Measurement of¹²⁹Xe frequency shift due to Cs—¹²⁹Xe collisions

Abstract

Enhancement factor κ 0 , which characterizes NMR and EPR frequency shifts for Cs-129 Xe, is measured for the first time. The enhancement factor κ 0 was measured to be (702±41) at 80 • C and (653±20) at 90 • C, using the NMR frequency shift, detected by atomic magnetometer at a low magnetic field of 100 nT. This result is useful for predicting the EPR frequency shifts for Cs and the NMR frequency shifts for 129 Xe in spin-exchange cells.

Collisional EPR Frequency Shifts in Cs-Rb-Xe Mixtures

“…A previous measurement of (κ 0 ) CsXe based on 129 Xe NMR frequency shifts made by Fang and co-workers [41] yielded 702 ± 41 at 80 • C and 653 ± 20 at 90 • C. Given the uncertainties in these measurements, they are not inconsistent with our result or with the absence of temperature dependence observed in our work. Temperature dependence for the heavier noble gases is expected to be weak at best, since κ 0 depends more on the location of the steep repulsive core of the interatomic potential than on the well depth [40].…”

Measuring the spin polarization of alkali-metal atoms using nuclear magnetic resonance frequency shifts of noble gases

“…23 The polarization measured with this method was P Rb ≈ 70%. Comparing with the calculation from the frequency shifts, the error may result from the gas pressure, temperature, cell conditions and the inhomogeneous laser intensity through the cell.…”

Comment on "Measuring the enhancement factor of the hyperpolarized Xe in nuclear magnetic resonance gyroscopes"

“…In [1], the authors propose several erroneous ideas regarding the nature of the enhancement factor κ and report an experimental result for it that is more than an order of magnitude greater than theoretical estimates [2] and previous experimental results [3]. Moreover, there is no plausible physical basis or discussion of how their experiment might have generated such a large discrepancy.…”

“…However, they repeatedly confuse enhancement of the field sensed by Cs atoms due to the Fermi-contact magnetic field produced by polarized 129 Xe atoms (i.e., the definition of κ), and enhancement of the 129 Xe nuclear polarization produced by SEOP. They appear to be unaware of the measurement of κ ≈ 700 for Cs-Xe made by Fang, et al [3] from 2014 and do not cite it. They make the further unphysical argument that their much larger value results from making their measurement in a low applied magnetic field of 2.5 µT; indeed, the measurement by Fang, et al [3] was made at an even lower applied field.…”

“…They appear to be unaware of the measurement of κ ≈ 700 for Cs-Xe made by Fang, et al [3] from 2014 and do not cite it. They make the further unphysical argument that their much larger value results from making their measurement in a low applied magnetic field of 2.5 µT; indeed, the measurement by Fang, et al [3] was made at an even lower applied field. The authors state, "In a weak field of about 10 −4 T, the Cs-129 Xe enhancement factor is reported to be 10 4 to 10 5 ," but no such measurement has ever been made.…”