Temperature dependence of the helium induced broadening and shift of the Rb D1 and D2 lines

Abstract

The rates for collisional broadening and shifting of the Rb D1 (52S1/2 – 52P1/2) and D2 (52S1/2 – 52P3/2) transition induced by 4He have been measured at elevated temperatures of 373–723 K. The shift coefficients exhibit an increase of 20% from 4.36 MHz/Torr to 5.35 MHz/Torr for the D1 line and an 80% increase from 0.42 MHz/Torr to 0.99 MHz/Torr for the D2 line over the observed temperature range. Broadening coefficients exhibit a 6% increase from 17.8 MHz/Torr to 18.9 MHz/Torr and 10% from 18.5 MHz/Torr to 20.5 MHz/Torr for the D1 and D2 lines, respectively. The experimental values agree well with prior reported values within the temperature overlap regions of T < 394 K. Comparison to prior predictions from the Anderson–Talman theory using spin orbit multi reference (SOCI) ab initio potentials are superior to quantum treatments involving Allard and Baranger coupling.