg, Germany
	Cae­sium Tel­luride (Cs2Te) pho­to­cath­odes, are the elec-tron source of choice, by many global ac­cel­er­a­tors such as Eu­ro­pean XFEL, FLASH and AWA. It of­fers high quan­tum ef­fi­ciency and rea­son­able op­er­a­tional life­time with lower vac­uum re­quire­ments than multi-al­kali pho­to­cath­odes. In this paper, we re­port on the first syn­the­sised CsxTe pho­to­cath­odes at ASTeC, using both se­quen­tial and co-de­po­si­tion of Te and Cs on Mo sub­strate. Te de­po­si­tion is car­ried out using ion beam de­po­si­tion whilst the Cs is de­posited using a SAES get­ter al­kali. The ion beam de­po­si­tion of Te pro­vides a high de­gree of con­trol to give a dense, smooth layer with a re­pro­ducible film thick­ness. The chem­i­cal state with re­spect to film com­po­si­tion of the de­posited CsxTe is de­ter­mined with in-situ XPS anal-yses. The films ex­hibit a quan­tum ef­fi­ciency be­tween 7.5 to 9 % at 266 nm wave­length.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS027
About •	Received ※ 07 June 2022 — Revised ※ 10 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 06 July 2022
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MOPOMS028	Stability and Lifetime Studies of Carbon Nanotubes for Electron Cooling in ELENA	699
	B. Galante, G. Tranquille CERN, Meyrin, Switzerland J. Resta-López, C.P. Welschpresenter Cockcroft Institute, Warrington, Cheshire, United Kingdom J. Resta-López, C.P. Welschpresenter The University of Liverpool, Liverpool, United Kingdom J. Resta-López ICMUV, Paterna, Spain
	Funding: Work supported by EU Horizon 2020 research and innovation programme under the Marie Sk’odowska-Curie grant agreement No 721559. Elec­tron cool­ing is a fun­da­men­tal process to guar­an­tee beam qual­ity in low en­ergy an­ti­mat­ter fa­cil­i­ties. In ELENA, the elec­tron cooler re­duces the emit­tance blow-up of the an­tipro­ton beam so that a fo­cused and bright beam can be de­liv­ered to the ex­per­i­ments at the un­prece­dent­edly low en­ergy of 100 keV. To achieve a cold beam at this low en­ergy, the elec­tron gun must emit a mono­en­er­getic and rel­a­tively in­tense elec­tron beam. An op­ti­miza­tion of the elec­tron gun in­volv­ing a cold cath­ode is stud­ied to in­ves­ti­gate the fea­si­bil­ity of using car­bon nan­otubes (CNTs) as cold elec­tron field emit­ters. CNTs are con­sid­ered among the most promis­ing field emit­ting ma­te­ri­als. How­ever, sta­bil­ity data for emis­sion over hun­dreds of hours, as well as life­time and con­di­tion­ing process stud­ies to en­sure op­ti­mal per­for­mance, are still in­com­plete or miss­ing, es­pe­cially if the aim is to use them in op­er­a­tion. This con­tri­bu­tion re­ports ex­per­i­ments that char­ac­ter­ize these prop­er­ties and as­sess whether CNTs are suit­able to be used as cold elec­tron field emit­ters for many hun­dreds of hours.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS028
About •	Received ※ 20 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022
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MOPOMS029	HPC Modeling of a High-Gradient C-Band Linac for Hard X-Ray Free-Electron Lasers	703
	T.B. Bolin, S. Biedron UNM-ECE, Albuquerque, USA S. Sosa ODU, Norfolk, Virginia, USA
	The pro­duc­tion of soft to hard x-rays (up to 25 keV) at XFEL (x-ray free-elec­tron laser) fa­cil­i­ties has en­abled new de­vel­op­ments in a broad range of dis­ci­plines. Great po­ten­tial ex­ists for new sci­en­tific dis­cov­ery at higher en­er­gies (42+ keV) such as en­vi­sioned at MaRIE (Mat­ter-Ra­di­a­tion In­ter­ac­tions in Ex­tremes) at Los Alamos Na­tional Lab­o­ra­tory. These in­stru­ments can re­quire a large amount of real es­tate, which quickly es­ca­lates costs: The dri­ver of the FEL is typ­i­cally an elec­tron beam lin­ear ac­cel­er­a­tor (LINAC) and the need for higher beam en­er­gies ca­pa­ble of gen­er­at­ing these X-rays can dic­tate that the linac be­comes longer. State of art ac­cel­er­at­ing tech­nol­ogy is re­quired to re­duce the linac length by re­duc­ing the size of the cav­i­ties, pro­vid­ing for com­pact, high-fre­quency, high ac­cel­er­a­tion gra­di­ents. Here, we de­scribe using the Ar­gonne Lead­er­ship Com­put­ing Fa­cil­ity (ALCF) to fa­cil­i­tate our in­ves­ti­ga­tions into de­sign con­cepts for fu­ture XFEL high-gra­di­ent LINAC’s in the C-band (~4-8 GHz). We in­ves­ti­gate two dif­fer­ent trav­el­ing wave (TW) geome­tries op­ti­mized for high-gra­di­ent op­er­a­tion as mod­eled at the ALCF using VSim soft­ware.* * https://www.txcorp.com
