Research on plane-parallel ionization chambers since the IAEA Code of Practice (TRS-277) was published in 1987 has expanded our knowledge on perturbation and other correction factors in ionization chamber dosimeter, and also constructional details of these chambers have been shown to be important. Different national organizations have published, or are in the process of publishing, recommendations on detailed procedures for the calibration and use of plane-parallel ionization chambers. An international working group was formed under the auspices of the IAEA, first to assess the status and validity of IAEA TRS-277, and second to develop an international Code of Practice for the calibration and use of plane-parallel ionization chambers in high-energy electron and photon beams. The purpose of this work is to describe the forthcoming Code of Practice. (author). 39 refs, 3 figs, 2 tabs.
Andreo, P;  Almond, P R;  Mattsson, O;  Nahum, A E;  Roos, M 
- Lunds Hospital, Lund (Sweden). Radiophysics Dept.
- J.G. Brown Cancer Center, Univ. of Lousville, Lousville, KY (United States). Dept. of Radiation Oncology
- Sahlgrenska Hospital, Gothenburg (Sweden). Dept. of Radiation Physics
- Royal Marsden Hospital, Sutton (United Kingdom). Joint Dept. of Physics
- Physikalisch-Technische Bundesanstalt, Braunschweig (Germany)