Calibration of proportional counters in microdosimetry
Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. This paper discusses the corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is due to differences in W-value of the radiation used for calibration and the radiation for which microdosimetric measurements are made. Both propane and methane base tissue-equivalent (TE) gases are used in these counters. When calibrating the detectors, it is important to use the correct stopping power value for that gas. Deviations in y-bar/sub F/ and y-bar/sub D/ are calculated for /sup 60/Co using different extrapolation procedures from 0.15 keV/..mu..m to zero event size. These deviations can be as large as 30%. Advantages of reporting microdosimetric parameters such as y-bar/sub F/ and y-bar/sub D/ above a certain minimum cut-off are discussed.
- Research Organization:
- Brookhaven National Lab., Upton, NY (USA)
- DOE Contract Number:
- AC02-76CH00016
- OSTI ID:
- 6926135
- Report Number(s):
- BNL-31777; CONF-820931-5; ON: DE82022048; TRN: 82-023219
- Resource Relation:
- Conference: 8. symposium on microdosimetry, Julich, F.R. Germany, 27 Sep 1982
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
07 ISOTOPES AND RADIATION SOURCES
GAMMA RADIATION
MICRODOSIMETRY
PROPORTIONAL COUNTERS
CALIBRATION
COBALT 60
CORRECTIONS
METHANE
PROPANE
RADIATION DOSES
ALKANES
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
COBALT ISOTOPES
DOSES
DOSIMETRY
ELECTROMAGNETIC RADIATION
HYDROCARBONS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IONIZING RADIATIONS
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MEASURING INSTRUMENTS
MINUTES LIVING RADIOISOTOPES
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
RADIATION DETECTORS
RADIATIONS
RADIOISOTOPES
YEARS LIVING RADIOISOTOPES
655003* - Medical Physics- Dosimetry
655002 - Medical Physics- Radiation Source Calibration & Standardization