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS029
About •	Received ※ 03 July 2022 — Accepted ※ 04 July 2022 — Issue date ※ 08 July 2022
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MOPOMS032	Compact-Two-Octave-Spanning Perpendicular Kicker of MeV Electrons Based on a Cubic Magnet Dipole Array	706
	T. Rohwer, R. Bazrafshan, F.X. Kärtner, N.H. Matlis Deutsches Elektronen Synchrotron (DESY) and Center for Free Electron Science (CFEL), Hamburg, Germany R. Bazrafshan University of Hamburg, Hamburg, Germany F.X. Kärtner The Hamburg Center for Ultrafast Imaging, University of Hamburg, Hamburg, Germany F.X. Kärtner CFEL, Hamburg, Germany P. Vagin DESY, Hamburg, Germany
	Funding: This work has been supported by the European Research Council under the European Union’s Seventh Framework Programme (FP7/2007-2013) through the Synergy Grant AXSIS (609920). New com­pact par­ti­cle ac­cel­er­a­tion struc­tures, in­clud­ing but not lim­ited to plasma, THz and di­rect laser dri­ven ac­cel­er­a­tors, have in com­mon that they cover a wide en­ergy range of po­ten­tial final en­er­gies and often show a large en­ergy spread. More­over, they may ini­tially have a rather large emit­tance. To an­a­lyze the en­ergy range of a sin­gle shot and/or to de­flect the beam to safely dump the elec­trons away from an end-sta­tion re­quires an elec­tron kicker cov­er­ing a large en­ergy range. Here, we pre­sent a mag­netic di­pole struc­ture based on a 2D Hal­bach array. For the cur­rent ex­per­i­men­tal test ac­cel­er­a­tor in AXSIS, an elec­tron beam in the en­ergy range from 4 to 20 MeV is de­flected by 90 de­gree and en­er­get­i­cally dis­persed. In di­rect con­trast to a sim­ple mag­netic di­pole, an array of cubic mag­net blocks with tai­lored mag­ne­ti­za­tion di­rec­tions al­lows a fo­cus­ing of the beam for both lon­gi­tu­di­nal and trans­verse di­rec­tions at 90 de­gree bend. A generic al­go­rithm op­ti­mizes the mag­netic field array to the pre­de­fined de­flec­tion angle and di­ver­gence. The mod­u­lar array struc­ture, in com­bi­na­tion with the al­go­rithm en­ables a sim­ple ex­change of mag­nets to adapt for dif­fer­ent beam pa­ra­me­ters.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS032
About •	Received ※ 08 June 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 14 June 2022
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MOPOMS033	Emittance Measurements of Nanoblade-Enhanced High Field Cathode	709
	G.E. Lawler, N. Majernik, J.I. Mann, N.E. Montanez, J.B. Rosenzweig UCLA, Los Angeles, California, USA V.S. Yu RadiaBeam, Santa Monica, California, USA
	Funding: This work was supported by the Center for Bright Beams, National Science Foundation Grant No. PHY-1549132. High bright­ness cath­odes are in­creas­ingly a focus for ac­cel­er­a­tor ap­pli­ca­tions rang­ing from free elec­tron lasers to ul­tra­fast elec­tron dif­frac­tion. There is fur­ther an in­creas­ing in­ter­est in fab­ri­ca­tion and con­trol of cath­ode sur­face to bet­ter con­trol the emis­sion char­ac­ter­is­tics and im­prove beam bright­ness. One method which we can con­sider is based on well-known sil­i­con nanofab­ri­ca­tion tech­niques which we use to cre­ate pat­terned cath­ode sur­faces. The sharp edges pro­duced lead to field emis­sion in­creases and high bright­ness emis­sion. We have demon­strated that a beam can be suc­cess­fully ex­tracted with a low emit­tance and we have re­con­structed