1-200 AMU TUNABLE PRETZEL MAGNET NOTCH-MASS-FILTER AND INJECTOR FOR TRACE-ELEMENT ACCELERATOR MASS-SPECTROMETRY

A novel recombinator and injector has been designed for the trace elem ent accelerator mass spectrometer (TEAMS) at the Naval Research Labora tory. It will allow parallel analysis of a broad range of impurities i n electronic, biological, and geological materials. The recombinator c onsists of a tunable Pretzel magnet that serves as a notch mass filter [1]. The mass filter has near-amu mass resolution over the range of 1 -200 amu for 40 keV ions. Masks positioned along the Pretzel's symmetr y axis block intense matrix-related beams, (e.g. Si, SiO, Si-3, etc.) while passing beams of interest into the accelerator. The primary and secondary columns of a Physical Electronics model 6300 quadrupole seco ndary ion mass spectrometer (SIMS) form the key components of the ion source for the injector. This commercially proven instrument facilitat es depth profiling, imaging, and the analysis of both conducting and i nsulating substrates at pressures as low as 10(-10) Torr.