Handheld isotope identification system

Abstract

A portable radiation detector using a high-purity germanium crystal as the sensing device. The crystal is fabricated such that it exhibits a length to width ratio greater than 1:1 and is oriented within the detector to receive radiation along the width of said crystal.

What is claimed is:  
     
         1 . A portable radiation detector, comprising: 
 a. a high-purity germanium crystal exhibiting a length to width ratio greater than 1:1 and oriented in said detector to receive radiation along the width of said crystal.    
     
     
         2 . The detector apparatus according to  claim 1 , said germanium crystal exhibiting a length to width ratio of 2:1.  
     
     
         3 . The detector apparatus according to  claim 1 , further including 
 a. at least two flanged mating elements to enclose said germanium crystal, and    b. an indium seal placed within said flange connections, to maintain near-zero leakage over a wide temperature range.    
     
     
         4 . The detector apparatus according to  claim 1 , further including, 
 a. a container holding said germanium crystal,    b. a mechanical sterling cycle cooler,    c. a copper braid connected to said container and said cooler, said copper braid attached to said container by a synthetic sapphire plate that conducts heat away from said container to said cooler while isolating electrical signals from said mechanical cooler to said container.    
     
     
         5 . The detector apparatus according to  claim 4 , further including, 
 a. a shield detector secured over said germanium detector used to reduce Compton scattering effect on said germanium detector and for use as a gross gamma ray detector,    b. a first He 3  neutron detector shielded by a neutron absorbing material and a second unshielded He 3  neutron detector, for determining a thickness of hydrogen polymer, water, or high explosive within a scanned item.    
     
     
         6 . The detector apparatus according to  claim 5 , where said shield detector incorporates aluminum and sorbothane as impact absorption materials to increase ruggedness of said detector.  
     
     
         7 . The detector apparatus according to  claim 5 , where said first He 3  neutron detector and said second He 3  neutron detector are incorporated into a carrying handle in order to further reduce detector size and increase portability.