a por­tion of the en­ergy spec­trum. Due to the sim­plic­ity of ex­tended geome­tries in nanofab­ri­ca­tion our beam uniquely pos­sesses a high as­pect ratio in its trans­verse cross sec­tion. We can begin to con­sider mod­i­fi­ca­tions for emit­tance ex­change beam­lines and hav­ing shown the pat­tern­ing prin­ci­ple is sound we can con­sider ad­di­tional pat­terns such as hol­low beams. Fu­ture work will con­tinue to char­ac­ter­ize the pro­duced beam and the ad­di­tion of fab­ri­ca­tion steps to re­move one of the blades in the dou­ble blade geom­e­try in order to more ac­cu­rately char­ac­ter­ize the emis­sion.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS033
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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MOPOMS034	Material Normal Energy Distribution for Field Emission Analyses From Monocrystalline Surfaces	713
	J.I. Mann, Y. Li, J.B. Rosenzweig UCLA, Los Angeles, California, USA T. Arias, J.K. Nangoi Cornell University, Ithaca, New York, USA
	Funding: National Science Foundation Grant No. PHY-1549132 Elec­tron field emis­sion is a com­pli­cated phe­nom­e­non which is sen­si­tive not only to the par­tic­u­lar ma­te­r­ial under il­lu­mi­na­tion but also to the spe­cific crys­talline ori­en­ta­tion of the sur­face. Sum­ma­riz­ing the abil­ity for a crys­tal to emit in a par­tic­u­lar di­rec­tion would be of great use when search­ing for good field emit­ters. In this paper we pro­pose a ma­te­r­ial nor­mal en­ergy dis­tri­b­u­tion which de­scribes the abil­ity of the bound elec­trons to tun­nel under an in­tense elec­tric field. This frame­work breaks a com­pu­ta­tion­ally ex­pen­sive 3-D sys­tem down to a source dis­tri­b­u­tion rep­re­sen­ta­tion ap­plic­a­ble for more ef­fi­cient 1-D mod­els. We use the Fowler-Nord­heim frame­work to study the yield and MTE (mean trans­verse en­ergy) from sources in­clud­ing gold, cop­per, and tung­sten in both monocrys­talline and poly­crys­talline forms. We find an in­crease in ef­fec­tive work func­tion for field emis­sion in the (111) di­rec­tion for gold and cop­per as­so­ci­ated with the Bragg plane in­ter­sec­tions of the Fermi sur­face.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS034
About •	Received ※ 20 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 06 July 2022
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MOPOMS036	Simulations of Laser Field Emission from Nanostructures with Image Charge Trapping and Band Structure Transitions	717
	B. Wang, G.E. Lawler, J.I. Mannpresenter, J.B. Rosenzweig UCLA, Los Angeles, California, USA T. Arias, J.K. Nangoi Cornell University, Ithaca, New York, USA S.S. Karkare Arizona State University, Tempe, USA
	Funding: National Science Foundation Grant No. PHY-1549132 Laser-in­duced field emis­sion from nanos­truc­tures as a means to cre­ate high bright­ness elec­tron beams has been a con­tin­u­ally grow­ing topic of study. Ex­per­i­ments using nanoblade emit­ters have achieved peak fields up­wards of 40 GV/m, beg­ging fur­ther in­ves­ti­ga­tion in this ex­treme regime. A re­cent paper has pro­vided an­a­lyt­i­cal re­duc­tions of the com­mon semi-in­fi­nite Jel­lium sys­tem for pulsed in­ci­dent lasers. We uti­lize these re­sults as well as sim­i­lar pre­vi­ous re­sults to fur­ther un­der­stand the physics un­der­ly­ing elec­tron rescat­ter­ing-type emis­sions. We progress in nu­mer­i­cally eval­u­at­ing the an­a­lyt­i­cal so­lu­tion to at­tempt to more ef­fi­ciently gen­er­ate spec­tra for this sys­tem. Ad­di­tion­ally, we use the full 1-D time-de­pen­dent Schrödinger equa­tion with a Hartree po­ten­tial and a dis­per­sion-re­la­tion tran­si­tion from ma­te­r­ial to vac­uum to study the same sys­tem. We de­ter­mine what im­por­tance the in­clu­sion of the ma­te­r­ial band struc­ture may have on emis­sions using this com­pu­ta­tion­ally chal­leng­ing ap­proach.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS036
