LOW-EMITTANCE 0.8AK(-SOURCE FOR THE LBL INDUCTION LINAC SYSTEM EXPERIMENT (ILSE)() ION)

A high-current injector for heavy-ion fusion presently under construct ion at Lawrence Berkeley Laboratory requires large sources of up to 17 cm in diameter and total potassium ion current of 790 mA with a low n ormalized transverse emittance of less than 0.5 mm mrad. A 1'' diamete r hot alumino silicate (zeolite) source was fabricated and tested in t he injector set-up of SBTE, an e;existing facility at LBL. Initial mea surements showed a maximum space-charge-limited ion current of 95mk Th e corresponding density of 19mA/cm(2) was limited by the source diode optics and not by the source emission. The density required for the hi gh-current injector is 4 mA/cm(2). The normalized emittance was measur ed to be 0.06 mm mrad, corresponding to a transverse temperature of 0. 2 eV. Nondestructive life tests showed that the source can be operated under continuous operating conditions of the high-current injector fo r more than a month (twenty eight-hour days, with 1 mu s long pulses a t 1 Hz). d.c. destructive life tests showed that similar to 30% of the total stored K can be ionized and extracted, allowing, in principle, for years of operation for the high-current injector. Furthermore, we shall describe the extension of the fabricating technique to large-dia meter sources (up to 17 cm) and report on measured ion emission perfor mance, measured surface temperature uniformity and heating power consi derations.