IBIC2013 - List of Authors (Kaufmann, W.)

Paper

Title

Page

Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring

101

M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh
GSI, Darmstadt, Germany
W. Ackermann
TEMF, TU Darmstadt, Darmstadt, Germany
M.H. Almalki
IAP, Frankfurt am Main, Germany
M.H. Almalki
KACST, Riyadh, Kingdom of Saudi Arabia
B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic
I-Tech, Solkan, Slovenia
C.S. Simon
CEA/DSM/IRFU, France

The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne⁴⁺ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.

Poster MOPC21 [1.622 MB]

WEPF35

Current Status of the Schottky Cavity Sensor for the CR at FAIR

907

M. Hansli, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
P. Hülsmann, W. Kaufmann
GSI, Darmstadt, Germany

Funding: This work was supported by the GSI. The author would like to thank the CST AG for providing CST Studio Suite.
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.

THAL1

Understanding the Tune Spectrum of High Intensity Beams

914

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

Tune spectra measurements are routinely performed in most synchrotrons. At high intensity and low energies (i.e. γ≈1), space charge effects can significantly modify the tune spectra in comparison to the classical low intensity spectra. Systematic studies were performed at GSI SIS-18 to observe these characteristic modifications, mainly resulting from the shift of the head-tail modes in direct dependence of beam intensity and synchrotron tune frequency. In this contribution, an interpretation of the tune spectra modification based on quasi-analytical models and numerical simulations will be presented. Extraction of elusive beam parameters such as incoherent tune shift, machine impedances, chromaticity, etc. from the spectra will be demonstrated. Further, the applications and relevance of these results for other synchrotrons will be discussed.

Slides THAL1 [3.807 MB]

Paper	Title	Page
MOPC21	Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring	101
	M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh GSI, Darmstadt, Germany W. Ackermann TEMF, TU Darmstadt, Darmstadt, Germany M.H. Almalki IAP, Frankfurt am Main, Germany M.H. Almalki KACST, Riyadh, Kingdom of Saudi Arabia B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic I-Tech, Solkan, Slovenia C.S. Simon CEA/DSM/IRFU, France
	The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne⁴⁺ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.
	Poster MOPC21 [1.622 MB]

WEPF35	Current Status of the Schottky Cavity Sensor for the CR at FAIR	907
	M. Hansli, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany P. Hülsmann, W. Kaufmann GSI, Darmstadt, Germany
	Funding: This work was supported by the GSI. The author would like to thank the CST AG for providing CST Studio Suite. 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.

THAL1	Understanding the Tune Spectrum of High Intensity Beams	914
	R. Singh, O. Chorniy, P. Forck, R. Haseitl, W. Kaufmann, P. Kowina, K. Lang GSI, Darmstadt, Germany R. Singh TEMF, TU Darmstadt, Darmstadt, Germany
	Tune spectra measurements are routinely performed in most synchrotrons. At high intensity and low energies (i.e. γ≈1), space charge effects can significantly modify the tune spectra in comparison to the classical low intensity spectra. Systematic studies were performed at GSI SIS-18 to observe these characteristic modifications, mainly resulting from the shift of the head-tail modes in direct dependence of beam intensity and synchrotron tune frequency. In this contribution, an interpretation of the tune spectra modification based on quasi-analytical models and numerical simulations will be presented. Extraction of elusive beam parameters such as incoherent tune shift, machine impedances, chromaticity, etc. from the spectra will be demonstrated. Further, the applications and relevance of these results for other synchrotrons will be discussed.
	Slides THAL1 [3.807 MB]