Non-Neutral Plasma Research at BYU and the Radioactive Decay of Beryllium-7

Bryan Peterson
Brigham Young University
Department of Physics and Astronomy


There are about 95 radioactive isotopes that decay exclusively through electron capture.  It should be possible to modify the decay rate of such an isotope if we can change the electron density in the vicinity of the nucleus.  Beryllium-7 has the distinction of being the lightest such isotope and, since it has only 4 electrons, its rate of decay would have the greatest sensitivity to modifications in the electron configuration.  It has been found that the decay rate can be measurably modified by such changes as chemical bonding, the application of high pressure, and by embedding the atom in various bulk materials.  In each of these cases the exact electron configuration is not known.  We are currently working to measure the decay rate of singly-ionized Be-7 to determine the rate when the electron configuration is well known.  A non-neutral plasma is an ideal environment for this measurement.  I will discuss how a non-neutral plasma is confined and some of the characteristics that make it ideal for this measurement.  I will also describe where Be-7 occurs naturally, how it is formed, and some of the unique applications and characteristics of this material.  Finally I will review the current state of our effort to determine the decay rate of Be-7 and what we may be able to learn from this measurement.