Portal trace detection systems for detection of imbedded particles

Abstract

A portal trace detection apparatus is provided for detecting minute particles of interest, such as traces of narcotics, explosives and other contraband. The apparatus includes a portal through which a human suspect will pass. A detection apparatus is disposed at least partly in the ceiling of the portal, and hence above the human subject in the portal. Particles of interest will be entrained in the human thermal plume that exists in the boundary adjacent the suspect, and will flow upwardly from the suspect to the detection apparatus in the ceiling of the portal. The ceiling is coated with an anti-static material so that particles are more likely to flow towards the detector and less likely to be affixed electrostatically to the ceiling.

1 . A portal trace detection system comprising a portal having a plurality of sidewalls and a passage between the sidewalls, a ceiling connecting the sidewalls and disposed above the passage, a particle detection apparatus having an inlet in the ceiling and communicating with the passage for receiving air flowing upwardly in the portal and towards the ceiling, at least the surface of the ceiling facing into the passage comprising an anti-static material for reducing electrostatic accumulation of particles of interest on the ceiling.  
   
   
       2 . The portal trace diction system of  claim 1 , wherein the ceiling is formed from a plastic material coated with the anti-static material.  
   
   
       3 . The portal trace detection system of  claim 1 , wherein the ceiling is formed from the anti-static material.  
   
   
       4 . The portal trace detection system of  claim 1 , wherein the ceiling includes a concave surface facing into the passage.  
   
   
       5 . The portal trace detections system of  claim 1 , further comprising a plurality of jets for directing air into the passage for dislodging particles from the suspect.  
   
   
       6 . A portal trace detection system comprising a portal having a plurality of sidewalls and a passage between the sidewalls, a ceiling connecting the sidewalls and disposed above the passage, a particle detection apparatus communicating with the passage for receiving air flowing adjacent to a suspect in the passage of the portal, at least selected surface areas of the portal facing into the passage comprising an anti-static material for reducing electrostatic accumulation of particles of interest on surfaces of the portal facing into the passage.  
   
   
       7 . The portal trace detection system of  claim 1 , wherein the anti-static material is on the ceiling.  
   
   
       8 . The portal trace detection system of  claim 6 , wherein the ceiling includes a concave surface facing into the portal.  
   
   
       9 . The portal trace detection system of  claim 7 , wherein the ceiling is formed from a plastic material coated with an anti-static material.  
   
   
       10 . The portal trace detection system of  claim 9 , wherein the detector has an inlet in the ceiling.