The Cooler Synchrotron (COSY) located at the Forschungszentrum Jülich along with the EDDA scintillation detectors have been used with a 0.97-GeV/c polarized deuteron beam to demonstrate the feasibility of high efficiency polarimetry, correction of systematic errors, and long spin coherence times in preparation for the design and construction of a new storage ring to search for an electric dipole moment on the proton, deuteron, or other light nuclei. Slow extraction of the stored beam onto a 1.5-cm thick carbon target yielded an efficiency (usefully detected particles divided by particles lost from the beam) near 10‒3 and average 3Ay/2 = 0.67(4). Calibration of the polarimeter’s sensitivity to geometric and rate-induced systematic errors made possible the real time correction of such errors based on combinations of the primary detector rates to the level of 10‒5 with the prospect for lower errors in the EDM search. Recently, new studies of manipulations of the stored beam polarization using an RF solenoid operating on the 1‒Gγ resonance demonstrated a spin coherence lifetime of minutes for a horizontally-polarized and electron-cooled beam without a Siberian Snake. Preparations are underway for examining the use of sextupole fields in the ring to lengthen this lifetime.
Polarimeter and Spin Coherence Time Developments at COSY for a Storage Ring EDM Search
LENISA, Paolo
2012
Abstract
The Cooler Synchrotron (COSY) located at the Forschungszentrum Jülich along with the EDDA scintillation detectors have been used with a 0.97-GeV/c polarized deuteron beam to demonstrate the feasibility of high efficiency polarimetry, correction of systematic errors, and long spin coherence times in preparation for the design and construction of a new storage ring to search for an electric dipole moment on the proton, deuteron, or other light nuclei. Slow extraction of the stored beam onto a 1.5-cm thick carbon target yielded an efficiency (usefully detected particles divided by particles lost from the beam) near 10‒3 and average 3Ay/2 = 0.67(4). Calibration of the polarimeter’s sensitivity to geometric and rate-induced systematic errors made possible the real time correction of such errors based on combinations of the primary detector rates to the level of 10‒5 with the prospect for lower errors in the EDM search. Recently, new studies of manipulations of the stored beam polarization using an RF solenoid operating on the 1‒Gγ resonance demonstrated a spin coherence lifetime of minutes for a horizontally-polarized and electron-cooled beam without a Siberian Snake. Preparations are underway for examining the use of sextupole fields in the ring to lengthen this lifetime.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
