CONSTRUCTION OF A SELF-SUPPORTING TISSUE-EQUIVALENT DIVIDING WALL AND OPERATIONAL CHARACTERISTICS OF A COAXIAL DOUBLE-CYLINDRICAL TISSUE-EQUIVALENT PROPORTIONAL COUNTER

An additional feature incorporated in a coaxial double-cylindrical tissue-equivalent proportional counter is the presence of a common tissue-equivalent dividing wall between the inner and outer counters of thickness equivalent to the corresponding maximum range of protons at the energy of interest. By appropriate use of an anti-coincidence arrangement with the outer counter, the inner counter could be used to discriminate microdosimetric spectra of neutrons at the desired low energy range from those of the faster neutrons. The construction of an A-150 self-supporting tissue-equivalent dividing wall and an anti-coincidence unit are described. Some operational characteristic tests have been performed to determine the operation of the new microdosimeter.