FIG. 15.

Results of the MEOP rate equations obtained using the same computer code as in (Batz et al., 2011) for typical operating conditions: 0.5 mbar ³He gas, T = 293 K, B = 1 mT, n_m = 1.2 × 10¹⁰ cm⁻³, ${\gamma }_{\mathrm{r}}^{\mathrm{S}}={10}^3{\mathrm{s}}^{-1},{\gamma }_{\mathrm{r}}^{\mathrm{P}}=0.16\times {10}^7{\mathrm{s}}^{-1}$. Atoms of all velocity classes are pumped with the same rates γ_ij (see text). (a) Distributions of the 2³S populations a_i for C₈, σ₊ optical pumping and γ_ij = γ/10, γ, and 10γ (bars from left to right and from light grey to black in each group) Surrounding red boxes are the spin-temperature populations. (b) Computed absorption coefficients are plotted as functions of reduced pumping rates for C₈ and C₉ optical pumping and different nuclear polarizations (see legend). For C₉ the two pumping rates for the two pumped sublevels jointly scale with the pumping light intensity, with a fixed ratio T_1,18/T_2,17 = 3. Introducing T_ij in the horizontal scales makes the reduced pumping rates identically proportional to the pump intensity. (c) Differences between nuclear polarizations in the 2³S and ground states are plotted as a functions of P_He for C₈ and C₉ pumping and different reduced pumping rates (see legend)