Design of gradient magnet system for cesium frequency standard

The design process and the magnetic measurements on a permanent magnet asymmetric dipole to be used for magnetic selection in a Cs beam frequency standard is presented. The design target is to create a magnetic induction gradient of 50 T/m in a zone extending 10 mm in width and 50 mm in length. The computer aided design process is outlined and design predictions are compared with measurements on the manufactured units. A process of automated optimization of the magnet pole piece profile in order to increase the Cs beam optics with particular attention to the transmission of atoms is presented and the first results obtained, leading to an increase of a factor of three in Cs transmission, are discussed.