IPAC2011 - List of Authors (Schempp, A.)

Paper

Title

Page

A Coupled RFQ-IH Combination for the Neutron Source FRANZ

74

M. Heilmann, O. Meusel, D. Mäder, U. Ratzinger, A. Schempp
IAP, Frankfurt am Main, Germany

Funding: HIC for FAIR
The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum is driven by a 2 MeV proton linac consisting of a 4-rod-radio-frequency-quadrupol (RFQ) and an 8 gap IH-DTL structure. RFQ and IH cavity will be powered by only one radio frequency (RF) amplifier to reduce costs. The RF-amplifier of the RFQ-IH combination is coupled into the RFQ. Internal inductive coupling along the axis connects the RFQ with the IH cavity ensuring the required power transition as well as a fixed phase relation between the two structures. The main acceleration of 120 keV up to 2.03 MeV will be reached by the RFQ-IH combination with 175 MHz and at a total length of 2.3 m. The losses in the RFQ-IH combination are about 200 kW.

MOPC028

Beam Acceleration of DPIS RFQ at IMP

128

Z.L. Zhang, X.H. Guo, Y. He, Y. Liu, S. Sha, A. Shi, L.P. Sun, H.W. Zhao
IMP, Lanzhou, People's Republic of China
R.A. Jameson, A. Schempp
IAP, Frankfurt am Main, Germany
M. Okamura
BNL, Upton, Long Island, New York, USA

Beam test of the direct plasma injection scheme (DPIS) is carried out successfully for the first time in China, by setting up a comprehensive test and research platform of RFQ and laser ion source. The C⁶⁺ beam is accelerated successfully, and the peak beam current reaches more than 6mA which is measured by a Faraday cup of unique structure. The RF power coupled into the RFQ cavity is also examined, and results reveal that it is the RF power of about 195kW that can produce the peak beam current.

WEPS034

A CW RFQ Prototype

2559

U. Bartz, A. Schempp
IAP, Frankfurt am Main, Germany

A short RFQ prototype was built for RF-tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. HF-simulations with CST Microwave Studio and measurements were done. The cw-tests with 20 kW/m RF-power and simulations of thermal effects with ALGOR were finished successfully. The optimization of some details of the HF design is on focus now. First results and the status of the project will be presented.

WEPS035

Beam Measurements with the New RFQ Beam Matching Section at the Frankfurt Funneling Experiment

2562

M. Baschke, A. Schempp, J.S. Schmidt
IAP, Frankfurt am Main, Germany
H. Zimmermann
Accelerator Services, Oberursel, Germany

Funding: BMBF
Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. A new beam transport system between RFQ accelerator and deflector has been constructed and mounted. With these extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefore unwanted emittance growth reduced. After first rf measurements current work are beam tests with the improved Two-Beam-RFQ. First results will be presented.

WEPS037

RF Design of a 325 MHz 4-ROD RFQ

2568

B. Koubek, A. Schempp, J.S. Schmidt
IAP, Frankfurt am Main, Germany
L. Groening
GSI, Darmstadt, Germany

Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.

WEPS039

General Layout of the 17 MeV Injector for MYRRHA

2574

H. Podlech, M. Busch, F.D. Dziuba, H. Klein, D. Mäder, U. Ratzinger, A. Schempp, R. Tiede, C. Zhang
IAP, Frankfurt am Main, Germany
M. Amberg
HIM, Mainz, Germany

Funding: European Union FP7 MAX Contract Number 269565
The MYRRHA Project (Multi Purpose Hybrid Reactor for High Tech Applications) at Mol/belgium will be a user facility with emphasis on research with neutron generated by a spallation source. One main aspect is the demonstration of nuclear waste technology using an accelerator driven system. A superconducting linac delivers a 4 mA, 600 MeV proton beam. The first accelerating section is covered by the 17 MeV injector. It consists of a proton source, an RFQ, two room temperature CH cavities and 4 superconducting CH-cavities. The initial design has used an RF frequency of 352 MHz. Recently the frequency of the injector has been set to 176 MHz. The main reason is the possible use of a 4-rod-RFQ with reduced power dissipation and energy, respectively. The status of the overall injector layout including cavity design is presented.

