A UHV compatible source for a highly polarized thermal atomic beam of radioactive Li-8

A beam of the radioactive isotope Li-8 is prepared at thermal velocities. T he nuclei are highly spin polarized by transverse optical pumping of the th ermal beam. The installation is ultra-high vacuum (UHV) compatible in a non -UHV accelerator environment. Since the atomic beam is used in a surface sc ience experiment, where contamination must be avoided, special emphasis is given to the vacuum coupling of the accelerator/Li-8 production/surface exp erimental areas. The atomic beam is produced by stopping the nuclear reacti on products and evaporating them again from high-temperature graphite. To e nhance the atomic beam, a novel tubular thermalizer is applied. The thermal polarized atomic beam intensity is approximately 5 x 10(8) atoms/s sr. (C) 2000 Elsevier Science B.V. All rights reserved.