Title :
H- temperature measurements by a slit diagnostic technique
Author :
Sherman, Joseph D. ; Smith, H. Vernon, Jr. ; Geisik, Carl ; Allison, Paul
Author_Institution :
Los Alamos Nat. Lab., NM, USA
Abstract :
H/sup -/ ion beams are extracted at 5-25 kV from a long, narrow slit on a Penning surface-plasma source (the 8X source). The extraction geometry produces negligible transverse electric field (focusing effects) along the slit length. Therefore, the ion angular spread reflects the distribution of ion energies at the plasma surface. The angular distributions are measured with an electric-sweep emittance scanner whose slits are oriented normal to the long dimension of the emission slit. The nearly Maxwellian angular distributions measured over the central portions of the ribbon beam give kT(H/sup -/) of 0.1 eV to 0.2 eV for a 2-A DC discharge and 0.8 eV to 1.0 eV for 350-A to 500-A pulsed discharges. This diagnostic technique has sufficient position resolution to allow measurement of the kT(H/sup -/) spatial distributions. It also allows study of the kT(H/sup -/) dependencies on ion source parameters (e.g. increasing the H/sub 2/ gas flow lowers kT(H/sup -/)).<>
Keywords :
hydrogen ions; ion sources; plasma devices; plasma diagnostics; 8X source; Penning surface-plasma source; angular spread; diagnostic technique; electric-sweep emittance scanner; extraction geometry; focusing effects; position resolution; ribbon beam; Electric variables measurement; Fault location; Geometry; Ion beams; Particle beam measurements; Plasma measurements; Plasma sources; Position measurement; Pulse measurements; Spatial resolution;
Conference_Titel :
Particle Accelerator Conference, 1991. Accelerator Science and Technology., Conference Record of the 1991 IEEE
Conference_Location :
San Francisco, CA, USA
Print_ISBN :
0-7803-0135-8
DOI :
10.1109/PAC.1991.164874
