Status of the MALT tandem electrostatic accelerator

Seven years have passed since the start of MALT (Micro Analysis Laboratory, Tandem accelerator). An increasing emphasis has been placed, among others, on the accelerator mass spectroscopy (AMS), and also on proton-induced X-ray emission analysis (PIXE). The present paper describes major recent modifications of the system. A cesium sputter ion source dedicated to carbon 14 AMS was manufactured. The contamination of a source plasma chamber and electrodes decreases markedly, but still insufficient. As is increased ion currents injected to the accelerator, the electric field near the beam inlet section may be distorted, and thus deteriorate the beam transmission. (M. Tanaka)