HB2012 - List of Authors (Singh, R.)

Paper

Title

Page

Measurements and Interpretation of the Betatron Tune Spectra of High Intensity Bunched Beam at SIS-18

310

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

The paper presents the status of the transverse tune measurements in the synchrotron SIS18 at GSI. Presently, there are two systems for tune measurements in operation in the SIS18, namely TOPOS (Tune, Orbit and POsition measurement System) and BBQ (Base Band tune measurement system). The first one is a digital system where the BPM signal is digitized and the bunch position is calculated numerically. The second system is an analog system, where the transverse bunch motion is detected using peak detector. Band limited noise and chirp excitations were used to excite the betatron oscillations. Measurements of the betatron tune spectra were done at injection energy at medium and high intensities. In the frequency spectra a number of peaks around the position of betatron tune were seen. The peaks can be attributed to different bunch head-tail modes which were observed in time domain. These modes were dependent on the beam intensity. In this paper we compare the tune spectra measured at high beam intensity with the theoretical model for the space charge affected head-tail modes.

Slides TUO1C05 [1.315 MB]

THO3C01

Optical Transition Radiation for Non-relativistic Ion Beams

580

B. Walasek-Höhne, C.A. Andre, F. Becker, P. Forck, A. Reiter, M. Schwickert, R. Singh
GSI, Darmstadt, Germany
A.H. Lumpkin
Fermilab, Batavia, USA

In this contribution, recent results of Optical Transition Radiation (OTR) measurements with a non-relativistic heavy-ion beam will be presented. This feasibility study was prompted by previous measurements [1] and the theoretical estimation of expected signal strengths for the GSI linear accelerator UNILAC. For this experiment, an 11.4 MeV/u Uranium beam was chosen to investigate OTR signal from several target materials and to evaluate the working regime for the used experimental setup. The OTR light was either observed directly with an Image Intensified CCD camera (ICCD) or indirectly via a spectrometer for wavelength resolved data. A moveable stripping foil allowed measurements with two different ion charge states. The theoretical q2 dependency of the OTR process predicts a six-fold increase in light yield which was confirmed experimentally. Obtained OTR beam profiles were compered to SEM-Grid data. Moreover, ICCD gating feature, as well as the emitted light spectrum ruled out contribution of any background sources with longer emission time constant e.g. blackbody radiation.
[1] C. Bal et al., "OTR from Non-relativistic Electrons", Proceedings of DIPAC03, PM04, Mainz Germany.

Slides THO3C01 [1.905 MB]

Paper	Title	Page
TUO1C05	Measurements and Interpretation of the Betatron Tune Spectra of High Intensity Bunched Beam at SIS-18	310
	R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang GSI, Darmstadt, Germany O. Boine-Frankenheim, R. Singh, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	The paper presents the status of the transverse tune measurements in the synchrotron SIS18 at GSI. Presently, there are two systems for tune measurements in operation in the SIS18, namely TOPOS (Tune, Orbit and POsition measurement System) and BBQ (Base Band tune measurement system). The first one is a digital system where the BPM signal is digitized and the bunch position is calculated numerically. The second system is an analog system, where the transverse bunch motion is detected using peak detector. Band limited noise and chirp excitations were used to excite the betatron oscillations. Measurements of the betatron tune spectra were done at injection energy at medium and high intensities. In the frequency spectra a number of peaks around the position of betatron tune were seen. The peaks can be attributed to different bunch head-tail modes which were observed in time domain. These modes were dependent on the beam intensity. In this paper we compare the tune spectra measured at high beam intensity with the theoretical model for the space charge affected head-tail modes.
	Slides TUO1C05 [1.315 MB]

THO3C01	Optical Transition Radiation for Non-relativistic Ion Beams	580
	B. Walasek-Höhne, C.A. Andre, F. Becker, P. Forck, A. Reiter, M. Schwickert, R. Singh GSI, Darmstadt, Germany A.H. Lumpkin Fermilab, Batavia, USA
	In this contribution, recent results of Optical Transition Radiation (OTR) measurements with a non-relativistic heavy-ion beam will be presented. This feasibility study was prompted by previous measurements [1] and the theoretical estimation of expected signal strengths for the GSI linear accelerator UNILAC. For this experiment, an 11.4 MeV/u Uranium beam was chosen to investigate OTR signal from several target materials and to evaluate the working regime for the used experimental setup. The OTR light was either observed directly with an Image Intensified CCD camera (ICCD) or indirectly via a spectrometer for wavelength resolved data. A moveable stripping foil allowed measurements with two different ion charge states. The theoretical q2 dependency of the OTR process predicts a six-fold increase in light yield which was confirmed experimentally. Obtained OTR beam profiles were compered to SEM-Grid data. Moreover, ICCD gating feature, as well as the emitted light spectrum ruled out contribution of any background sources with longer emission time constant e.g. blackbody radiation. [1] C. Bal et al., "OTR from Non-relativistic Electrons", Proceedings of DIPAC03, PM04, Mainz Germany.
	Slides THO3C01 [1.905 MB]