Author: Jansson, A.
Paper Title Page
TUPC01 Overview of the European Spallation Source Warm Linac Beam Instrumentation 346
 
  • B. Cheymol, C. Böhme, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson, T.J. Shea, L. Tchelidze
    ESS, Lund, Sweden
  
  The nor­mal con­duct­ing front end of the Eu­ro­pean Spal­la­tion source will ac­cel­er­ate the beam com­ing for the ion source up to 90 MeV. The ESS front end will con­sist in an ion source, a low en­ergy beam trans­port line, a radio fre­quency quadru­pole, a medium en­ergy beam trans­port line and a drift tube linac. The warm linac will be equipped with beam di­ag­nos­tics to mea­sure the beam po­si­tion, the trans­verse and lon­gi­tu­di­nal pro­file as well as beam cur­rent and beam losses. This will pro­vide ef­fi­cient op­er­a­tion of ESS, and en­sure keep­ing the losses at a low level. This paper gives an overview of the beam di­ag­nos­tics de­sign and their main fea­tures.  
 
TUPC13 System Overview and Design Considerations of the BPM System of the ESS Linac 388
 
  • H. Hassanzadegan, A. Jansson, R. Zeng
    ESS, Lund, Sweden
  • A.J. Johansson
    Lund University, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  • A. Young
    SLAC, Menlo Park, California, USA
  
  The ESS Linac will in­clude in total more than 140 Beam Po­si­tion Mon­i­tors of dif­fer­ent sizes and types. The BPM sys­tem needs to mea­sure the beam po­si­tion, phase and in­ten­sity in all fore­seen beam modes with a pulse rate of 14 Hz, du­ra­tion of 2.86 ms and am­pli­tude rang­ing form 5 mA to 62.5 mA. With re­spect to the BPM con­nec­tion to the Ma­chine In­ter­lock Sys­tem, the total re­sponse time must be less than 10 us. The sig­nal level vari­a­tions from one BPM to an­other along the Linac should be as small as pos­si­ble to meet the re­quire­ments on the ana­log gain of the front-end elec­tron­ics and the dy­namic range of the dig­i­tizer card input. The other re­quire­ment is that the BPM sys­tem needs to give at least a rough es­ti­ma­tion of the beam po­si­tion and phase, even if the beam is sig­nif­i­cantly de­bouched, ex. dur­ing the Linac tun­ing phase. These re­quire­ments and their im­pact on the de­sign of the BPM de­tec­tor, the ana­log front-end elec­tron­ics and the se­lec­tion of the dig­i­tizer card are dis­cussed in this paper along with a gen­eral de­scrip­tion of the BPM sys­tem.  
poster icon Poster TUPC13 [3.050 MB]  
 
WEPC06 Beam Instrumentation in the ESS Cold Linac 667
 
  • C. Böhme, B. Cheymol, I. Dolenc Kittelmann, H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  
  Parts of the linac of the Eu­ro­pean Spal­la­tion Source will con­sist of cryo­genic cav­ity mod­ules. In be­tween these will be warm sec­tions at room tem­per­a­ture to host amongst oth­ers the beam in­stru­men­ta­tion. Each of the warm sec­tions will host two beam po­si­tion mon­i­tors and one or two other in­stru­ments, which might be a beam cur­rent mon­i­tor, in­va­sive and non-in­va­sive trans­verse beam pro­file mon­i­tor, bunch shape mon­i­tor, or halo mon­i­tor. The con­cept of the warm sec­tion lay­out will be shown and the planned in­stru­men­ta­tion will be pre­sented.  
 
