Nuclear Magnetic Relaxation of 11B and F in BF3 Gas

The longitudinal nuclear magnetic relaxations of the ¹¹B and F nuclei in BF₃ gas have been measured as a function of pressure at temperatures of 270, 300, and 350°K, and the relaxation times $T_1$ have been determined as a function of density. The purpose of the investigation was to determine whether or not there is a steplike dependence of $T_1$ or $T_1\mathrm{\hspace{0.17em}/\hspace{0.17em}\rho }$ on density $\rho$ for nuclei relaxed by quadrupole interactions in gas molecules. The $T_1$ of ¹¹B was found to increase linearly with density at low densities, and less rapidly than linearly at high densities, but no evidence of a steplike dependence on density was found.