Increasing the pump-up rate to polarize 3He gas using spin-exchange optical pumping method

Wai Tung Lee; Xin Tong; Dennis Rich; Yun Liu; Michael Fleenor; Akbar Ismaili; Joshua Pierce; Mark Hagen; Jonny Dadras; J. Lee Robertson

doi:10.1016/j.physb.2009.06.037

Increasing the pump-up rate to polarize ³He gas using spin-exchange optical pumping method

Wai Tung Lee, Xin Tong, Dennis Rich, Yun Liu, Michael Fleenor, Akbar Ismaili, Joshua Pierce, Mark Hagen, Jonny Dadras, J. Lee Robertson

HFIR Low Temperature and Magnets

Research output: Contribution to journal › Article › peer-review

2 Scopus citations

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
Pages (from-to)	2670-2672
Number of pages	3
Journal	Physica B: Physics of Condensed Matter
Volume	404
Issue number	17
DOIs	https://doi.org/10.1016/j.physb.2009.06.037
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
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

Access to Document

10.1016/j.physb.2009.06.037

Cite this

@article{197feda97dc64fd196e179461b9aa733,

title = "Increasing the pump-up rate to polarize 3He gas using spin-exchange optical pumping method",

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.",

keywords = "Neutron spin filter, Polarized He, Spin destruction, Spin exchange, Spin-exchange optical pumping",

author = "Lee, {Wai Tung} and Xin Tong and Dennis Rich and Yun Liu and Michael Fleenor and Akbar Ismaili and Joshua Pierce and Mark Hagen and Jonny Dadras and Robertson, {J. Lee}",

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T1 - Increasing the pump-up rate to polarize 3He gas using spin-exchange optical pumping method

AU - Lee, Wai Tung

AU - Tong, Xin

AU - Rich, Dennis

AU - Liu, Yun

AU - Fleenor, Michael

AU - Ismaili, Akbar

AU - Pierce, Joshua

AU - Hagen, Mark

AU - Dadras, Jonny

AU - Robertson, J. Lee

PY - 2009/9/1

Y1 - 2009/9/1

N2 - 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.

AB - 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.

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KW - Polarized He

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KW - Spin exchange

KW - Spin-exchange optical pumping

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