Keyword: resonance
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SUPB014 RF Setup of the MedAustron RFQ rfq, simulation, ion, pick-up 35
 
  • B. Koubek, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
  • J. Haeuser
    Kress GmbH, Biebergemuend, Germany
 
  A Radio Frequency Quadrupole (RFQ) was built for the injector of the cancer treatment facility MedAuston in Austria. For the RF design simulations were performed using CST Microwave Studio and the structure was manufactured by Firma Kress in Biebergemuend, Germany. The simulations and the RF setup of the delivered RFQ are presented in this paper.  
 
SUPB017 Tuning Studies on 4-rod-RFQs rfq, simulation, linac, coupling 44
 
  • J.S. Schmidt, B. Klump, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  A NI LabVIEW based Tuning Software has been devel- oped to structure the tuning process of 4-rod Radio Fre- quency Quadrupole s (RFQs). Its results are compared to measurement data of 4-rod RFQs in different frequency ranges. For the optimization of RFQ design parameters, a certain voltage distribution along the electrodes of an RFQ is assumed. Therefore an accurate tuning of the voltage distribution is very important for the beam dynamic prop- erties of an RFQ. A variation can lead to particle losses and reduced beam quality especially at higher frequencies. Our electrode design usually implies a constant longitudi- nal voltage distribution. For its adjustment tuning plates are used between the stems of the 4-rod-RFQ. These pre- dictions are based, in contrast to other simulations, on mea- surements to define the characteristics of the RFQ as it was build - not depending on assumptions of the design. This will lead to a totally new structured process of tuning 4- rod-RFQs in a broad range of frequencies by using the pre- dictions of a software. The results of these studies are pre- sented in this paper.  
 
SUPB028 The Superconducting CH Cavity Development in IMP* cavity, simulation, linac, niobium 74
 
  • M.X. Xu, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Z.J. Wang, J.W. Xia, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  Funding: Work supported by 91026001 Nature Science Foundation of China
The Cross-Bar H-type (CH) cavity is a multi-gap drift tube structure operated in the H21 mode [1]. The Institute of Modern Physics (IMP) has been doing research and development on this type of superconducting CH cavity which can work at the C-ADS (accelerator driver sub-critical system of China). A new geometry CH cavity has been proposed which have smaller radius. It’s suitable in fabrication, and it’s can reduce cost too .Detailed numerical simulations with CST MicroWave Studio have been performed. An overall surface reduction of 30% against the old structure seems feasible. A copper model CH cavity is being fabrication for validating the simulations and the procedure of fabricating niobium cavity.
 
 
MOPLB10 FRIB Technology Demonstration Cryomodule Test cavity, cryomodule, SRF, solenoid 165
 
  • J. Popielarski, E.C. Bernard, S. Bricker, S. Chouhan, C. Compton, A. Facco, A. Fila, L.L. Harle, M. Hodek, L. Hodges, S. Jones, M. Leitner, D. R. Miller, S.J. Miller, D. Morris, R. Oweiss, J.P. Ozelis, L. Popielarski, K. Saito, N.R. Usher, J. Weisend, Y. Zhang, S. Zhao, Z. Zheng
    FRIB, East Lansing, USA
  • M. Klaus
    Technische Universität Dresden, Dresden, Germany
 
  A Technology Demonstration Cryomodule (TDCM) has been developed for a systems test of technology being developed for FRIB. The TDCM consists of two half wave resonators (HWRs) which have been designed for an optimum velocity of β=v/c=0.53 and a resonant frequency of 322 MHz. The resonators operate at 2 K. A superconducting 9 T solenoid is placed in close proximity to one of the installed HWRs. The 9 T solenoid operates at 4 K. A complete systems test of the cavities, magnets, and all ancillary components is presented in this paper.
This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661.
 
slides icon Slides MOPLB10 [2.530 MB]  
 
MOPB059 The Superconducting CH Cavity Development in IMP* cavity, simulation, linac, niobium 309
 
