Author: Yun, J.C.
Paper Title Page
MOPA23 Tests of the Extended Range SRF Cavity Tuners for the LCLS-II HE Project 100
 
  • C. Contreras-Martinez, T.T. Arkan, A.T. Cravatta, B.D. Hartsell, J.A. Kaluzny, T.N. Khabiboulline, Y.M. Pischalnikov, S. Posen, G.V. Romanov, J.C. Yun
    Fermilab, Batavia, Illinois, USA
 
  The LCLS-II HE su­per­con­duct­ing linac will pro­duce multi-en­ergy beams by sup­port­ing mul­ti­ple un­du­la­tor lines si­mul­ta­ne­ously. This could be achieved by using the cav­ity SRF tuner in the off-fre­quency de­tune mode. This off-fre­quency op­er­a­tion method was tested in the ver­i­fi­ca­tion cry­omod­ule (vCM) and CM 1 at Fer­mi­lab at 2 K. In both cases, the tuners achieved a fre­quency shift of -565±80 kHz. This study will dis­cuss cav­ity fre­quency dur­ing each step as it is being as­sem­bled in the cry­omod­ule string and fi­nally when it is being tested at 2 K. Track­ing the cav­ity fre­quency helped en­able the tuners to reach this large fre­quency shift. The spe­cific pro­ce­dures of tuner set­ting dur­ing as­sem­bly will be pre­sented.  
poster icon Poster MOPA23 [0.654 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA23  
About • Received ※ 03 August 2022 — Revised ※ 11 August 2022 — Accepted ※ 19 August 2022 — Issue date ※ 31 August 2022
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MOPA25 Simulated Lorentz Force Detuning Compensation with a Double Lever Tuner on a Dressed ILC/1.3 GHz Cavity at Room Temperature 106
 
  • C. Contreras-Martinez, Y.M. Pischalnikov, J.C. Yun
    Fermilab, Batavia, Illinois, USA
 
  Pulsed SRF linacs with high ac­cel­er­at­ing gra­di­ents ex­pe­ri­ence large fre­quency shifts caused by Lorentz force de­tun­ing (LFD). A piezo­elec­tric ac­tu­a­tor with a res­o­nance con­trol al­go­rithm can main­tain the cav­ity fre­quency at the nom­i­nal level thus re­duc­ing the RF power. This study uses a dou­ble lever tuner with a piezo­elec­tric ac­tu­a­tor for com­pen­sa­tion and an­other piezo­elec­tric ac­tu­a­tor to sim­u­late the ef­fects of the Lorentz force pulse. A dou­ble lever tuner has an ad­van­tage by in­creas­ing the stiff­ness of the cav­ity-tuner sys­tem thus re­duc­ing the ef­fects of LFD. The tests are con­ducted at room tem­per­a­ture and with a dressed 1.3 GHz 9-cell cav­ity.  
poster icon Poster MOPA25 [0.931 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA25  
About • Received ※ 03 August 2022 — Revised ※ 09 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 13 August 2022
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MOPA27 Validation of the 650 MHz SRF Tuner on the Low and High Beta Cavities for PIP-II at 2 K 109
 
  • C. Contreras-Martinez, S.K. Chandrasekaran, S. Cheban, G.V. Eremeev, I.V. Gonin, T.N. Khabiboulline, Y.M. Pischalnikov, O.V. Prokofiev, A.I. Sukhanov, J.C. Yun
    Fermilab, Batavia, Illinois, USA
 
  The PIP-II linac will in­clude thirty-six BG=0.61 and twenty-four BG=0.92 650 MHz 5 cell el­lip­ti­cal SRF cav­i­ties. Each cav­ity will be equipped with a tun­ing sys­tem con­sist­ing of a dou­ble lever slow tuner for coarse fre­quency tun­ing and a piezo­elec­tric ac­tu­a­tor for fine fre­quency tun­ing. The same tuner will be used for both the BG=0.61 and BG=0.92 cav­i­ties. Re­sults of test­ing the cav­ity-tuner sys­tem for the BG=0.61 will be pre­sented for the first time.  
poster icon Poster MOPA27 [0.782 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA27  
About • Received ※ 03 August 2022 — Revised ※ 10 August 2022 — Accepted ※ 11 August 2022 — Issue date ※ 04 October 2022
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MOPA38 Accelerated Lifetime Test of the SRF Dressed Cavity/Tuner System for the LCLS II HE Project 136
 
  • Y.M. Pischalnikov, T.T. Arkan, C. Contreras-Martinez, B.D. Hartsell, J.A. Kaluzny, Y.M. Orlov, R.V. Pilipenko, J.C. Yun
    Fermilab, Batavia, Illinois, USA
  • W. Lahmadi
    Wahid Lahmadi, Williston, USA
 
  The off-fre­quency de­tune method is being con­sid­ered for ap­pli­ca­tion in the LCLS-II-HE su­per­con­duct­ing linac to pro­duce multi-en­ergy elec­tron beams for sup­port­ing mul­ti­ple un­du­la­tor lines si­mul­ta­ne­ously. De­sign of the tuner has been changed to de­liver roughly 3 times larger fre­quency tun­ing range. Work­ing re­quire­ments for off-fre­quency op­er­a­tion (OFO) state that cav­i­ties be tuned at least twice a month. This spec­i­fi­ca­tion re­quires the in­crease of the tuner longevity by 30 times com­pared with LCLS-II de­mands. Ac­cel­er­ated longevity tests of the LCLS-II HE dressed cav­ity with tuner were con­ducted at FNAL’s HTS. De­tail analy­sis of wear­ing and im­pacts on per­for­mances of the tuner’s piezo and step­per motor ac­tu­a­tors will be pre­sented. Ad­di­tion­ally, re­sults of longevity test­ing of the dressed cav­ity bel­low, when cooled down to 2 K and com­pressed by 2.6 mm for roughly 2000 cy­cles, will be pre­sented.  
poster icon Poster MOPA38 [3.026 MB]  
DOI • reference for this paper ※ doi:10.18429/JACoW-NAPAC2022-MOPA38  
About • Received ※ 29 July 2022 — Revised ※ 06 August 2022 — Accepted ※ 09 August 2022 — Issue date ※ 11 August 2022
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