Author: Intermite, A.
Paper Title Page
TUPC151 Cherenkov Fibre Optic Beam Loss Monitor at ALICE 1383
 
  • A. Intermite
    The University of Liverpool, Liverpool, United Kingdom
  • A. Intermite, M. Putignano, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  The need for re­al-time mon­i­tor­ing of beam loss­es, in­clud­ing eval­u­a­tion of their in­ten­si­ty and the lo­cal­iza­tion of their exact po­si­tion, to­geth­er with the pos­si­bil­i­ty to over­come the lim­i­ta­tions due to the re­duced space for the di­ag­nos­tics, makes op­ti­cal fi­bres (using the Cherenkov Ef­fect) one of the most suit­able and ex­plored can­di­date for beam loss mon­i­tor­ing. In this con­tri­bu­tion, we re­port on an op­ti­cal fibre beam loss mon­i­tor based on large nu­mer­i­cal aper­ture pure sil­i­con fi­bres and sil­i­con pho­to­mul­ti­pli­ers, test­ed at ALICE, Dares­bury Lab­o­ra­to­ries, UK. The orig­i­nal de­sign of the sen­sor has the ad­van­tage to com­bine the func­tions of a real time de­tec­tor and a trans­mis­sion line. It also al­lows read­ing the sig­nals in­de­pen­dent­ly and de­ter­min­ing the time and po­si­tion of the loss­es with­out the use of an ex­ter­nal trig­ger.  
 
TUPC152 Comparative Study of Performance of Silicon Photomultipliers for Use in Cherenkov Fibre Optic Beam Loss Monitors 1386
 
  • A. Intermite
    The University of Liverpool, Liverpool, United Kingdom
  • A. Intermite, M. Putignano, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Sil­i­con Pho­to­mul­ti­pli­ers (SiPMs) are semi­con­duc­tor pho­to-sen­si­tive de­vices built from a ma­trix of Sin­gle Pho­ton Avalanche Diodes (SPADs) on a com­mon sil­i­con sub­strate, work­ing in the lim­it­ed Geiger mode and with a com­mon read­out. The fast count­ing abil­i­ty, high tim­ing res­o­lu­tion, im­mu­ni­ty to mag­net­ic field up to 15 T, low power con­sump­tion and rel­a­tive small tem­per­a­ture de­pen­dence to­geth­er with the small di­men­sions make SiPMs ex­cel­lent can­di­dates as com­mer­cial­ly avail­able solid state de­tec­tors, and a promis­ing al­ter­na­tive to tra­di­tion­al pho­to­mul­ti­pli­er tubes for sin­gle pho­ton de­tec­tion. Nev­er­the­less, SiPMs do suf­fer from er­ro­neous count­ing due to noise ef­fects that can de­te­ri­o­rate their per­for­mances. These ef­fects are, in gen­er­al, heav­i­ly de­pen­dent on man­u­fac­tur­ing qual­i­ty. In this con­tri­bu­tion, re­sults are re­port­ed of the char­ac­ter­i­za­tion of dif­fer­ent mod­els of SiPMs in terms of noise spec­tra and re­sponse to light, and a pro­ce­dure for de­ter­min­ing qual­i­ty man­u­fac­tur­ing pa­ram­e­ters is de­scribed.  
 
TUPC152 Comparative Study of Performance of Silicon Photomultipliers for Use in Cherenkov Fibre Optic Beam Loss Monitors 1386
 
  • A. Intermite
    The University of Liverpool, Liverpool, United Kingdom
  • A. Intermite, M. Putignano, A. Wolski
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Sil­i­con Pho­to­mul­ti­pli­ers (SiPMs) are semi­con­duc­tor pho­to-sen­si­tive de­vices built from a ma­trix of Sin­gle Pho­ton Avalanche Diodes (SPADs) on a com­mon sil­i­con sub­strate, work­ing in the lim­it­ed Geiger mode and with a com­mon read­out. The fast count­ing abil­i­ty, high tim­ing res­o­lu­tion, im­mu­ni­ty to mag­net­ic field up to 15 T, low power con­sump­tion and rel­a­tive small tem­per­a­ture de­pen­dence to­geth­er with the small di­men­sions make SiPMs ex­cel­lent can­di­dates as com­mer­cial­ly avail­able solid state de­tec­tors, and a promis­ing al­ter­na­tive to tra­di­tion­al pho­to­mul­ti­pli­er tubes for sin­gle pho­ton de­tec­tion. Nev­er­the­less, SiPMs do suf­fer from er­ro­neous count­ing due to noise ef­fects that can de­te­ri­o­rate their per­for­mances. These ef­fects are, in gen­er­al, heav­i­ly de­pen­dent on man­u­fac­tur­ing qual­i­ty. In this con­tri­bu­tion, re­sults are re­port­ed of the char­ac­ter­i­za­tion of dif­fer­ent mod­els of SiPMs in terms of noise spec­tra and re­sponse to light, and a pro­ce­dure for de­ter­min­ing qual­i­ty man­u­fac­tur­ing pa­ram­e­ters is de­scribed.  
 
