Andris Faltens

An integrated systems model for heavy ion drivers

A source-to-target computer model for an induction linac driver for heavy ion fusion has been developed and used to define a reference case driver that meets the requirements of one current target design. Key features of the model are discussed, and the design parameters of the reference case design are described. Examples of the systems analyses leading to the point design are given, and directions for future work are noted.

Large Aperture Contact Ionized Cs+1 Ion Source for an Induction Linac

A 500 KeV one-ampere Cs+1 ion beam has been generated by contact ionization with a 30 cm dia. iridium hot plate. Reproducibility of space charge limited ion current wave forms at repetition rates up to 1 Hz has been verified. The beam is characterized to be very bright and suitable as an ion source for the induction linac based heavy ion fusion scheme. The hot anode plate was found to be reliable and self-cleaning during the operation.

A pulsed vapor source for use in ion sources for heavy‐ion accelerators

A pulsed cesium vapor source for use in ion sources for high‐current heavy‐ion accelerators is described. The source employs a vacuum spark in Cs and its properties are measured with a hot‐filament Cs detector.

Studies on longitudinal beam compression in induction accelerator drivers

Longitudinal beam compression is an integral part of the U.S. induction accelerator development effort for heavy ion fusion. It occurs before final focus and fusion chamber beam transport and is a key process determining initial conditions for final focus hardware. Determining the limits for maximal performance of key accelerator components is an essential element of the effort to reduce driver costs. We outline here studies directed towards defining the limits of final beam compression including considerations such as: maximal available compression, effects of longitudinal dispersion and beam emittance, combining pulse‐shaping with beam compression to reduce the totial number of beam manipulations, etc. We summarize inital results on these limits gleaned from a survey including already more than 30 runs of 20–30 minutes each on our Cray computers.In addition, we illustrate one of several possible techniques for utilizing the beam compression process to provide the pulse shapes required by a number of tar...

Investigation of Re-X Glass Ceramic for Accelerator Insulating Columns

In an induction linac the accelerating voltage appears along a voltage-graded vacuum insulator column which is a performance limiting and major cost component. Re-X glass ceramic insulators have the long-sought properties of allowing cast-in gradient electrodes, good breakdown characteristics, and compatibility with high vacuum systems. Re-X is a glass ceramic developed by General Electric for use in the manufacture of electrical apparatus, such as vacuum arc interrupters. We have examined vacuum outgassing behavior and voltage breakdown in vacuum and find excellent performance. The housings are in the shape of tubes with type 430 stainless steel terminations. Due to a matched coefficient of thermal expansion between metal and insulator, no vacuum leaks have resulted from any welding operation. The components should be relatively inexpensive to manufacture in large sizes and appear to be a very attractive accelerator column. We are planning to use a standard GE housing in our MBE-4 induction linac.

Ion Accelerators as Drivers for Inertial Confinement Fusion

A representation of the state of ion driver technology is shown in Table II. As in any such superficial treatment there are some subjective conclusions but the clear generalization is that the light ion machines have the necessary power and energy but lack rep rate and reliability. The heavy ion drivers, on the other hand, are based on developed accelerator technology which is demonstrated to be of high rep rate and reliability, but is still not at the required energy or power levels.

Development of 3D simulations for heavy-ion fusion beam transport and compression problems

Abstract Longitudinal beam compression and the possibility of concurrent pulse shaping have been the subject of previous studies using analytical methods and 1D