Compression of Polarized 3He

This article gives a status report on the polarized 3He target development work at Mainz. It is based on the optical pumping of the 3S1 state of 3He with subsequent metastability spin exchange to the ground state atoms. This pumping scheme is very efficient at 3He pressures of about 1 Torr; for high density targets, however, a mechanical compression of the polarized gas is needed in a second step. First results with a Toepler compression pump look promising and will be discussed in the following.