  • M.X. Xu, S. He, Y. He, S.C. Huang, Y.L. Huang, T.C. Jiang, R.X. Wang, Z.J. Wang, J.W. Xia, Y.Z. Yang, W.M. Yue, C. Zhang, S.H. Zhang, S.X. Zhang, H.W. Zhao
    IMP, Lanzhou, People's Republic of China
 
  Funding: Work supported by 91026001 Nature Science Foundation of China
The Cross-Bar H-type (CH) cavity is a multi-gap drift tube structure operated in the H21 mode [1]. The Institute of Modern Physics (IMP) has been doing research and development on this type of superconducting CH cavity which can work at the C-ADS (accelerator driver sub-critical system of China). A new geometry CH cavity has been proposed which have smaller radius. It’s suitable in fabrication, and it’s can reduce cost too .Detailed numerical simulations with CST MicroWave Studio have been performed. An overall surface reduction of 30% against the old structure seems feasible. A copper model CH cavity is being fabrication for validating the simulations and the procedure of fabricating niobium cavity.
 
 
MOPB090 FRIB Technology Demonstration Cryomodule Test cavity, cryomodule, SRF, solenoid 386
 
  • J. Popielarski, E.C. Bernard, S. Bricker, S. Chouhan, C. Compton, A. Facco, A. Fila, L.L. Harle, M. Hodek, L. Hodges, S. Jones, M. Leitner, D. R. Miller, S.J. Miller, D. Morris, R. Oweiss, J.P. Ozelis, L. Popielarski, K. Saito, N.R. Usher, J. Weisend, Y. Zhang, S. Zhao, Z. Zheng
    FRIB, East Lansing, USA
  • M. Klaus
    Technische Universität Dresden, Dresden, Germany
 
  A Technology Demonstration Cryomodule (TDCM) has been developed for a systems test of technology being developed for FRIB. The TDCM consists of two half wave resonators (HWRs) which have been designed for an optimum velocity of β=v/c=0.53 and a resonant frequency of 322 MHz. The resonators operate at 2 K. A superconducting 9 T solenoid is placed in close proximity to one of the installed HWRs. The 9 T solenoid operates at 4 K. A complete systems test of the cavities, magnets, and all ancillary components is presented in this paper.
This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE SC0000661.
 
 
TUPB033 Piezoelectric Actuator Based Phase Locking System for IUAC Linac controls, linac, heavy-ion, high-voltage 549
 
  • B.K. Sahu, R. Ahuja, G.K. Chowdhury, R.N. Dutt, S. Ghosh, D. Kanjilal, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, A. Pandey, P. Patra, A. Rai, A. Roy, S.K. Suman
    IUAC, New Delhi, India
 
  The linac of IUAC consists of three main accelerating modules with each one housing eight superconducting quarter wave resonators. Currently, the phase locking of the resonator is performed by a combination of fast I-Q based electronic tuner and helium gas flow based mechanical tuner. Microphonics measurement on the resonators found the presence of lower frequency vibrations along with main mechanical mode (~60 Hz) of the resonators. Although main mechanical mode of the resonator is damped by using SS balls, the presence of lower frequency vibrations demand more RF power from the amplifier, as the existing mechanical tuner works in time scale of seconds. A combination of piezoelectric actuator based fast tuner along with stepper motor based coarse tuner operating in the time scale of milliseconds is being developed. This scheme is implemented on a few resonators in last linac cryostat. Initial results show that this mechanism can arrest all low frequency vibrations thereby reducing a substantial load from the electronic tuner and improve the dynamics of the phase locking scheme. The implementation scheme along with test results will be presented in detail.  
 
TUPB091 176 MHz Solid State Microwave Generator Design impedance, linac, simulation, scattering 672
 
  • A.Yu. Smirnov, E.V. Ivanov, A.A. Krasnov, K.I. Nikolskiy, N.V. Tikhomirova
    Siemens Research Center, Moscow,, Russia
  • O. Heid, T.J.S. Hughes
    Siemens AG, Erlangen, Germany
 
  This paper concerns the R&D work upon design of a compact RF amplifier to be used for superconducting CW cavities. The machine under development will operate at 176 MHz with output power of 25 kW in continuous wave regime. It consists of 50 push-pull PCB modules (approx. 500W output power each), connected in parallel to several radial filter rings, which both allow class-F operation and combine the power from the modules, delivering it to a single 50 Ω coax cable. The CST simulations ad the design of 324 MHz test prototype are presented.  
 
