TY - JOUR
T1 - Lifetime behaviour and polarization stability in 3He neutron spin filter cells
AU - Boag, S.
AU - Jiang, C. Y.
AU - Tong, X.
AU - Parnell, S. R.
PY - 2014
Y1 - 2014
N2 - The successful use of 3He cells in polarized neutron applications demands that once polarized the gas has both a long relaxation time and high polarization. In spin-exchange optical pumping the cell characteristics determine the maximum polarization as well as the lifetime. We report on our experience of neutron spin filter cells, showing results on the orientation dependence of such cells. We observe a previously observed lifetime hysterisis effect in 3He cell relaxation lifetime and include new measurements of the angular dependence of the relaxation lifetime, that are characteristic of a dipolar effect which diminishes upon repeated pumping/cooling cycles. We present demonstrations of magnetization effects in 3He and 129Xe cells and show the applicability of using sol-gel coatings on reducing the magnetization effect in 129Xe cells. We report recent results of the stability of the polarization in new SEOP cells, which was evident for 2 states, one with high energy spin state, low T1 orientation and the second with low energy spin state, high T 1 orientation. These results are suggestive of an abnormal relaxation and have only been observed for cells with short (T1 <10 Hours) lifetimes.
AB - The successful use of 3He cells in polarized neutron applications demands that once polarized the gas has both a long relaxation time and high polarization. In spin-exchange optical pumping the cell characteristics determine the maximum polarization as well as the lifetime. We report on our experience of neutron spin filter cells, showing results on the orientation dependence of such cells. We observe a previously observed lifetime hysterisis effect in 3He cell relaxation lifetime and include new measurements of the angular dependence of the relaxation lifetime, that are characteristic of a dipolar effect which diminishes upon repeated pumping/cooling cycles. We present demonstrations of magnetization effects in 3He and 129Xe cells and show the applicability of using sol-gel coatings on reducing the magnetization effect in 129Xe cells. We report recent results of the stability of the polarization in new SEOP cells, which was evident for 2 states, one with high energy spin state, low T1 orientation and the second with low energy spin state, high T 1 orientation. These results are suggestive of an abnormal relaxation and have only been observed for cells with short (T1 <10 Hours) lifetimes.
UR - http://www.scopus.com/inward/record.url?scp=84906225142&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/528/1/012019
DO - 10.1088/1742-6596/528/1/012019
M3 - Conference article
AN - SCOPUS:84906225142
SN - 1742-6588
VL - 528
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012019
T2 - International Workshop on Neutron Optics and Detectors, NOP and D 2013
Y2 - 2 July 2013 through 5 July 2013
ER -