Poster WEPS039 [2.281 MB]

WEPS041

Tuning of the New 4-Rod RFQ for FNAL

2580

J.S. Schmidt, B. Koubek, A. Schempp
IAP, Frankfurt am Main, Germany

For the injector upgrade at FNAL a 4-rod Radio Frequency Quadrupole (RFQ) with a resonance frequency of 200 MHz has been build. With this short structure of only 1.3 m a very compact injector design has been realized. Simulations with CST Microwave Studio® were performed for the design. Their results leading to the RF characterizations of the RFQ and the final RF setup which has been accomplished at IAP of the Goethe-University Frankfurt are presented in this paper.

WEPS043

From EUROTRANS to MAX: New Strategies and Approaches for the Injector Development

2583

C. Zhang, H. Klein, D. Mäder, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
IAP, Frankfurt am Main, Germany

Funding: The research leading to these results has received funding from the European Atomic Energy Community’s (Euratom) Seventh Framework Programme FP7/2007-2011 under grant agreement n° [269565].
As the successor of the EUROTRANS project, the MAX project is aiming to continue the R&D effects for a European Accelerator-Driven System and to bring the conceptual design to reality. The layout of the driver linac for MAX will follow the reference design made for the XT-ADS phase of the EUROTRANS project. For the injector part, new design strategies and approaches, e.g. half resonant frequency, half transition-energy between the RFQ and the CH-DTL, and using the 4-rod RFQ structure instead of the originally proposed 4-vane RFQ, have been conceived and studied to reach a more reliable CW operation at reduced costs. In this paper, the design and simulation results of the MAX injector are presented.

WEPS068

Progress towards an RFQ-based Front End for LANSCE

2658

R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk
LANL, Los Alamos, New Mexico, USA
A. Schempp
IAP, Frankfurt am Main, Germany

Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396.
The LANSCE linear accelerator at Los Alamos National Laboratory provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.

WEPS040

The Driver Linac of the Neutron Source FRANZ

2577

U. Ratzinger, B. Basten, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, M. Lotz, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, A. Schempp, W. Schweizer, K. Volk, C. Wiesner, C. Zhang
IAP, Frankfurt am Main, Germany

FRANZ is under construction at the Goethe University Frankfurt. A 2MeV ± 100 keV proton beam will produce 1 keV to 200 keV neutrons on a Li7 target. Experiments are planned in the field of nuclear astrophysics as well as in applied physics. A dc operated proton source with a maximum beam current of 200 mA was successfully beam tested end of 2010. FRANZ will have two experimental areas: One for activation experiments with cw proton beams of a few mA generating a usable neutron flux of some 10 billion per square cm per second, the other one for 250 kHz, 1 ns short neutron bunches generated by 1 ns proton pulses of a few Ampere beam current. A special 2 MeV, 175 MHz high current cavity is realized at present as a RFQ-DTL combination. Novel techniques have been invented to reach the needed pulsed target beam current by a bunch compressor system.
Work supported by HICforFAIR and GSI.

Paper	Title	Page
MOPC006	A Coupled RFQ-IH Combination for the Neutron Source FRANZ	74
	M. Heilmann, O. Meusel, D. Mäder, U. Ratzinger, A. Schempp IAP, Frankfurt am Main, Germany
	Funding: HIC for FAIR The Frankfurt Neutron Source at the Stern-Gerlach-Zentrum is driven by a 2 MeV proton linac consisting of a 4-rod-radio-frequency-quadrupol (RFQ) and an 8 gap IH-DTL structure. RFQ and IH cavity will be powered by only one radio frequency (RF) amplifier to reduce costs. The RF-amplifier of the RFQ-IH combination is coupled into the RFQ. Internal inductive coupling along the axis connects the RFQ with the IH cavity ensuring the required power transition as well as a fixed phase relation between the two structures. The main acceleration of 120 keV up to 2.03 MeV will be reached by the RFQ-IH combination with 175 MHz and at a total length of 2.3 m. The losses in the RFQ-IH combination are about 200 kW.

