Answer to Question #43 Submitted to "Ask the Experts"

Q

I am looking for a Web page or spreadsheet application for radioactive decays chains, specifically the activity concentrations of ²²²Rn and its progeny as a function of time.

A

Grove Engineering of Rockville, Maryland, has distributed a PC-based code called RADDECAY which includes decay chain information for hundreds of radionuclides. The code allows for calculation of decay product activities at any time after initial production of the parent. David Kocher, Ph.D. Oak Ridge National Laboratory I copied the following off the website for Grove Engineering. Gen Roessler, Editor HPS website RADIATION DECAY provides radioactive decay information for 497 radionuclides. Data provided include the half life, radioactive daughter nuclides, decay chain series, probabilities per decay, and decay product energies for alphas, betas, positrons, electrons, x rays, and photons. The radionuclide can be selected from an Alphabetical list, or selected from a Periodic Table. (These are available from the 'Select' item of the menu bar.) Full copying to clipboard and output to printer is supported. The radioactive elements can be searched to find an element that emits a particular photon. For example, say a spectrum gives two photon peaks at 150 keV and 420 keV. The radioactive elements can be searched for photons that give a 150 keV, then the previously found elements can be searched for the 420 keV photon. Hence spectrums can be matched to photon emitters. This program is essentially a Windows duplicate of the shareware DOS program RADDECAY.EXE. The initial program was written by: 1987 Grove Engineering, Inc. 15215 Shady Grove Rd., Suite 202, Rockville, MD 20850 301-258-2727