Ultra-low emissivity alpha-particle detection

New alpha counters make accurate measurements of low emissivity samples possible. Modeling results set lower limits for measurements at sea level of silicon substrates to about 0.3α khr-cm2. Our measurements demonstrate the effect of cosmic ray shielding on the measured alpha-particle emissivity. A few atoms of radon contamination can cause elevated emissivities many days after exposure. © 1963-2012 IEEE.