F19, Na23, and Al27(α, n) Reactions

Abstract

The ${\mathrm{F}}^{19}$, ${\mathrm{Na}}^{23}$, and ${\mathrm{Al}}^{27}(\alpha , n)$ yield curves are given from threshold to about 4 Mev. Convenient resonances for alpha particle energy calibration in these reactions and in the ${\mathrm{C}}^{13}(\alpha , n)$ reaction are pointed out. "Slow-fast" neutron data and $\gamma$ ray data for ${\mathrm{F}}^{19}(\alpha , n)$ agree with the proposed 593- and 666-kev ${\mathrm{Na}}^{22}$ levels. The ${\mathrm{Al}}^{26m}\left(228\mathrm{} \mathrm{kev}\right)$ $\beta$ activity was observed in the ${\mathrm{Na}}^{23}(\alpha , n)$ reaction. The neutron resonance absorption technique gave $Q=-1959\mathrm{}\pm 10$ kev for ${\mathrm{F}}^{19}(\alpha , n)$. The 32°±3° angle cut-off of ${\mathrm{Na}}^{23}(\alpha , n)$ neutrons at $T_{\alpha }=3492\mathrm{}\pm 3$ kev gave a $Q$ value of -2969±4 kev. The threshold for ${\mathrm{P}}^{30}$ $\beta$ activity gave $Q>~-2662\mathrm{}\pm 5$ kev for ${\mathrm{Al}}^{27}(\alpha , n)$.