Printer Friendly

Unraveling the details of beta decay.

Many radioactive atoms decay by emitting beta particles, or electrons, thereby transforming themselves into new elements. For each atomic isotope, these beta particles emerge from nuclei with a characteristic distribution, or spectrum, of energies. Theorist Steven E. Koonin of the California Institute of Technology in Pasadena has now shown that electrons surrounding an atomic nucleus have a discernible but hitherto overlooked effect on a given radioactive isotope's beta-decay spectrum. Reporting in the Dec. 12 NATURE, he notes that this newly identified quantum-mechanical effect would typically produce a sequence of minute oscillations that slightly distort a low-energy beta-particle spectrum.

The existence of this quantum effect and the "fine structure" it produces in a spectrum may have important consequences in the search for heavy neutrinos (SN:4/27/91, p.260). Each beta decay produces not only an electron but also an invisible neutrino, and researchers have long relied on measurements of beta-decay spectra for information about the accompanying neutrinos. Koonin cautions that the presence of fine structure could change the interpretation of certain experiments designed to search for heavy neutrinos.

This characteristic spectral fingerprint may also serve as a means of gleaning information about the chemical, or electronic, environment surrounding an atomic nucleus, Koonin suggests. For example, he says, by precisely measuring the shape and size of the fine-structure spectrum resulting from tritium (a radioactive hydrogen isotope) embedded in a crystal, researchers could map the location of hydrogen in solids.
COPYRIGHT 1992 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1992, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Title Annotation:beta particles
Publication:Science News
Date:Jan 11, 1992
Previous Article:Asbestos linked to colon polyps.
Next Article:Recipe for liquid-nitrogen SQUID.

Related Articles
Neutrino mass: a tritium disagreement.
Double-beta decay caught in the act.
Double or nothing: physicists bet the neutrino's its own eerie twin.
Radiative corrections for neutron decay and search for new physics.
On the measurement of the neutron lifetime using ultracold neutrons in a vacuum quadrupole trap.
On the measurement of the electron-neutrino correlation in neutron beta decay.
Radiative neutron [beta]-decay in effective field theory.
Search for radiative [beta]-decay of the free neutron.
Detecting the radiative decay mode of the neutron.
Monte Carlo study of the abBA experiment: detector response and physics analysis.

Terms of use | Privacy policy | Copyright © 2020 Farlex, Inc. | Feedback | For webmasters