Measurement of Cs-buffer gas collisional frequency shift using CPT pulsed clock

In this paper we present separate measurements of the temperature coefficients of the Cs clock frequency shift caused by Cs-buffer gas (Ne, Ar, N2) collisions, using the CPT interaction. The setup is based on the combination of two original techniques: double-lambda scheme of CPT-resonance excitation and a temporal Ramsey interrogation technique. The measured pressure coefficients and linear temperature coefficients are in good agreement with previously published values. For the first time the quadratic temperature coefficients for Ne and N2 have been measured for the Cs clock transition. For Ar this coefficient is much smaller and an upper limit is given.