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The article discusses preliminary observations on proton magnetic resonance in biological samples, examining the signals in various tissues. Higher proton signals were observed in fat, cartilage, and fibrous tissue, potentially due to proton binding in fatty acid chains and increased water viscosity. Proton relaxation time appeared shorter compared to water, and water exchange was studied using proton magnetic resonance in red blood cells.

Abstract: Diodes processed on n-type epitaxial silicon with a thickness of 25, 50 and 75μm had been irradiated with reactor neutrons and high-energy protons (24GeV/c) up to integrated fluences of Φ eq=1016 cm−2. Systematic experiments on radiation-induced damage effects revealed the following results: in contrast to standard and oxygen-enriched float zone (FZ) silicon devices no space charge sign inversion was observed after irradiation. It is shown that the radiation-generated concentration of deep acceptors, dominating the behavior of n-type FZ diodes, is compensated by creation of shallow donors. Thus a positive space charge is maintained throughout the irradiation up to the highest fluence and even during prolonged elevated-temperature annealing cycles. Defect analysis studies using thermally stimulated current measurements attribute the effect to a damage-induced shallow donor at E C−0.23eV. It is argued that, as in the case of thermal donors, oxygen dimers, out diffusing from the Cz substrate during the diode processing, are responsible precursers. Results from extensive annealing experiments at elevated temperatures are verified by comparison with prolonged room-temperature annealing. These results showed that in contrast to FZ detectors, which always have to be cooled, room-temperature storage during beam off periods of future elementary particle physics experiments would even be beneficial for n-type epi-silicon detectors. A dedicated experiment at CERN-PS had successfully proven this expectation. It was verified, that in such a scenario the depletion voltage for the epi-detector could always be kept at a moderate level throughout the full S-LHC operation (foreseen upgrade of the large hadron collider). Practically no difference with respect to FZ-silicon devices was found in the damage-induced bulk generation current. The charge trapping measured with 90Sr electrons (mip''s) is also almost identical to what was expected. A charge collection efficiency of 60% (2500e) in 50μm n-type epi-diodes after 24GeV/c proton irradiation with Φ eq=6.2×1015 cm−2 was reported recently, independent of the operating temperature down to −20°C. [Copyright &y& Elsevier]

Radiation damage effects in silicon detectors under severe hadron and gamma-irradiation are surveyed, focusing on bulk effects. Both macroscopic detector properties (reverse current, depletion voltage and charge collection) as also the underlying microscopic defect generation are covered. Basic results are taken from the work done in the CERN-RD48 (ROSE) collaboration updated by results of recent work. Preliminary studies on the use of dimerized float zone and Czochralski silicon as detector material show possible benefits. An essential progress in the understanding of the radiation-induced detector deterioration had recently been achieved in gamma irradiation, directly correlating defect analysis data with the macroscopic detector performance. [Copyright &y& Elsevier]

Diodes manufactured on a thin and highly doped epitaxial silicon layer grown on a Czochralski silicon substrate have been irradiated by high energy lithium ions in order to investigate the effects of high bulk damage levels. This information is useful for possible developments of pixel detectors in future very high luminosity colliders because these new devices present superior radiation hardness than nowadays silicon detectors. The reverse current increase, the variation of the depletion voltage, and their annealing characteristics, as well as the charge collection properties, are presented and discussed. [ABSTRACT FROM AUTHOR]