About •	Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 27 June 2022 — Issue date ※ 01 July 2022
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MOPOMS039	Study of Material Choice in Beam Dumps for Energetic Electron Beams	721
	D. Zhu, R.T. Dowd, Y.E. Tanpresenter AS - ANSTO, Clayton, Australia
	Lead is typ­i­cally used as the ini­tial tar­get in a de­sign for beam dumps for high en­ergy elec­tron beams (>20 MeV). Elec­tron beams with en­er­gies above 20 MeV are usu­ally built within con­crete bunkers and there­fore the de­sign of any beam dump would just be a lead block (very cost ef­fec­tive) as close to the elec­tron source as pos­si­ble, after a vac­uum flange of some sort. In a study of a hy­po­thet­i­cal 100 MeV elec­tron beam in­side a con­crete bunker with an ex­tremely low dose rate con­straint out­side the bunker, the thick­ness of lead re­quired would have been too re­stric­tive for a com­pact de­sign. In this study we in­ves­ti­gate the po­ten­tial ben­e­fits of de­signs that in­corpo-rate low Z ma­te­ri­als like graphite as the pri­mary tar­get ma­te­r­ial in vac­uum fol­lowed by pro­gres­sively higher Z ma­te­ri­als up to lead. The re­sults show the more dif­fuse elas­tic scat­ter­ing from the pri­mary tar­get re­duces the back scat­tered pho­tons and re­duces the over­all neu­tron gen­era-tion. The ef­fect was a more com­pact de­sign for the beam dump to meet the same dose rate con­straint.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS039
About •	Received ※ 08 June 2022 — Revised ※ 09 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 19 June 2022
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MOPOMS040	Radiation Shielding Design for the X-Band Laboratory for Radio-Frequency Test Facility - X-Lab - at the University of Melbourne	724
	M. Volpi, R.P. Rassool, S.L. Sheehy, G. Taylor, S.D. Williams The University of Melbourne, Melbourne, Victoria, Australia D. Banon-Caballero IFIC, Valencia, Spain M. Boronat, N. Catalán Lasheras CERN, Meyrin, Switzerland R.T. Dowd AS - ANSTO, Clayton, Australia S.L. Sheehy ANSTO, Kirrawee DC New South Wales, Australia
	Here we re­port ra­di­a­tion dose es­ti­mates cal­cu­lated for the X-band Lab­o­ra­tory for Ac­cel­er­a­tors and Beams (X-LAB) under con­struc­tion at the Uni­ver­sity of Mel­bourne (UoM). The lab will host a CERN X-band test stand con­tain­ing two 12 GHz 6 MW kly­stron am­pli­fiers. By power com­bi­na­tion through hy­brid cou­plers and the use of pulse com­pres­sors, up to 50 MW of peak power can be sent to any of to ei­ther of the two test slots at pulse rep­e­ti­tion rates up to 400 Hz. The test stand is ded­i­cated to RF con­di­tion­ing and test­ing CLIC’s high gra­di­ent ac­cel­er­at­ing struc­tures be­yond 100 MV/m. This paper also gives a brief overview of the gen­eral prin­ci­ples of ra­di­a­tion pro­tec­tion leg­is­la­tion; ex­plains ra­di­o­log­i­cal quan­ti­ties and units, in­clud­ing some basic facts about ra­dioac­tiv­ity and the bi­o­log­i­cal ef­fects of ra­di­a­tion; and gives an overview of the clas­si­fi­ca­tion of ra­di­o­log­i­cal areas at X-LAB, ra­di­a­tion fields at high-en­ergy ac­cel­er­a­tors, and the ra­di­a­tion mon­i­tor­ing sys­tem used at X-LAB. The bunker de­sign to achieve a dose rate less than an­nual dose limit of 1 mSv is also shown.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS040
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 15 June 2022
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MOPOMS041	Concrete Shielding Activation for Proton Therapy Systems Using BDSIM and FISPACT-II	728
SUSPMF096	use link to see paper's listing under its alternate paper code
	E. Ramoisiaux, E. Gnacadja, C. Hernalsteens, N. Pauly, R. Tesse, M. Vanwelde ULB, Bruxelles, Belgium C. Hernalsteens CERN, Meyrin, Switzerland F. Stichelbaut IBA, Louvain-la-Neuve, Belgium
