GSI, Darmstadt, Germany
FSU Jena, Jena, Germany
HIJ, Jena, Germany
For the measurement of the very low ion beam current -down to nA range- foreseen in the High Energy Transport sections of the upcoming FAIR facility, an improved Cryogenic Current Comparator (CCC) is under development at GSI. The existing CCC unit, initially operated at the high energy beam transport section after the GSI synchrotron SIS18, has been upgraded as a prototype for FAIR. The upgraded CCC is presently being re-commissioned. In this contribution we report on beam current measurements with the improved detector unit down to 5 nA simulated by a wire loop wound around the magnetic sensor. As mechanical vibrations strongly influence the sensitive SQUID detector, vibration analyses have been carried out using an accelerometer. Noise contributions from various mechanical as well as electrical sources were studied and the achieved detector performance is presented
TU Darmstadt, Darmstadt, Germany
GSI, Darmstadt, Germany
In this paper the current status of the Schottky Cavity Sensor development for the Collector Ring at FAIR, a dedicated storage ring for secondary particles, rare isotopes, and antiprotons, is presented. Designed for longitudinal and transversal Schottky signals, the Sensor features a pillbox cavity with attached waveguide filters utilizing the Monopole mode at 200 MHz for longitudinal and the Dipole mode at around 330 MHz for transversal Schottky measurements. Separated coupling structures allow for mode-selective coupling to measure the different Schottky planes independently. A ceramic vacuum shielding inside the pillbox is implemented to enable non-hermetic adjustable coupling, tuning devices and waveguide structures. Simulations of the structure with focus on the impact of the coupling structures and the ceramic vacuum shielding on the R-over-Q values and the coupling are presented as well as measurements of a scaled demonstrator including comparisons with the simulations.