The 270 MeV deuteron beam polarimeter at the Nuclotron Internal Target Station

Abstract

A deuteron beam polarimeter has been constructed at the Internal Target Station at the Nuclotron of JINR. The polarimeter is based on spin-asymmetry measurements in the d − p elastic scattering at large angles and the deuteron kinetic energy of 270 MeV. It allows to measure vector and tensor components of the deuteron beam polarization simultaneously.

First results on the measurements of the proton beam polarization at internal target at Nuclotron1

“…The ITS deuteron beam polarimeter [5] has been used to measure the proton beam polarization at 500 MeV using pp-quasi-elastic scattering.…”

“…The polarimeter based on the use of dp-elastic scattering at large angles (θ cm ≥ 60 • ) at 270 MeV [5], where precise data on analyzing powers [6,7,8] exist, has been developed at internal target station (ITS) at Nuclotron [9]. The accuracy of the determination of the deuteron beam polarization achieved with this method is better than 2% because of the values of the analyzing powers were obtained for the polarized deuteron beam, which absolute polarization had been calibrated via the 12 C(d, α) 10 B * [2 + ] reaction [8].…”

“…These measurements were performed using internal target station at Nuclotron [9] with new control and data acquisition system [10]. The polarimeter has been upgraded [5] by new VME based DAQ [11], new MPod based high voltage system [12,13], new system of monitors etc.…”

“…In the current experiment the spin modes with the maximal ideal values of (P z ,P zz )= (0,0), (-1/3,+1) and (-1/3, +1) were used. The deuteron beam polarization has been measured at 270 MeV [5]. The dpelastic scattering events at 270 MeV were selected using correlation of the energy losses and time-of-flight difference for deuteron and proton detectors.…”

“…In this paper we report first results of the proton beam polarization measurements performed using upgraded polarimeter [5] at the Nuclotron internal target station.…”