Patent Number: H00002356
Section: claims

1. In a toroidal fusion plasma device, including inner and outer confining walls, and a particle beam source for injecting a particle beam into said toroidal fusion plasma device, an arrangement for in-situ determination of species energy yields of said injected particle beam, said arrangement comprising: (a) beam stop means having a target surface, and predetermined geometry and material properties, said beam stop means positioned on said inner confining wall such that said injected particle beam is incident on said beam stop and said incident particle beam is elastic Rutherford backscattered by said beam stop; and  (b) particle energy analyzing means positioned on the outboard side of said toroidal fusion plasma device, for obtaining an energy yield characteristic response of said elastic Rutherford backscattered beam particles such that the species energy yields of said injected particle beam is determined from a Rutherford backscattering analysis.  (a) elastic Rutherford backscattering said particle beam by a beam stop, positioned on said inner confining wall, having a target surface and predetermined geometry and material properties;  (b) obtaining an energy yield characteristic response of said elastic Rutherford backscattered beam particles; and  (c) determining the species energy yields of said injected particle beam from a Rutherford backscattering analysis of the obtained energy yield characteristic response and said predetermined geometric and material properties of said beam stop. 2. In a toroidal fusion plasma device which includes inner and outer confining walls, and a particle beam source for injecting a particle beam into said toroidal fusion plasma device, a method for in-situ determination of species energy yields of said injected beam, said method comprising: 3. The arrangement of claim 1 wherein said characteristic response consists essentially of a near-surface approximation of the characteristic response of the back-scattering of said beam particles by said beam stop. 4. The arrangement of claim 1 wherein said particle energy analyzing means further comprises means for simultaneously detecting the energies of said backscattered beam particles corresponding to a plurality of target positions on said target surface from which said particle beam is backscattered. 5. The arrangement of claim 1 wherein said particle energy analyzing means comprises a charge-exchange analyzer which electrostatically determines the energy of said backscattered beam particles. 6. The arrangement of claim 1 wherein the toroidal fusion plasma device further includes inner wall armor and wherein said beam stop comprised said inner wall armor of a fusion plasma device.