MC7: Accelerator Technology
T16: Pulsed Power Technology

Paper	Title	Page
THPOST040	Commissioning of an X-Band Cavity for Longitudinal Phase Space Linearization at UCLA PEGASUS Laboratory	2533
	P.E. Denham, P. Musumeci, A. Ody UCLA, Los Angeles, USA
	This paper dis­cusses the com­mis­sion­ing of an X-band (9.6 Ghz) lin­earizer cav­ity at the UCLA PE­GA­SUS beam­line. The pho­toin­jec­tor gun and booster linac op­er­ate at S-band (2.856 GHz) and the lin­earizer cav­ity can be used to com­pen­sate tem­po­rally cor­re­lated en­ergy spread in­her­ited by the use of rel­a­tively long (many ps) laser pulses at the pho­to­cath­ode. The cav­ity is com­prised of 7 cells for a total length of a 9.45 cm, and is in­stalled in the drift sec­tion be­tween the gun and the linac. It can be used to re­move higher order cor­re­la­tions and min­i­mize the beam en­ergy spread of 13 ps long beams to 10-4.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOST040
About •	Received ※ 08 June 2022 — Revised ※ 21 June 2022 — Accepted ※ 22 June 2022 — Issue date ※ 27 June 2022
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THPOTK015	Solid-State Pulsed Power Supply for a 100 keV Electron Source of the New Synchrotron Facility in Thailand	2803
	W. Phacheerak, S. Bootiew, T. Chanwattana, Ch. Dhammatong, N. Juntong, K. Kittimanapun SLRI, Nakhon Ratchasima, Thailand K. Manasatitpong Synchrotron Light Research Institute (SLRI), Muang District, Thailand
	The new syn­chro­tron light source pro­ject in Thai­land will uti­lize a thermionic DC elec­tron gun. The max­i­mum op­er­a­tion of the gun is 100 keV, which re­quires a pulsed power sup­ply of 100kV. The pre­sent syn­chro­tron ma­chine uses a con­ven­tional de­sign of the gun power sup­ply. To im­prove the high volt­age pulsed qual­ity, the solid-state de­sign of the gun power sup­ply is uti­lized. The out­put pulse width can be ad­justed eas­ily and the droop is less com­pared to the con­ven­tional de­sign. The de­signed out­put of 100 kV am­pli­tude with 5 µs pulsed width can be achieved with this de­sign. It also pro­duces a less droop of 1.8%. The de­sign process and re­sults will be pre­sented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK015
About •	Received ※ 08 June 2022 — Revised ※ 13 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 26 June 2022
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THPOTK040	Few-Nanosecond Stripline Kickers for Top-Up Injection into PETRA IV	2858
	G. Loisch, V. Belokurov, F. Obier DESY, Hamburg, Germany
	PETRA IV is the planned ul­tralow-emit­tance up­grade of the PETRA III syn­chro­tron light source at DESY, Ham­burg. The cur­rent base­line in­jec­tion scheme is an off-axis, top-up in­jec­tion with few-nanosec­ond stripline kick­ers, which would allow for ac­cu­mu­la­tion and least dis­tur­bance of ex­per­i­ments dur­ing in­jec­tion. Be­sides the re­quire­ments on kick-strength, field qual­ity, pulse rise-rate, and heat man­age­ment, two me­chan­i­cal de­signs with dif­fer­ent aper­tures are nec­es­sary, as the de­vices will be used for in­jec­tion and the trans­verse multi-bunch feed­back sys­tem. In this con­tri­bu­tion we will pre­sent the cur­rent sta­tus of 3D fi­nite el­e­ment sim­u­la­tions of elec­tro­mag­netic fields and heat­ing as well as the me­chan­i­cal de­sign and first pulse elec­tron­ics tests.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK040
About •	Received ※ 20 May 2022 — Revised ※ 17 June 2022 — Accepted ※ 25 June 2022 — Issue date ※ 29 June 2022
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THPOTK041	Development of Programmable Bipolar Multi kHz Kicker Drivers for Long Pulse Superconducting Electron Linacs	2862
	J.L. Teichgräber, W. Decking, J. Kahl, F. Obier DESY, Hamburg, Germany
