Reply to Vargas and de Soto: On the determination of 223Ra and 224Ra from their daughter products in electrodeposited sources of radium

✍ Scribed by Gary J. Hancock; Paul Martin

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 188 KB
• Volume: 47
• Category: Article
• ISSN: 0969-8043
• DOI: 10.1016/0969-8043(95)00268-5

✦ Synopsis

In their letter entitled "On the determination of 223Ra and 224Ra from their daughter products in electrodeposited sources of radium", Vargas and de Soto 0995) used 222Rn retention measurements of an electrodeposited source to determine a diffusion factor, D, for 222Rn. Using this factor, they inferred that the loss of both 219Rn and 22°Rn by diffusion from the source is negligible due to their short half-lives. They concluded that no correction need be made for proportionally higher losses of 22°Rn relative to 219Rn when determining 223Ra and 224Ra activities on the source, as described in our paper (Hancock and Martin, 1991). If this were true, then 22JRa and 224Ra could be determined directly from the activities of their progeny on the source, greatly simplifying the analysis procedure.

However, their conclusion is not supported by our data, which included experimental measurements of the retention of 2t9Rn and 22°Rn. As discussed below, the calculations of Vargas and de Soto (1996) raise interesting questions regarding the distribution of radon atoms in thin radium sources.