IPAC2011 - List of Authors (Ackermann, W.)

Paper	Title	Page
TUPC077	Investigations on High Sensitive Sensor Cavity for Longitudinal and Transversal Schottky for the CR at FAIR	1180
	M. Hansli, A. Angelovski, R. Jakoby, A. Penirschke TU Darmstadt, Darmstadt, Germany W. Ackermann, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany P. Hülsmann GSI, Darmstadt, Germany
	Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351 For the Collector Ring (CR) at the FAIR (Facility for Antiproton and Ion Research) accelerator complex a sensitive Schottky sensor is required. The CR covers different modes of operation, like pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For longitudinal Schottky measurements the concept of a resonant cavity had been introduced [Hansli2011]. Due to limited space inside the ring, the integration of transversal Schottky analysis into this cavity is desired. In this paper the demands and required changes to implement also transversal Schottky measurements are discussed. An analysis of the expected signal characteristics featuring equivalent circuit is shown, as well as numerical full wave simulations of the cavity. * M. Hansli, A. Penirschke, R. Jakoby, W. Kaufmann, W. Ackermann, T. Weiland, "Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR", DIPAC2011.

WEPC088	Embedding Finite Element Results for Accelerator Components in a Moment Approach Beam Dynamics Code*	2217
	T. Roggen, H. De Gersem, B. Masschaele KU Leuven, Kortrijk, Belgium W. Ackermann, S. Franke, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: This research is funded by grant ''KUL 3E100118'' ''Electromagnetic Field Simulation for Future Particle Accelerators''. A moment based beam dynamics code has particular advantages, i.e. accuracy and efficiency, over macro-particle tracking and full particle-in-cell (PIC) codes respectively. Instead of embedding analytical descriptions of the accelerator components in the beam dynamics model, it is proposed to insert a surrogate model obtained from the finite element model of individual accelerator components. We apply the V-Code, which accepts moments up to the sixth order and accounts for space charge effects. We construct and calculate finite element and finite difference time domain models using the CST Studio Suite 2011 software package. An interface is implemented using VBA and MATLAB. As an example of the accuracy of this cascadic simulation approach, we compare the beam dynamics of an S-DALINAC quadrupole obtained by directly tracking particles to the calculated fields with the results for the cascadic approach with the V-Code. This work was performed during a three month research visit at the Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt, Germany.

WEPC092	Moment-Based Simulation of the S-DALINAC Recirculations*	2223
	S. Franke, W. Ackermann, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany R. Eichhorn, F. Hug, C. Klose, N. Pietralla, M. Platz TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by DFG under contract SFB 634. The Superconducting Linear Accelerator S-DALINAC installed at the institute of nuclear physics (IKP) at TU Darmstadt is designed as a re-circulating linear accelerator. The length of the beam line and the numerous accelerating structures as well as dipole and quadrupole magnets require a highly efficient numerical simulation tool in order to assist the operators by providing a detailed and almost instantaneous insight into the actual machine status. A suitable approach which enables a fast online calculation of the beam dynamics is given by the so-called moment approach where the particle distribution is represented by means of a discrete set of moments or by multiple discrete sets of moments in a multi-ensemble environment. Following this approach the V-Code simulation tool has been implemented at the Computational Electromagnetics Laboratory (TEMF) at TU Darmstadt. In this contribution an overview of the numerical model is presented together with new V-Code simulation results regarding the S-DALINAC recirculation sections.

WEPC093	Various Approaches to Electromagnetic Field Simulations for RF Cavities	2226
	C. Liu, W. Ackermann, W.F.O. Müller, T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Work supported by BMBF under contract 05H09RD5 In the Superconducting Proton Linac (SPL) cavity, there is not only the fundamental mode for the particle acceleration but also many higher order modes (HOMs), which can lead to particle beam instabilities. This is very dangerous for SPL cavity. Therefore it is necessary to simulate the electromagnetic field in the SPL cavity, so that the field distribution and the shunt impedance for every higher order mode can be precisely calculated. At TEMF this research work can be done in three different ways: field simulation with hexahedron mesh in frequency domain, field simulation with hexahedron mesh in time domain and field simulation with tetrahedral mesh and higher order curvilinear elements. Finally the HOM coupler will be considered for the effective damping of higher order modes in the SPL cavity.

