PXAMS - projectile X-ray AMS: X-ray yields and applications

Characteristic X-rays have recently been explored as a method for the detection and identification of ions in accelerator mass spectrometry (AMS) [H. Artigalas et al., Nucl. Instr. and Meth. B 92 (1994) 227; M. Wagner et al., Nucl. Instr. and Meth. B 89 (1994) 266]. After analysis in the AMS spectrometer, the ions stop in an appropriately chosen target and the induced X-rays identify the ions by atomic number. For the application of AMS to higher mass isotopes, characteristic X-rays allow significantly better discrimination of competing atomic isobars than is possible using energy loss detectors. Characteristic X-rays also show promise as a convenient component in hybrid detection systems. Measurements of X-ray yields are presented for Si, Fe, Ni, Se, Mo, and Pd ions of 0.5-2 MeV/amu. The yields rise by more than a factor of 10 over this energy range, and approach 1 X-ray per incident ion at 2 MeV/amu for the lighter ions. Preliminary work on the application of PXAMS to the detection of 79Se is described. (orig.)