	Pro­ton ther­apy sys­tems are used world­wide for pa­tient treat­ment and fun­da­men­tal re­search. The gen­er­a­tion of sec­ondary par­ti­cles when the beam in­ter­acts with the beam­line el­e­ments is a well-known issue. In par­tic­u­lar, the en­ergy de­grader is the dom­i­nant source of sec­ondary ra­di­a­tion. This poses new chal­lenges for the con­crete shield­ing of com­pact sys­tems and beam­line el­e­ments ac­ti­va­tion com­pu­ta­tion. We use a novel method­ol­ogy to seam­lessly sim­u­late all the processes rel­e­vant to the ac­ti­va­tion eval­u­a­tion. A re­al­is­tic model of the sys­tem is de­vel­oped using Beam De­liv­ery Sim­u­la­tion (BDSIM), a Geant4-based par­ti­cle track­ing code that al­lows a sin­gle model to sim­u­late pri­mary and sec­ondary par­ti­cle track­ing and all par­ti­cle-mat­ter in­ter­ac­tions. The sec­ondary par­ti­cle fluxes ex­tracted from the sim­u­la­tions are pro­vided as input to FIS­PACT-II to com­pute the ac­ti­va­tion by solv­ing the rate equa­tions. This ap­proach is ap­plied to the Ion Beam Ap­pli­ca­tions (IBA) Pro­teus®ONE (P1) sys­tem and the shield­ing of the pro­ton ther­apy re­search cen­tre of Charleroi, Bel­gium. Pro­ton loss dis­tri­b­u­tions are used to model the pro­duc­tion of sec­ondary neu­trals in­side the ac­cel­er­a­tor struc­ture. Two mod­els for the dis­tri­b­u­tion of pro­ton losses are com­pared for the com­pu­ta­tion of the clear­ance index at spe­cific lo­ca­tions of the de­sign. Re­sults show that the vari­a­tion in the ac­cel­er­a­tor loss mod­els can be char­ac­terised as a sys­tem­atic error.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS041
About •	Received ※ 19 May 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 22 June 2022
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MOPOMS042	Comparison Between Run 2 TID Measurements and FLUKA Simulations in the CERN LHC Tunnel of the Atlas Insertion Region	732
	D. Prelipcean, K. Biłko, F. Cerutti, A. Ciccotelli, D. Di Francesca, R. García Alía, B. Humannpresenter, G. Lerner, D. Ricci, M. Sabaté-Gilarte CERN, Meyrin, Switzerland B. Humannpresenter TU Vienna, Wien, Austria
	In this paper we pre­sent a sys­tem­atic bench­mark be­tween the sim­u­lated and the mea­sured data for the ra­di­a­tion mon­i­tors use­ful for Ra­di­a­tion to Elec­tron­ics (R2E) stud­ies at the Large Hadron Col­lider (LHC) at CERN. For this pur­pose, the ra­di­a­tion lev­els in the main LHC tun­nel on the right side of the In­ter­ac­tion Point 1 (ATLAS de­tec­tor) are sim­u­lated using the FLUKA Monte Carlo code and com­pared against Total Ion­is­ing Dose (TID) mea­sure­ments per­formed with the Beam Loss Mon­i­tor­ing (BLM) sys­tem, and 180 m of Dis­trib­uted Op­ti­cal Fibre Ra­di­a­tion Sen­sor (DOFRS). Con­sid­er­ing the com­plex­ity and the scale of the sim­u­la­tions as well as the va­ri­ety of the LHC op­er­a­tional pa­ra­me­ters, we find a gen­er­ally good agree­ment be­tween mea­sured and sim­u­lated ra­di­a­tion lev­els, typ­i­cally within a fac­tor of 2 or bet­ter.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS042
About •	Received ※ 08 June 2022 — Revised ※ 23 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 09 July 2022
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MOPOMS043	Automated Analysis of the Prompt Radiation Levels in the CERN Accelerator Complex	736
	K. Biłko, R. García Alía, J.B. Potoinepresenter CERN, Meyrin, Switzerland
	The CERN in­jec­tor com­plex is es­sen­tial in pro­vid­ing high-en­ergy beams to var­i­ous ex­per­i­ments and to the world’s largest ac­cel­er­a­tor, the Large Hadron Col­lider (LHC). Beam losses linked to its op­er­a­tion re­sult in a mixed ra­di­a­tion field which, through both cu­mu­la­tive and sin­gle-event ef­fects poses a threat to the elec­tronic equip­ment ex­posed in the tun­nel. There­fore, de­tailed knowl­edge of the ra­di­a­tion dis­tri­b­u­tion and evo­lu­tion is nec­es­sary in order to im­ple­ment ad­e­quate Ra­di­a­tion to Elec­tron­ics mit­i­ga­tion and pre­ven­tion mea­sures, re­sult­ing in an im­prove­ment of the ac­cel­er­a­tor ef­fi­ciency and avail­abil­ity. In this study, we pre­sent the au­to­mated analy­sis scheme put in place to ef­fi­ciently process and vi­su­alise the ra­di­a­tion data pro­duced by var­i­ous ra­di­a­tion mon­i­tors, dis­trib­uted at the four largest CERN ac­cel­er­a­tors, namely the Pro­ton Syn­chro­tron Booster, Pro­ton Syn­chro­tron, Super Pro­ton Syn­chro­tron, and the LHC, where a pro­ton beam is ac­cel­er­ated grad­u­ally from 160 MeV up to 7 TeV.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS043