TUPC153 Study of the Response of Silicon Photomultipliers in Presence of Strong Cross-talk Noise 1389
 
  • M. Putignano, A. Intermite
    The University of Liverpool, Liverpool, United Kingdom
  • M. Putignano, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: Work supported by STFC, the EU under GA-ITN-215080, the Helmholtz Association and GSI under VH-NG-328.
Sil­i­con Pho­to­mul­ti­pli­ers (SiPM) are in­ter­est­ing de­tec­tors for beam di­ag­nos­tics ap­pli­ca­tions where they could re­place pho­to­mul­ti­pli­er tubes as large dy­nam­ic range pho­ton count­ing de­vices due to their re­duced di­men­sions and costs, high­er pho­ton de­tec­tion ef­fi­cien­cy, im­mu­ni­ty to mag­net­ic fields and low op­er­a­tion volt­age. Pos­si­ble ap­pli­ca­tions in­clude lon­gi­tu­di­nal beam pro­file mea­sure­ments by syn­chrotron light imag­ing, de­tec­tion of op­ti­cal tran­si­tion ra­di­a­tion for en­er­gy spec­trum mea­sure­ments and med­i­cal imag­ing. How­ev­er, quan­ti­ta­tive mea­sure­ment with SiPMs are jeop­ar­dized by the sys­tem­at­ic read­ing error due to Op­ti­cal Cross-talk (OC), i.e. op­ti­cal cou­pling be­tween neigh­bor­ing diodes in the array. OC re­sults in over­es­ti­ma­tion of the im­ping­ing light level, and re­flects the prob­a­bil­i­ty of a trig­gered avalanche cre­at­ing a pho­ton of suit­able en­er­gy and di­rec­tion to fire a sec­ond avalanche in an­oth­er diode. In this paper, we de­rive a gen­er­al­ized re­sponse dis­tri­bu­tion for SiPM in pres­ence of cross-talk noise, which over­comes the lim­i­ta­tions of as­sump­tions cur­rent­ly made in lit­er­a­ture and pro­vides a cor­rec­tion of the SiPM re­sponse dis­tri­bu­tion valid for ar­bi­trary large lev­els of cross-talk. 		 
 
TUPC154 Commissioning of the Detection System for a Supersonic Gas-jets Based Transverse Beam Profile Monitor 1392
 
  • M. Putignano, D. Borrows, A. Intermite
    The University of Liverpool, Liverpool, United Kingdom
  • M. Putignano, M.R.F. Siggel-King, C.P. Welsch
    Cockcroft Institute, Warrington, Cheshire, United Kingdom
  
  Funding: Work supported by STFC, the EU under GA-ITN-215080, the Helmholtz Association and GSI under VH-NG-328.
We pre­sent the com­mis­sion­ing re­sults of the Mi­cro-Chan­nel-Plate (MCP) based, ion ex­trac­tion and de­tec­tion sys­tem cur­rent­ly in use for an ex­per­i­men­tal test stand aimed at demon­strat­ing the op­er­a­tion of a least-in­ter­cep­tive trans­verse beam pro­file mon­i­tor based on a pla­nar su­per­son­ic gas-jet. This mon­i­tor­ing de­sign fea­tures least-in­ter­cep­tive op­er­a­tion under ex­cel­lent vac­u­um con­di­tions and pro­vides fast ac­qui­si­tion of a fully bi-di­men­sion­al trans­verse pro­file. It bears ap­pli­ca­tion for ul­tra-low en­er­gy par­ti­cle beams at fu­ture stor­age rings, but also for e.g. linacs at high cur­rents and light source in­jec­tors. For in­stance, the Ul­tra-low en­er­gy Stor­age Ring (USR), part of the Fa­cil­i­ty for An­tipro­ton and Ion Re­search (FAIR) in Ger­many will store an­tipro­tons at en­er­gies of 20-300 keV. In this con­tri­bu­tion, we re­port nu­mer­i­cal sim­u­la­tions and ex­per­i­men­tal re­sults ob­tained by cal­i­bra­tion of the de­tec­tion sys­tem with a low en­er­gy elec­tron beam to demon­strate a 1 mm imag­ing res­o­lu­tion only lim­it­ed by re­coil­ing ion drift.