Ex-Situ Polarized 3He Electron Beam Target

Nuclear physics experiments conducted at the Thomas Jefferson National Accelerator Facility utilize targets consisting of nuclear polarized 3He. These experiments utilize the high energy electron beam for months at a time to answer fundamental questions of how matter is composed of quarks. Over the next decade, the energy capability of the beam is scheduled to be upgraded from 6 GeV to 12 GeV. This upgrade will extend the experiments to kinematical regions where the present sensitivity is insufficient. The sensitivity of these experiments could be increased by increasing the polarization. This project will adapt a prototype, large-scale 3He polarizer, developed for medical diagnostic imaging, for use as an ex-situ polarized target. The system would sit beside a beam line and produce up to 100 liters per day of 3He, polarized as high as 65 percent or more. A non­ferrous compressor will be utilized to pressurize the polarized 3He into a titanium target cell that can withstand the full 100 microanstrom current that the facility now provides. A two-order-of-magnitude improvement to the experimental sensitivity is expected, which would significantly increase the efficiency of experiments. Commercial Applications and other Benefits as described by the awardee: Polarized 3He has applications as an electron beam target, as a neutron spin filter for producing polarized neutrons, as a neutron spin analyzer to measure magnetic properties of thin films, and as a promising contrast agent for measuring regional pulmonary function in diagnostic magnetic resonance imaging. The technology would provide benefits to science, diagnostic medicine, and society