Frequency Dependence ofT1forHe3in SolidHe4

Measurements are reported of $T_1\left(\omega \right)$ for ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ impurity in solid ${}_{}{}^4{}_{}{}^{}\mathrm{He}$ at molar volume 21 ${\mathrm{cm}}^3$ and temperature 0.6 K. Data for fractional impurity concentrations $x_3$ of 1.0×${10}^{-3\mathrm{}}$, 0.5×${10}^{-3\mathrm{}}$, and 0.25×${10}^{-3\mathrm{}}$ show striking anomalies at about 1.3 and 2.6 MHz, superimposed on a background obeying $x_3{T}_1=1.3\mathrm{}\times {10}^{-2\mathrm{}} \exp (\frac{\omega }{7.4}\times {10}^6)$ sec. A theory is proposed which fits this background and yields a value for the ${}_{}{}^3{}_{}{}^{}\mathrm{He}$-${}_{}{}^4{}_{}{}^{}\mathrm{He}$ tunneling frequency of about 1 MHz. The anomalies are not fully explained.