Electronic background rejection in a new ultra-low background alpha-particle counter

摘要: Abstract Low background alpha-particle (α) counting is required in the semiconductor industry, where α’s produce single event errors. Industry road maps call for measuring α emissivities at 0.0005 α/cm 2 /h, while current commercial counter backgrounds are 0.005 α/cm a factor of 10 too high. This paper shows that by designing an ionization chamber so tracks collected from sample have long risetimes those anode short risetimes, signal risetime analysis can distinguish emanation location within counter. Coupled with guard electrode to reject emitted sidewalls, method achieve approaching 0.0001 α/cm 20 lower.