About •	Received ※ 07 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 30 June 2022
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MOPOMS044	Implications and Mitigation of Radiation Effects on the CERN SPS Operation during 2021	740
	Y.Q. Aguiar, A. Apollonio, K. Biłko, M. Brucoli, M. Cecchetto, S. Danzeca, R. García Alía, T. Ladzinski, G. Lerner, J.B. Potoinepresenter, A. Zimmaro CERN, Meyrin, Switzerland
	Dur­ing the Long Shut­down 2 (LS2, 2019-2020), the CERN ac­cel­er­a­tor com­plex has un­der­gone major up­grades, mainly in prepa­ra­tion for the High-Lu­mi­nos­ity (HL) LHC era, the ul­ti­mate ca­pac­ity for its physics pro­duc­tion. There­fore, sev­eral novel equip­ment and sys­tems were de­signed and de­ployed through­out the ac­cel­er­a­tor com­plex. To com­ply with the ra­di­a­tion level spec­i­fi­ca­tions and avoid ma­chine down­time due to ra­di­a­tion ef­fects, the elec­tron­ics sys­tems ex­posed to ra­di­a­tion need to fol­low Ra­di­a­tion Hard­ness As­sur­ance (RHA) method­olo­gies de­vel­oped and val­i­dated by the Ra­di­a­tion to Elec­tron­ics (R2E) pro­ject at CERN. How­ever, the es­tab­lish­ment of such pro­ce­dures is not yet fully im­ple­mented in the LHC in­jec­tor chain, and some R2E fail­ures were de­tected in the SPS dur­ing the 2021 op­er­a­tion. This work is de­voted to de­scrib­ing and analysing the R2E fail­ures and their im­pact on op­er­a­tion, in the con­text of the re­lated ra­di­a­tion lev­els and equip­ment sen­si­tiv­ity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS044
About •	Received ※ 07 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 26 June 2022 — Issue date ※ 08 July 2022
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MOPOMS045	Vacuum Control System Upgrade for ALPI Accelerator	744
	G. Savarese, L. Antoniazzi, D. Bortolato, A. Conte, F. Gelainpresenter, D. Marcato, C.R. Roncolato INFN/LNL, Legnaro (PD), Italy
	The vac­uum sys­tem of ALPI ac­cel­er­a­tor in­cludes about 40 pump­ing groups based on tur­bo­mol­e­c­u­lar pumps. The in­stru­men­ta­tion of the ac­cel­er­a­tors com­plex is mainly the one in­stalled in 90s, with con­se­quent main­te­nance is­sues. The con­trol and su­per­vi­sion sys­tems were de­vel­oped in the same pe­riod by an ex­ter­nal com­pany, which pro­duced cus­tom so­lu­tions for the HW and SW parts. Con­trol de­vices are based on cus­tom PLCs, while the su­per­vi­sion sys­tem is based on C and C#. The com­mu­ni­ca­tion be­tween the field and the su­per­vi­sor is com­posed of mul­ti­ple lev­els: RS-232 stan­dard is used to trans­fer con­trol pa­ra­me­ter from the field de­vices up to cus­tom mul­ti­plex­ers; RS-485 trans­mis­sion is used from the mul­ti­plex­ers to two PC servers cov­er­ing dif­fer­ent sec­tions of the in­stal­la­tion; while Eth­er­net, is used to con­nect the servers and the op­er­a­tion con­sole. Ob­so­les­cence and rigid­ity of the sys­tem, deficit of spare parts and im­pos­si­bil­ity of repa­ra­tion or mod­i­fi­ca­tion with­out ex­ter­nal sup­port, re­quired a com­plete ren­o­va­tion of the vac­uum sys­tem and rel­a­tive con­trols in the next years. This paper de­scribes the adopted strat­egy and the im­ple­men­ta­tion sta­tus.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS045
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 30 June 2022
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MOPOMS046	Reliability Analysis of the HL-LHC Energy Extraction System	747
	M.R. Blaszkiewicz, A. Apollonio, T. Cartier-Michaud, B.I. Panev, M. Pojer, D. Wollmannpresenter CERN, Meyrin, Switzerland
