Author: Ratzinger, U.
Paper Title Page
THPWO069 Development of the NICA Injection Facility 3915
 
  • A.V. Butenko, E.D. Donets, E.E. Donets, V.V. Fimushkin, A. Govorov, A.D. Kovalenko, K.A. Levterov, I.N. Meshkov, V. Monchinsky, A.Yu. Ramsdorf, A.O. Sidorin, G.V. Trubnikov
    JINR, Dubna, Moscow Region, Russia
  • H. Hoeltermann, H. Podlech, U. Ratzinger, A. Schempp
    BEVATECH OHG, Offenbach/Main, Germany
  • A. Kolomiets, G. Kropachev, T. Kulevoy
    ITEP, Moscow, Russia
  • S.M. Polozov
    MEPhI, Moscow, Russia
 
  The new accelerator complex Nuclotron-based Ion Collider fAcility (NICA) is assumed to operate using two injectors: the Alvarez-type linac LU-20 as injector for light ions, polarized protons and deuterons and a new linac HILac for heavy ions. The main features of ion sources and both linacs are presented. Upgrade for pre-accelerator of LU-20 is described.  
 
MOPFI010 Initial Beam Loss and Control of Dynamic Vacuum Effects in SIS18 300
 
  • Y. El-Hayek
    FIAS, Frankfurt am Main, Germany
  • M.M. Kirk, D. Ondreka, P.J. Spiller
    GSI, Darmstadt, Germany
  • U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  To stabilize the dynamic pressure in the SIS18, the systematic initial beam loss must be minimized. Beam Particles, which are lost on the vaccum chamber cause a local pressure increase. Thereby the collision rate between beam ions and residual gas particles and consequently beam loss by ionization is enhanced. The reduction and control of beam loss in the injection channel, during multiturn injection and during the Rf capture process has an outstanding importance for the vacuum dynamics. One way to minimize the initial losses in the synchrotron is to displace the beam loss into the transfer channel (TK) between UNILAC and SIS. In the transfer channel, the beam edges are trimmed by means of a collimator system and a sharply defined phase space area can be injected into SIS18. The effect of reduced initial beam loss on the vaccum dynamics is presented.  
 
TUPWO008 High-Current Beam Transport Simulations Including Gabor Lenses in Varying Non-Neutral Plasma States 1892
 
  • M. Droba, H. Dinter, O. Meusel, D. Noll, U. Ratzinger, K. Schulte
    IAP, Frankfurt am Main, Germany
 
  The Gabor space charge lens has theoretically and experimentally been investigated at IAP for many years. Especially the application in high current, Low Energy Beam Transport (LEBT) sections seems efficient and attractive. The focusing properties and imaging quality of this lens type depend on the transverse and longitudinal confinement of the electron column. Different non-neutral plasma states have been observed and calculated. In general, they can be disturbed by the interaction with ion beams. This results in a shift and in a modification of the work function with a rise of aberrations and beam emittance growth. It is necessary to understand such processes for transport channels using intense ion beams to preserve the high beam brilliance. The beam transport simulations including Gabor lenses in various non-neutral plasma states will be presented and compared with experimental results.  
 
WEPWO005 Microphonics Analysis of the SC 325 MHz CH-Cavity 2319
 
  • M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • M. Amberg, K. Aulenbacher
    HIM, Mainz, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
 
  Since the walls of superconducting (sc) cavities are kept very thin to support the cooling process, even small mechanical disturbances can detune the cavity. One of the main sources of detuning a cavity is microphonics. These low-frequent vibrations caused by vacuum pumps or underground noise are transferred to the cryostat and excite mechanical resonances of the cavity which may lead to frequency shifts larger than the bandwidth. To determine the mechanical resonance frequencies of the sc 325 MHz CH-cavity (Crossbar-H-Mode) simulations with ANSYS Workbench have been performed in a first step. Additionally, microphonics measurements were taken at room temperature as well as in a vertical cryostat at 4K in the cryo-lab of the IAP, Frankfurt University. Furthermore, the contraction of the cavity walls and the resulting frequency shift due to the cavity cool-down has been measured. A comparison between simulation results and the measured values is presented in this paper.  
 