Paper

Title

Page

Investigations on High Sensitive Sensor Cavity for Longitudinal and Transversal Schottky for the CR at FAIR

1180

M. Hansli, A. Angelovski, R. Jakoby, A. Penirschke
TU Darmstadt, Darmstadt, Germany
W. Ackermann, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
P. Hülsmann
GSI, Darmstadt, Germany

Funding: Funded by the Federal Ministry of Education and Research (BMBF): 06DA90351
For the Collector Ring (CR) at the FAIR (Facility for Antiproton and Ion Research) accelerator complex a sensitive Schottky sensor is required. The CR covers different modes of operation, like pre-cooling of antiprotons at 3 GeV, pre-cooling of rare isotope beams at 740 MeV/u and an isochronous mode for mass measurements. For longitudinal Schottky measurements the concept of a resonant cavity had been introduced [Hansli2011]. Due to limited space inside the ring, the integration of transversal Schottky analysis into this cavity is desired. In this paper the demands and required changes to implement also transversal Schottky measurements are discussed. An analysis of the expected signal characteristics featuring equivalent circuit is shown, as well as numerical full wave simulations of the cavity.
* M. Hansli, A. Penirschke, R. Jakoby, W. Kaufmann, W. Ackermann, T. Weiland, "Conceptual Design of a High Sensitive Versatile Schottky Sensor for the Collector Ring at FAIR", DIPAC2011.

WEPC088

Embedding Finite Element Results for Accelerator Components in a Moment Approach Beam Dynamics Code*

2217

T. Roggen, H. De Gersem, B. Masschaele
KU Leuven, Kortrijk, Belgium
W. Ackermann, S. Franke, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: This research is funded by grant ''KUL 3E100118'' ''Electromagnetic Field Simulation for Future Particle Accelerators''.
A moment based beam dynamics code has particular advantages, i.e. accuracy and efficiency, over macro-particle tracking and full particle-in-cell (PIC) codes respectively. Instead of embedding analytical descriptions of the accelerator components in the beam dynamics model, it is proposed to insert a surrogate model obtained from the finite element model of individual accelerator components. We apply the V-Code, which accepts moments up to the sixth order and accounts for space charge effects. We construct and calculate finite element and finite difference time domain models using the CST Studio Suite 2011 software package. An interface is implemented using VBA and MATLAB. As an example of the accuracy of this cascadic simulation approach, we compare the beam dynamics of an S-DALINAC quadrupole obtained by directly tracking particles to the calculated fields with the results for the cascadic approach with the V-Code.
This work was performed during a three month research visit at the Technische Universität Darmstadt, Institut für Theorie Elektromagnetischer Felder, Darmstadt, Germany.

WEPC092

Moment-Based Simulation of the S-DALINAC Recirculations*

2223

S. Franke, W. Ackermann, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany
R. Eichhorn, F. Hug, C. Klose, N. Pietralla, M. Platz
TU Darmstadt, Darmstadt, Germany

Funding: Work supported by DFG under contract SFB 634.
The Superconducting Linear Accelerator S-DALINAC installed at the institute of nuclear physics (IKP) at TU Darmstadt is designed as a re-circulating linear accelerator. The length of the beam line and the numerous accelerating structures as well as dipole and quadrupole magnets require a highly efficient numerical simulation tool in order to assist the operators by providing a detailed and almost instantaneous insight into the actual machine status. A suitable approach which enables a fast online calculation of the beam dynamics is given by the so-called moment approach where the particle distribution is represented by means of a discrete set of moments or by multiple discrete sets of moments in a multi-ensemble environment. Following this approach the V-Code simulation tool has been implemented at the Computational Electromagnetics Laboratory (TEMF) at TU Darmstadt. In this contribution an overview of the numerical model is presented together with new V-Code simulation results regarding the S-DALINAC recirculation sections.

WEPC093

Various Approaches to Electromagnetic Field Simulations for RF Cavities

2226

C. Liu, W. Ackermann, W.F.O. Müller, T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Work supported by BMBF under contract 05H09RD5
In the Superconducting Proton Linac (SPL) cavity, there is not only the fundamental mode for the particle acceleration but also many higher order modes (HOMs), which can lead to particle beam instabilities. This is very dangerous for SPL cavity. Therefore it is necessary to simulate the electromagnetic field in the SPL cavity, so that the field distribution and the shunt impedance for every higher order mode can be precisely calculated. At TEMF this research work can be done in three different ways: field simulation with hexahedron mesh in frequency domain, field simulation with hexahedron mesh in time domain and field simulation with tetrahedral mesh and higher order curvilinear elements. Finally the HOM coupler will be considered for the effective damping of higher order modes in the SPL cavity.