Dependence of Neutron/Proton Production Rate on Discharged Current in Spherical Inertial Electrostatic Confinement Plasmas
T.Matsuo, H.Matsuura, Y.Nakao and K.Kudo
Department of Applied Quantum Physics and Nuclear Engineering,
The spherical inertial electrostatic confinement (SIEC) is a concept for electrostatically confining high-energy fuel ions in potential well. In ideal SIEC plasmas, the ions converge toward the center of the device, and their space charge forms a virtual anode. The cold electrons emitted from the cathode also converge toward the virtual anode, and are thought to create a virtual cathode inside the virtual anode. So far, neutrons (protons) more than 108 n/s produced by D(d,n)3He (3He(d,p)4He) reactions have been observed on several devices. In parallel with the neutron/proton production, in some devices, the double peak in radial profile of the neutron/proton production rate was measured. On the other hand, in recent experiment using a spherical glow discharge as ion source, an operation mode in which the neutron production rate increases in proportion to 1.3-2.0th power of the discharged current was observed. To improve further the device performance, it is important to understand the physics of the SIEC plasmas. We have previously developed an analysis model for deuterium-gas system[1,2], and have explained the above phenomena[3].
References
[1] H.Matsuura, et al., Nuclear Fusion, 40 (2000) 1951.
[2] H.Matsuura, et al., Fusion Technology, 39 (2001) 1167. [3] H.Matsuura, et al., to be published in Nuclear Fusion.
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