IPAC2015 - List of Authors (Ratzinger, U.)

Paper	Title	Page
MOPWA036	Status of Injection Studies into the Figure-8 Storage Ring	187
	J.F. Wagner, A. Ates, M. Droba, O. Meusel, H. Niebuhr, D. Noll, U. Ratzinger IAP, Frankfurt am Main, Germany
	The ongoing investigations on the design of the Figure-8 Storage Ring* at Frankfurt University focus on the beam injection. The research includes simulations as well as a scaled down experiment. The studies for an optimized adiabatic magnetic injection channel, starting from a moderate magnetic field up to a maximum of 6 Tesla, with a realistic field model of toroidal coils due to beam dynamics with space charge will be shown. For the envisaged ExB kicker system the simulations deal with beam potential constraints and a multi-turn injection concept in combination with an adiabatic magnetic compression. To investigate the concept of the beam injection into a toroidal magnetic field, a scaled down room temperature experiment is implemented at the university. It is composed of two 30 degree toroidal segments, two volume ion sources, two solenoids and two different types of beam detectors. The experiment is used to investigate the beam transport and dynamics of the laterally injected and “circulating” beam through the magnetic configuration. To set up the injection experiment, theoretical calculations and beam simulations with bender** are used. * M. Droba et al., Proc. of IPAC'14, Dresden, Germany, TUPRO045 ** D. Noll, M. Droba, O. Meusel, U. Ratzinger, K. Schulte, C.Wiesner, Proc. of HB2014, East Lansing, USA, WEO4LR02
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MOPHA025	Control System for FRANZ Facility	830
	S.M. Alzubaidi, O. Meusel, U. Ratzinger, C. Wagner IAP, Frankfurt am Main, Germany
	The Frankfurt Neutron Source at the Stern- Gerlach Zentrum (FRANZ) will use the reaction of 7Li(p, n)7Be to produce an intense neutron beam. The neutron energy will be between 10 and 500 keV depending on the primary proton beam, which is variable between 1.8 and 2.2 MeV. A volume type ion source will be used to deliver a 120 keV proton beam with currents up to 200 mA. Like any other facility, FRANZ will need a powerful and reliable control system that also allows monitoring the whole accelerator target areas and experiments. Also interlock and safety systems have to be included to protect personnel from radiation hazards associated with accelerator operations and accompanying experiments. The FRANZ control system is still under development. The ion source will be the first element to be controlled, and to gain experience. A test ion source will be used for testing and examining the performance of this control system. In this paper, the plasma properties, filament ageing and an internal control loop for stable beam production with respect to controlling issues will be discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA025
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TUXB1	FRANZ and Small-Scale Accelerator-Driven Neutron Sources	1276
	C. Wiesner, S.M. Alzubaidi, M. Droba, M. Heilmann, O. Hinrichs, B. Klump, O. Meusel, D. Noll, O. Payir, H. Podlech, U. Ratzinger, A. Schempp, S. Schmidt, P.P. Schneider, M. Schwarz, W. Schweizer, K. Volk, C. Wagner IAP, Frankfurt am Main, Germany R. Reifarth IKF, Frankfurt-am-Main, Germany
	This paper gives an overview of the opportunities and challenges of high-intensity, low-energy light-ion accelerators for neutron production. Applications of this technology range from the study of stellar nucleosynthesis and astrophysical phenomena to medical applications such as Boron neutron capture therapy (BNCT). The paper includes details of the FRANZ facility, under development at Frankfurt University.
	Slides TUXB1 [3.514 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUXB1
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TUXB2	Upgrade of the Unilac for Fair	1281
	L. Groening, A. Adonin, R. M. Brodhage, X. Du, R. Hollinger, O.K. Kester, S. Mickat, A. Orzhekhovskaya, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao GSI, Darmstadt, Germany H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede IAP, Frankfurt am Main, Germany
	The UNIversal Linear Accelerator (UNILAC) at GSI serves as injector for all ion species from protons to uranium since four decades. Its 10⁸ MHz Alvarez type DTL providing acceleration from 1.4 MeV/u to 11.4 MeV/u has suffered from material fatigue. The DTL will be replaced by a completely new section with almost same design parameters, i.e. pulsed current of up to 15 mA of 238U²⁸⁺ at 11.4 MeV/u. A dedicated terminal & LEBT for operation with 238U⁴⁺ is currently constructed. The uranium sources need to be upgraded in order to provide increased beam brilliances and for operation at 3 Hz. In parallel a 70 MeV / 70 mA proton linac based on H-mode cavities is under design and construction. This contribution will also give a brief summary of the overall status of the FAIR project.
	Slides TUXB2 [4.634 MB]
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THPF011	Status of the FAIR Proton Linac	3702
	R. M. Brodhage, M. Kaiser, W. Vinzenz, M. Vossberg GSI, Darmstadt, Germany U. Ratzinger IAP, Frankfurt am Main, Germany
	For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Within the last years, the assembly and tuning of the first power prototype was finished. The cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. Afterwards, the final drift tube structure has been welded inside the main tanks and the galvanic copper plating has taken place at GSI workshops. This paper will report on the recent advances with the prototype as well as on the current status of the overall p-Linac project.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF011