	Deutsches Elek­tro­nen-Syn­chro­tron DESY, Notkestrasse 85, 22607 Ham­burg, Ger­many Su­per­con­duct­ing cav­i­ties allow for long rf-pulses, which en­able the ac­cel­er­a­tion of thou­sands of elec­tron bunches within one rf-pulse. Due to tran­sient ef­fects, e.g. cou­pler kicks, eddy cur­rents or wake­fields, bunch prop­er­ties like the beam tra­jec­tory can change along the pulse train. To com­pen­sate for this, kicker sys­tems based on high-cur­rent op­er­a­tional am­pli­fiers have been de­vel­oped for the free elec­tron lasers Eu­ro­pean XFEL and FLASH at DESY in Ham­burg. Here, we pre­sent the lay­out of the kicker sys­tem, the setup of the pulse elec­tron­ics, and op­er­a­tional re­sults with beam.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK041
About •	Received ※ 03 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 19 June 2022
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THPOTK042	Non-Linear Phenomena Studies in High-Gradient RF Technology for Hadrontherapy at IFIC	2865
SUSPMF117	use link to see paper's listing under its alternate paper code
	P.M.R. Martinez-Reviriego, C. Blanch Gutiérrez, D. Esperante Pereira, J. Fuster, N. Fuster-Martínez, B. Gimeno, D. Gonzalez-Iglesias, P. Martín-Luna IFIC, Valencia, Spain
	High-Gra­di­ent ac­cel­er­at­ing cav­i­ties are one of the main re­search lines in the de­vel­op­ment of com­pact lin­ear col­lid­ers. How­ever, the op­er­a­tion of such cav­i­ties is cur­rently lim­ited by non-lin­ear ef­fects that are in­ten­si­fied at high elec­tric fields, such as dark cur­rents and ra­di­a­tion emis­sion or RF break­downs. A new nor­mal-con­duct­ing High Gra­di­ent S-band Back­ward Trav­el­ling Wave ac­cel­er­at­ing cav­ity for med­ical ap­pli­ca­tion (v=0.38c) de­signed and con­structed at CERN is being tested at IFIC. In this paper, we pre­sent ex­per­i­men­tal mea­sure­ments and sim­u­la­tion of such non-lin­ear ef­fects. The main goal of these stud­ies is to es­tab­lish the vi­a­bil­ity of using these tech­niques in lin­ear ac­cel­er­a­tors, in order to im­prove our un­der­stand­ing in such ef­fects. The main goal of these stud­ies is to de­ter­mine the vi­a­bil­ity of using this tech­niques in lin­ear ac­cel­er­a­tors for hadron­ther­apy treat­ments in hos­pi­tals.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK042
About •	Received ※ 08 June 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 20 June 2022
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THPOTK043	Mitigation of High Voltage Breakdown of the Beam Screen of a CERN SPS Injection Kicker Magnet	2868
	M.J. Barnes, W. Bartmann, M. Díaz Zumel, L. Ducimetière, L.M.C. Feliciano, T. Kramer, V. Namora, T. Stadlbauer, D. Standen, P. Trubacova, F.M. Velotti, C. Zannini CERN, Meyrin, Switzerland
	The SPS in­jec­tion kicker mag­nets (MKP) were de­vel­oped in the 1970’s, be­fore beam in­duced power de­po­si­tion was con­sid­ered an issue. These mag­nets are very lossy from a beam im­ped­ance per­spec­tive: this is ex­pected to be an issue dur­ing SPS op­er­a­tion with the higher in­ten­sity beams needed for HL-LHC. A de­sign, with serig­ra­phy ap­plied to an alu­mina car­rier, has been de­vel­oped to sig­nif­i­cantly re­duce the broad­band beam cou­pling im­ped­ance and hence mit­i­gate the heat­ing is­sues. Dur­ing high volt­age pulse test­ing there were elec­tri­cal dis­charges as­so­ci­ated with the serig­ra­phy. De­tailed math­e­mat­i­cal mod­els have been de­vel­oped to aid in un­der­stand­ing the tran­siently in­duced volt­ages and to re­duce the mag­ni­tude and du­ra­tion of elec­tric field. In this paper, we dis­cuss the so­lu­tions im­ple­mented to mit­i­gate the elec­tri­cal dis­charges while main­tain­ing an ad­e­quately low beam-cou­pling im­ped­ance. In ad­di­tion, the re­sults of high volt­age tests are re­ported. The alu­mina sub­strate has a high sec­ondary elec­tron yield and thus elec­tron-cloud could be an issue, with SPS beam, if mit­i­gat­ing mea­sures were not taken: this paper also dis­cusses the mea­sures im­ple­mented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK043
