Author: Kramer, T.
Paper Title Page
TUPAB363 Feasibility Study for the Novel CERN PS Fast Extraction Septum 2363
 
  • T. Helseth, M.G. Atanasov, B. Balhan, J.C.C.M. Borburgh, L. Ducimetière, M.A. Fraser, T. Kramer
    CERN, Geneva, Switzerland
  
  In the frame­work of ac­cel­er­a­tor con­sol­i­da­tion, a fea­si­bil­ity study for a novel CERN PS ex­trac­tion sep­tum has been con­ducted. Func­tional re­quire­ments have been es­tab­lished and, ac­cord­ingly, a sys­tem of two septa mag­nets and their as­so­ci­ated pulse gen­er­a­tor is pro­posed. The mag­netic sep­tum de­sign is based on eddy cur­rent topol­ogy. Mag­netic sim­u­la­tions in Flux 2D and Opera 3D of a con­cep­tual de­sign have been car­ried out. The short length and high am­pli­tude of the cur­rent pulse re­quired to drive the eddy cur­rent septa imply that none of the power con­vert­ers cur­rently used for septa mag­nets at CERN will be suit­able. Pulse gen­er­a­tor topolo­gies de­rived from kicker gen­er­a­tors have there­fore been ex­plored and sim­u­lated in Spice. The con­cep­tual mag­net and gen­er­a­tor de­sign along with sim­u­la­tion re­sults are pre­sented in this paper.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB363  
About • paper received ※ 18 May 2021       paper accepted ※ 17 June 2021       issue date ※ 10 August 2021  
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WEPAB343 Inductive Adder Prototype for FCC-hh Injection Kicker System 3494
 
  • D. Woog, M.J. Barnes, T. Kramer
    CERN, Meyrin, Switzerland
  • H. De Gersem
    TEMF, TU Darmstadt, Darmstadt, Germany
  
  The fu­ture cir­cu­lar col­lider (FCC) re­quires a highly re­li­able in­jec­tion kicker sys­tem. Pre­sent day kicker sys­tems often rely on thyra­tron-based pulse gen­er­a­tors and a pulse form­ing net­work or line: the thyra­tron is sus­cep­ti­ble to self-trig­ger­ing. Hence, an al­ter­na­tive pulse gen­er­a­tor topol­ogy, based on fast semi­con­duc­tor switches, is con­sid­ered for the FCC. One pos­si­bil­ity is an in­duc­tive adder (IA). A pro­to­type IA has been de­signed and built: the main chal­lenges are the fast rise time, high out­put cur­rent, low sys­tem im­ped­ance and a 2.3 us pulse du­ra­tion com­bined with low droop. This paper pre­sents the re­sults of mea­sure­ments on the pro­to­type IA where the rated out­put cur­rent and out­put volt­age were achieved sep­a­rately. Sug­gested im­prove­ments to the IA hard­ware are iden­ti­fied and pro­pos­als are pre­sented that could help im­prove the kicker sys­tem per­for­mance.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB343  
About • paper received ※ 16 May 2021       paper accepted ※ 01 July 2021       issue date ※ 17 August 2021  
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WEPAB347 Design, Construction and Testing of a Magnetic Probe for Fast Kicker Magnets 3510
 
  • N. Ayala, A. Ferrero Colomo, T. Kramer
    CERN, Geneva 23, Switzerland
  
  The CERN PS in­jec­tion kicker has been mod­i­fied in the frame­work of the LHC In­jec­tor Up­grade (LIU) pro­ject to allow in­ject­ing pro­ton beams with an en­ergy of 2 GeV. One of the most im­por­tant items of the sys­tem pa­ra­me­ter val­i­da­tion is the mea­sure­ment and analy­sis of the mag­netic field in the mag­net aper­ture. To meet the re­quired mea­sure­ment pre­ci­sion with­out com­pro­mis­ing the mag­net vac­uum per­for­mance, a ded­i­cated mag­netic probe has been de­signed, con­structed and tested. The re­sults are pre­sented in this paper high­light­ing the mit­i­ga­tions of elec­tri­cal, me­chan­i­cal and vac­uum com­pli­ca­tions. The paper con­cludes with an analy­sis of the probe per­for­mance dur­ing the first mag­netic field mea­sure­ments in the lab­o­ra­tory.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB347  
About • paper received ※ 19 May 2021       paper accepted ※ 07 July 2021       issue date ※ 02 September 2021  
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WEPAB351 Requirements for an Inductive Voltage Adder as Driver for a Kicker Magnet with Short Circuit Termination 3521
 
  • J. Ruf, M.J. Barnes, T. Kramer
    CERN, Geneva 23, Switzerland
  • M. Sack
    KIT, Karlsruhe, Germany
  