WEPC45 Beam Loss Monitoring at the European Spallation Source 795
 
  • L. Tchelidze, H. Hassanzadegan, A. Jansson, M. Jarosz
    ESS, Lund, Sweden
  
  At the Eu­ro­pean Spal­la­tion Source pro­ton lin­ear ac­cel­er­a­tor will gen­er­ate 5 MW pro­tons to be de­liv­ered to a tar­get. This high power ac­cel­er­a­tor will re­quire sig­nif­i­cant amount of beam in­stru­men­ta­tion, among which the beam loss mon­i­tor­ing sys­tem is one of the most im­por­tant for op­er­a­tion. An LHC type ion­iza­tion cham­ber will be used with ~54 uC/Gy sen­si­tiv­ity. At most 1.5 mGy/sec ra­di­a­tion lev­els are ex­pected close to the beam pipe dur­ing nor­mal op­er­a­tion, re­sult­ing in up to 80 nA cur­rent sig­nal in de­tec­tors. Loss mon­i­tor elec­tron­ics is de­signed to be able to mea­sure cur­rents as lit­tle as 1% of the ex­pected cur­rent up to as much as 1% of the total beam loss, thus ~800 pA – few mA. In order to study beam loss pat­tern along the ac­cel­er­a­tor a co­her­ent model of the whole ma­chine is cre­ated for the pur­poses of Monte Carlo par­ti­cle trans­port sim­u­la­tions. Data ob­tained using the model will be stored in a data­base to­gether with the ini­tial beam loss con­di­tions. The con­tents of the data­base will then be processed using cus­tom neural net­work al­go­rithms to op­ti­mize num­ber and po­si­tion of the loss mon­i­tors and to pro­vide ref­er­ence on the beam loss lo­cal­iza­tion dur­ing op­er­a­tion of the ma­chine.  
poster icon Poster WEPC45 [1.784 MB]  
 
WEPF10 Wire Scanner Design for the European Spallation Source 830
 
  • B. Cheymol, A. Jansson, T.J. Shea
    ESS, Lund, Sweden
  
  The Eu­ro­pean Spal­la­tion Source (ESS), to be built in the south of Swe­den, will use a 2 GeV su­per­con­duct­ing LINAC to pro­duce the world's most pow­er­ful neu­tron source with a beam power of 5 MW. The beam power is a chal­lenge for in­ter­cep­tive beam di­ag­nos­tics like wire scan­ner, the ther­mal load on in­ter­cept­ing de­vices im­plies to re­duce the beam power in order to pre­serve the de­vice in­tegrity. For nom­i­nal op­er­a­tion, non-dis­turb­ing tech­niques for pro­file mea­sure­ments are planned, while for the com­mis­sion­ing phase, ac­cu­rate mea­sure­ments and cross check­ing, wire scan­ners will be used. This paper de­scribes the pre­lim­i­nary de­sign of the wire scan­ner sys­tem in the nor­mal con­duc­ing LINAC as well as in the su­per­con­duct­ing LINAC.  
 
WEPF30 System Overview and Preliminary Test Results of the ESS Beam Current Monitor System 891
 
  • H. Hassanzadegan, A. Jansson
    ESS, Lund, Sweden
  • K. Strniša
    Cosylab, Ljubljana, Slovenia
  
  The ESS Linac will in­clude in total 21 Beam Cur­rent Mon­i­tors, mostly of ACCT type, to mea­sure the av­er­age cur­rent over the 2.86 ms beam pulse, the pulse charge and the pulse pro­file. It is also planned to use a few Fast Cur­rent Trans­form­ers to check the per­for­mance of the fast beam chop­pers with a rise time as short as 10 ns. In ad­di­tion to the ab­solute cur­rent mea­sure­ment, the BCM sys­tem needs to mea­sure the dif­fer­en­tial beam cur­rent and act on the Ma­chine In­ter­lock Sys­tem if the dif­fer­ence ex­ceeds some thresh­olds. The dif­fer­en­tial cur­rent mea­sure­ment is par­tic­u­larly im­por­tant in the low en­ergy part of the Linac, where Beam Loss Mon­i­tors can­not re­li­ably de­tect beam losses. This paper gives an overview of the ESS BCM sys­tem and pre­sents some pre­lim­i­nary test re­sults with a com­mer­cial ACCT and MTCA.4 elec­tron­ics.  
poster icon Poster WEPF30 [6.267 MB]