Author: Melnikov, A.A.
Paper Title Page
MOPOTK024 Quasi-Frozen Spin Concept of Magneto-Optical Structure of NICA Adapted to Study the Electric Dipole Moment of the Deuteron and to Search for the Axion 492
 
  • Y. Senichev, A.E. Aksentyev, S.D. Kolokolchikov, A.A. Melnikov
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • V. Ladygin, E. Syresin
    JINR/VBLHEP, Dubna, Moscow region, Russia
  • N. Nikolaev
    Landau ITP, Chernogolovka, Russia
 
  Funding: We acknowledge a support by the joint Deutsche ForschungsGemeinschaft (DFG) and Russian Science Foundation (RSF) grant 22-42-04419
The "frozen spin" method is based on the fact that at a certain parameters of the ring, the particle spin rotates with the frequency of the momentum, creating conditions for the continuous growth of the electric dipole moment signal. Since a straightforward implementation of the frozen spin regime at NICA is not possible, we suggest an alternative quasi-frozen spin approach concept. In this new regime, the spin oscillates about particle orbit with the spin phase advance pi*gamma*G/2, locally recovering the longitudinal orientation at the location of the electric-magnetic Wien filters in the straight sections. In the case of deuterons, thanks to the small magnetic anomaly G, the spin continuously oscillates relative to the direction of the momentum with a small amplitude of a few degrees and the expected EDM effect is reduced only by a few percent. In this paper, we study the spin-orbital motion with the aim of using the NICA collider to measure the EDM. We also comment on the potential of NICA as an axion antenna in both the quasi-frozen spin regime and beyond.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-MOPOTK024  
About • Received ※ 16 May 2022 — Revised ※ 11 June 2022 — Accepted ※ 12 June 2022 — Issue date ※ 01 July 2022
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WEPOPT004 Acceleration and Crossing of Transition Energy Investigation Using an RF Structure of the Barrier Bucket Type in the NICA Accelerator Complex 1829
 
  • S.D. Kolokolchikov, A.A. Melnikov, Y. Senichev
    RAS/INR, Moscow, Russia
  • E. Syresin
    JINR, Dubna, Moscow Region, Russia
 
  The dynamic of longitudinal motion in Barrier Bucket RF structure is considered. To preserve the stability of the proton beam during the acceleration to the experiment energy it is necessary to cross the transition energy and a rapid jump of transition energy is possible. The influence of the second-order slip factor is taking into account, as well as the space charge effect. The dynamic aperture is investigated for various gradients of focusing quadrupoles and corresponding working points which is necessary for transition crossing.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT004  
About • Received ※ 16 May 2022 — Revised ※ 15 June 2022 — Accepted ※ 16 June 2022 — Issue date ※ 23 June 2022
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WEPOPT005 Investigation of Polarized Proton Spin Coherence Time at Storage Rings 1832
SUSPMF004   use link to see paper's listing under its alternate paper code  
 
  • A.A. Melnikov, A.E. Aksentyev, Y. Senichev
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • E. Syresin
    JINR/VBLHEP, Dubna, Moscow region, Russia
 
  Funding: We appreciate a support of this study by the Russian Science Foundation grant 22-42-04419 and the ERC Advanced Grant of the European Union (proposal number 694340).
The idea of the Electric Dipole Moment (EDM) search using the storage ring with polarized beam demands long Spin Coherence Time (SCT). It is the time during which the RMS spread of the orientation of spins of all particles in the bunch reaches one radian. Long SCT is needed to observe a coherent effect on polarization induced by the EDM. The possibility of getting a 1000 s SCT for deuterons has been shown experimentally at COoler SYnchrotron (COSY), accelerator at FZJ Jülich, Germany. Reaching high values of SCT for protons is more challenging due to a higher anomalous magnetic moment. Obtaining sufficient proton SCT is obligatory for planned EDM search experiments at COSY and the ProtoType EDM Ring (PTR). It has been shown that the second order momentum compaction factor (alpha1) has to be optimized along with chromaticities to get high SCT. Three families of sextupoles have to be used. The optimal values of chromaticities and alpha1 are discussed. The racetrack option of PTR is investigated.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT005  
About • Received ※ 16 May 2022 — Revised ※ 14 June 2022 — Accepted ※ 15 June 2022 — Issue date ※ 02 July 2022
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WEPOPT006 Investigation of Spin-Decoherence in the NICA Storage Ring for the Future EDM-Measurement Experiment 1835
 
  • A.E. Aksentyev, A.A. Melnikov, Y. Senichev
    RAS/INR, Moscow, Russia
  • A.E. Aksentyev
    MEPhI, Moscow, Russia
  • V. Ladygin, E. Syresin
    JINR, Dubna, Moscow Region, Russia
 
  Funding: We acknowledge support by the joint Deutsche ForschungsGemeinschaft (DFG) and Russian Science Foundation (RSF) grant 22-42-04419
A new experiment to measure electric dipole moments (EDMs) of elementary particles, based on the Frequency Domain method, has been proposed for implementation at the NICA facility (JINR, Russia). EDM experiments in general, being measurement-of-polarization experiments, require long spin-coherence times at around 1,000 seconds. The FD method involves a further complication (well paid off in orders of precision) of switching the polarity of the guiding field as part of its CW-CCW injection procedure. This latter procedure necessitates a calibration process, during which the beam polarization axis changes its orientation from the radial (used for the measurement) to the vertical (used for the calibration) direction. If this change occurs adiabatically, the beam particles’ spin-vectors follow the direction of the polarization axis, which undermines the calibration technique; however, concerns were raised as to whether violation of adiabaticity could damage spin-coherence.
 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2022-WEPOPT006  
About • Received ※ 16 May 2022 — Accepted ※ 15 June 2022 — Issue date ※ 22 June 2022  
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