Eur. Phys. J. A (2010) 44: 55-61
https://doi.org/10.1140/epja/i2010-10932-0

Regular Article - Experimental Physics

A high-pressure polarized ³He gas target for nuclear-physics experiments using a polarized photon beam

¹ Triangle Universities Nuclear Laboratory and Department of Physics, Duke University, 27708, Durham, NC, USA
² Department of Physics, College of William and Mary, Williamsburg, VA, USA
³ Department of Physics, University of Virginia, 22904, Charlottesville, VA, USA

^* e-mail: yq@phy.duke.edu

Received: 15 September 2009
Revised: 31 December 2009
Accepted: 26 January 2010
Published online: 26 February 2010

Abstract

Following the first experiment on three-body photodisintegration of polarized ³He utilizing circularly polarized photons from High-Intensity Gamma Source (HI S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized ³He target cell made of pyrex glass coated with a thin layer of sol-gel doped with aluminum nitrate nonahydrate has been built in order to reduce the photon beam-induced background. The target is based on the technique of spin exchange optical pumping of hybrid rubidium and potassium and the highest polarization achieved is ∼ 62% determined from both NMR-AFP and EPR polarimetries. The phenomenological parameter that reflects the additional unknown spin relaxation processes, X , is estimated to be ∼ 0.10 and the performance of the target is in good agreement with theoretical predictions. We also present beam test results from this new target cell and the comparison with the GE180 ³He target cell used previously at HI S. This is the first time that the sol-gel coating technique has been used in a polarized ³He target for nuclear-physics experiments.