Tissue-equivalent proportional counters in a high-energy neutron field at CERN

Within the framework of a research program of the Commission of European Communities (CEC) the reference radiation facility at CERN provided recently a mixed high-energy radiation field simulating the one found at civil aviation altitudes of about 10 km. In order to calibrate radiation detectors and to investigate their response to high-energy neutrons a series of measurements using five different instruments equipped with Low Pressure Tissue-Equivalent Proportional Counter (TEPC) and one Recombination Chamber (REM-2) has been carried out. The reference radiation field at CERN was produced by reactions of a primary beam mixed of 2/3 protons and 1/3 pions with a copper target and moderated by a concrete shielding. The paper summarises the results obtained with the five TEPC instruments and the REM-2, and discusses their characteristics.