85 research outputs found

    New technique for measuring photonuclear cross sections and its applications to the CU-63(y,n)CU-62 and C-12(y,n)C-11 reactions

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    A new technique for the determination of photonuclear cross sections is described in detail. It was applied to the CU-63(y,n)CU-62 and C-12(y,n)C-11 reactions from thresholds up to 60 Mev. The results obtained are consistent and are in good agreement with results obtained by different methods (1,2)

    Cloud chamber identification of photodeuterons from copper

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    Evidence has been reported (1,2) for the production of deuterons in the disintegration of copper and sulfur by bromsstrahlung before 24 Mev. energy. In the more direct of these investigations (1), the presence of a deuteron group was inferred on the basis of range and grain-density measurement in nuclear emulsions, and led to a ratio of photodeuterons to photoprotons cited as 0.31 for copper. Due to the bearing which such a large deuteron group must have on the theory of photonuclear processes, an independent investigation of the photodeuteron yield from copper was undertaken

    Cloud chamber measurement of electron pairs for determination of synchrotron spectrum

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    The x-ray spectrum of the Iowa State College synchrotron operating at 65 Mev. has been measured. The method consisted of the observation, in a magnetic cloud chamber, of the momentum of each member of electron pairs produced in the air filling of the chamber. Using the theoretical values of cross section for pair production and the results of recent experiments, the energy spectrum of the x-ray quanta was computed. Due to the pronounced forward directional characteristic of electron pairs produced at extreme relativistic energies, discrimination of one energy region with respect to another was avoided and no solid angle corrections were necessary . The results are in agreement with the energy spectrum predicted by the Bethe-Heitler theory

    Radiations of certain synchrotron-induced radioactivities

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    This work has born out the usefulness of scintillation counter techniques in connection with radioactivities produced by synchrotron irradiation. The activity of the sources produced has been ample for obtaining good statistical accuracy in short counting periods

    A Method for Static-Field Compression in an Electron-Ring Accelerator

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    The Disintegration of Praseodymium 142

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    The radiations from Pr-142 have been examined with a thin lens spectrometer. One gamma-ray was found having an energy of 1.576 Mev. The beta-spectrum is complex, the two groups observed having maximum kinetic energies of 2.154 Mev and 0.636 Mev. It is suggested that the high energy beta-group gives a transition to the ground state of Nd-142 and that the gamma-ray follows the low energy beta-transition. The half-life was found to be 19.1 hr. The electron distribution produced by bremsstrahlung, due to the absorption of the beta-rays, was observed

    Education and older adults at the University of the Third Age

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    This article reports a critical analysis of older adult education in Malta. In educational gerontology, a critical perspective demands the exposure of how relations of power and inequality, in their myriad forms, combinations, and complexities, are manifest in late-life learning initiatives. Fieldwork conducted at the University of the Third Age (UTA) in Malta uncovered the political nature of elder-learning, especially with respect to three intersecting lines of inequality - namely, positive aging, elitism, and gender. A cautionary note is, therefore, warranted at the dominant positive interpretations of UTAs since late-life learning, as any other education activity, is not politically neutral.peer-reviewe
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