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Characteristics of a RF-Driven Ion Source for a Neutron Generator Used For Associated Particle Imaging

Description: We present recent work on a prototype compact neutron generator for associated particle imaging (API). API uses alpha particles that are produced simultaneously with neutrons in the deuterium-tritium (2D(3T,n)4 alpha) fusion reaction to determine the direction of the neutrons upon exiting the reaction. This method determines the spatial position of each neutron interaction and requires the neutrons to be generated from a small spot in order to achieve high spatial resolution. The ion source for API is designed to produce a focused ion beam with a beam spot diameter of 1-mm or less on the target. We use an axial type neutron generator with a predicted neutron yield of 108 n/s for a 50 muA D/T ion beam current accelerated to 80 kV. The generator utilizes a RF planar spiral antenna at 13.56 MHz to create a highly efficient inductively-coupled plasma at the ion source. Experimental results show that beams with an atomic ion fraction of over 80percent can be obtained while utilizing only 100 watts of RF power in the ion source. A single acceleration gap with a secondary electron suppression electrode is used in the tube. Experimental results, such as the current density, atomic ion fraction, electron temperature, and electron density, from ion source testing will be discussed.
Date: August 8, 2008
Creator: Wu, Ying; Hurley, John P.; Ji, Qing; Kwan, Joe & Leung, Ka-Ngo
Partner: UNT Libraries Government Documents Department

Recent results in the theory of the three-nucleon systems

Description: This paper concentrates on calculational results obtained by the Los Alamos-Iowa Faddeev group and on related calculations. Most of the interest of this group has centered on the Helium 3 and Hydrogen 3 ground states, including the effects of the Coulomb interactions between the two protons in Helium 3. Recent progress in treating the alpha particle is reported and zero energy n-d and p-d scattering and an improved understanding of the scattering lengths for these systems are also discussed. Simple physical pictures for these results are presented where possible. 54 refs., 9 figs. (DWL)
Date: June 1, 1987
Creator: Friar, J.L.
Partner: UNT Libraries Government Documents Department