About •	Received ※ 07 June 2022 — Revised ※ 12 June 2022 — Accepted ※ 13 June 2022 — Issue date ※ 17 June 2022
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THPOTK044	Ultra-Fast Generator for Impact Ionization Triggering	2872
	A.A. del Barrio Montañés, Y. Dutheil, T. Kramer, V. Senaj CERN, Meyrin, Switzerland M. Sack KIT, Karlsruhe, Germany
	Im­pact ion­iza­tion trig­ger­ing can be suc­cess­fully ap­plied to stan­dard thyris­tors, thus boost­ing their dI/dt ca­pa­bil­ity by up to 1000x. This ground­break­ing trig­ger­ing re­quires ap­ply­ing sig­nif­i­cant over­volt­age on the an­ode-cath­ode of thyris­tor with a slew rate > 1kV/ns. Com­pact pulse gen­er­a­tors based on com­mer­cial off-the-shelf (COTS) com­po­nents would allow the spread of this tech­nol­ogy into nu­mer­ous ap­pli­ca­tions, in­clud­ing fast kicker gen­er­a­tors for par­ti­cle ac­cel­er­a­tors. In our ap­proach, the be­gin­ning of the trig­ger­ing chain is a HV SiC MOS with an ul­tra-fast su­per-boost­ing gate dri­ver. The super boost­ing of a 1.7kV rated SiC MOS al­lows to re­duce the MOS rise time by a fac­tor of > 25 (datasheet tr = §I{20}{ns} vs. mea­sured tr < 800ps, re­sult­ing in an out­put volt­age slew rate > 1kV/ns and an am­pli­tude > 1kV. Ad­di­tional boost­ing is ob­tained by a Marx gen­er­a­tor with GaAs diodes, reach­ing an out­put volt­age slew rate > 11kV/ns. The final stage will be a Marx gen­er­a­tor with medium size thyris­tors trig­gered in im­pact ion­iza­tion mode with suf­fi­cient volt­age and cur­rent rat­ing nec­es­sary for the trig­ger­ing of a big thyris­tor. This paper pre­sents the im­pact ion­iza­tion trig­ger­ing of a small size thyris­tor.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK044
About •	Received ※ 16 May 2022 — Revised ※ 13 June 2022 — Accepted ※ 14 June 2022 — Issue date ※ 06 July 2022
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THPOTK045	Branch Module for an Inductive Voltage Adder for Driving Kicker Magnets with a Short Circuit Termination	2875
	J. Ruf, M.J. Barnes, Y. Dutheil, T. Kramer CERN, Meyrin, Switzerland M. Sack KIT, Karlsruhe, Germany
	For dri­ving kicker mag­nets ter­mi­nated in a short cir­cuit, a branch mod­ule for an in­duc­tive volt­age adder has been de­signed and as­sem­bled. The mod­ule has been de­signed for a max­i­mum charg­ing volt­age of 1.2 kV and an out­put cur­rent of 200 A con­sid­er­ing the cur­rent dou­bling due to the short cir­cuit ter­mi­na­tion. It fea­tures three con­sec­u­tive modes of op­er­a­tion: en­ergy in­jec­tion, free­wheel­ing, and en­ergy ex­trac­tion. There­fore, the topol­ogy of the branch mod­ule con­sists of two in­de­pen­dently con­trolled SiC MOS­FET switches and one diode switch. In order not to ex­tend the field rise time of the kicker mag­net sig­nif­i­cantly be­yond the mag­net fill time, the pulse must have a fast rise time. Hence, the switch for en­ergy in­jec­tion is dri­ven by a gate boost­ing dri­ver fea­tur­ing a half bridge of GaN HEMTs and a dri­ving volt­age of 80 V. Mea­sure­ments of the drain source volt­age of this switch showed a fall time of 2.7 ns at a volt­age of 600 V re­sult­ing in a volt­age rise time of 5.4 ns at the out­put ter­mi­nated with a re­sis­tive load. To meet both the rise time and cur­rent re­quire­ments, a par­al­lel con­fig­u­ra­tion of four SiC MOS­FETs was im­ple­mented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-THPOTK045
About •	Received ※ 16 May 2022 — Accepted ※ 14 June 2022 — Issue date ※ 10 July 2022
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