Metallic capillary atom source for cross beam collision study

A metallic capillary atom beam source of simple and compact design is described. As the first test, thulium is evaporated and the cations which are mainly due to the thermal ionization are measured. The strongpoint of small power and high temperature of atom source is proved by temperature approaching 2 300 K corresponding to only 180 W power. The stability of thulium atom beam for two hours is better than 5 %. An atom beam density of about 8×1012cm－3 in the region at a distance 35 mm beyond the source exit is easily attained and can be sustained for about 8 hours. The test has testified that the metallic capillary atom beam source is suitable for crossed beam study of collision processes involving electrons, ions or photons where the collision products may be studied by methods based on