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Comment on "Enhanced polarization and mechanisms in optically pumped hyperpolarized 3He in the presence of 4He"



Thomas R. Gentile, M E. Hayden, P.J. Nacher, A K. Petukhov, B Saam, T G. Walker


H.H. Chen et al [1] claim that adding 4He to spin-exchange optical pumping (SEOP) cells confines 3He atoms to a diffusion-limited region, which effectively reduces the wall relaxation factor X. Here X is a phenomenological parameter used to characterize typical SEOP cells; it quantifies the observation that the measured linear slope of the relaxation rate with alkali density exceeds the spin-exchange rate. In addition they claim to demonstrate that magnetic field gradients cause a diffusive motion of 3He. We argue that these claims and other central conclusions drawn by the the authors of [1] are unjustified and/or unphysical. We also draw attention to several additional issues and shortcomings associated with the results, analysis, and presentation of data in [1] that confound clear interpretation."
Physical Review A


He3, He4, spin-exchange optical pumping


, T. , Hayden, M. , Nacher, P. , Petukhov, A. , Saam, B. and Walker, T. (2013), Comment on "Enhanced polarization and mechanisms in optically pumped hyperpolarized <sup>3</sup>He in the presence of <sup>4</sup>He", Physical Review A (Accessed April 14, 2024)
Created July 24, 2013, Updated February 19, 2017