Table 12.
Summary of half-lives determined in this study. For the NIST HPGe half-lives, the fits performed using Genie, 2000 were used to calculate the half-lives for each gamma-ray emission and the summation of all three. For both NPL and NIST, the reported half-life of 224Ra by HPGe was taken from the summation of the net peak areas of the three gamma-ray emissions analyzed. The uncertainty on the final NPL and NIST HPGe half-life is the combined standard uncertainty of the components in Tables 10 and 13. The “final” half-lives are given in bold.
| Line/keV | Fit | T1/2/d | uc/d | |
|---|---|---|---|---|
| NIST - IC | 3.6321 | 0.0028 | ||
|
| ||||
| NIST - HPGe | 238 | Genie (2000) | 3.6327 | 0.0027 |
| 241 | 3.6317 | 0.0035 | ||
| 583 | 3.6307 | 0.0028 | ||
| Σ238,241,583 | 3.6323 | 0.0027 | ||
|
|
|
|||
| NPL - HPGe | Σ238,241 | LET + HET | 3.6269 | 0.0048 |
| 583 | 3.6235 | 0.0048 | ||
| Σ238,241,583 | 3.6262 | 0.0048 | ||