Status of experiments leading to a small recirculator

A heavy ion linear induction accelerator is considered to be the leading driver candidate for an Inertial Fusion Energy reactor. To deliver a space-charge-dominated beam at the appropriate energy (several GeV), such an accelerator would be several kilometers in length. Since total length has a strong influence on accelerator cost, we are considering the potential advantages and practical implementation of a recirculating induction accelerator. To address the critical scientific and technical challenges of a recirculating space-charge-dominated heavy ion beam, we have begun to develop the elements of a scaled “small recirculator”. An operating recirculator must demonstrate full beam control including multi-lap operation, beam insertion/extraction, acceleration and pulse compression. At present, experiments have been conducted using a 2 mA, 80 keV K+ beam transported through a 45° bend; experiments on a 90° bend with five induction modulators will begin soon. This paper briefly summarizes the recirculator specifications and operational features and reports the latest experimental data as well as the developmental status of beam diagnostics.