2014 An atomic beam source for negative polarized lithium ions is operated at the Heidelberg EN-Tandem since 1974. A highly efficient surface ionizer is used. Vector and tensor polarized beams of 6Li (I = 1) and 7Li (I = 3/2) have been produced with currents up to 150 nA of Li3+ at the target. The second rank tensor polarization of both beams is calibrated absolutely. Preliminary results of producing a polarized 23Na beam are reported. REVUE DE PHYSIQUE APPLIQUEE TOME 12, OCTOBRE 1977, PAGE Sources for negative polarized light ions (p and d) are frequently used at Tandem accelerators as a tool in nuclear physics [1, 2]. Attempts to produce negative polarized beams of heavier particles have resulted in the Los Alamos source for tritium ions [3] and the Heidelberg source for alkali ions [4, 5] which FIG. 1. Source for negative polarized alkali ions. (*) On leave from the Instytut Badan Jadrowych, Warsaw. is subject of the present paper. An interesting aspect of polarized alkali beams is the large nuclear deformation of 7Li and 23Na which seems to be of great interest in heavy ion physics [6]. 1. Polarized atomic beam. The ion source shown in figure 1 makes use of the atomic beam FIG. 2. Hfs splitting in an external magnetic field for J = 1/2, 1= 3/2 (7Li, 23Na). The critical fields Be are given in table 1. Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/rphysap:0197700120100156700