Patent Number: 
Section: claims

1. A system for scanning a moving target comprising:a scanning zone located between a radiation source and a radiation source detector;a first sensor located adjacent to the scanning zone for starting the scanning once the moving target has entered the scanning zone and stopping the scanning once the moving target has exited the scanning zone; anda shutter comprising at least one shielding block driven by a dual solenoid configuration, wherein the shutter is located near the radiation source, wherein the first sensor sends a signal to the shutter to open, allowing radiation to pass from the radiation source through the scanning zone when the moving target is present in the scanning zone and to close, stopping the emission of radiation, when the moving target is no longer present in the scanning zone. 2. The system in claim 1 wherein the first sensor distinguishes between a first portion of the moving target passing through the scanning zone and a second portion of moving target passing through the scanning zone, wherein the first portion of the moving target does not trigger the first sensor to initiate a scan and the second portion of the moving target does trigger the first sensor to initiate the scan. 3. The system in claim 1 wherein the radiation source emits gamma-rays and the radiation source detector detects gamma-rays. 4. The system in claim 1 wherein the radiation source detector includes at least one detector array including a plurality of gamma-ray detectors. 5. The system in claim 4 wherein the at least one detector array is comprised of 20-60 gamma-ray detectors. 6. The system in claim 4 wherein the gamma-ray detectors are scintillation counter-type detectors. 7. The system of claim 1 wherein the shutter fails-safe to a closed position. 8. The system of claim 1 wherein at least one radiation sensor senses radiation levels outside the scanning zone. 9. The system of claim 1 wherein the radiation from the radiation source is detected by the radiation source detector and is used to image the contents of the moving target using photon counting. 10. A method for scanning a moving target comprising:creating a scanning zone for the moving target to pass through, where the scanning zone is located between a radiation source and a radiation source detector;positioning a first sensor adjacent to the scanning zone for sensing when to start and stop the scanning process when a moving target has entered the scanning zone;sending a signal from the first sensor to a shutter when the moving target has entered the scanning zone, wherein the shutter comprises at least one shielding block driven by a dual solenoid configuration;opening the shutter to allow radiation from the radiation source to pass through the scanning zone when the moving target is present; andclosing the shutter to stop the emission of radiation when the moving target is no longer present in the scanning zone. 11. The method in claim 10 further comprising, distinguishing between a first portion of the moving target passing through the scanning zone and a second portion of the moving target passing through the scanning zone, wherein the first portion of the moving target does not trigger the first sensor to initiate the scan and the second portion of the moving target does trigger the first sensor to initiate the scan. 12. The method in claim 10 further comprising, emitting gamma rays from the radiation source towards the moving target and detecting gamma-rays that pass through the moving target. 13. The method of claim 10 further comprising, sensing radiation levels outside of the scanning zone. 14. The method of claim 10 further comprising, imaging the contents of the moving target using photon counting. 15. A system for scanning a moving target comprising:a scanning zone located between a radiation source and a radiation source detector, wherein the radiation from the radiation source is detected by the radiation source detector, further wherein the radiation source detector includes at least one detector array employing a plurality of scintillation counter-type, gamma-ray detectors;a first sensor located adjacent to the scanning zone for starting the scanning once the moving target has entered the scanning zone and stopping the scanning once the moving target has exited the scanning zone; anda shutter comprising at least one shielding block driven by a dual solenoid configuration, wherein the shutter is located near the radiation source, wherein the first sensor sends a signal to the shutter to open to allow radiation to pass from the radiation source through the scanning zone when the moving target is present in the scanning zone and to close, stopping the emission of radiation, when the moving target is no longer present in the scanning zone. 16. The system of claim 15 wherein the at least one detector array is coupled to a preamplifier within a 16-channel data processing circuit. 17. The system of claim 16 wherein the data processing circuit is coupled to a discriminator. 18. The system of claim 17 wherein the discriminator is coupled to a pulse generator that generates pulses for each photon received into the at least one detector array; further wherein the pulse generator is coupled to a line driver. 19. The system in claim 18 wherein a computer receives the pulses from the data processing circuit and the pulses are processed to generate an image of the moving target.