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The light emitted when pion irradiated glucose is dissolved in luminol solution has been found to be proportional to the pion beam depth dose distribution in water as determined by a TE ionisation chamber. The lyoluminescence of glucose overlaps very closely with the response profile of the ionisation chamber to the 170 MeV/c Ir--mesons giving a Bragg peak to plateau ratio of 3 : 1. In comparison, the thermoluminescence response of LiF (TLD-700) to pions has been found to deviate significantly from this ratio. The close tissue equivalence of glucose, non-toxicity and its excellent lyoluminescent retention properties are important advantages over currently used dosemeters in clinical pion therapy, especially when direct in v i m measurements are considered.Pion doses ranging between 0.5 Gy (50 rad) and 30 Gy (3000 rad) were measured with an accuracy *s0/o and reproducibility 3-5%.

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PACS. 72.15R -Quantum localization. PACS. 05.45 -Theory and models of chaotic systems. Abstract. -The energy level separation distribution of a fermionic disordered many-particle system is studied. For a non-interacting system, a crossover is observed from a Wigner (GOE) distribution for the frst and second excitations to a different form which depends on the number of particles for low-lying excitations and then to a Poisson distribution for high excitations. This behaviour also holds for weakly interacting systems, while for stronger interactions a transition of the high excitations to a Wigner distribution is observed.