Pressure broadening and shift of the rubidium D1 transition and potassium D2 transitions by various gases with comparison to other alkali rates

•Measured unknown broadening and shifts rates for the alkali D1 and D2 transitions.•Provided a comparison between the broadening cross-sections for all alkali.•Improved the fidelity of the measurement of the broadening and shift rates.•Revealed possible discrepancies on rates associated with the potassium transitions.

The pressure broadening and shift rates for the K D2 (4P3/22←4S1/22) transition with N2, CH4, C2H6, C3H8, n-C4H10, and the noble gases were obtained for pressures up to 80 Torr and at a temperature of 55 °C by means of laser absorption spectroscopy. Additionally, the broadening and shift rates for the Rb D1 (5P1/22←5S1/22) transition for He, CH4, C2H6, C3H8, and n-C4H10 were obtained using the same techniques and under similar conditions. The K D2 collisional broadening rate, γL, for He, Ne, Ar, Kr, Xe, N2, CH4, C2H6, C3H8, and n-C4H10 are 19.84, 8.88, 18.65, 19.17, 22.19, 18.98, 27.78, 27.60, 27.70, and 33.48 MHz/Torr, respectively. The uncertainty in the broadening rates is typically less than 2.1%. The corresponding pressure induced shift rates, δ, are 0.52, −2.06, −5.52, −5.42, −7.01, −5.66, −8.38, −8.04, −9.22, and −9.37 MHz/Torr with an uncertainty of less than 1.8%. The Rb D1 collisional broadening rates for He, CH4, C2H6, C3H8, and n-C4H10 are 20.80, 32.78, 30.49, 33.05, and 29.61 with uncertainties typically less than 2.2%. The collisional shift rates for the Rb D1 transition are 5.80, −6.96, −7.88, −8.61, and −9.43 with uncertainties on the order of 1.1%. A comparison with the other alkali broadening and shift cross-sections is presented.