Phase Locking the Spin Precession in a Storage Ring.

N Hempelmann,G Macharashvili,A Saleev,V Kamerdzhiev,A Magiera,A Nass,H Ströher,R Stassen,D Eversmann,R Talman,A Vassiliev,I Keshelashvili,G Tagliente,P Wüstner,W Augustyniak,S Chekmenev,V Hejny,S Mey,V Shmakova,D Mchedlishvili,N Lomidze,L Barion,P Maanen,J Slim,T Hanraths,P Thörngren Engblom,G Ciullo,F Trinkel,H Soltner,A Wrońska,K Grigoryev,V Schmidt,P Lenisa,J Pretz,D Prasuhn,Z Bagdasarian,S Dymov,F Rathmann,Yu Valdau,D Grzonka,A Kacharava,A Lehrach,M Żurek,H Stockhorst,I A Koop ,A Stahl,Martin Berz ,Н Н Николаев ,Mei Bai ,M Rosenthal,Fabian Müller ,Dirk Heberling ,Y K Semertzidis ,Eremey Valetov ,M Tabidze,Christian Weidemann ,E J Stephenson ,Fabian Hinder ,R Gebel,M Gaißer ,P Żuprański ,А И Куликов ,Greta Guidoboni ,B Lorentz,A Pesce,J Hetzel,Alexander J Silenko ,Yu N Uzikov ,F.j Etzkorn

doi:10.1103/physrevlett.119.014801

Abstract

This Letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV/c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (≈121 kHz) and the phase of the horizontal polarization component. Real time synchronization with a radio frequency (rf) solenoid made possible the rotation of the polarization out of the horizontal plane, yielding a demonstration of the feedback method to manipulate the polarization. In particular, the rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a 1 standard deviation range of σ=0.21 rad. The minimum possible adjustment was 3.7mHz out of a revolution frequency of 753kHz, which changes the precession rate by 26 mrad/s. Such a capability meets a requirement for the use of storage rings to look for an intrinsic electric dipole moment of charged particles.

Highlights

This Letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV=c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (≈121 kHz) and the phase of the horizontal polarization component
This work was carried out in the context of the effort to search for an intrinsic electric dipole moment (EDM) of charged particles circulating in the ring [1]
An EDM aligned along the particle spin axis is CP violating and any observation of such a moment would be a signal of new physical processes possibly related to the matter-antimatter asymmetry of the universe [2,3]

Summary

Introduction

This Letter reports the successful use of feedback from a spin polarization measurement to the revolution frequency of a 0.97 GeV=c bunched and polarized deuteron beam in the Cooler Synchrotron (COSY) storage ring in order to control both the precession rate (≈121 kHz) and the phase of the horizontal polarization component. The rotation rate shows a sinusoidal function of the horizontal polarization phase (relative to the rf solenoid), which was controlled to within a 1 standard deviation range of σ 1⁄4 0.21 rad.

Results

Conclusion