	The en­ergy ex­trac­tion sys­tems for the pro­tec­tion of the new HL-LHC su­per­con­duct­ing mag­net cir­cuits are based on vac­uum break­ers. This tech­nol­ogy al­lows to sig­nif­i­cantly re­duce the switch open­ing time and in­creases the over­all sys­tem re­li­a­bil­ity with re­duced main­te­nance needs. This paper pre­sents the re­sults of de­tailed re­li­a­bil­ity stud­ies per­formed on these new en­ergy ex­trac­tion sys­tems. The study quan­ti­fies the risk of a fail­ure which pre­vents cor­rect pro­tec­tion of a mag­net cir­cuit and iden­ti­fies the most crit­i­cal com­po­nents of the sys­tem. For this, the model con­sid­ers fac­tors such as block or com­po­nent level fail­ure prob­a­bil­i­ties, dif­fer­ent main­te­nance strate­gies and re­pair pro­ce­dures. The re­li­a­bil­ity sim­u­la­tions have been per­formed with Avail­Sim4, a novel Monte Carlo code for avail­abil­ity and re­li­a­bil­ity sim­u­la­tions. The re­sults are com­pared with the sys­tem re­li­a­bil­ity re­quire­ments and pro­vides in­sights into the most crit­i­cal com­po­nents.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS046
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 07 July 2022
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MOPOMS047	Control and Functional Safety Systems Design for Real-Time Conditioning of RF Structures at TEX	751
	S. Pioli, R. Gargana, D. Moriggipresenter LNF-INFN, Frascati, Italy F. Cardelli, P. Ciuffetti, C. Di Giulio INFN/LNF, Frascati, Italy
	We re­port the sta­tus of the de­vel­op­ment of an High Power RF Lab­o­ra­tory in X-Band called TEX (TEst-stand for X-Band). TEX is part of the LATINO (Lab­o­ra­tory in Ad­vanced Tech­nolo­gies for IN­nO­va­tion) ini­tia­tive that is on­go­ing at the Fras­cati Na­tional Lab­o­ra­to­ries (LNF) of the Ital­ian In­sti­tute for Nu­clear Physics (INFN) that cov­ers many dif­fer­ent areas fo­cused on par­ti­cle ac­cel­er­a­tor tech­nolo­gies. TEX is a RF test fa­cil­ity based on solid-state K400 mod­u­la­tor from Scan­di­Nova with a 50MW class X-band (11.994 GHz) kly­stron tube model VKX8311A op­er­at­ing at 50 Hz. This RF source will op­er­ate as re­source for test and re­search pro­grams such as the RF break­down on RF wave­guide com­po­nents as well as high power test­ing of ac­cel­er­at­ing struc­tures for fu­ture high gra­di­ent lin­ear ac­cel­er­a­tor such as Eu­PRAXIA and CLIC. In this con­text we will pre­sent the whole EPICS con­trol sys­tem de­sign fo­cus­ing on archiv­ing, user in­ter­faces and cus­tom de­vel­op­ment made as part of the func­tional safety to de­liver real-time RF break­down de­tec­tion in­te­grated with the tim­ing sys­tem of the fa­cil­ity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS047
About •	Received ※ 16 June 2022 — Revised ※ 16 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 27 June 2022
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MOPOMS048	Fast Trigger System for Beam Abort System in SuperKEKB	754
	H. Ikeda, T. Mimashi, S. Nakamura, T. Oki, S. Sasaki KEK, Ibaraki, Japan
	In order to pro­tect the hard­ware com­po­nents of the de-tec­tor and ac­cel­er­a­tor from sud­den beam loss of high beam cur­rents, the fast beam abort sys­tem is de­vel­oped in the Su­perKEKB. The pre­vi­ous abort sys­tem was not fast enough for sud­den beam loss that caused QCS quench, and it gave a dam­age to the col­li­ma­tor and the Belle-II de­tec­tor. A fast abort sys­tem is re­quired to pre-vent­ing such dam­age. The abort sys­tem con­sists of sev-eral sen­sors that gen­er­ate in­ter­lock sig­nal (the loss moni-tor, dose in the Bell-II de­tec­tor, and the mag­net fail­ure etc.), op­ti­cal cable sys­tem to trans­fer the in­ter­lock sig­nal to cen­tral con­trol room (CCR), the abort trig­ger sig­nal gen­er­a­tion sys­tem and the abort kicker. To re­duce total time, we re­duce trans­mis­sion time from local con­trol room to CCR by chang­ing sig­nal cable route. Since the in­ter­lock sig­nal pro­duced by mag­net power sup­ply was slow, we mod­i­fied the mag­net power sup­ply. For more quick gen­er­a­tion of abort trig­ger sig­nal, we in­creased num­ber of the abort gap. By these im­prove­ments, an av­er­age abort time is re­duced from 31µsec to 25µsec. This im­prove­ment looks small, but it brought pre­vent­ing the se­ri­ous ra­di­a­tion dam­age to many hard­ware compo-nents. De­tail of the sys­tem and re­sult is pre­sented in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS048
