Activity ofN16andHe6

Abstract

An interrupted flow method of handling short lived gases is described. By use of the method, pure ${\mathrm{N}}^{16}$ and pure ${\mathrm{He}}^6$ are readily produced. Geiger counter measurements on the ${\mathrm{N}}^{16}$ give a period of 7.3±0.3 sec. Presence of gamma-rays having energy greater than 5 Mev is demonstrated with a cloud chamber and absorption measurements. A lower limit to the end point of the ${\mathrm{N}}^{16}$ spectrum is derived from absorption curves, and an upper limit fixed by excitation measurements. By taking into account the barrier of ${\mathrm{N}}^{16}$ against emission of a proton, and excluding the electron self-energy, the maximum electron energy of the decay may be set at 10±0.5 Mev. The electron absorption curves show the beta-spectrum to be complex with a softer component having an end point at approximately 4 Mev corresponding to decay to an excited state of ${\mathrm{O}}^{16}$ in the region of 6 Mev. The ${\mathrm{He}}^6$ period found is 0.85±0.05 sec., and its end point 3.5±0.6 Mev, in agreement with Bjerge and Bröstrum.