MOPC028	Beam Acceleration of DPIS RFQ at IMP	128
	Z.L. Zhang, X.H. Guo, Y. He, Y. Liu, S. Sha, A. Shi, L.P. Sun, H.W. Zhao IMP, Lanzhou, People's Republic of China R.A. Jameson, A. Schempp IAP, Frankfurt am Main, Germany M. Okamura BNL, Upton, Long Island, New York, USA
	Beam test of the direct plasma injection scheme (DPIS) is carried out successfully for the first time in China, by setting up a comprehensive test and research platform of RFQ and laser ion source. The C⁶⁺ beam is accelerated successfully, and the peak beam current reaches more than 6mA which is measured by a Faraday cup of unique structure. The RF power coupled into the RFQ cavity is also examined, and results reveal that it is the RF power of about 195kW that can produce the peak beam current.

WEPS034	A CW RFQ Prototype	2559
	U. Bartz, A. Schempp IAP, Frankfurt am Main, Germany
	A short RFQ prototype was built for RF-tests of high power RFQ structures. We will study thermal effects and determine critical points of the design. HF-simulations with CST Microwave Studio and measurements were done. The cw-tests with 20 kW/m RF-power and simulations of thermal effects with ALGOR were finished successfully. The optimization of some details of the HF design is on focus now. First results and the status of the project will be presented.

WEPS035	Beam Measurements with the New RFQ Beam Matching Section at the Frankfurt Funneling Experiment	2562
	M. Baschke, A. Schempp, J.S. Schmidt IAP, Frankfurt am Main, Germany H. Zimmermann Accelerator Services, Oberursel, Germany
	Funding: BMBF Funneling is a method to increase low energy beam currents in multiple stages. The Frankfurt Funneling Experiment is a model of such a stage. The experiment is built up of two ion sources with electrostatic lens systems, a Two-Beam-RFQ accelerator, a funneling deflector and a beam diagnostic system. The two beams are bunched and accelerated in a Two-Beam RFQ. A funneling deflector combines the bunches to a common beam axis. A new beam transport system between RFQ accelerator and deflector has been constructed and mounted. With these extended RFQ-electrodes the drift between the Two-Beam-RFQ and the rf-deflector will be minimized and therefore unwanted emittance growth reduced. After first rf measurements current work are beam tests with the improved Two-Beam-RFQ. First results will be presented.

WEPS037	RF Design of a 325 MHz 4-ROD RFQ	2568
	B. Koubek, A. Schempp, J.S. Schmidt IAP, Frankfurt am Main, Germany L. Groening GSI, Darmstadt, Germany
	Usually 4-ROD Radio Frequency Quadrupoles (RFQ) are built for frequencies up to 216 MHz. For higher frequencies 4-VANE structures are more common. The advantages of 4-Rod structures, the greater flexibility for tuning and being more comfortable for maintenance, are motivating the development of a 4-Rod RFQ for higher frequencies than 216 MHz. In particular a 325 MHz RFQ with an output energy of 3 MeV is needed for the proton linac for the FAIR project of GSI. This paper reports about the design studies and the latest developments of this RFQ.

WEPS039	General Layout of the 17 MeV Injector for MYRRHA	2574
	H. Podlech, M. Busch, F.D. Dziuba, H. Klein, D. Mäder, U. Ratzinger, A. Schempp, R. Tiede, C. Zhang IAP, Frankfurt am Main, Germany M. Amberg HIM, Mainz, Germany
	Funding: European Union FP7 MAX Contract Number 269565 The MYRRHA Project (Multi Purpose Hybrid Reactor for High Tech Applications) at Mol/belgium will be a user facility with emphasis on research with neutron generated by a spallation source. One main aspect is the demonstration of nuclear waste technology using an accelerator driven system. A superconducting linac delivers a 4 mA, 600 MeV proton beam. The first accelerating section is covered by the 17 MeV injector. It consists of a proton source, an RFQ, two room temperature CH cavities and 4 superconducting CH-cavities. The initial design has used an RF frequency of 352 MHz. Recently the frequency of the injector has been set to 176 MHz. The main reason is the possible use of a 4-rod-RFQ with reduced power dissipation and energy, respectively. The status of the overall injector layout including cavity design is presented.
	Poster WEPS039 [2.281 MB]

