Electron equilibrium and confinement in a modified Penning trap and its application to Penning fusion

摘要

The Penning fusion concept is described. Recent theoretical work on eliminating limitations on thermonuclear gain (Q) associated with ion-ion collisions is reviewed. A critical issue identified is the demonstration of the desired spherical electron configuration. Constraints on the electron distribution function are derived. A small combined trap (majority electrons), PFX-I (Penning Fusion eXperiment-Ions) has been constructed to study these issues. PFX-I is described. Two diagnostics described for electrons are destructive dumping of trapped electrons and noninvasive optical detection of impact induced fluorescence. Initial results of PFX-I operation at applied voltages V-0 up to 2 kV and magnetic fields B up to 1.14 T are described. Electron equilibrium is found to be consistent with trap filling to the space charge limit, with inventory proportional to V-0 and independent of B. Electron confinement times range from 1 to 10 ms and are determined by neutral pressure. These results are interpreted and future directions sketched. (C) 2000 American Institute of Physics. [S1070-664X(00)93505-5]. [References: 25]