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THPF019	Status and First Measurement Results for a High Gradient CH-Cavity	3724
	A. Almomani, U. Ratzinger IAP, Frankfurt am Main, Germany
	Funding: BMBF, contract no. 05P12RFRB9 This pulsed linac activity aims on compact designs and on a considerable increase of the voltage gain per meter. A high gradient CH-cavity operated at 325 MHz was developed at IAP-Frankfurt. The mean effective accelerating field for this cavity is expected well above 10 MV/m at β = 0.164. This cavity is developed within a funded project. The results might influence the rebuilt of the UNILAC-Alvarez section, aiming to achieve the beam intensities specified for the GSI - FAIR project (15 mA U²⁸⁺). Another motivation is the development of an efficient pulsed ion accelerator for significantly higher energies like 60 AMeV. The new GSI 3 MW Thales klystron test stand will be used for the cavity RF power tests. Detailed studies on two different types of copper plating will be performed with this cavity.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF019
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THPF023	Massless Beam Separation System for Intense Ion Beams	3736
	O. Payir, M. Droba, O. Meusel, D. Noll, U. Ratzinger, P.P. Schneider, C. Wiesner IAP, Frankfurt am Main, Germany
	The ExB chopper* in the Low Energy Beam Transport (LEBT) section of the accelerator-driven neutron source FRANZ** will form the required pulses with a repetition rate of 257 kHz out of the primary 120 keV, 50 mA DC proton beam. A following beam separation system will extract the deflected beam out of the beamline and minimize the thermal load by beam losses in the vacuum chamber. To further avoid an uncontrolled production of secondary particles, a novel massless septum system is designed for the beam separation. The septum system consists of a static C-magnet with optimized pole shapes, which will extract the beam with minimal losses, and a magnetic shielding tube, which will shield the transmitted pulsed beam from the fringing field of the dipole. The magnetic field and the beam transport properties of the system were numerically investigated. A main deflection field of about 250 mT was achieved, whereas the fringing field was reduced to below 0.3 mT on the beam axis at 60 mm distance from the dipole. With this settings, the beam was numerically transported through the system with minimal emittance growth. Manufacturing of the septum system has started. * Wiesner, C., et al. "Chopping High-Intensity Ion Beams at FRANZ", WEIOB01, LINAC 2014. ** Meusel, O., et al. "FRANZ–Accelerator Test Bench And Neutron Source", MO3A03, LINAC 2012.
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THPF025	Beam Dynamics for the SC CW Heavy Ion LINAC at GSI	3742
	M. Schwarz, M. Amberg, M. Basten, F.D. Dziuba, H. Podlech, U. Ratzinger, R. Tiede IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, M. Miski-Oglu HIM, Mainz, Germany W.A. Barth, V. Gettmann, M. Heilmann, S. Mickat, A. Orzhekhovskaya, S. Yaramyshev GSI, Darmstadt, Germany
	Funding: Work supported by BMBF contr. No. 05P12RFRBL For future experiments with heavy ions near the coulomb barrier within the SHE (super-heavy elements) research project a multi-stage R&D program of GSI, HIM and IAP is currently in progress. It aims at developing a superconducting (sc) continuous wave (cw) LINAC with multiple CH cavities as key components downstream the High Charge Injector (HLI) at GSI. The beam dynamics concept is based on EQUUS (equidistant multigap structure) constant-beta cavities. Advantages of its periodicity are a high simulation accuracy, easy manufacturing and tuning with minimized costs as well as a straightforward energy variation. The next milestone will be a full performance beam test of the first LINAC section, comprising two solenoids and a 15-gap CH cavity inside a cryostat (Demonstrator). W. Barth et al., ‘‘Further R&D for a new Superconducting cw Heavy Ion LINAC@GSI'', THPME004, IPAC'14, Dresden, Germany (2014)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF025
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THPF026	Development of a 325 MHz Ladder-RFQ of the 4-Rod Type	3745
	M. Schütt, U. Ratzinger IAP, Frankfurt am Main, Germany R. M. Brodhage GSI, Darmstadt, Germany
	For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. In the low energy section, between the Ion Source and the main linac an RFQ will be used. The 325 MHz RFQ will accelerate protons from 95 keV to 3.0 MeV. This particular high frequency for an RFQ creates difficulties, which are challenging in developing this cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with a ladder type RFQ, which has been investigated since 2013. We present recent 3D simulations of the general layout and of a complete cavity demonstrating the power of a ladder type RFQ as well as measurements of a 0,8 m prototype RFQ, which was manufactured in late 2014 and designed for RF power and vacuum tests. We will outline a possible RF layout for the RFQ within the new FAIR proton injector and highlight the mechanical advantages.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF026
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Paper

