Handheld isotope identification system

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,

b. a container pressurized with ultra-pure nitrogen, said high-purity germanium crystal located within said container, and

c. a cryostat with a vacuum within, where said container is located within said cryostat.

2. 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,

b. a shield detector, used to reduce Compton scattering effect, secured over said high-purity germanium crystal, and

c. 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.

3. The detector apparatus according to claim 2 , further comprising,

d. a container pressurized with ultra-pure nitrogen, said high-purity germanium crystal located within said container, and

e. a cryostat with a vacuum within, where said container is located within said cryostat.

4. The detector apparatus according to claim 2 , where said shield detector incorporates aluminum and visco-elastic polymer as impact absorption materials to increase ruggedness of said detector.

5. The detector apparatus according to claim 2 , 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.