Author: Carli, C.
Paper Title Page
MOPAB177 ELENA Commissioning and Status 598
 
  • C. Carli, M.E. Angoletta, W. Bartmann, L. Bojtár, F. Butin, B. Dupuy, Y. Dutheil, M.A. Fraser, P. Freyermuth, D. Gamba, L.V. Jørgensen, B. Lefort, O. Marqversen, M. McLean, S. Ogur, S. Pasinelli, L. Ponce, G. Tranquille
    CERN, Geneva, Switzerland
  
  The Extra Low EN­ergy An­tipro­ton ring ELENA is a small syn­chro­tron re­cently con­structed and com­mis­sioned to de­cel­er­ate an­tipro­tons in­jected from the An­tipro­ton De­cel­er­a­tor AD with a ki­netic en­ergy of 5.3 MeV down to 100 keV. Con­trolled de­cel­er­a­tion in the syn­chro­tron, equipped with an elec­tron cooler to re­duce losses and gen­er­ate dense bunches, al­lows the ex­per­i­ments, typ­i­cally cap­tur­ing the an­tipro­tons in traps and ma­nip­u­lat­ing them fur­ther, to im­prove the trap­ping ef­fi­ciency by one to two or­ders of mag­ni­tude. Dur­ing 2018, bunches with an en­ergy of 100 keV with pa­ra­me­ters close to nom­i­nal have been demon­strated, and first beams have been pro­vided to an ex­per­i­ment in a new ex­per­i­men­tal zone. The mag­netic trans­fer lines from the AD to the ex­per­i­ments have been re­placed by elec­tro­sta­tic lines from ELENA. Com­mis­sion­ing of the new trans­fer lines and, in par­al­lel, stud­ies to bet­ter un­der­stand the ring with H− beams from a ded­i­cated source, have started in au­tumn 2020. The first 100 keV an­tipro­ton physics run using ELENA will start in late sum­mer 2021.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB177  
About • paper received ※ 18 May 2021       paper accepted ※ 14 June 2021       issue date ※ 23 August 2021  
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MOPAB178 Systematic Effects Limiting the Sensitivity of "Magic Energy" Proton EDM Rings 602
 
  • C. Carli, M. Haj Tahar
    CERN, Geneva, Switzerland
  
  Pro­pos­als to mea­sure a pos­si­ble Elec­tric Di­pole Mo­ment (EDM) of pro­tons in an elec­tro-sta­tic stor­age ring are stud­ied by a world-wide com­mu­nity. The ma­chine is op­er­ated at the so-called "magic en­ergy" to sat­isfy the "frozen spin" con­di­tion such that, with­out im­per­fec­tions and with the well known mag­netic mo­ment of the par­ti­cle, the spin is al­ways ori­ented par­al­lel to the di­rec­tion of move­ment. The ef­fect of a fi­nite EDM is a build-up of a ver­ti­cal spin com­po­nent. Any ef­fect, other than a fi­nite EDM, lead­ing as well to a build-up of a ver­ti­cal spin lim­its the sen­si­tiv­ity of the ex­per­i­ment. Such "sys­tem­atic ef­fects" are caused by ma­chine im­per­fec­tions, such as mag­netic fields in­side the mag­netic shield sur­round­ing the ring, and mis­align­ments of elec­tro-sta­tic el­e­ments or of the RF cav­ity. Op­er­a­tion of the ma­chine with counter-ro­tat­ing beams helps mit­i­gat­ing some of the ef­fects. The most dan­ger­ous ef­fects are those, which can­not be dis­en­tan­gled from an EDM by com­bin­ing mea­sure­ments from both counter-ro­tat­ing beams, such as an av­er­age resid­ual ra­dial mag­netic field pen­e­trat­ing the mag­netic shield or a com­bi­na­tion of mag­netic fields and mis­align­ments of elec­tric el­e­ments.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2021-MOPAB178  
About • paper received ※ 18 May 2021       paper accepted ※ 17 June 2021       issue date ※ 20 August 2021  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)