Patent ID: 8110807

Claim:
A radiation detector capable of detecting a radiation source at speed in commerce comprising: at least two passive neutron sensors for detecting neutrons comprising a means to send a signal indicating the presence of neutrons in excess of normal atmospheric neutrons; at least two passive gamma ray sensors for detecting gamma rays comprising a means to send a signal indicating the presence of gamma rays in excess of normal atmospheric gamma rays; at least two sensor aggregators for aggregating and processing the signals from the passive neutron sensor and the passive gamma ray sensor; a means for producing a pulse of monoenergetic gamma rays and low energy neutrons sufficient to induce a fissile reaction producing neutrons and gamma rays from the radiation source traveling at speed in commerce, wherein the pulse of monoenergetic gamma rays and low energy neutrons provides a timing marker which is used to turn on the passive gamma ray detector and the passive neutron detector after the pulse so as to avoid saturation and to enable measuring the spectrum of the fast neutrons using time of flight; and wherein the passive neutron sensor and passive gamma ray sensor detect the neutron and gamma ray product from the fissile reaction; wherein a first passive neutron sensor and a first passive gamma ray sensor are connected to a first sensor aggregator and the first passive neutron and gamma ray sensors and first sensor aggregator are positioned prior to the means for producing a pulse of monoenergetic gamma rays and low energy neutrons such that the first sensor aggregator activates the means for producing a pulse of monoenergetic gamma rays and low energy neutrons when a predetermined level of neutrons and gamma rays are sensed by the first passive neutron sensor and the first passive gamma ray sensor; and wherein a second passive neutron sensor and a second passive gamma ray sensor are connected to a second sensor aggregator and the second passive neutron and gamma ray sensors and second sensor aggregator are positioned after the means for producing a pulse of monoenergetic gamma rays and low energy neutrons such that the second passive neutron and gamma ray sensors can detect any neutrons and gamma rays resulting from the fissile reaction after activation of the means for producing a pulse of monoenergetic gamma rays and low energy neutrons.