Title

Page

Status of Injection Studies into the Figure-8 Storage Ring

187

J.F. Wagner, A. Ates, M. Droba, O. Meusel, H. Niebuhr, D. Noll, U. Ratzinger
IAP, Frankfurt am Main, Germany

The ongoing investigations on the design of the Figure-8 Storage Ring* at Frankfurt University focus on the beam injection. The research includes simulations as well as a scaled down experiment. The studies for an optimized adiabatic magnetic injection channel, starting from a moderate magnetic field up to a maximum of 6 Tesla, with a realistic field model of toroidal coils due to beam dynamics with space charge will be shown. For the envisaged ExB kicker system the simulations deal with beam potential constraints and a multi-turn injection concept in combination with an adiabatic magnetic compression. To investigate the concept of the beam injection into a toroidal magnetic field, a scaled down room temperature experiment is implemented at the university. It is composed of two 30 degree toroidal segments, two volume ion sources, two solenoids and two different types of beam detectors. The experiment is used to investigate the beam transport and dynamics of the laterally injected and “circulating” beam through the magnetic configuration. To set up the injection experiment, theoretical calculations and beam simulations with bender** are used.
* M. Droba et al., Proc. of IPAC'14, Dresden, Germany, TUPRO045
** D. Noll, M. Droba, O. Meusel, U. Ratzinger, K. Schulte, C.Wiesner, Proc. of HB2014, East Lansing, USA, WEO4LR02

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MOPHA025

Control System for FRANZ Facility

830

S.M. Alzubaidi, O. Meusel, U. Ratzinger, C. Wagner
IAP, Frankfurt am Main, Germany

The Frankfurt Neutron Source at the Stern- Gerlach Zentrum (FRANZ) will use the reaction of 7Li(p, n)7Be to produce an intense neutron beam. The neutron energy will be between 10 and 500 keV depending on the primary proton beam, which is variable between 1.8 and 2.2 MeV. A volume type ion source will be used to deliver a 120 keV proton beam with currents up to 200 mA. Like any other facility, FRANZ will need a powerful and reliable control system that also allows monitoring the whole accelerator target areas and experiments. Also interlock and safety systems have to be included to protect personnel from radiation hazards associated with accelerator operations and accompanying experiments. The FRANZ control system is still under development. The ion source will be the first element to be controlled, and to gain experience. A test ion source will be used for testing and examining the performance of this control system. In this paper, the plasma properties, filament ageing and an internal control loop for stable beam production with respect to controlling issues will be discussed.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-MOPHA025

