Vorschau

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Abstract

Studying the rapid neutron capture process (r-process) in stellar environment, that leads to the creation of about half of elements heavier than Fe, remains one of the fundamental questions of modern physics and therefore an active field of interdisciplinary research within nuclear structure, atomic and plasma physics, particle physics as well as nuclear astrophysics. Apart from other key measurable like neutron capture cross sections and decay lifetimes, nuclear masses are of utmost importance for pinpointing the r-process using theoretical and experimen- tal approaches. Exotic nuclides which participate in the r-process typically have extremely low production yields and short half-lifes. Those, accessible today at radioactive-ion beam facilities can be efficiently investigated in a storage ring. In such facilities non-destructive methods of particle detection are often used for in-flight measurements based on a frequency analysis. Due to low particle number and thus inevitably the low signal level, the detectors should be very sensitive and fast. While there are many sensitive detectors available to provide the information on particle’s revolution frequency, the main idea of this work is to design a position-sensitive cavity doublet for the Rare-Ri storage ring in RIKEN, Japan. Additionally, a new data acquisition system based on the software defined radio (SDR) was developed and tested with an existing resonant Schottky pickup during an experimental campaign in the ESR at GSI Darmstadt. SDR based data acquisition systems are essential for use in future distributed pickup systems such as those planned in the collector ring (CR) of the FAIR project. Finally a fully automated measurement system has been developed that can be used to measure the field profiles of such cavities in conjunction with the above mentioned data acquisition system. A toy model of such a position-sensitive resonant Schottky cavity doublet has been designed, constructed, manufactured and tested using the automated measurement system in the lab as well as at the linear accelerator S-DALINAC at University of Darmstadt.