Patent ID: 7105831
Filing Date: 2006-09-12
Classification: G01T,H01J

Abstract:
1. An ionized alpha particle detector for direct measurement of alpha activity in ambient air, comprising: a cylindrical open-air ionization chamber; a means for collecting ions is positioned within said ionization chamber; a means for charging is connected to a voltage source; said ionization chamber, having a cylindrical axis, a metal interior wall connected to said voltage source, an insulation layer, a plurality of apertures and an outer RF shield, permits said ambient air to circulate freely within said ionization chamber, said ambient air including a plurality of oxygen ions and a plurality of alpha particles; said charging means and said ion collection means create an electrical field; said charging means ionizes said plurality of alpha particles and said electrical field prevents said plurality of oxygen ions from attracting electrons away from said plurality of alpha particles and creating a plurality of unwanted negative ions; said charging means, having ionized said plurality of alpha particles, preserves said plurality of alpha particles and generates a plurality of alpha pulses; said ion collection means attracts said plurality of alpha pulses and sends an ion collection signal input to said charging means; and said charging means provides an alpha particle pulse count output to a means for recording alpha pulses, said alpha particle pulse count output, being directly proportional to a level of alpha particle intensity in said ambient air, is provided in units of disintegrations per minute per liter (dpm