DESIGN AND FABRICATION OF RADIATION DOSIMETRY INSTRUMENTS FOR TISSUE EQUIVALENT PLASTIC MANIKINS
Abstract
An instrumentation system to measure the absorbed dose due to ionizing radiations was designed for use with a tissue-equivalent manikin in space flights. The ionization chambers described are fabricated from tissue-equivalent materials to match those of the manikin and conform in design to the Bragg-Gray principle. Experimental curves show saturation conditions, pressure exrapolations, and directional dependence. Further, the design has minimized directional dependence with average losses ranging from 5 to 20% due to shielding of the first-stage electronics, which have been incorporated directly with the ionization chamber. The electrical signal generated by the radiation absorbed dose rate as recorded by the chambers is then processed electronically and telemetered back to earth. The electronic instrumentation functions continuously over a dose range of 0.01 to 100 rads per hour and has a logarithmic response. The chambers are designed to be placed in the tissue-equivalent manikin at the following sites: femur, abdomen, mediastinum, humeri, and spinal column. Automatic calibration is provided for in both the femur and abdomen electronics. The calibration data were obtained by using the gamma rays emitted by cobalt-60.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1963
- Accession Number
- AD0405122
Entities
People
- Kay M. Hoalst
Organizations
- HRL Laboratories