THPWO007 Advanced Superconducting CW Heavy Ion Linac R&D 3770
 
  • W.A. Barth, S. Mickat, A. Orzhekhovskaya
    GSI, Darmstadt, Germany
  • M. Amberg, K. Aulenbacher, V. Gettmann, S. Jacke
    HIM, Mainz, Germany
  • F.D. Dziuba, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  An advanced upgrade program has to be realized in the next years, such that enhanced primary beam intensities are available. For this a new sc 28 GHz full performance ECR ion source has to be established. Via a new low energy beam line an already installed new RFQ and an IH-DTL will provide for cw-heavy ion beams with high average beam intensity. It is foreseen to build a new cw-heavy ion-linac behind this high charge state injector. In preparation an advanced R&D program is defined: The first linac section comprising a sc CH-cavity embedded by two sc solenoids (financed by HIM and partly by HGF-ARD-initiative) as a demonstrator will be tested in 2014). After successfull testing an advanced cryomodule comprising up to 4 rf cavities is foreseen. First layout scenarios of this advanced test bench will be presented.  
 
THPWO008 Status of the 70 MeV FAIR Proton Injector 3773
 
  • G. Clemente, W.A. Barth, R. Bereznov, P. Forck, L. Groening, R. Hollinger, M. Kaiser, A. Krämer, F. Maimone, C. Mühle, J. Pfister, G. Schreiber, J. Trüller, W. Vinzenz, C. Will
    GSI, Darmstadt, Germany
  • R. M. Brodhage, B. Koubek, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
  • N. Chauvin, O. Delferrière
    CEA/IRFU, Gif-sur-Yvette, France
  • B. Launé, J. Lesrel
    IPN, Orsay, France
  • C.S. Simon, O. Tuske
    CEA/DSM/IRFU, France
 
  Funding: BMBF
The FAIR project requires a dedicated proton injector for the creation of high intensity secondary antiproton beams. This machine will be the first high intensity linear accelerator based on CH-DTL. The status of the project, with particular emphasis on the construction of the first RF prototype is presented.
 
 
THPWO009 Beam Dynamics Error and Loss Investigation of the FAIR Proton Injector 3776
 
  • G. Clemente, W.A. Barth, P. Forck, L. Groening, R. Hollinger, M. Kaiser, J. Pfister, W. Vinzenz, S.G. Yaramyshev, C. Zhang
    GSI, Darmstadt, Germany
  • R. M. Brodhage, B. Koubek, H. Podlech, U. Ratzinger, A. Schempp, R. Tiede
    IAP, Frankfurt am Main, Germany
  • N. Chauvin, C.S. Simon, O. Tuske
    CEA/DSM/IRFU, France
  • O. Delferrière
    CEA/IRFU, Gif-sur-Yvette, France
  • B. Launé, J. Lesrel
    IPN, Orsay, France
 
  The FAIR Proton Linac is a 70mA, 70 MeV. 325 MHz linear accelerator based on CH cavities. The focusing scheme is provided by an asynchronous KONUS lattice period. Random misalignment and rotation errors of the quadrupoles, together with phase and RF settings of the power source plays a major role in beam losses. Those effects are investigated and the beam dynamics results, including several source of errors, are presented and discussed.  
 
THPWO012 High Gradient Room Temperature Cavity Development for 10 – 100 AMeV Beams 3785
 
  • A. Almomani, U. Ratzinger
    IAP, Frankfurt am Main, Germany
 
  Funding: BMBF, 05P12RFRB9
These linac activities are aimed to increase the accelerating field gradient. In IAP – Frankfurt, a CH – design was proposed to post-accelerate a proton bunch, generated by an intense laser, from 10 – 15.2 MeV. The accelerating field gradient is expected to reach > 10 MV/m. Within a funded project, this cavity will be further developed towards a high gradient cavity. The availability of the GSI 3 MW klystron test stand will be very important for these investigations. The results will influence the rebuilt of the Unilac - Alvarez section, where the existing linac tunnel with 1 m thick concrete walls should house a powerful pulsed heavy ion linac, optimized for achieving finally the beam intensities specified for the GSI-FAIR project. The status of the cavity design will be presented.
 
 
THPWO014 Design Study of a High Frequency Proton Ladder RFQ 3788
 
  • R. M. Brodhage, A. Almomani, 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. In the low energy section, between the Ion Source and the main linac an RFQ has to be designed. Accelerating protons from 95 keV to 3.0 MeV the RFQ will oscillate at 325 MHz. 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 an ladder type RFQ, especially concerning the dipole component of the accelerating fields, which is almost not noticeable. This paper will show 3D simulations of the general layout and a whole cavity demonstrating the power of a ladder type RFQ. It will outline a possible layout for the RFQ within the new FAIR proton injector.  
 
