[en] Lyoluminescence is the light emitted when irradiated solid substances are dissolved. A large range of organic materials exhibit lyoluminescence, among the more sensitive of which are monosaccharides and amino acids. A dose response curve for mannose (C₆H₁₂O₆) and an example of lyoluminescence apparatus are illustrated. The principle advantage of lyoluminescence dosimetry is that lyoluminescent phosphors may be used which closely approximate the chemical composition of tissue. Therefore all radiation fields KERMA in the phosphor approximates KERMA in tissue, and by design of dosimeter there will be a similar correspondence for absorbed dose. There are indications that the light conversion efficiency of lyoluminescent phosphors is not as dependent on LET as observed for thermoluminescent phosphors, and the possibility exists therefore, of an approximate tissue equivalent response in neutron and mixed radiation fields

[en] The paper discusses: the field of application for tissue-equivalent detectors, and the composition of standard human tissue, tissue-equivalent plastics, gases and scintillators, and gives examples of tissue-equivalent detectors. (author)

[en] A new working-area monitor based on a tissue equivalent, low-pressure proportional counter (TEPC) has been designed and constructed, which hereafter is referred to as the Juelich counter. The detector was optimized with regard to it's wall thickness to match the ambient dose equivalent H^*(10), i.e. the dose equivalent at 10mm depth in the ICRU sphere. The dimensions of the counter were chosen so that the sensitivity of the counter meets the desired specifications for area monitoring. In order to cover a dynamic range of about six decades in lineal energy, y, a nonlinear amplifying system was developed. The calculated response of the Juelich counter, with respect to H^*(10) as a function of incident neutron energy, is compared to experimental results. Furthermore, the statistical precision of the integral readings of the Juelich, counter as a function of simulated diameter, has been estimated. 8 refs., 4 figs. (Author)

[en] A small scale neutron dosimetry intercomparison has been carried out to resolve the existing discrepancies, to determine possible operational errors and to obtain knowledge on detector characteristics. The results showed large discrepancies, emphasising the need for uniform procedures and techniques for measuring chamber response and for applying the appropriate corrections. (Auth./C.F.)

No abstract available

[en] Short communication

[en] The ICRP recommended a dose limitation system based on numerical evaluation of the dose equivalent to organs or tissues, H_T, which are used to calculate the effective dose, H_E, by weighting. The ICRU proposed new operational quantities accessible to measurement which are conservative with respect to these recommendations. The objective of this paper is to recall briefly the basic recommendations and to find out if radiation protection instruments presently used calibrated in terms of the previous quantities are capable to measure these new quantities. A dozen of practical cases are presented

No abstract available

[en] Gas amplification in tissue- and muscle-equivalent proportional counters and air was determined by a double parametrisation analytic technique. An expression for the Townsend ionisation coefficient was first fitted to the experimental data from various workers, for the single gas components of the mixtures, to obtain the relevant constants. The ionisation coefficients for the mixtures were obtained by appropriate scaling, which enabled important parameters for these coefficients to be determined. These were then used to evaluate the fundamental gas gain equation. The resulting data were again fitted with a three-parameter analytic formula. The gas gain data are compared with experimental values from some authors. The α/P data obtained for methane tissue-equivalent gas are also compared with those resulting from the use of the Boltzmann equation. A discussion of factors that may account for differences between theoretical and experimental gas gain data is also presented. (Author)

[en] Table sugar (sucrose) is a convenient, common, tissue-equivalent material suitable for electron spin resonance (ESR) dosimetry of ionising radiation. The simple free radical signal in irradiated sugar is stabilised if the sugar is made into pellets using an inert silicone elastomer (Dow Corning 732). Such pellets, which offer greater convenience and signal stability and reproducibility, have been prepared and tested for their radiation response, sensitivity and post-irradiation stability. Irradiated sugar is detectable at ≥0.1 Gy, the signal intensity is linear with dose, and the fading of the signal, post-irradiation, is minimal for samples kept under ambient conditions. These pellets themselves, given sufficient post-irradiation signal stability, may be useful for environmental monitoring to determine long-term exposures in remote areas or at strategic locations. (Author)