About •	Received ※ 08 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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MOPOMS050	Rigorous Approach for Calculation of Radiation of a Charged Particle Bunch Exiting an Open-Ended Dielectrically Loaded Waveguide	757
	S.N. Galyamin Saint Petersburg State University, Saint Petersburg, Russia S. Baturinpresenter ITMO University, Saint Petersburg, Russia
	Funding: Work supported by Russian Science Foundation (Grant No. 18-72-10137). Beam-dri­ven ra­di­a­tion sources based on open-ended wave­guide struc­tures with di­elec­tric fill­ing are of es­sen­tial in­ter­est due to their at­trac­tive pos­si­bil­i­ties to gen­er­ate high-power nar­row-band Cherenkov ra­di­a­tion*. An im­por­tant prob­lem here is to ef­fec­tively ex­tract the ra­di­a­tion from the wave­guide to the open space. There­fore, fur­ther de­vel­op­ment of this scheme re­quires rig­or­ous math­e­mat­i­cal ap­proach de­scrib­ing the in­ter­ac­tion of both charged par­ti­cle bunch and pro­duced ra­di­a­tion with the open end of a wave­guide. In this re­port, we pre­sent the cor­re­spond­ing an­a­lyt­i­cal ap­proach based on our re­cent paper** where dif­frac­tion of a wave­guide mode at the open end of a di­elec­tri­cally loaded wave­guide has been rig­or­ously in­ves­ti­gated. * D. Wang et al., Rev. Sci. Instruments, Vol. 89, 093301 (2018). ** S.N. Galyamin et al., IEEE Trans. Microwave Theory Techn., Vol. 69, 2429-2438 (2021).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS050
About •	Received ※ 09 June 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 03 July 2022
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MOPOMS052	6 MeV Novel Hybrid (Standing Wave - Traveling Wave) Photo-Cathode Electron Gun for a THz Superradiant FEL	760
	A. Nause, L. Feigin, A. Friedman, A. Weinberg Ariel University, Ariel, Israel A. Fukasawa, J.B. Rosenzweig UCLA, Los Angeles, California, USA B. Spataro LNF-INFN, Frascati, Italy
	A novel 6 MeV hy­brid photo in­jec­tor was de­signed and com­mis­sioned at Ariel Uni­ver­sity in Is­rael as an on-go­ing col­lab­o­ra­tion with UCLA. This unique, new gen­er­a­tion de­sign pro­vides a rad­i­cally sim­pler ap­proach to RF feed­ing of a gun/buncher sys­tem, lead­ing to a much shorter beam via ve­loc­ity bunch­ing owed to an at­tached trav­el­ing wave sec­tion of the photo-in­jec­tor. This de­sign re­sults in bet­ter per­for­mance in beam pa­ra­me­ters, pro­vid­ing a high qual­ity elec­tron beam, with en­ergy of 6 MeV, emit­tance of less than 3 ’m, and a 150 fs pulse du­ra­tion at up to 1 nC per pulse. The Hy­brid gun is dri­ven by a SLAC XK5 Kly­stron as the high power RF source, and third har­monic of a fs level IR Laser am­pli­fier (266 nm) to ex­tract elec­trons from the Cath­ode. The unique e-gun will pro­duce a bunched elec­tron pulse to drive a THz FEL, which will op­er­ate at the su­per-ra­di­ance regime, and there­fore re­quires ex­tra­or­di­nary beam prop­er­ties. It will also be used for MeV UED ex­per­i­ments in a sep­a­rate line using a dog­leg sec­tion. Here we de­scribe the gun and pre­sents ex­per­i­men­tal re­sults from the gun and its sub-sys­tems, in­clud­ing en­ergy and charge mea­sure­ments, com­pared with the de­sign sim­u­la­tions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOMS052
About •	Received ※ 11 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 17 June 2022 — Issue date ※ 18 June 2022
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