Position sensitive detectors of thermal neutrons for radiography examinations of the closed objects, developed in Physical-technical Institute named after S.U.Umarov of the Academy of Sciences of the Republic of Tajikistan

Present article is devoted to position sensitive detectors of thermal neutrons for radiography examinations of the closed objects, which were developed in Physical-technical Institute named after S.U.Umarov. Neutron radiography methods, in particular transmission and emissive tomography can find applications at customs inspection of loads and baggage. Emissive tomography can applied to searching of fission isotopes. Transmission tomography can applied to searching of substances containing isotopes with the high cross-section of interacting with neutrons, and light substances - hydrogen or other. In a combination with X-ray scanners, presume to searches the fission isotopes, explosives, and drugs also. The important part of tomographs is a computerized position sensitive detectors of thermal neutrons. The paper presents works carried out about designing of multiwire proportional chambers with a ³He converter and a multistep avalanche chamber with a solid-state gadolinium converter. Both detectors intended for a position-sensitive registration of thermal neutrons at neutron radiographic investigation. (author)