Author: Burrows, P.
Paper Title Page
TUPAB019 A High-Resolution, Low-Latency, Bunch-by-Bunch Feedback System for Nano-Beam Stabilization 1378
 
  • R.L. Ramjiawan, D.R. Bett, N. Blaskovic Kraljevic, T. Bromwich, P. Burrows, G.B. Christian, C. Perry
    JAI, Oxford, United Kingdom
  • D.R. Bett
    CERN, Geneva, Switzerland
  • N. Blaskovic Kraljevic
    ESS, Lund, Sweden
  • G.B. Christian
    DLS, Oxfordshire, United Kingdom
  
  A low-la­tency, bunch-by-bunch feed­back sys­tem em­ploy­ing high-res­o­lu­tion cav­ity Beam Po­si­tion Mon­i­tors (BPMs) has been de­vel­oped and tested at the Ac­cel­er­a­tor Test Fa­cil­ity (ATF2) at the High En­ergy Ac­cel­er­a­tor Re­search Or­ga­ni­za­tion (KEK), Japan. The feed­back sys­tem was de­signed to demon­strate nanome­ter-level ver­ti­cal sta­bi­liza­tion at the focal point of the ATF2 and can be op­er­ated using ei­ther a sin­gle BPM to pro­vide local beam sta­bi­liza­tion, or by using two BPMs to sta­bi­lize the beam at an in­ter­me­di­ate lo­ca­tion. The feed­back cor­rec­tion is im­ple­mented using a stripline kicker and the feed­back cal­cu­la­tions are per­formed on a dig­i­tal board con­structed around a Field Pro­gram­ma­ble Gate Array (FPGA). The feed­back per­for­mance was tested with trains of two bunches, sep­a­rated by 280ns, at a charge of ~1nC, where the ver­ti­cal off­set of the first bunch was mea­sured and used to cal­cu­late the cor­rec­tion to be ap­plied to the sec­ond bunch. The BPMs have been demon­strated to achieve an op­er­a­tional res­o­lu­tion of ~20nm. With the ap­pli­ca­tion of sin­gle-BPM and two-BPM feed­back, beam sta­bi­liza­tion of below 50nm and 41nm re­spec­tively has been achieved with a la­tency of 232ns.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB019  
About • paper received ※ 18 May 2021       paper accepted ※ 09 June 2021       issue date ※ 14 August 2021  
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TUPAB020 A Sub-Micron Resolution, Bunch-by-Bunch Beam Trajectory Feedback System and Its Application to Reducing Wakefield Effects in Single-Pass Beamlines 1382
 
  • D.R. Bett, P. Burrows, C. Perry, R.L. Ramjiawan
    JAI, Oxford, United Kingdom
  • D.R. Bett
    CERN, Geneva, Switzerland
  • K. Kubo, T. Okugi, N. Terunuma
    KEK, Ibaraki, Japan
  
  A high-pre­ci­sion in­tra-bunch-train beam orbit feed­back cor­rec­tion sys­tem has been de­vel­oped and tested at the KEK Ac­cel­er­a­tor Test Fa­cil­ity, ATF2. The sys­tem uses the ver­ti­cal po­si­tion of the bunch mea­sured at two beam po­si­tion mon­i­tors to cal­cu­late a pair of kicks which are ap­plied to the next bunch using two up­stream kick­ers, thereby cor­rect­ing both the ver­ti­cal po­si­tion and tra­jec­tory angle. Using trains of two elec­tron bunches sep­a­rated in time by 187.6ns, the sys­tem was op­ti­mised so as to sta­bi­lize the beam off­set at the feed­back BPMs to bet­ter than 350nm, yield­ing a local tra­jec­tory angle cor­rec­tion to within 250n­rad. The qual­ity of the cor­rec­tion was ver­i­fied using three down­stream wit­ness BPMs and the re­sults were found to be in agree­ment with the pre­dic­tions of a lin­ear lat­tice model used to prop­a­gate the beam tra­jec­tory from the feed­back re­gion. This same model pre­dicts a cor­rected be am jit­ter of c.1nm at the focal point of the ac­cel­er­a­tor. Mea­sure­ments with a beam size mon­i­tor at this lo­ca­tion demon­strate that re­duc­ing the tra­jec­tory jit­ter of the beam by a fac­tor of 4 also re­duces the in­crease in the mea­sured beam size as a func­tion of beam charge by a fac­tor of ~1.6.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-TUPAB020  
About • paper received ※ 13 May 2021       paper accepted ※ 01 July 2021       issue date ※ 11 August 2021  
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WEPAB043 Consolidation and Future Upgrades to the CLEAR User Facility at CERN 2700
 
