EXTRACTION OF HIGHLY CHARGED AU IONS FROM A MULTIAMPHERE ELECTRON BEAM EBIS AT BNL

Excellent progress has been made in the operation of the BNL Electron Beam Ion Source (EBIS), which is a prototype for an EBIS that could meet requirements for a RHIC preinjector. We have achieved very stable operation of the electron beam at 10 A through the EBIS trap. Ion injection of low charge gold ions from a LEVA[1] ion source and subsequent extraction of these ions with most probable charge state AU(sup 34+) has been demonstrated with electron beams up to 8A. The total ion charge for gold measured on current transformer at the EBIS exit was 55nC after a 30ms confinement period. This corresponds to(approx)85% of the theoretical ion trap capacity and exceeds our goal of 50% neutralization. The collected ion charge is proportional to the electron current and the gold charge state scales with the electron current density. Details of the EBIS configuration, total charge measurements, and TOF spectra are given