Beam-Injector Experiments

Over the next two years, the HIF-VNL will carry out a series of experiments with high-current-density sources that could lead to brighter, more durable, and more compact injectors.  The two source geometries now being studied are large-area sources and compact sources that merge many small beamlets into a larger beam.  There are several key scientific issues that affect the choice between these two geometries:

Beam merging will be studied in scaled experiments on the STS-500 facilitity, a 500 kV test stand currently under construction at Lawrence Livermore National Laboratory.  An existing test stand, the 100kV STS-100, will be used in parallel to develop ion sources.  A variety of sources will be tested and characterized for both injection geometries, with surface-ionization sources being studied first, followed by plasma sources.

In addition to source development, the STS-500 facility will be used during the next several years to study electrostatic interactions in multiple-beam bundles, beam-gas interactions in long-duration pulses, and advanced accelerator concepts using very high voltage gradients.  The experiments on multiple-beam effects are important for driver-scale accelerators because repulsion between beams within accelerator gaps is expected to affect beam centering.

For comments or questions contact or  Work described here was supported by the Office of Fusion Energy at the US Department of Energy under contracts  DE-AC03-76SF00098 and W-7405-ENG-48.  This document was last revised June, 2002.