Patent Number: 
Section: claims

1. A radiation-monitoring diagnostic hodoscope system for monitoring or measuring a radiation source or radiation sources from a target location, said system comprising:A) at least one pair of radiation-monitoring hodoscope units, each unit of each pair:) being adapted to detect gamma or neutron or gamma and neutron radiation in a limited radiation beam of less than 50 degrees defming a field of view and2) being positioned so that their beams overlap in a region containing all or a part of the target location, and comprising:1) a collimating means adapted to identify said limited radiation beam and2) at least one radiation detector adapted to produce electrical signals corresponding to intensities of gamma and or neutron radiation in said limited radiation beam;B) a computer processor programmed with an algorithm adapted to examine the data recorded by the at least two hodoscope units so as to determine the correlation of the recorded data so as to estimate the extent to which the radiation source or sources originate in the overlap region. 2. The system as in claim 1, wherein each pair of units are positioned so that their fields of view are orthogonal to each other. 3. The system as in claim 1, wherein each pair of units are positioned so that their fields of view are approximately orthogonal to each other. 4. The system as in claim 1, wherein the fields of view of each unit in each pair of units define a center line and the center lines define an angle, originating at a central location in the target region, of less than 30 degrees. 5. The system as in claim 1, wherein the system is adapted for used in circumstances wherein the fields of view include background radiation sources from regions outside the target location. 6. The system as in claim 5, wherein the background radiation detected is large compared to the radiation detected from the target region. 7. The system as in claim 6, wherein the at least one pair of detectors are adapted to record radiation in counts per interval for a series of intervals. 8. The system as in claim 6, wherein the algorithm is adapted to use an analysis of covariance technique to determine to correlation of the data from the two detectors. 9. The system as in claim 8, wherein analysis technique includes Ftest analysis of covariance statistical concepts. 10. The system as in claim 1, wherein the system is a passive system adapted to monitor natural radioactive decay. 11. The system as in claim 1, wherein the system is an active system adapted to monitor radiation produced by activation of a material by neutron source of other source of radiation that originates outside the target region or by other forms of radiation excited by any type of external source. 12. The system as in claim 1, wherein the system is a scatter system adapted to monitor scattered radiation form a source that originates outside the target region. 13. The system as in claim 1, wherein the system is adapted to monitor regions at a nuclear reactor. 14. The system as in claim 1, wherein the system is adapted to monitor regions at a damaged nuclear reactor. 15. The system as in claim 1, wherein the system is adapted to monitor a cargo container or portions of a cargo container.