DIPAC2011 - List of Authors (Kowina, P.)

Paper

Title

Page

Beam Diagnostic Layout for SIS100 at FAIR

41

M. Schwickert, P. Forck, T. Hoffmann, P. Kowina, H. Reeg
GSI, Darmstadt, Germany

The SIS100 heavy ion synchrotron will be the central machine of the FAIR (Facility for Antiprotons and Ions Research) project currently designed at GSI. The unique features of SIS100, like e.g. the acceleration of high intensity beams of 2.5·10¹³ protons and 5·10¹¹ Uranium ions near the space charge limit, the anticipated large tune spread, extreme UHV conditions of the cryogenic system for superconducting magnets and fast ramp rates of 4 T/s, make challenging demands on the beam diagnostic components. This contribution describes the conceptual design for SIS100 beam diagnostics and reports on the present status of prototype studies. Exemplarily the progress concerning beam position monitors, beam current transformers and beam-loss monitors is presented.

MOPD69

Tune Measurements with High Intensity Beams at SIS-18

206

R. Singh, P. Forck, W. Kaufmann, P. Kowina
GSI, Darmstadt, Germany
R. Singh
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
To achieve high current operation close to the space charge limit in a synchrotron, a precise tune measurement during a full accelerating cycle is required. A tune measurement system that was recently commissioned at GSI synchrotron SIS-18 allows for online evaluation of the actual tune. This system consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations of the beam. The BPM signals thus induced are digitized by fast ADCs at 125 MSa/s and then the post processing electronics integrates the data bunch by bunch to obtain one position value per bunch. Subsequently base band tune is determined by Fourier transformation of the position data. The tune variation during acceleration for various beam conditions was measured using this system and is discussed. A detailed investigation of the incoherent tune shift was conducted with Uranium ion beams at the injection energy of 11.6 MeV/u. The results show the influence of beam current on the tune spectrum. In addition, the effects of the measurement method on the beam emittance and beam losses are discussed.

TUPD20

Pre-amplifier Impedance Matching for Cryogenic BPMs

347

P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann
GSI, Darmstadt, Germany
N. Sobel, F. Völklein
Hochschule RheinMain, Wiesbaden, Germany

Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.

Poster TUPD20 [0.655 MB]

TUPD24

Design Status of Beam Position Monitors for the FAIR Proton Linac

356

C.S. Simon, F. Senée
CEA/DSM/IRFU, France
G. Clemente, P. Forck, W. Kaufmann, P. Kowina
GSI, Darmstadt, Germany

Beam Position Monitors (BPM) based on capacitive buttons are designed for the FAIR Proton-LINAC, constructed as an extension of the existing GSI facility. This LINAC is aiming to produce a maximum design current of 70 mA at the 70 MeV energy with an accelerating frequency of 325 MHz. At 14 locations, the BPMs will measure the transverse beam position, the relative beam current and the mean beam energy by time-of-flight method. Depending of the location, the BPM design has to be optimized, taking into account an energy range from 3 MeV to 70 MeV, a short insertion and a beam pipe aperture changes from 30 mm to 50 mm. Some of BPMs will be mounted very close to the CH cavities and special care must be taken to suppress the pickup of the strong rf-field from that cavities. In this contribution, the status of the BPM design will be presented.

TUPD66

Sensor Optimizations for a Cryogenic Current Comparator

458

R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
P. Kowina, F. Kurian, M. Schwickert
GSI, Darmstadt, Germany
R. von Hahn
MPI-K, Heidelberg, Germany

We present a non-destructive superconducting monitoring system for charged particles beams. The system uses the Cryogenic Current Comparator (CCC) principle with a low temperature DC-SQUID. The Cryogenic Current Comparator has shown its capability in the Horizontal Bi-Cavity Test Facility at the Helmholtz-Zentrum Berlin under noisy conditions. In this test facility for superconducting cavities the CCC setup was able to detect dark currents in the nA range. The suitability of the Cryogenic Current Comparator as a beam monitor for the Facility of Antiproton and Ion Research at GSI Darmstadt as well as for the Cryogenic Storage Ring at MPI Heidelberg will be pointed out and discussed. Special attention will be given to the ferromagnetic core materials embedded in the pickup coil.

