Bonn 2010 – wissenschaftliches Programm
HK 36.40: Poster
Mittwoch, 17. März 2010, 14:00–16:00, HG Aula
Baseband Tune Measurements at the GSI SIS18 using direct digitized BPM Signals — •Peter Forck, Peter Hülsmann, Piotr Kowina, Kevin Lang, and Udo Springer — GSI, Darmstadt
Precise setting of the tune is crucial for high current operation of GSI SIS 18 synchrotron especially for the storage of low energy ion beams with a large tune spread. For tune measurement the broadband signals of a Beam Position Monitor are digitized by a fast 125 MSa/s ADC and digitally integrated over the actual bunch length. The tune is determined by Fourier-Transformation of the position data of individual bunches. This very sensitive ’baseband’ processing delivers the tune value without any additional input parameters. Since transverse emittance blow-up has to be avoided, the excitation power, as required for the excitation of coherent betatron oscillations, must be as low as possible. Extensive system tests were performed to demonstrate the large sensitivity and accuracy of this evaluation method using state-of-the-art digital data processing.