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Maynard S. Dewey (Fed)

Professional Interest: 

A major thrust of Dr. Maynard S Dewey’s research is focused on precise measurements of decay parameters in neutron beta decay in order to probe the Standard Model (e.g. the neutron lifetime and the correlation between the outgoing electron and electron-antineutrino momenta). This includes precise measurements of thermal and cold neutron fluences in order to reduce the uncertainty in beam-type measurements of the neutron lifetime, to measure important neutron capture cross sections (e.g. boron and lithium), and to re-calibrate the national neutron source NBS-1 which underpins our neutron source and detector calibration services.  A second thrust is precise measurements of neutron source intensities using the manganese bath method in order to reduce the uncertainty of neutron source calibrations for industry and government.

Dr. Dewey has been a member of the Neutron Physics group since 1990, after working in precise gamma-ray spectroscopy in the Quantum Metrology Group/Division for his first three years at NIST. Before coming to NIST in late 1987, he was a postdoctoral fellow at Princeton University where he continued his Ph.D. thesis work on a precise measurement of the Lamb shift in hydrogen-like 4He.  He received his Ph.D. in Physics from Princeton University in 1984 with a thesis in atomic physics under Prof. Robert Dunford entitled “A Precise Measurement of the 2S-2P Lamb Shift in Hydrogen-like Helium” and his B.S. in Physics from the State University of New York at Stony Brook in 1978. 

Dr. Dewey was awarded a NIST Bronze Medal in 2020; he was elected to Fellowship in the American Physical Society in 2017 through the Topical Group on Precision Measurements and Fundamental Constants; and he is an author on about 60 peer-reviewed publications.

Publications

Comment on "Search for explanation of the neutron lifetime anomaly"

Author(s)
Fred Wietfeldt, Ripan Biswas, Jimmy Caylor, Bret Crawford, Maynard Dewey, Nadia Fomin, Geoffrey Greene, Christopher Haddock, Shannon Hoogerheide, Hans Mumm, Jeffrey Nico, William Snow, Joseph Zuchegno
We respond to issues raised by Serebrov et al. in a recent paper regarding systematic effects in the beam neutron lifetime experiment performed at NIST. We show

Progress on the BL2 beam measurement of the neutron lifetime

Author(s)
Shannon M. Hoogerheide, Jimmy P. Caylor, Evan R. Adamek, Eamon S. Anderson, Ripan Biswas, B. E. Crawford, Christina DeAngelis, Maynard S. Dewey, N Fomin, David M. Gilliam, Kyle Grammer, G L. Greene, Robert W. Haun, Jonathan Mulholland, Hans Pieter Mumm, Jeffrey S. Nico, William M. Snow, F E. Wietfeldt, Andrew Yue
A precise value of the neutron lifetime is important in several areas of physics, including determinations of the quark-mixing matrix element |Vud|, related

Neutron Polarimetry Using a Polarized 3He Cell for the aCORN Experiment

Author(s)
Benjamin C. Schafer, W A. Byron, Wangchun Chen, B Collett, Maynard S. Dewey, Thomas R. Gentile, Md. T. Hassan, Gordon L. Jones, Alexander Komives, Fred E. Wietfeldt
The neutron polarization of the NG-C beamline at the NIST Center for Neutron Research was measured as part of the aCORN neutron beta decay experiment. Neutron t

Precision determination of absolute neutron flux

Author(s)
Jeffrey S. Nico, Maynard S. Dewey, David M. Gilliam, Andrew T. Yue, Eamon Anderson, Geoff Greene, Alexander Laptev, William M. Snow
A technique for establishing the total neutron rate of a highly-collimated monochromatic cold neutron beam was demonstrated using the method of an alpha- gamma
Created October 9, 2019, Updated December 8, 2022