Nuclear Spin Relaxation in Acetylene Gas

Proton spin–lattice relaxation times ${\mathrm{(T}}_1)$ have been measured in acetylene gas between −50 °C and 19°C using a CAT for signal averaging. $T_1$ was found to depend linearly on the number density $\rho$ in the range of these measurements (0.1 to 0.9 amagat). The temperature dependence of the ratio $T_1\mathrm{/\rho }$ indicates that the spin–rotational interaction provides the dominant relaxation mechanism. Cross sections for the transfer of angular momentum are presented.