Ionization chamber measurements of the half-lives of 24Na, 42K, 76As and 198Au

Believable Statements of Uncertainty and Believable Science

Nearly fifty years ago, two landmark papers appeared that should have cured the problem of ambiguous uncertainty statements in published data. Eisenhart's paper in Science called for statistically meaningful numbers, and Currie's Analytical Chemistry paper revealed the wide range in common definitions of detection limit. Confusion and worse can result when uncertainties are misinterpreted or ignored. The recent stories of cold fusion, variable radioactive decay, and piezonuclear reactions provide cautionary examples in which prior probability has been neglected. We show examples from our laboratory and others to illustrate the fact that uncertainty depends on both statistical and scientific judgment.

Evaluation of half-life of 198Au

The half-life of the important radioisotope (198)Au is evaluated by using several different statistical methods, such as weighted mean (WM), limitation of statistical weights method (LWM), normalized residuals method (NRM), Rajeval technique (RT), Bootstrap median (BM) and Mandel-Paule method (MP). After comparing and analyzing the results from these methods, a final value of 2.6948±0.0012d is recommended based on the stability and sensitivity of the methods and the resulting uncertainties.

Nuclear decay data: Observations and reflections

Decay data constitute an important feature of nuclear physics that plays a significant role in the various work programmes of members and associates of the International Committee for Radionuclide Metrology (ICRM). At the invitation of the ICRM, a review has been undertaken with the joint aims of emphasising decay-data achievements over the previous 10 years, and highlighting inadequacies that remain to be addressed in the future.