Abstract
In recent years, polarized 3He gas has increasingly been used as neutron polarizers and polarization analyzers. Two of the leading methods to polarize the 3He gas are the spin-exchange optical pumping (SEOP) method and the meta-stable exchange optical pumping (MEOP) method. At present, the SEOP setup is comparatively compact due to the fact that it does not require the sophisticated compressor system used in the MEOP method. The temperature and the laser power available determine the speed, at which the SEOP method polarizes the 3He gas. For the quantity of gas typically used in neutron scattering work, this speed is independent of the quantity of the gas required, whereas the polarizing time using the MEOP method is proportional to the quantity of gas required. Currently, using the SEOP method to polarize several bar-liters of 3He to 70% polarization would require 20-40 h. This is an order of magnitude longer than the MEOP method for the same quantity of gas and polarization. It would therefore be advantageous to speed up the SEOP process. In this article, we analyze the requirements for temperature, laser power, and the type of alkali used in order to shorten the time required to polarize 3He gas using the SEOP method.
Original language | English |
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Pages (from-to) | 2670-2672 |
Number of pages | 3 |
Journal | Physica B: Physics of Condensed Matter |
Volume | 404 |
Issue number | 17 |
DOIs | |
State | Published - Sep 1 2009 |
Funding
The authors acknowledge Tom Gentile of the National Institute of Standards and Technology for his advice. The Oak Ridge National Laboratory is managed by UT-Battelle, LLC for the US Department of Energy under contract DE-AC05-00OR22725.
Funders | Funder number |
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U.S. Department of Energy | DE-AC05-00OR22725 |
Oak Ridge National Laboratory |
Keywords
- Neutron spin filter
- Polarized He
- Spin destruction
- Spin exchange
- Spin-exchange optical pumping