Calorimetric Determination of the Mean β-Energy and Half-Life of Promethium-147¹

Abstract

Measurements of the decomposition pressure for the reaction ThN(s) = Th(l) + VsNsCg) in the temperature range 2416 to 2790°are described. ThN melts congruently at 2790 ± 30°under a nitrogen pressure somewhat less than 1 atm. The presence of Th02 as an impurity in the ThN was found to have a large effect on the melting point and decomposition pressure. The decomposition pressure -temperature relation for pure ThN is described by the equation log p (atm.

Classical radionuclidic calorimetry

“…In addition to the determination of the activity of radionuclides, calorimetry has had many other uses within the discipline of radioactivity. Only a few examples will be cited, but these applications include calorimetry's use for the determination of: half-lives, such as that for 3 [32]; alpha emission energies, such as for 239 Pu [35]; and burn-up of nuclear fuels [36,37]. For the past few decades, calorimetry has been mainly used for the assay of tritium and special nuclear materials in the nuclear-power and -weapons industries and for fusion technology [38][39][40][41].…”