Characteristics of an Extrapolation Chamber FWT Type EIC.1 in Beta Radiation Fields

The characteristics of an extrapolation chamber FWT type EIC.1 have been determined to aid its utilisation as a transfer instrument for the characterisation of beta radiation field in terms of absorbed dose in tissue. This detector, made of A-150 tissue-equivalent material, is fitted with a window 7 mg.cm-2 thick. It can be used either with ambient air or with a tissue-equivalent gas flow. Some changes have been made to the commercial model (alteration of the variable spacing of the thickness of the cavity, and of the circuit of gas flow) so that it could be used correctly for low energy radiation.