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TUXB1

FRANZ and Small-Scale Accelerator-Driven Neutron Sources

1276

C. Wiesner, S.M. Alzubaidi, M. Droba, M. Heilmann, O. Hinrichs, B. Klump, O. Meusel, D. Noll, O. Payir, H. Podlech, U. Ratzinger, A. Schempp, S. Schmidt, P.P. Schneider, M. Schwarz, W. Schweizer, K. Volk, C. Wagner
IAP, Frankfurt am Main, Germany
R. Reifarth
IKF, Frankfurt-am-Main, Germany

This paper gives an overview of the opportunities and challenges of high-intensity, low-energy light-ion accelerators for neutron production. Applications of this technology range from the study of stellar nucleosynthesis and astrophysical phenomena to medical applications such as Boron neutron capture therapy (BNCT). The paper includes details of the FRANZ facility, under development at Frankfurt University.

Slides TUXB1 [3.514 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUXB1

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TUXB2

Upgrade of the Unilac for Fair

1281

L. Groening, A. Adonin, R. M. Brodhage, X. Du, R. Hollinger, O.K. Kester, S. Mickat, A. Orzhekhovskaya, B. Schlitt, G. Schreiber, H. Vormann, C. Xiao
GSI, Darmstadt, Germany
H. Hähnel, U. Ratzinger, A. Seibel, R. Tiede
IAP, Frankfurt am Main, Germany

The UNIversal Linear Accelerator (UNILAC) at GSI serves as injector for all ion species from protons to uranium since four decades. Its 10⁸ MHz Alvarez type DTL providing acceleration from 1.4 MeV/u to 11.4 MeV/u has suffered from material fatigue. The DTL will be replaced by a completely new section with almost same design parameters, i.e. pulsed current of up to 15 mA of 238U²⁸⁺ at 11.4 MeV/u. A dedicated terminal & LEBT for operation with 238U⁴⁺ is currently constructed. The uranium sources need to be upgraded in order to provide increased beam brilliances and for operation at 3 Hz. In parallel a 70 MeV / 70 mA proton linac based on H-mode cavities is under design and construction. This contribution will also give a brief summary of the overall status of the FAIR project.

Slides TUXB2 [4.634 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-TUXB2

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THPF011

Status of the FAIR Proton Linac

3702

R. M. Brodhage, M. Kaiser, W. Vinzenz, M. Vossberg
GSI, Darmstadt, Germany
U. Ratzinger
IAP, Frankfurt am Main, Germany

For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. The main acceleration of this room temperature linac will be provided by six CH cavities operated at 325 MHz. Within the last years, the assembly and tuning of the first power prototype was finished. The cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. Afterwards, the final drift tube structure has been welded inside the main tanks and the galvanic copper plating has taken place at GSI workshops. This paper will report on the recent advances with the prototype as well as on the current status of the overall p-Linac project.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF011

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THPF019

Status and First Measurement Results for a High Gradient CH-Cavity

3724

A. Almomani, U. Ratzinger
IAP, Frankfurt am Main, Germany

Funding: BMBF, contract no. 05P12RFRB9
This pulsed linac activity aims on compact designs and on a considerable increase of the voltage gain per meter. A high gradient CH-cavity operated at 325 MHz was developed at IAP-Frankfurt. The mean effective accelerating field for this cavity is expected well above 10 MV/m at β = 0.164. This cavity is developed within a funded project. The results might influence the rebuilt of the UNILAC-Alvarez section, aiming to achieve the beam intensities specified for the GSI - FAIR project (15 mA U²⁸⁺). Another motivation is the development of an efficient pulsed ion accelerator for significantly higher energies like 60 AMeV. The new GSI 3 MW Thales klystron test stand will be used for the cavity RF power tests. Detailed studies on two different types of copper plating will be performed with this cavity.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF019

