A Potential High Energy Resolution Iodine Negative Ion Source,

Abstract

The dissociative attachment reaction e + HI to H + I(-) is suggested as a source of I(-) ions. The desirable characteristics of the source are: (1) large attachment cross section, (2) small value of the H/I mass ratio, (3) nearly thermoneutral attachment, and (4) insensitive to the electron beam energy spread. When formed from stationary HI, these factors combine to give an I(-) energy spread of 2-3 millivolts. The dominant I(-) spread results from the thermal motion of HI, and is estimated to be 0.03 - 0.06 eV, FWHM. By using the heavy I(-) ion to bombard a stationary light target molecule, a large difference in laboratory and center-of-mass (CM) energy scales further improves energy resolution and calibration. The reaction I(-) + H2 to H2(-) + I is suggested for measuring the electron affinity of H2. For this case, the energy scale compression factor is 64.5 and the energy spread in the CM system, due to the I(-) spread, is estimated to be the order of one millivolt. (Author)

Document Details

Document Type
Technical Report
Publication Date
Nov 01, 1970
Accession Number
AD0720871

Entities

People

  • Howard Myers
  • Ronald L. Cowperthwaite

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Attachment
  • Calibration
  • Charged Particles
  • Compression
  • Electron Beams
  • Electrons
  • Energy
  • High Energy
  • Ion Sources
  • Ions
  • Molecules
  • Stationary

Fields of Study

  • Physics

Readers

  • Molecular Photonics/Laser Physics
  • Plasma Physics.
  • Pulsed Power and Plasma Physics.

Technology Areas

  • Directed Energy
  • Directed Energy - Lasers
  • Microelectronics