  • L.A. Dyks, P. Korysko
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • P. Burrows
    JAI, Oxford, United Kingdom
  • R. Corsini, S. Curt, W. Farabolini, D. Gamba, L. Garolfi, A. Gilardi, E. Granados, G. McMonagle, H. Panuganti
    CERN, Meyrin, Switzerland
  • W. Farabolini
    CEA-DRF-IRFU, France
  • A. Gilardi
    University of Napoli Federico II, Napoli, Italy
  • K.N. Sjobak
    University of Oslo, Oslo, Norway
  
  The CERN Lin­ear Elec­tron Ac­cel­er­a­tor for Re­search (CLEAR) at CERN has been op­er­at­ing since 2017 as a ded­i­cated user fa­cil­ity pro­vid­ing beams for a var­ied range of ex­per­i­ments. CLEAR con­sists of a 20 m long lin­ear ac­cel­er­a­tor (linac), able to pro­duce beams from a Cs2Te pho­to­cath­ode and ac­cel­er­ate them to en­er­gies of be­tween 60 MeV and 220 MeV. Fol­low­ing the linac, an ex­per­i­men­tal beam­line is lo­cated, in which ir­ra­di­a­tion tests, wake­field and im­ped­ances tud­ies, plasma lens ex­per­i­ments, beam di­ag­nos­tics de­vel­op­ment, and ter­a­hertz (THz) emis­sion stud­ies, are per­formed. In this paper, we pre­sent re­cent up­grades to the en­tire beam­line, as well as the de­sign of fu­ture up­grades, such as a dog­leg sec­tion con­nect­ing to an ad­di­tional pro­posed ex­per­i­men­tal beam­line. The gain in per­for­mance due to these up­grades is pre­sented with a full range of avail­able beam prop­er­ties doc­u­mented.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-WEPAB043  
About • paper received ※ 18 May 2021       paper accepted ※ 24 June 2021       issue date ※ 19 August 2021  
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THPAB130 Design of a Very Low Energy Beamline for NA61/SHINE 4017
 
  • C.A. Mussolini, N. Charitonidis
    CERN, Geneva, Switzerland
  • P. Burrows
    JAI, Oxford, United Kingdom
  • P. Burrows
    Oxford University, Physics Department, Oxford, Oxon, United Kingdom
  • Y. Nagai
    Colorado University at Boulder, Boulder, Colorado, USA
  • Y. Nagai
    ELTE, Budapest, Hungary
  • E.D. Zimmerman
    CIPS, Boulder, Colorado, USA
  
  A new, low-en­ergy beam­line branch is cur­rently under con­sid­er­a­tion for the H2 beam­line at the CERN North Area. This new branch would ex­tend the ca­pa­bil­i­ties of the cur­rent in­fra­struc­ture en­abling the study of par­ti­cles in the very low, 1-13 GeV/c, mo­men­tum range. The de­sign of this new beam­line in­volves var­i­ous stages. Firstly, a study of the sec­ondary tar­gets to max­imise the yield of sec­ondary hadrons. Sec­ondly, the de­vel­op­ment of high ac­cep­tance trans­verse op­tics with high mo­men­tum res­o­lu­tion on the order of a few %. Fi­nally, we dis­cuss the first con­sid­er­a­tions on in­stru­men­ta­tion to en­able par­ti­cle iden­ti­fi­ca­tion and back­ground re­jec­tion. The first ex­per­i­ment to profit from this new line could be NA61/SHINE, but other pos­si­ble fu­ture fixed tar­get ex­per­i­ments or test-beams in­stalled in the down­stream zones could also use the low-en­ergy par­ti­cles pro­vided. The aim is to ar­rive at a com­plete de­sign of this branch by the end of 2021, which, pend­ing the ap­proval of the CERN sci­en­tific com­mit­tees, could be en­vis­aged for con­struc­tion after 2024. This timescale is com­pat­i­ble with re­quests for mea­sure­ments by var­i­ous large in­ter­na­tional col­lab­o­ra­tions, in the next 10-year hori­zon.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-THPAB130  
About • paper received ※ 15 May 2021       paper accepted ※ 27 July 2021       issue date ※ 27 August 2021  
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