Paper	Title	Page
MOPD05	Beam Diagnostic Layout for SIS100 at FAIR	41
	M. Schwickert, P. Forck, T. Hoffmann, P. Kowina, H. Reeg GSI, Darmstadt, Germany
	The SIS100 heavy ion synchrotron will be the central machine of the FAIR (Facility for Antiprotons and Ions Research) project currently designed at GSI. The unique features of SIS100, like e.g. the acceleration of high intensity beams of 2.5·10¹³ protons and 5·10¹¹ Uranium ions near the space charge limit, the anticipated large tune spread, extreme UHV conditions of the cryogenic system for superconducting magnets and fast ramp rates of 4 T/s, make challenging demands on the beam diagnostic components. This contribution describes the conceptual design for SIS100 beam diagnostics and reports on the present status of prototype studies. Exemplarily the progress concerning beam position monitors, beam current transformers and beam-loss monitors is presented.

MOPD69	Tune Measurements with High Intensity Beams at SIS-18	206
	R. Singh, P. Forck, W. Kaufmann, P. Kowina GSI, Darmstadt, Germany R. Singh 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 To achieve high current operation close to the space charge limit in a synchrotron, a precise tune measurement during a full accelerating cycle is required. A tune measurement system that was recently commissioned at GSI synchrotron SIS-18 allows for online evaluation of the actual tune. This system consists of three distinct parts; an exciter which provides power to excite coherent betatron oscillations of the beam. The BPM signals thus induced are digitized by fast ADCs at 125 MSa/s and then the post processing electronics integrates the data bunch by bunch to obtain one position value per bunch. Subsequently base band tune is determined by Fourier transformation of the position data. The tune variation during acceleration for various beam conditions was measured using this system and is discussed. A detailed investigation of the incoherent tune shift was conducted with Uranium ion beams at the injection energy of 11.6 MeV/u. The results show the influence of beam current on the tune spectrum. In addition, the effects of the measurement method on the beam emittance and beam losses are discussed.

TUPD20	Pre-amplifier Impedance Matching for Cryogenic BPMs	347
	P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann GSI, Darmstadt, Germany N. Sobel, F. Völklein Hochschule RheinMain, Wiesbaden, Germany
	Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.
	Poster TUPD20 [0.655 MB]

TUPD24	Design Status of Beam Position Monitors for the FAIR Proton Linac	356
	C.S. Simon, F. Senée CEA/DSM/IRFU, France G. Clemente, P. Forck, W. Kaufmann, P. Kowina GSI, Darmstadt, Germany
	Beam Position Monitors (BPM) based on capacitive buttons are designed for the FAIR Proton-LINAC, constructed as an extension of the existing GSI facility. This LINAC is aiming to produce a maximum design current of 70 mA at the 70 MeV energy with an accelerating frequency of 325 MHz. At 14 locations, the BPMs will measure the transverse beam position, the relative beam current and the mean beam energy by time-of-flight method. Depending of the location, the BPM design has to be optimized, taking into account an energy range from 3 MeV to 70 MeV, a short insertion and a beam pipe aperture changes from 30 mm to 50 mm. Some of BPMs will be mounted very close to the CH cavities and special care must be taken to suppress the pickup of the strong rf-field from that cavities. In this contribution, the status of the BPM design will be presented.

TUPD66	Sensor Optimizations for a Cryogenic Current Comparator	458
	R. Geithner, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany P. Kowina, F. Kurian, M. Schwickert GSI, Darmstadt, Germany R. von Hahn MPI-K, Heidelberg, Germany
	We present a non-destructive superconducting monitoring system for charged particles beams. The system uses the Cryogenic Current Comparator (CCC) principle with a low temperature DC-SQUID. The Cryogenic Current Comparator has shown its capability in the Horizontal Bi-Cavity Test Facility at the Helmholtz-Zentrum Berlin under noisy conditions. In this test facility for superconducting cavities the CCC setup was able to detect dark currents in the nA range. The suitability of the Cryogenic Current Comparator as a beam monitor for the Facility of Antiproton and Ion Research at GSI Darmstadt as well as for the Cryogenic Storage Ring at MPI Heidelberg will be pointed out and discussed. Special attention will be given to the ferromagnetic core materials embedded in the pickup coil.