A new micro-DIGE set-up for the analysis of light elements

The present work shows a relatively simple and inexpensive way of converting the sample chamber of a conventional OM type microprobe into an easily useable micro-DIGE set-up. The basic idea of the set-up is to increase the image distance of the microprobe by moving the focus out of the sample chamber into an extension tube, which is connected to the 0 deg. port of the chamber. This new position of the focus, and so the sample, enables the use of different type of γ-ray detectors in enlarged solid angles increasing the sensitivity of the technique. The degradation of the lateral resolution of the system as a consequence of the increased image distance was theoretically and experimentally investigated. The measured geometric spot size was 15 x 17 μm2. Archaeological and ecological applications of the new set-up are also presented here