A High-Pressure Polarized ${}^3$He Gas Target for Nuclear Physics Experiments Using A Polarized Photon Beam

Abstract

Following the first experiment on three-body photodisintegration of polarized ${}^3$He utilizing circularly polarized photons from High Intensity Gamma Source (HI$\gamma$S) at Duke Free Electron Laser Laboratory (DFELL), a new high-pressure polarized ${}^3$He 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 $\sim$62% determined from both NMR-AFP and EPR polarimetry. The $X$ parameter is estimated to be $\sim 0.06$ 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 ${}^3$He target cell used previously at HI$\gamma$S. This is the first time that sol-gel coating technique has been used in a polarized ${}^3$He target for nuclear physics experiments.

8 pages, 3 figures

References in corpus (5)

• The neutron charge form factor and target analyzing powers from pol.3He(pol e,e'n)-scattering
• Precision Measurement of the Neutron Spin Asymmetry $A_1^n$ and Spin-Flavor Decomposition in the Valence Quark Region
• Q^2 Evolution of the Neutron Spin Structure Moments using a He-3 Target
• Extraction of the Neutron Magnetic Form Factor from Quasi-Elastic 3He(pol)(e(pol),e') at Q^2 = 0.1 - 0.6 (GeV/c)^2
• Relaxation of Spin Polarized ${}^3$He in Mixtures of ${}^3$He and ${}^4$He at $\sim$330 mK

Cited by in corpus (7)

• Optically Polarized ${}^3$He
• Measurements of $d_2^n$ and $A_1^n$: Probing the neutron spin structure
• Polarization Limits in K-Rb Spin-Exchange Mixtures
• First Measurements of Spin-Dependent Double-Differential Cross Sections and the GDH Integrand from \vec{^3He}(\vecγ,n)pp at Incident Photon Energies of 12.8 and 14.7 MeV
• Search for Spin-Dependent Short-Range Force Using Optically Polarized ${}^3$He Gas
• Measurement of the Doubly-Polarized $\overrightarrow{{}^{3}He}(\vec{\gamma },n)pp$ Reaction at 16.5 MeV and Its Implications for the GDH Sum Rule
• First Measurement of the Asymmetry and the Gerasimov-Drell-Hearn Integrand from $\overrightarrow{{}^{3}He}(\vec{\gamma },p)d$ reaction at the Incident Photon Energy of 29 MeV