Half-life of Mn51
AbstractThe half-life of Mn51 was measured by serial gamma spectrometry of the 511-keV annihilation photon following decay by β+ emission. Data were collected every 100 seconds for 100,000–230,000 seconds within each measurement (n=4). The 511-keV incidence rate was calculated from the 511-keV spectral peak area and count duration, corrected for detector dead time and radioactive decay. Least-squares regression analysis was used to determine the half-life of Mn51 while accounting for the presence of background contaminants, notably Co55. The result was 45.59±0.07 min, which is the highest precision measurement to date and disagrees with the current Nuclear Data Sheets value by over 6σ.