Heavy Ion Fusion Accelerator Research Research Articles

Heavy Ion Fusion Accelerator Research

This paper describes an economical program for heavy ion fusion accelerator research. The heavy ion accelerator research program is part of a larger national research program to develop inertial fusion for commercial power production.

Induction accelerator development for heavy-ion fusion

For approximately a decade, the Heavy-Ion Fusion Accelerator Research (HIFAR) group at LBL has been exploring the use of induction accelerators with multiple beams as the driver for inertial-fusion targets. Scaled experiments have investigated the transport of space-charge-dominated beams (SBTE), and the current amplification and transverse emittance control in induction linacs (MBE-4) with very encouraging results. In order to study many of the beam manipulations required by a driver and to further developed economically competitive technology, a proposal has been made in partnership with LLNL to build a 10 MeV accelerator and to conduct a series of experiments collectively called the Induction Linac System Experiments (ILSE). The major components critical to the ILSE accelerator are currently under development. We have constructed a full-scale induction module and we have tested a number of amorphous magnetic materials developed by Allied Signal to establish an overall optimal design. The electric and magnetic quadrupoles critical to the transport and focusing of heavy-ion beams are also under development. The hardware is intended to be economically competitive for a driver without sacrificing any of the physics or performance requirements. This paper will concentrate on the recent developments and tests of the major components required by the ILSE accelerator.

ILSE: The next step in heavy ion fusion research

Induction Linac Systems Experiments is the next experiment planned by the Heavy Ion Fusion Accelerator Research (HIFAR) group at LBL, following the recent completion of the MBE-4 experiment. ILSE at 10 MeV will address many of the key physics and technology issues of HIF such as performance of a multiple beam, high voltage injector, high intensity electrostatically-focused transport, beam combining, high intensity magnetically-focused transport, drift-compression and energy-tilt removal, high intensity transport around a magnetic bend, and, possibly, recirculation. Presuming a “new start” in FY 94, experiments could begin with ILSE in FY 97.

Particle Accelerators — Applications in Technology and Research

"Particle Accelerators — Applications in Technology and Research." Fusion Technology, 19(2), p. 395 Additional informationNotes on contributorsWilliam B. HerrmannsfeldtWilliam B. Herrmannsfeldt (PhD, physics, University of Illinois, 1958) has worked in accelerator physics at the Stanford Linear Accelerator Center since 1962. He is active in heavy ion fusion accelerator research and was chairman of the steering committee for the heavy ion fusion systems assessment program. His special interests include high intensity beam transport issues and the numerical simulation of accelerator components.

Induction linac drivers for heavy ion fusion

The Heavy Ion Fusion Accelerator Research (HIFAR) program of the U.S. Dept. of Energy has for several years concentrated on developing linear induction accelerators as Inertial Fusion (IF) drivers. This accelerator technology is suitable for the IF application because it is readily capable of accelerating short, intense pulses of charged particles with good electrical efficiency. The principal technical difficulty is in injecting and transporting the intense pulses while maintaining the necessary beam quality. The approach used has been to design a system of multiple beams so that not all of the charge has to be confined in a single beam line. The beams are finally brought together in a common focus at the target. This paper will briefly present the status and future plans of the program, and will also briefly review systems study results for HIF.

U.S. Accelerator Research Program for Heavy-Ion Fusion

The U.S. heavy-ion fusion program emphasizes research and development (R and D) on linear induction accelerators. This strategy emerged in 1983, after the U.S. Department of Energy established the heavy-ion fusion accelerator research (HIFAR) program to acquire an appropriate data base for future decisions on heavy-ion inertial fusion. Since that time, HIFAR has advanced the understanding of high-current ion beam transport, and accelerator technology through laboratory-scale experiments and supporting theoretical studies. Although each program element will continue to contribute to the HIFAR data base over the next few years, present accelerator experiments cannot supply sufficient data to adequately satisfy the program objective. Consequently, HIFAR is approaching a transition between the research and accelerator demonstration phases. The history, status, and short-term plans of HIFAR are examined. The program structure, review of the technical status, and introduction of a proposed R and D program that can minimally meet the HIFAR objective are discussed.

Alumino-Silicate Ion Sources for Accelerator Applications

As part of the program of Heavy Ion Fusion Accelerator Research at the Lawrence Berkeley Laboratory, ion sources have been developed using thermionic emitters of singly charged alkali metal ions. These emitters are flat surfaces of alumino-silicate, loaded with the apropriate ion. They have become convenient and reliable sources producing pulsed beams of very low emittance. Thermionic emission of ions from alumino-silicates has been known for a very long time [1]. Here we focus on the practical application as accelerator ion sources. We discuss the fabrication and heating of large area emitters, uniformity of emission and the maximum ion current density which can be extracted under space charge limited conditions, with zero electric field on the emitter surface. Results are presented for Na, K and Cs ions showing maximum space charge limited current densities of 25, 40 and 120 mAcm-2 respectively. In the case of cesium we have produced a 5 mA beam at a kinetic energy of 200 keV with normalized emittance 1.2×l0-7 ? m rad.

Transportable Charge in a Periodic Alternating Gradient System

A simple set of formulas is derived which relate emittance, line charge density, matched maximum and average envelope radii, occupancy factors, and the (space charge) depressed and vacuum values of tune. This formulation is an improvement on the smooth limit approximation; deviations from exact (numerically determined) relations are on the order of ±2%, while the smooth limit values are in error by up to ±30%. This transport formalism is used to determine the limits of transportable line charge density in an electrostatic quadrupole array, with specific application to the low energy portion of the High Temperature Experiment of Heavy Ion Fusion Accelerator Research. The line charge density limit is found to be essentially proportional to the voltage on the pole faces and the fraction of occupied aperture area. A finite injection energy (?2 MeV) is required to realize this limit, independent of particle mass.