X-RAY METHOD FOR DETECTION OF MATERIAL USING ITS ATOMIC NUMBER Russian patent published in 1997 - IPC

FIELD: inspection of luggage, baggage and other objects using radiation during custom or special examination, in particular, detection of materials which are prohibited for carriage by air or for board crossing (such as narcotics, poisons, explosive materials) in presence of different enclosures inside object to be tested. SUBSTANCE: method involves exposition of tested object to X rays, detection of ray, which are passed from object, in two spectral regions with different effective power, detection of signals which are proportional to intensity of rays which are passed through background material and combination of background and tested material. Then method involves selection scaling function using absorption of rays by background material. Each point of this curve corresponds to intensity values of signal of greater effective power and intensity values of lesser effective power of rays which are passed through combination of material to be detected and scaling background material which is equivalent to background material of object with respect to signal intensity. Then method involves comparison of values of scaling function signals to values of detected recorded signals of absorption of combination of background material and material to be detected. If scaling function has signals which values are equal to values of detected signal, then atomic numbers of present material and material to be found are judged to be equal. Scaling functions are defined for same characteristics of receiver and emitter of X-ray equipment as for screening object to be detected. EFFECT: spectrum of X-rays and background material presence are taken into account. 2 cl, 1 tbl, 4 dwg