Ultra-cold neutrons (UCN), neutrons with energies low enough to be confined by the Fermi potential in material bottles, are playing an increasing role in measurements of fundamental properties of the neutron. The ability to manipulate UCN with material guides and bottles, magnetic fields, and gravity can lead to experiments with lower systematic errors than have been obtained in experiments with cold neutron beams. The UCN densities provided by existing reactor sources limit these experiments. The promise of much higher densities from solid deuterium sources has led to proposed facilities coupled to both reactor and spallation neutron sources. In this paper we report on the performance of a prototype spallation neutron-driven solid deuterium source. This source produced bottled UCN densities of 145 +/-7 UCN/cm3, about three times greater than the largest bottled UCN densities previously reported. These results indicate that a production UCN source with substantially higher densities should be possible

Absolute differential cross sections for the elastic scattering of alpha particles by N 15 have been measured in a differentially-pumped gas scattering chamber. The measurements were made at center-of-mass angles of 169.1, 149.5, 140.8, 125.3, 90.0, and 70.0 degrees for alpha-particle energies from 1.75 to 5.50 Mev, corresponding to 5.37-to 8.33-Mev excitation of the compound nucleus F 19 . The experimental widths of the levels observed below approximately 3.5-Mev bombarding energy are generally narrow, in most cases less than 10 kev. Above 3.5 Mev a marked increase in the level width was observed. As a result of an analysis based on the Wigner-Eisenbud reaction theory, values of /, ir, E\, and Y\ 2 were assigned to 16 levels in F 19 .

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