skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Injector based on electric insulation for the controlled ballistic focusing of light ion beams

Journal Article · · J. Appl. Phys.; (United States)
DOI:https://doi.org/10.1063/1.329839· OSTI ID:6200554

An injector design is described which uses a space-charge-limited source of alkali ions and accelerates the ions through two stages of acceleration and slight deceleration stage (to retard the neutralizing electrons) before matched phase space neutralization with an electron reflex triode source occurs. For typical conditions of a 200-ns pulse and a 1-MeV 1-10 A/cm/sup 2/ lithium ion beam, computer simulation experiments demonstrate that 55% of the beam trajectories have an angular divergence less than 250 ..mu..rad (thereby meeting an order of magnitude more stringent constraint at more than an order of magnitude higher power density than any previous electrostatically focused injector design). The method of achieving the low angular divergence profile at readily attainable voltages of 200 kV, current densities of 150 mA/cm/sup 2/, and vacuum stresses of 50 kV/cm is described. By simply increasing the voltage towards 1 MV, state-of-the-art advances in all the parameter areas can be made without altering the angular divergence profile. Discussions of other issues, such as source temperature, neutralization, self-magnetic fields, and electrostatic field error contributions to the angular divergence are presented. Finally, the benefits of additional stages of acceleration (needed for future MeV operation) are disclosed and justified.

Research Organization:
Occidental Research Corporation, 2100 S. E. Main Street, Irvine, California 92713
OSTI ID:
6200554
Journal Information:
J. Appl. Phys.; (United States), Vol. 52:6
Country of Publication:
United States
Language:
English