Gordon Jones
|
Address:
B.A. Williams College, 1989. M.A. Princeton University, 1991. Ph.D. Princeton University, 1996. Thesis: "A Measurement of the Beta Decay Asymmetry of 19Ne as a Test of the Standard Model" NRC Post-Doc, NIST, Gaithersburg, MD, 1996-1998. Visiting Scientist, Indiana University, 1998-1999. (Stationed at NIST, Gaithersburg, MD). Assistant Professor of Physics, Hamilton College, 1999-Present. |
My research combines nuclear and atomic physics in two areas related to cold neutron beams: 1) tests of the weak interaction using neutrons and 2) neutron polarizers based on polarized 3He. The two areas are beginning to merge as neutron polarizers improve and the demand for high precision neutron polarimetry increases. The electroweak tests involve medium sized collaborations spread across a number of institutions. The polarizers are table top apparatus built at Hamilton and brought to neutron facilities. In both cases, I build apparatus.
Weak Interaction Tests with Cold Neutrons
In testing the weak interaction, I have recently worked on three experiments with cold neutrons.
emiT: This experiment at the National Institute for Standards and Technology (NIST) will measure the triple-correlation (Dsn·pe×pn) in the beta decay of polarized neutrons. This angular correlation provides a test of time-reversal invariance in neutron decay. My involvement includes magnetic field alignment and monitoring.
NPDGamma: This experiment at Los Alamos National Lab will measure the parity-violating gamma asymmetry resulting from polarized cold neutron capture on hydrogen ( n + p à d + g). This small (A~10-8) parity-violating asymmetry will provide a theoretically clean measurement of the weak pion-nucleon coupling constant. My involvement centers on the 3He-based neutron polarizer and its associated NMR.
Little a: This proposed experiment will measure the beta-neutrino angular correlation coefficient (commonly called “Little a”) in cold neutron beta decay at Indiana University and NIST. The angular correlation provides a test of CKM unitarity and a search for physics beyond the standard electroweak model. I am designing the magnetic field and alignment systems.
My initial work on 3He-based polarizers was geared toward nuclear physics measurements such as the NPDGamma experiment listed above. However, neutron spin-filters are particularly well suited to materials science experiments at the new Spallation Neutron Source (SNS) being built in Oak Ridge, TN. About half of my time is spent on spin-exchange optical pumping of 3He.
Optically Pumped 3He/Neutron Polarizers: I am applying polarized 3He spin-filters to both nuclear physics experiments and neutron scattering instruments at NIST (SANS, reflectometer) and at Argonne National Lab (SCD). A polarizer built for the SCD instrument at Argonne is a prototype for the SCD instrument planned for the SNS.
