Radiative Orbital Electron Capture in Vanadium-49

The x-radiation and the continuous electromagnetic radiation accompanying orbital electron capture in vanadium-49 have been studied by means of an argon-methane proportional counter and a well-type sodium iodide scintillation spectrometer. The observed pulse-height distribution was corrected for background, energy resolution, escape of degraded radiation from the crystal, gamma-ray detection and geometrical efficiency of the crystal, and absorption of the radiation between the source and detector. The transition energy of the V⁴⁹ decay is 616±{}10 kev, giving a total disintegration energy of 621±{}10 kev. The half-life is measured as 327±{}20 days, giving a $logft=6.2$, which is consistent with other allowed spectra with initial and final states in the f7/2 shell.