An Isochronous Stacking Ring Approach to the HTE

Abstract

The problem of finding a suitable apparatus for demonstrating heavy ion fusion is a difficult one to approach in moderate steps. Ideally, such apparatus would be useful for testing beam transport, focusing and targeting concepts, and target behavior in the plasma regime, and the technology used in this ''high temperature experiment'' (HTE) would also be extended to construct a prototype fusion facility. A meaningful test of many of these concepts could be achieved with a device capable of heating a disk of material to plasma temperatures in the neighborhood of 100 eV or 1 million degrees K. Target heating for the HTE requires a short beam burst on the order of tens of nanoseconds with a total beam energy of a kilojoule or more. The RF linac falls far short of this capacity. A number of studies have looked at the use of storage rings for accumulating beam current. This paper looks at an alternative means: the use of a RF linac followed by an isochronous storage ring (ISR) producing rapidly the high multiplication of beam current required. This method avoids the necessity for beam manipulations such as splitting and bunching. Also, because of the fast transit time in themore » ISR, storage ring instabilities pose no problem. The paper discusses beam stacking with an isochronous ring and then addresses the use of an ISR for the HTE and the design and performance of an apparatus--consisting of an ion source, a RF linac, a stacking ring, and a number of beam lines to transfer beam bunches to the target--for such an application.« less