LINAC2012 - List of Authors (Neumann, A.)

Paper

Title

Page

Alternative Approaches for HOM-Damped Cavities

330

B. Riemann, T. Weis
DELTA, Dortmund, Germany
A. Neumann
HZB, Berlin, Germany

Funding: this work is partly funded by BMBF contract no. 05K10PEA
Elliptical cavities have been a standard in SRF linac technology for 30 years. We present another approach to base cell geometry based on Bezier splines, that leads to equal performance levels and is much more flexible in terms of optimization. Using the BERLinPro main linac as an example, a spline multicell cavity is designed with equal performance goals. For the damping of higher order modes (HOMs), the installation of waveguides at the ends of a multicell cavity is a common approach.

MOPB067

Results and Performance Simulations of the Main Linac Design for BERLinPro

333

A. Neumann, W. Anders, J. Knobloch
HZB, Berlin, Germany
K. Brackebusch, T. Flisgen, T. Galek, K. Papke, U. van Rienen
Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany
B. Riemann, T. Weis
DELTA, Dortmund, Germany

Funding: this work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC
The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities damped by on the whole five waveguides at both ends. Eigenmode computations for geometrical figures of merit show that the present design should allow successful CW linac operation at the maximum beam current of 100 mA/77 pC bunch charge. To verify the results, the external Q factors are compared to the results of S-Parameter simulations that are postprocessed by a pole-fitting technique. First results of scattering parameter measurement on a room-temperature aluminium model are discussed. An outlook presenting the possibilities of combined multi-cavity simulations is included.

THPLB12

Photoinjector SRF Cavity Development for BERLinPro

837

A. Neumann, W. Anders, T. Kamps, J. Knobloch
HZB, Berlin, Germany
E.N. Zaplatin
FZJ, Jülich, Germany

In 2010 HZB has received approval to build BERLinPro, an ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.5 MeV kinetic energy while limited by fundamental power coupler performance to about 200 kW forward power. In oder to achieve these goals the injector cavity is being developed in a three stage approach. The current design studies focus on implementing a normal conducting cathode insert into a newly developed superconducting photoinjector cavity. In this paper the fundamental RF design calculations concerning cell shape for optimized beam dynamics as well as SRF performance will be presented. Further studies concentrate on the HZDR based choke cell design to implement the high quantum efficiency normal conducting cathode with the SRF cavity.

Slides THPLB12 [1.431 MB]

THPB066

Photoinjector SRF Cavity Development for BERLinPro

993

A. Neumann, W. Anders, T. Kamps, J. Knobloch
HZB, Berlin, Germany
E.N. Zaplatin
FZJ, Jülich, Germany

In 2010 HZB has received approval to build BERLinPro, an ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.5 MeV kinetic energy while limited by fundamental power coupler performance to about 200 kW forward power. In oder to achieve these goals the injector cavity is being developed in a three stage approach. The current design studies focus on implementing a normal conducting cathode insert into a newly developed superconducting photoinjector cavity. In this paper the fundamental RF design calculations concerning cell shape for optimized beam dynamics as well as SRF performance will be presented. Further studies concentrate on the HZDR based choke cell design to implement the high quantum efficiency normal conducting cathode with the SRF cavity.

THPB069

Beam Dynamics Studies for SRF Photoinjectors

999

T. Kamps, A. Neumann, J. Völker
HZB, Berlin, Germany

The SRF photoinjector combines the advantages of photo-assisted production of high brightness, short electron pulses and high gradient, low-loss continuous wave (CW) operation of a superconducting radiofrequency (SRF) cavity. The paper discusses beam dynamics considerations for FEL and ERL class applications of SRF photoinjectors. One case of particular interest is the design of the SRF photoinjector for BERLinPro, an ERL test facility demanding a high brightness beam with an emittance better than 1 mm mrad at 77 pC and average current of 100 mA.

