Abstract:
:The poor agreement in the photon calibrations of tissue-equivalent ionisation chambers between different participants in two major neutron dosimetry intercomparisons is noted. The methods of converting measurements made with a calibrated secondary standard exposure meter to the absorbed dose in the wall of a tissue-equivalent chamber are discussed. Calibrations of a TE ionisation chamber were made in five photon beams (250 kV, 300 kV, 137Cs, 60Co and 4 MV) and the different calibration factors were compared both for in-air and in-phantom measurements. Good agreement was found in these factors provided that allowance was made for the attenuation and scattering in the wall and build-up cap of the TE chamber for the in-air measurements, and that revised values of C lambda were used for the in-phantom measurements at the two higher energies.
journal_name
Phys Med Bioljournal_title
Physics in medicine and biologyauthors
Williams JR,Greening JRdoi
10.1088/0031-9155/25/2/002subject
Has Abstractpub_date
1980-03-01 00:00:00pages
215-24issue
2eissn
0031-9155issn
1361-6560journal_volume
25pub_type
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