Special state standard of absorbed dose unit of x-ray radiation with maximum photon energy from 3 to 9 fJ (20 to 60 keV)
The special State standard reproduces the absorbed dose unit of x-ray radiation in an absorber within the range from 1 to 5 J/kg. The unit is reproduced by calorimetric techniques which is the only method of direct and absolute measurement of absorbed radiation energy. In compliance with the ICRU recommendations, the absorber material is graphite. The block diagram of the standard is shown. The x-ray radiation source is an RUM-7 x-ray machine used in medical institutions for short-focus surface therapy. The standard includes a single and a double calorimeter for the reproduction of the absorbed dose unit of x-ray radiation. The absorbing blocks of the calorimeters consist of an absorber and two concentric shields for thermal insulation of the absorber, active thermostatic control, and to provide identical conditions in calibration and radiation heating. Thermistors are used as temperature sensors. Heaters mounted in the calorimeters are used for electrical calibration and for setting up the necessary temperature field. The absorber blocks are mounted in housings consisting of vacuum-tight chambers, passive thermal insulation, and jackets. (WHK)
- OSTI ID:
- 7326564
- Journal Information:
- Meas. Tech. (USSR) (Engl. Transl.); (United States), Vol. 19:3; Other Information: Translated from Izmer. Tekh.; 19: No. 3, 56-58(Mar 1976)
- Country of Publication:
- United States
- Language:
- English
Similar Records
Sci-Sat AM: Radiation Dosimetry and Practical Therapy Solutions - 09: Stability of a water calorimetry system as a primary standard for absorbed dose to water
Direct determination of dose-to-water using a water calorimeter