Tests of nuclear half-lives as a function of the host medium and temperature: refutation of recent claims

When radioactive isotopes that decay by alpha, beta(-), beta(+) and electron-capture transitions are placed in a conducting host material, it has recently been claimed that their half-lives show a significant dependence on temperature-up to a 6% difference between room temperature and 12K. We have refuted two of these claims by measuring: (1) the beta(-) decay of (198)Au in gold, for which we find the half life to be the same within 0.04% between room temperature and 19K; and (2) the electron-capture decay of (97)Ru in ruthenium, for which we find any half-life difference to be <0.1%.