WEPS041	Tuning of the New 4-Rod RFQ for FNAL	2580
	J.S. Schmidt, B. Koubek, A. Schempp IAP, Frankfurt am Main, Germany
	For the injector upgrade at FNAL a 4-rod Radio Frequency Quadrupole (RFQ) with a resonance frequency of 200 MHz has been build. With this short structure of only 1.3 m a very compact injector design has been realized. Simulations with CST Microwave Studio® were performed for the design. Their results leading to the RF characterizations of the RFQ and the final RF setup which has been accomplished at IAP of the Goethe-University Frankfurt are presented in this paper.

WEPS043	From EUROTRANS to MAX: New Strategies and Approaches for the Injector Development	2583
	C. Zhang, H. Klein, D. Mäder, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede IAP, Frankfurt am Main, Germany
	Funding: The research leading to these results has received funding from the European Atomic Energy Community’s (Euratom) Seventh Framework Programme FP7/2007-2011 under grant agreement n° [269565]. As the successor of the EUROTRANS project, the MAX project is aiming to continue the R&D effects for a European Accelerator-Driven System and to bring the conceptual design to reality. The layout of the driver linac for MAX will follow the reference design made for the XT-ADS phase of the EUROTRANS project. For the injector part, new design strategies and approaches, e.g. half resonant frequency, half transition-energy between the RFQ and the CH-DTL, and using the 4-rod RFQ structure instead of the originally proposed 4-vane RFQ, have been conceived and studied to reach a more reliable CW operation at reduced costs. In this paper, the design and simulation results of the MAX injector are presented.

WEPS068	Progress towards an RFQ-based Front End for LANSCE	2658
	R.W. Garnett, S.S. Kurennoy, J.F. O'Hara, L. Rybarcyk LANL, Los Alamos, New Mexico, USA A. Schempp IAP, Frankfurt am Main, Germany
	Funding: This work is supported by the U. S. Department of Energy Contract DE-AC52-06NA25396. The LANSCE linear accelerator at Los Alamos National Laboratory provides H⁻ and H⁺ beams to several user facilities that support Isotope Production, NNSA Stockpile Stewardship, and Basic Energy Science programs. These beams are initially accelerated to 750 keV using Cockcroft-Walton (CW) based injectors that have been in operation for over 37 years. They have failure modes which can result in prolonged operational downtime due to the unavailability of replacement parts. To reduce long-term operational risks and to realize future beam performance goals in support of the Materials Test Station (MTS) and the Matter-Radiation Interactions in Extremes (MaRIE) Facility, plans are underway to develop a Radio-Frequency Quadrupole (RFQ) based front end as a modern injector replacement for the existing CW injectors. Our progress to date will be discussed.

WEPS040	The Driver Linac of the Neutron Source FRANZ	2577
	U. Ratzinger, B. Basten, L.P. Chau, H. Dinter, M. Droba, M. Heilmann, M. Lotz, O. Meusel, I. Müller, D. Mäder, Y.C. Nie, D. Noll, H. Podlech, A. Schempp, W. Schweizer, K. Volk, C. Wiesner, C. Zhang IAP, Frankfurt am Main, Germany
	FRANZ is under construction at the Goethe University Frankfurt. A 2MeV ± 100 keV proton beam will produce 1 keV to 200 keV neutrons on a Li7 target. Experiments are planned in the field of nuclear astrophysics as well as in applied physics. A dc operated proton source with a maximum beam current of 200 mA was successfully beam tested end of 2010. FRANZ will have two experimental areas: One for activation experiments with cw proton beams of a few mA generating a usable neutron flux of some 10 billion per square cm per second, the other one for 250 kHz, 1 ns short neutron bunches generated by 1 ns proton pulses of a few Ampere beam current. A special 2 MeV, 175 MHz high current cavity is realized at present as a RFQ-DTL combination. Novel techniques have been invented to reach the needed pulsed target beam current by a bunch compressor system. Work supported by HICforFAIR and GSI.