US 11,835,477 B2
System and method for identifying nuclear threats
Massimo Morichi, Madison, CT (US)
Assigned to CAEN TECHNOLOGIES, INC., New York, NY (US)
Filed by CAEN TECHNOLOGIES, INC., New York, NY (US)
Filed on Jul. 14, 2021, as Appl. No. 17/375,743.
Claims priority of provisional application 63/051,408, filed on Jul. 14, 2020.
Prior Publication US 2022/0074876 A1, Mar. 10, 2022
Int. Cl. G01N 23/204 (2006.01); G01N 23/20 (2018.01); G01T 3/00 (2006.01); G01V 5/00 (2006.01); G01T 3/06 (2006.01)
CPC G01N 23/204 (2013.01) [G01N 23/20083 (2013.01); G01T 3/00 (2013.01); G01T 3/06 (2013.01); G01V 5/0091 (2013.01)] 10 Claims
OG exemplary drawing
 
1. A method for identifying a radioactive source comprising the steps of:
a) detecting, using a gamma spectroscopic Type I detector, gamma emitting sources of said radioactive source;
b) detecting, using a gamma/neutron Type II detector, a plurality of impulses of said radioactive source, said plurality of impulses being associated with respective neutron emissions and gamma emissions;
c) identifying a first portion of said plurality of impulses associated with respective neutron emissions and a second portion of said plurality of impulses associated with respective gamma emissions, said step of identifying said first portion and said second portion of impulses including a calculation for each impulse of a respective total integral Ltot of the impulse, and further comprising the steps of:
d) determining a first number nn of impulses belonging to the first portion of said plurality of impulses and a second number nγ of impulses belonging to the second portion of said plurality of impulses;
e) calculating a first average value En and a second average value Eγ of the total integral Ltot, wherein En=ΣNn (Ltot/nn), and Eγ=Σnγ (Ltot/nγ);
f) calculating datum parx=nγ/nn and datum pary=Eγ/En;
g) identifying if the radioactive source belongs to a first group of neutron sources or to a second group of gammas sources by the data parx, pary;
h) if in step (g), the radioactive source belongs to the first group of neutron sources, identifying gamma sources detected with the first group of neutron sources using the Type I detector, through spectroscopy;
i) double confirming identification of the radioactive source of step (g) if both gamma and neutron sources are detected;
j) detecting a masking condition of neutrons in presence of gamma emissions, performed by merging results of the identification from the Type I detector with the results of the identification from the Type II detector; and
k) detecting and identifying gamma and neutron sources in presence of moderators and/or shielding materials through the Type II detector.