Accelerator mass spectrometry at the University of North Texas

An accelerator mass spectrometry system designed for analysis of electronic materials is being developed and installed on the University of North Texas 3 MV tandem accelerator National Electrostatics Corporation 9-SDH). High-resolution magnetic (400 deflection, M/ΔM ≅ 350, maximum mass-energy product 69 MeV u) and electrostatic (450 deflection, E/q of 4.8 MeV, E/ΔE ≅ 730) analysis, coupled with a 1.5 m time-of-flight path and total energy detection (surface barrier detector) forms the basis of the detection system. In order to provide stable element detection capability at the parts-per-trillion level in electronic materials (Si, GaAs, HgCdTe), a custom ion source, incorporating mass analysis of the sputtering beam, ultraclean slits, low cross-contamination and UHV capability, is being constructed. (orig.)