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arXiv · 1512.09351

High-Sensitivity Measurement of 3He-4He Isotopic Ratios for Ultracold Neutron Experiments

H. P. Mumm·M. G. Huber·W. Bauder·N. Abrams·C. M. Deibel·C. R. Huffer·P. R. Huffman·K. W. Schelhammer·C. M. Swank·R. Janssens·C. L. Jiang·R. H. Scott·R. C. Pardo·K. E. Rehm·R. Vondrasek·C. M. O'Shaughnessy·M. Paul·L. Yang
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Abstract

Research efforts ranging from studies of solid helium to searches for a neutron electric dipole moment require isotopically purified helium with a ratio of 3He to 4He at levels below that which can be measured using traditional mass spectroscopy techniques. We demonstrate an approach to such a measurement using accelerator mass spectroscopy, reaching the 10e-14 level of sensitivity, several orders of magnitude more sensitive than other techniques. Measurements of 3He/4He in samples relevant to the measurement of the neutron lifetime indicate the need for substantial corrections. We also argue that there is a clear path forward to sensitivity increases of at least another order of magnitude.

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H. P. Mumm, M. G. Huber, W. Bauder, N. Abrams, C. M. Deibel, C. R. Huffer, P. R. Huffman, K. W. Schelhammer, C. M. Swank, R. Janssens, C. L. Jiang, R. H. Scott, R. C. Pardo, K. E. Rehm, R. Vondrasek, C. M. O'Shaughnessy, M. Paul, L. Yang. 2015-12-31. High-Sensitivity Measurement of 3He-4He Isotopic Ratios for Ultracold Neutron Experiments. https://doi.org/10.1103/physrevc.93.065502

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