Magnetic moment ofβ-emittingSi27

Abstract

Polarized $\ensuremath{\beta}$-emitting $^{27}\mathrm{Si}$ nuclei (${I}^{\ensuremath{\pi}}={\frac{5}{2}}^{+}$, ${T}_{\frac{1}{2}}=4.1$ s) were produced in the reaction $^{27}\mathrm{Al}(\stackrel{\ensuremath{\rightarrow}}{\mathrm{p}},\mathrm{n})^{27}\mathrm{Si}$, ${E}_{p}=8.5$ MeV, in a thick single crystal of sapphire (${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$) which also served as host for the implanted $^{27}\mathrm{Si}$ nuclei. The polarization transferred to the $^{27}\mathrm{Si}$ nuclei was observed by measuring the $\ensuremath{\beta}$-decay asymmetry parallel to the proton polarization. The $^{27}\mathrm{Si}$ polarization was preserved during the nuclear lifetime by a magnetic holding field and by cooling the host crystal. The magnetic dipole moment of $^{27}\mathrm{Si}$ measured by a nuclear magnetic resonance technique, is $|\ensuremath{\mu}|=[0.8554(4)]{\ensuremath{\mu}}_{\mathrm{N}}$. This result includes the diamagnetic shielding correction.