| Author(s): |
Thomas R. Gentile; B Saam; |
| Title: |
Comment on "Pressure dependence of wall relaxation in polarized He3 gaseous cells" |
| Published: |
April 26, 2012 |
| Abstract: |
W. Zheng et al. [Phys. Rev. A 83, 061401(R) (2011)] measure under certain conditions a linear pressure dependence of the wall-induced nuclear relaxation rate of 3He in glass cells typically used to generate and/or store hyperpolarized 3He. Their interpretation is that this linear dependence is a general characteristic of paramagnetic wall relaxation, regardless of the relationship between the diffusion time tau_d across the cell and the longitudinal nuclear relaxation time T1. The authors'proposed modi¯cation of the polarization diffusion equation to account for this dependence cannot be valid for T1 >> tau_d, which holds for all of their measurements. Numerous previous studies support a broadly valid pressure-independent model for wall relaxation. The likely explanation for the linear dependence observed by the authors is diffusion through a capillary to a re¯lling valve that has a much higher probability per collision to relax 3He. |
| Citation: |
Physical Review A |
| Pages: |
pp. 047401-1 - 047401-3 |
| Keywords: |
3He; linear pressure dependence; nuclear relaxation; |
| Research Areas: |
Nuclear Physics |
| PDF version: |
 Click here to retrieve PDF version of paper (121KB) |
