Author: Derbenev, Y.S.
Paper Title Page
MOPGW104 Equilibria and Synchrotron Stability in Two Energy Storage Rings 364
 
  • B. Dhital, J.R. Delayen, G.A. Krafft
    ODU, Norfolk, Virginia, USA
  • J.R. Delayen, Y.S. Derbenev, D. Douglas, G.A. Krafft, F. Lin, V.S. Morozov, Y. Zhang
    JLab, Newport News, Virginia, USA
  
  In a dual energy storage ring, the electron beam passes through two loops at markedly different energies EL, and EH, i.e., energies for low energy loop and high energy loop respectively. These loops use a common beamline where a superconducting linac at first accelerates the beam from EL to EH and then decelerates the beam from EH to EL in the next pass. There are two basic solutions to the equilibrium problems possible, i.e., ’Storage Ring’ (SR) equilibrium and ’Energy Recovery Linac’ (ERL) equilibrium. SR equilibrium mode more resembles the usual single loop storage ring with strong synchrotron motion and ERL equilibrium mode is the case where RF in two beam passes nearly cancels. Calculations based on linear transfer matrix formalism show that longitudinal stability exists for both SR mode and ERL mode in two energy storage rings.  
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-MOPGW104  
About • paper received ※ 14 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
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WEPGW122 EXPERIMENTAL VERIFICATION OF TRANSPARENT SPIN MODE IN RHIC 2783
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • P. Adams, H. Huang, F. Méot, V. Ptitsyn, W.B. Schmidke
    BNL, Upton, Long Island, New York, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
  
  Funding: Supported in part by the U.S. DoE under Contract No. DE-AC05-06OR23177 and by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DoE.
High electron and ion polarizations are some of the key design requirements of a future Electron Ion Collider (EIC). The transparent spin mode, a concept inspired by the figure 8 ring design of JLEIC, is a novel technique for preservation and control of electron and ion spin polarizations in a collider or storage ring. It makes the ring lattice "invisible" to the spin and allows for polarization control by small quasi-static magnetic fields with practically no effect on the beam’s orbital characteristics. It offers unique opportunities for polarization maintenance and control in Jefferson Lab’s JLEIC and in BNL’s eRHIC. The transparent spin mode has been demonstrated in simulations and we now plan to test it experimentally. We present a design of an experiment using a polarized proton beam stored in one of the RHIC rings. In the experiment, one of the RHIC rings is configured in the transparent spin mode by aligning the axes of its two Siberian snakes. The experiment goals, procedures, hardware requirements and expected results are presented. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW122  
About • paper received ※ 15 May 2019       paper accepted ※ 21 May 2019       issue date ※ 21 June 2019  
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WEPGW124 Spin Response Function for Spin Transparency Mode of RHIC 2791
 
  • V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
    JLab, Newport News, Virginia, USA
  • P. Adams, H. Huang, F. Méot, V. Ptitsyn, W.B. Schmidke
    BNL, Upton, Long Island, New York, USA
  • Y. Filatov
    MIPT, Dolgoprudniy, Moscow Region, Russia
  • H. Huang
    ODU, Norfolk, Virginia, USA
  • A.M. Kondratenko, M.A. Kondratenko
    Science and Technique Laboratory Zaryad, Novosibirsk, Russia
  
  Funding: Supported by the U.S. DoE under Contracts No. DE-AC05-06OR23177 and DE-AC02-98CH10886.
In the Spin Transparency (ST) mode of RHIC, the axes of its Siberian snakes are parallel. The spin tune in the ST mode is zero and the spin motion becomes degenerate: any spin direction repeats every particle turn. In contrast, the lattice of a conventional collider determines a unique stable periodic spin direction, so that the collider operates in the Preferred Spin (PS) mode. Contributions of perturbing magnetic fields to the spin resonance strengths in the PS mode are usually calculated using the spin response function. However, in that form, it is not applicable in the ST mode. This paper presents a response function formalism expanded for the ST mode of operation of conventional colliders with two identical Siberian snakes in the highly-relativistic limit. We present calculations of the spin response function for RHIC in the ST mode. 		 
DOI • reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2019-WEPGW124  
About • paper received ※ 01 May 2019       paper accepted ※ 18 May 2019       issue date ※ 21 June 2019  
Export • reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)