AMS with stable isotopes and primordial radionuclides for material analysis and background detection

摘要

For the ultrasensitive detection of stable isotopes and primordial radionuclides, a new ultra clean ion source (UCS) was developed at the accelerator laboratory in Garching. The produced ions are detected by an AMS system. The characteristics of the ultra clean source are: 1, a magnetically analyzed cesium sputter beam, 2, an ultra high vacuum (10~(-10) hPa) in the sputter chamber and a large volume of the sputter chamber to supporess cross contamination of the samples, and e, the use of supra pure metals for slits, electrodes and the target holder. The new ion source is installed on a new negative ion injector of the Munich MP tandem accelerator. At the high-energy side of the tandem, the secondary ions are detected by a Bragg ionization chamber. The first experiments were performanced in order to determine disturbing ~(40)K background in cryogenic sapphire detectors which are used for the detection of dark matter particles. Impurities in semiconductor materials have also been investigated.