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THPF023

Massless Beam Separation System for Intense Ion Beams

3736

O. Payir, M. Droba, O. Meusel, D. Noll, U. Ratzinger, P.P. Schneider, C. Wiesner
IAP, Frankfurt am Main, Germany

The ExB chopper* in the Low Energy Beam Transport (LEBT) section of the accelerator-driven neutron source FRANZ** will form the required pulses with a repetition rate of 257 kHz out of the primary 120 keV, 50 mA DC proton beam. A following beam separation system will extract the deflected beam out of the beamline and minimize the thermal load by beam losses in the vacuum chamber. To further avoid an uncontrolled production of secondary particles, a novel massless septum system is designed for the beam separation. The septum system consists of a static C-magnet with optimized pole shapes, which will extract the beam with minimal losses, and a magnetic shielding tube, which will shield the transmitted pulsed beam from the fringing field of the dipole. The magnetic field and the beam transport properties of the system were numerically investigated. A main deflection field of about 250 mT was achieved, whereas the fringing field was reduced to below 0.3 mT on the beam axis at 60 mm distance from the dipole. With this settings, the beam was numerically transported through the system with minimal emittance growth. Manufacturing of the septum system has started.
* Wiesner, C., et al. "Chopping High-Intensity Ion Beams at FRANZ", WEIOB01, LINAC 2014.
** Meusel, O., et al. "FRANZ–Accelerator Test Bench And Neutron Source", MO3A03, LINAC 2012.

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THPF025

Beam Dynamics for the SC CW Heavy Ion LINAC at GSI

3742

M. Schwarz, M. Amberg, M. Basten, F.D. Dziuba, H. Podlech, U. Ratzinger, R. Tiede
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, M. Miski-Oglu
HIM, Mainz, Germany
W.A. Barth, V. Gettmann, M. Heilmann, S. Mickat, A. Orzhekhovskaya, S. Yaramyshev
GSI, Darmstadt, Germany

Funding: Work supported by BMBF contr. No. 05P12RFRBL
For future experiments with heavy ions near the coulomb barrier within the SHE (super-heavy elements) research project a multi-stage R&D program of GSI, HIM and IAP is currently in progress*. It aims at developing a superconducting (sc) continuous wave (cw) LINAC with multiple CH cavities as key components downstream the High Charge Injector (HLI) at GSI. The beam dynamics concept is based on EQUUS (equidistant multigap structure) constant-beta cavities. Advantages of its periodicity are a high simulation accuracy, easy manufacturing and tuning with minimized costs as well as a straightforward energy variation. The next milestone will be a full performance beam test of the first LINAC section, comprising two solenoids and a 15-gap CH cavity inside a cryostat (Demonstrator).
*W. Barth et al., ‘‘Further R&D for a new Superconducting cw Heavy Ion LINAC@GSI'', THPME004, IPAC'14, Dresden, Germany (2014)

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF025

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THPF026

Development of a 325 MHz Ladder-RFQ of the 4-Rod Type

3745

M. Schütt, U. Ratzinger
IAP, Frankfurt am Main, Germany
R. M. Brodhage
GSI, Darmstadt, Germany

For the research program with cooled antiprotons at FAIR a dedicated 70 MeV, 70 mA proton injector is required. In the low energy section, between the Ion Source and the main linac an RFQ will be used. The 325 MHz RFQ will accelerate protons from 95 keV to 3.0 MeV. This particular high frequency for an RFQ creates difficulties, which are challenging in developing this cavity. In order to define a satisfactory geometrical configuration for this resonator, both from the RF and the mechanical point of view, different designs have been examined and compared. Very promising results have been reached with a ladder type RFQ, which has been investigated since 2013. We present recent 3D simulations of the general layout and of a complete cavity demonstrating the power of a ladder type RFQ as well as measurements of a 0,8 m prototype RFQ, which was manufactured in late 2014 and designed for RF power and vacuum tests. We will outline a possible RF layout for the RFQ within the new FAIR proton injector and highlight the mechanical advantages.

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reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2015-THPF026

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