3He spin exchange cells for magnetic resonance imaging

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Publication Type Journal Article
School or College College of Science
Department Physics
Creator Saam, Brian
Other Author Jacob, R. E.; Morgan, S. W.
Title 3He spin exchange cells for magnetic resonance imaging
Date 2002
Description We present a protocol for the consistent fabrication of glass cells to provide hyperpolarized (HP) 3He for pulmonary magnetic resonance imaging. The method for producing HP 3He is spin-exchange optical pumping. The valved cells must hold of order 1 atm.L of gas at up to 15 atm pressure. Because characteristic spin-exchange times are several hours, the longitudinal nuclear relaxation time T1 for 3He must be several tens of hours and robust with respect to repeated refilling and repolarization. Collisions with the cell wall are a significant and often dominant cause of relaxation. Consistent control of wall relaxation through cell fabrication procedures has historically proven difficult. With the help of the discovery of an important mechanism for wall relaxation that involves magnetic surface sites in the glass, and with the further confirmation of the importance of Rb metal to long wall-relaxation times, we have developed a successful protocol for fabrication of 3He spin exchange cells from inexpensive and easily worked borosilicate (Pyrex) glass. The cells are prepared under vacuum using a high-vacuum oil-free turbomolecular pumping station, and they are sealed off under vacuum after ≥ 100 mg of distilled Rb metal is driven in. Filling of cells with the requisite 3He-N2 mixture is done on an entirely separate gas-handling system. Our cells can be refilled and the gas repolarized indefinitely with no significant change in their wall properties. Relaxation data are presented for about 30 cells; the majority of these reach a ‘‘40/40'' benchmark: T1>.40 h, and 3He polarizations reach or exceed 40%. Typical polarization times range from 12 to 20 h; 20% polarization can be achieved in 3-5 h.
Type Text
Publisher American Institute of Physics (AIP)
Journal Title Journal of Applied Physics
Volume 92
Issue 3
First Page 1588
Last Page 1597
DOI 10.1063/1.1487438
citatation_issn 218979
Subject 3He; Spin exchange cells; Hyperpolarized 3He; Pulmonary magnetic resonance imaging; Spin-exchange optical pumping; SEOP; Glass cells
Subject LCSH Helium; Magnetic resonance imaging; Polarization (Nuclear physics)
Language eng
Bibliographic Citation Jacob, R. E., Morgan, S. W., & Saam, B. (2002). 3He spin exchange cells for magnetic resonance imaging. Journal of Applied Physics, 92(3), 1588-97.
Rights Management (c)American Institute of Physics. The following article appeared in Jacob, R. E., Morgan, S. W., & Saam, B., Journal of Applied Physics, 92(3) 2002 and may be found at http://dx.doi.org/10.1063/1.1487438
Format Medium application/pdf
Format Extent 390,478 bytes
Identifier ir-main,10859
ARK ark:/87278/s6ms4bfh
Setname ir_uspace
Date Created 2012-06-13
Date Modified 2021-05-06
ID 707427
Reference URL https://collections.lib.utah.edu/ark:/87278/s6ms4bfh
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