TY - JOUR
T1 - Measuring gas temperature during spin-exchange optical pumping process
AU - Normand, E.
AU - Jiang, C. Y.
AU - Brown, D. R.
AU - Robertson, L.
AU - Crow, L.
AU - Tong, X.
PY - 2016/5/11
Y1 - 2016/5/11
N2 - The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.
AB - The gas temperature inside a Spin-Exchange Optical Pumping (SEOP) laser-pumping polarized 3He cell has long been a mystery. Different experimental methods were employed to measure this temperature but all were based on either modelling or indirect measurement. To date there has not been any direct experimental measurement of this quantity. Here we present the first direct measurement using neutron transmission to accurately determine the number density of 3He, the temperature is obtained using the ideal gas law. Our result showed a surprisingly high gas temperature of 380°C, compared to the 245°C of the 3He cell wall temperature and 178°C of the optical pumping oven temperature. This experiment result may be used to further investigate the unsolved puzzle of the "X-factor" in the SEOP process which places an upper bound to the 3He polarization that can be achieved. Additional spin relaxation mechanisms might exist due to the high gas temperature, which could explain the origin of the X-factor.
UR - http://www.scopus.com/inward/record.url?scp=84977524164&partnerID=8YFLogxK
U2 - 10.1088/1742-6596/711/1/012012
DO - 10.1088/1742-6596/711/1/012012
M3 - Conference article
AN - SCOPUS:84977524164
SN - 1742-6588
VL - 711
JO - Journal of Physics: Conference Series
JF - Journal of Physics: Conference Series
IS - 1
M1 - 012012
T2 - 10th International Conference on Polarised Neutrons for Condensed Matter Investigations, PNCMI 2014
Y2 - 15 September 2014 through 19 September 2014
ER -