BIW2012 - List of Authors (Singh, R.)

Paper	Title	Page
TUPG042	High Intensity Effects on Betatron Tune at GSI SIS-18	219
	R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang GSI, Darmstadt, Germany T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: This work is supported by DITANET (novel DIagnostic Techniques for future particle Accelerators: A Marie Curie Initial Training NETwork),Project Number ITN-2008-215080 The tune measurement system (TOPOS) at GSI SIS-18 consists of, a band limited noise exciter which excites coherent betatron oscillations in the bunched beam; Fast ADCs to digitize the BPM signals at 125 MSa/s and FPGAs to calculate position from the digitized BPM signals. Baseband tune is thus determined by Fourier transformation of the individual bunch position data. Several tune measurement campaigns were performed with U⁷³⁺ and Ar¹⁸⁺ ion beam at highest achievable intensities of 2x10⁹ and 2.5x10¹⁰ respectively using TOPOS. The goal of these measurements was to understand the high current effects on the tune spectra. Substantial modification of the tune spectra were observed and attributed to the bunch head tail oscillations after further investigations. Coherent tune shift in dependence of beam intensity were also measured. This contribution reports on the modified tune spectra, corresponding space charge effects and further experimental details.

Paper

Title

Page

High Intensity Effects on Betatron Tune at GSI SIS-18

219

R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang
GSI, Darmstadt, Germany
T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This work is supported by DITANET (novel DIagnostic Techniques for future particle Accelerators: A Marie Curie Initial Training NETwork),Project Number ITN-2008-215080
The tune measurement system (TOPOS) at GSI SIS-18 consists of, a band limited noise exciter which excites coherent betatron oscillations in the bunched beam; Fast ADCs to digitize the BPM signals at 125 MSa/s and FPGAs to calculate position from the digitized BPM signals. Baseband tune is thus determined by Fourier transformation of the individual bunch position data. Several tune measurement campaigns were performed with U⁷³⁺ and Ar¹⁸⁺ ion beam at highest achievable intensities of 2x10⁹ and 2.5x10¹⁰ respectively using TOPOS. The goal of these measurements was to understand the high current effects on the tune spectra. Substantial modification of the tune spectra were observed and attributed to the bunch head tail oscillations after further investigations. Coherent tune shift in dependence of beam intensity were also measured. This contribution reports on the modified tune spectra, corresponding space charge effects and further experimental details.