THPWO015 First Coupled CH Power Cavity for the FAIR Proton Injector 3791
 
  • R. M. Brodhage, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • G. Clemente, W. Vinzenz
    GSI, Darmstadt, 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. Each cavity will be powered by a 2.5 MW Klystron. For the second acceleration unit from 11.5 MeV to 24.2 MeV a 1:2 scaled model has been built. Low level RF measurements have been performed to determine the main parameters and to prove the concept of coupled CH cavities. In Summer 2012, the assembly and tuning of the first power prototype was finished. Until then, the cavity was tested with a preliminary aluminum drift tube structure, which was used for precise frequency and field tuning. Before Spring 2013 the final drift tube structure will be welded inside the main tanks and the preparation for copper plating will take place. This paper will report on the main tuning and commissioning steps towards that novel type of DTL and it will show the latest results measured on a fully operational CH proton cavity.  
 
THPWO016 Superconducting CH Cavities for Heavy Ion Acceleration 3794
 
  • F.D. Dziuba, M. Amberg, M. Busch, H. Podlech, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
    HIM, Mainz, Germany
  • K. Aulenbacher
    IKP, Mainz, Germany
  • W.A. Barth, S. Mickat
    GSI, Darmstadt, Germany
 
  Funding: Work supported by HIM, GSI and BMBF Contr. No. 06FY7102
To demonstrate the operation ability of superconducting (sc) Crossbar-H-mode (CH) cavity technology a 217 MHz structure of this type is under development at the Institute for Applied Physics (IAP) of Frankfurt University. The cavity has 15 accelerating cells and a design beta of 0.059. It will be equipped with all necessary auxiliaries like a 10 kW power coupler and a tuning system. Currently, the cavity is under construction. Furthermore, this cavity will serve as demonstrator for a sc continuous wave (cw) LINAC at GSI. The proposed cw LINAC is highly requested to fulfil the requirements of nuclear chemistry and especially for a competitive production of new Super Heavy Elements (SHE) in the future. A full performance test by injecting and accelerating a beam from the GSI High Charge Injector (HLI) is planned in 2014. The current status of the sc CH cavity and the demonstrator project is presented.
 
 
THPWO017 A Coupled RFQ-IH Cavity for the Neutron Source FRANZ 3797
 
  • M. Heilmann, C. Claessens, O. Meusel, D. Mäder, U. Ratzinger, A. Schempp, M. Schwarz
    IAP, Frankfurt am Main, Germany
 
  The Frankfurt neutron Source at the Stern-Gerlach-Zentrum (FRANZ) delivers neutrons in the energy range from 1 to 300 keV at high intensities. The neutrons are produced using the the 7Li(p,n)7Be reaction with 2 MeV protons. The linac accelerator cavities consists of a 4-rod-RFQ coupled with an 8 gap interdigital H-type drift tube section with a total cavity length of 2.3 m. It accelerates the 120 keV beam to 2.03 MeV at a frequency of 175 MHz. The combined cavity will be powered by one RF amplifier to reduce investment and operation costs. The inductive power coupler will be located at the RFQ part. The coupling into the IH – section is provided by direct inductive coupling within the cavity. The coupled RFQ-IH combination is investigated with CST-MWS-simulations and by an RF model. The linac combination has to match the resonance frequency, flatness along the RFQ and the voltage ratio between both cavity sections. Beam operation will be cw (a few mA) and pulsed 250 kHz, 50 ns (up to 50 mA and beyond). The thermal cavity losses are about 200 kW and the cooling is the challenging topic.  
 
THPWO021 Gabor Lens Performance Studies at the GSI High Current Test Injector 3806
 
  • K. Schulte, M. Droba, O. Meusel, U. Ratzinger
    IAP, Frankfurt am Main, Germany
  • A. Adonin, R. Berezov, R. Hollinger, J. Pfister
    GSI, Darmstadt, Germany
 
  At the Institute for Applied Physics (IAP) the application of Gabor space charge lenses as a focusing device for low energy ion beams has already been studied for several years. Inside Gabor lenses electrons are confined by external fields. In case of a homogeneously distributed electron cloud the resulting linear electric space charge field enables the focusing of high intensity heavy ion beams without aberrations. Therefore, the Gabor lens is a promising approach for mass-independent focusing and possible space charge compensation of ion beams. In mid-2012 the performance of a prototype lens has successfully been tested at the GSI High Current Test Injector (HOSTI). GSI and IAP are currently investigating the possible application of such a device for the continuous operation at the High Current Injector (HSI) for FAIR. This contribution will present the results of beam transport experiments at HOSTI as well as the determination of related plasma properties.