The AUSTRALIS microbeam ion source

Abstract The AUSTRALIS (AMS for Ultra Sensitive TRAce eLement and Isotopic Studies) system being developed at the HIAF laboratory is a microbeam AMS system designed for in situ microanalysis of geological samples. The microbeam source was implemented by modifying a HICONEX source, resulting in a versatile source for microbeam as well as high intensity macrobeam operations. The source features a high magnification sample viewing system, enabling live observation of the sputtering process and visual tuning of the primary beam. Microbeam of Cs + as small as 30 μm in diameter has been obtained in the tests. The secondary ion extraction system features a “screen” electrode that is used to correct the primary beam trajectory affected by the extraction field, in order to return it to the geometric center of the sample. The paper will describe the source, and results of the test of the source and the injector system.