Accelerator Mass Spectrometry (AMS) demonstrates more than a million times more sensitivity for C-14 than classical beta particle detection. In cancer research, this improved sensitivity can assist in the understanding of the role that xenobiotics, at ambient concentrations, plays in initiating mutations. In addition, the small sample size needed and the high detection sensitivity make AMS ideal for measurements on small quantities of easily accessible human cells. Also, therapeutic parameters for individuals could be determined through administration of small doses of C-14 labeled pharmaceuticals. At the present stage of AMS development, it is necessary to transform biochemical samples into graphite. This conversion is foreign to biomedical worKers and is a time consuming and expensive task that is prone to errors. A CO2 to C- converter (ion source) will be designed, fabricated and tested that will bypass the graphite requirement completely. In Phase I of the present program, testing of the source will be carried out on a test stand. Phase II will include testing of the source system using the AMS facility at Lawrence Livermore National Laboratory.