Development of a Data Aquisition System at a Nuclear Microprobe with Applications in the Geo- and Biosciences

Sammanfattning: This thesis is divided in two parts, one that deals with the development of the new data acquisition system at Lund Nuclear Microprobe, and a second part that deals with different applications. A CAMAC based data acquisition system has been installed at the Lund Nuclear Microprobe facility. The system is a true multi-parameter and multi-detector system with fast FERA bus readout and in crate memory buffer. Each event in a detector produces a gate to all of the multiple parameters that should be acquired in coincidence. The system reads and tags each event and scaler word with X-Y position. The charge is measured by a current digitiser connected to a scaler. The beam scanning part is software controlled through a Timed D/A converter, this allows for fast scanning of the beam, this unit generates the coordinates. The work with the development of this system is described. Applications in various fields are discussed: Otolith analyses and micro fossil analyses. To know a fish life history (or the age of the fish) is an important factor in assessment of fish populations. Otolith growth is a combination of seasonal and daily increments combined with random events. The otolith develops in rings from its center (incremental zone), a tiny ring presents when the fish hatches. The Sr level in this point is transferred from the mother. The analyses of otoliths from Salmo trutta and Anguilla anguilla are reported.