  At CERN pulse gen­er­a­tors based on Thyra­tron switches and SF6 gas filled pulse form­ing lines, used for dri­ving kicker mag­nets, are to be re­placed with semi­con­duc­tor tech­nol­ogy. Pre­lim­i­nary in­ves­ti­ga­tions show the in­duc­tive volt­age adder is suit­able as a pulse gen­er­a­tor for this ap­pli­ca­tion. To in­crease the mag­netic field with­out rais­ing the sys­tem volt­age, a short-cir­cuit ter­mi­na­tion is often ap­plied to a kicker mag­net. Be­cause of the elec­tri­cal length of a trans­mis­sion line mag­net, wave prop­a­ga­tion needs to be con­sid­ered. To allow for the wave­front re­flected from the short-cir­cuit ter­mi­na­tion back to the gen­er­a­tor, a novel ap­proach for an in­duc­tive adder ar­chi­tec­ture has been in­ves­ti­gated. It is based on a mod­i­fied gen­er­a­tor in­ter­face, cir­cu­lat­ing the cur­rent back into the load, until the stored en­ergy is ab­sorbed at the end of the pulse. This ap­proach al­lows for a smaller mag­netic core size com­pared to a con­ven­tional de­sign with a matched load. More­over, it en­ables more en­ergy-ef­fi­cient op­er­a­tion in­volv­ing smaller stor­age ca­pac­i­tors. This paper sum­ma­rizes the con­cep­tual de­sign fea­tures and fur­ther­more gives an overview of the pa­ra­me­ter space for pos­si­ble ap­pli­ca­tions at CERN.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB351  
About • paper received ※ 18 May 2021       paper accepted ※ 11 June 2021       issue date ※ 17 August 2021  
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THPAB340 Sub-Nanosecond Switching of HV SiC MOS Transistors for Impact Ionisation Triggering 4454
 
  • V. Senaj, T. Kramer, A.A. del Barrio Montañés
    CERN, Geneva 23, Switzerland
  • M. Sack
    KIT, Karlsruhe, Germany
  
  Pulse gen­er­a­tors with multi kV/kA pulses are nec­es­sary for the par­ti­cle ac­cel­er­a­tor en­vi­ron­ment for beam trans­fer mag­nets. Tra­di­tion­ally these gen­er­a­tors are using thyra­trons - until re­cently the only switches ca­pa­ble of switch­ing such pulses within tens of ns. There is a strong de­mand to re­place thyra­trons with semi­con­duc­tor switches to avoid their fu­ture ob­so­les­cence. Very promis­ing can­di­dates are com­po­nents from the fam­ily of fast ion­iza­tion dynis­tors trig­gered by im­pact ion­iza­tion. Their sub-nanosec­ond switch­ing time and ex­treme cur­rent den­si­ties can pro­vide per­for­mances su­pe­rior to that of thyra­trons. Re­cent in­ves­ti­ga­tions showed that im­pact ion­iza­tion trig­ger­ing is fea­si­ble also in cheap in­dus­trial thyris­tors. The main issue is the gen­er­a­tion of trig­ger­ing pulses with slew rates in the multi kV/ns re­gion and with the re­quired out­put cur­rent for charg­ing the par­a­sitic ca­pac­i­tance of the thyris­tor. We pre­sent an ap­proach of gen­er­at­ing > 1 kV/ns pulses by ul­tra-boosted gate dri­ving of HV SiC MOS tran­sis­tors. We found that the MOS life­time under these ex­treme trig­ger­ing con­di­tions can still reach more than 108 pulses, enough for kicker gen­er­a­tor ap­pli­ca­tions.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB340  
About • paper received ※ 18 May 2021       paper accepted ※ 01 July 2021       issue date ※ 27 August 2021  
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THPAB354 Deployment and Commissioning of the CERN PS Injection Kicker System for Operation with 2 GeV Beams in Short Circuit Mode 4489
 
  • T. Kramer, N. Ayala, J.C.C.M. Borburgh, P.A.H. Burkel, E. Carlier, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, M.A. Fraser, L.A. Govertsen, R. Noulibos, S. Pavis, L. Sermeus
    CERN, Geneva, Switzerland
  
  Within the frame­work of the LHC In­jec­tor Up­grade (LIU) pro­ject, the fea­si­bil­ity and de­sign of an up­grade of the ex­ist­ing CERN PS pro­ton in­jec­tion kicker sys­tem have been out­lined in pre­vi­ous pub­li­ca­tions al­ready. This paper de­scribes the ad­just­ments of final de­sign choices, test­ing, and de­ploy­ment as well as the val­i­da­tion and com­mis­sion­ing of the new 2 GeV in­jec­tion kicker sys­tem. The up­grade pays par­tic­u­lar at­ten­tion to the re­duc­tion of pulse re­flec­tions un­avoid­ably in­duced by a mag­net in short cir­cuit mode con­fig­u­ra­tion whilst keep­ing a fast 104 ns rise and fall time. An adapted thyra­tron trig­ger­ing sys­tem to re­duce jit­ter and en­hance thyra­tron life­time is out­lined. Ad­di­tion­ally, im­prove­ments to the mag­net entry box and the elim­i­na­tion of SF6 gas in the mag­net con­nec­tion box and the as­so­ci­ated pulse trans­mis­sion lines are dis­cussed.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB354  
About • paper received ※ 19 May 2021       paper accepted ※ 14 July 2021       issue date ※ 10 August 2021  
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