An analysis of major frequency shifts in the LPTF optically pumped primary frequency standard

An analysis of the major frequency shifts of our optically pumped cesium beam primary frequency standard is presented, together with a description of the most relevant characteristics of the device. The short term frequency stability was measured against a hydrogen maser. The square root of the Allan variance (/spl sigma//sub y/(/spl tau/) is at present 5.8.10/sup /spl minus/13//spl tau//sup /spl minus/1/2/, with a flicker level at 3.3.10/sup /spl minus/15/. This extremely good frequency stability enables a highly precise analysis of the most important systematic frequency shifts to be performed in a short time. Our first accuracy evaluation results in an uncertainty (1/spl sigma/) of 1.1.10/sup /spl minus/13/.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>