Patent ID: 6822238
Filing Date: 2004-11-23
Classification: G01T,H01J

Abstract:
An instrument for monitoring alpha emitting sources on an item or location, the alpha emitting sources emitting alpha particles that produce ions, the instrument comprising:a housing bounding a chamber, an opening being formed on the chamber so as to provide fluid communication between the chamber and exterior of the housing; at least one electrode disposed in the chamber for discharging ions within the chamber; a monitor for monitoring the ions discharged in the chamber; and means for forming a seal between the housing and a portion of the item or location disposed exterior of the housing, the seal being adapted to bound a segment of the item or location such that alpha particles from the segment or ions produced by those alpha particles are free to be monitored in the chamber, the seal reducing the passage of ions from exterior of the seal into the chamber while enabling the housing or the item or location to freely move relative to the other, the means for forming a seal comprising an electric field, a magnetic field, or positive pressure within the chamber.