Paper	Title	Page
MOPB066	Alternative Approaches for HOM-Damped Cavities	330
	B. Riemann, T. Weis DELTA, Dortmund, Germany A. Neumann HZB, Berlin, Germany
	Funding: this work is partly funded by BMBF contract no. 05K10PEA Elliptical cavities have been a standard in SRF linac technology for 30 years. We present another approach to base cell geometry based on Bezier splines, that leads to equal performance levels and is much more flexible in terms of optimization. Using the BERLinPro main linac as an example, a spline multicell cavity is designed with equal performance goals. For the damping of higher order modes (HOMs), the installation of waveguides at the ends of a multicell cavity is a common approach.

MOPB067	Results and Performance Simulations of the Main Linac Design for BERLinPro	333
	A. Neumann, W. Anders, J. Knobloch HZB, Berlin, Germany K. Brackebusch, T. Flisgen, T. Galek, K. Papke, U. van Rienen Rostock University, Faculty of Computer Science and Electrical Engineering, Rostock, Germany B. Riemann, T. Weis DELTA, Dortmund, Germany
	Funding: this work is partly funded by BMBF contract no. 05K10PEA and 05K10HRC The Berlin Energy Recovery Linac Project (BERLinPro) is designed to develop and demonstrate CW LINAC technology for 100-mA-class ERLs. High-current operation requires an effective damping of higher-order modes (HOMs) of the 1.3 GHz main-linac cavities. We have studied elliptical 7-cell cavities damped by on the whole five waveguides at both ends. Eigenmode computations for geometrical figures of merit show that the present design should allow successful CW linac operation at the maximum beam current of 100 mA/77 pC bunch charge. To verify the results, the external Q factors are compared to the results of S-Parameter simulations that are postprocessed by a pole-fitting technique. First results of scattering parameter measurement on a room-temperature aluminium model are discussed. An outlook presenting the possibilities of combined multi-cavity simulations is included.

THPLB12	Photoinjector SRF Cavity Development for BERLinPro	837
	A. Neumann, W. Anders, T. Kamps, J. Knobloch HZB, Berlin, Germany E.N. Zaplatin FZJ, Jülich, Germany
	In 2010 HZB has received approval to build BERLinPro, an ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.5 MeV kinetic energy while limited by fundamental power coupler performance to about 200 kW forward power. In oder to achieve these goals the injector cavity is being developed in a three stage approach. The current design studies focus on implementing a normal conducting cathode insert into a newly developed superconducting photoinjector cavity. In this paper the fundamental RF design calculations concerning cell shape for optimized beam dynamics as well as SRF performance will be presented. Further studies concentrate on the HZDR based choke cell design to implement the high quantum efficiency normal conducting cathode with the SRF cavity.
	Slides THPLB12 [1.431 MB]

THPB066	Photoinjector SRF Cavity Development for BERLinPro	993
	A. Neumann, W. Anders, T. Kamps, J. Knobloch HZB, Berlin, Germany E.N. Zaplatin FZJ, Jülich, Germany
	In 2010 HZB has received approval to build BERLinPro, an ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.5 MeV kinetic energy while limited by fundamental power coupler performance to about 200 kW forward power. In oder to achieve these goals the injector cavity is being developed in a three stage approach. The current design studies focus on implementing a normal conducting cathode insert into a newly developed superconducting photoinjector cavity. In this paper the fundamental RF design calculations concerning cell shape for optimized beam dynamics as well as SRF performance will be presented. Further studies concentrate on the HZDR based choke cell design to implement the high quantum efficiency normal conducting cathode with the SRF cavity.

THPB069	Beam Dynamics Studies for SRF Photoinjectors	999
	T. Kamps, A. Neumann, J. Völker HZB, Berlin, Germany
	The SRF photoinjector combines the advantages of photo-assisted production of high brightness, short electron pulses and high gradient, low-loss continuous wave (CW) operation of a superconducting radiofrequency (SRF) cavity. The paper discusses beam dynamics considerations for FEL and ERL class applications of SRF photoinjectors. One case of particular interest is the design of the SRF photoinjector for BERLinPro, an ERL test facility demanding a high brightness beam with an emittance better than 1 mm mrad at 77 pC and average current of 100 mA.