THPLB07 Experience with a 4-Rod CW Radio Frequency Quadrupole rfq, ion, damping, linac 825
 
  • P. Gerhard, W.A. Barth, L.A. Dahl, W. Hartmann, G. Schreiber, W. Vinzenz, H. Vormann
    GSI, Darmstadt, Germany
 
  Since 1991 the High Charge State Injector (HLI) provides heavy ion beams for the linear accelerator UNILAC at GSI*. It is equipped with an ECR ion source and an RFQ-IH linac which accelerates highly charged ion beams with high duty factor of up to 30% to 1.4 MeV/u for further acceleration in the Alvarez DTL of the UNILAC. Main user of these beams is the Super Heavy Element (SHE) research, one of the outstanding projects at GSI**. Experiments like TASCA and SHIP strongly benefit from the high average beam intensities. After two decades of successful operation the four-rod Radio Frequency Quadrupole (RFQ) accelerator was replaced in 2010 by a newly designed RFQ of the same type**. Besides higher beam transmission, the principal intention of this upgrade was to raise the duty factor up to 100%, since the HLI is foreseen as injector for the upcoming cw linac dedicated to the SHE program**. Commissioning and operational experience from the first years revealed that this goal could not be reached easily. In this paper we present the RFQ design, commissioning results, operational experience and future activities.
* N. Angert et al., EPAC92, Berlin, Germany (1992), p. 167
** L. Dahl et al., LINAC10, Tsukuba, Japan (2010), MOP042, and references therein
 
slides icon Slides THPLB07 [0.986 MB]  
 
THPB025 325 MHz CW Room Temperature High Power Bunching Cavity for the China ADS MEBT1 cavity, bunching, impedance, vacuum 903
 
  • S. Pei, X. Li, H.F. Ouyang, J.R. Zhang
    IHEP, Beijing, People's Republic of China
 
  Two room temperature high power bunching cavities are required to be located in the ADS MEBT1 section. Double re–entrant nose cone geometry has been adopted as the type of the bunching cavity for its simplicity, higher shunt impedance and lower risk of multipacting. SUPERFISH is used to optimize the internal dimensions of the bunching cavity, then the RF–thermal–structural–RF coupled analysis were carried out in ANSYS to obtain the preliminary mechanical design, the layout of the cooling channels is optimized to suppress the frequency shift as much as possible. The cavity was specially designed to have the capability to withstand the 1 atm air pressure effect. In addition, the main dimensions of the coupler and tuner are also estimated.
*peisl@ihep.ac.cn
 
 
THPB035 Experience with a 4-Rod CW Radio Frequency Quadrupole rfq, ion, damping, linac 930
 
  • P. Gerhard, W.A. Barth, L.A. Dahl, W. Hartmann, G. Schreiber, W. Vinzenz, H. Vormann
    GSI, Darmstadt, Germany
 
  Since 1991 the High Charge State Injector (HLI) provides heavy ion beams for the linear accelerator UNILAC at GSI*. It is equipped with an ECR ion source and an RFQ-IH linac which accelerates highly charged ion beams with high duty factor of up to 30% to 1.4 MeV/u for further acceleration in the Alvarez DTL of the UNILAC. Main user of these beams is the Super Heavy Element (SHE) research, one of the outstanding projects at GSI**. Experiments like TASCA and SHIP strongly benefit from the high average beam intensities. After two decades of successful operation the four-rod Radio Frequency Quadrupole (RFQ) accelerator was replaced in 2010 by a newly designed RFQ of the same type**. Besides higher beam transmission, the principal intention of this upgrade was to raise the duty factor up to 100%, since the HLI is foreseen as injector for the upcoming cw linac dedicated to the SHE program**. Commissioning and operational experience from the first years revealed that this goal could not be reached easily. In this paper we present the RFQ design, commissioning results, operational experience and future activities.
* N. Angert et al., EPAC92, Berlin, Germany (1992), p. 167
** L. Dahl et al., LINAC10, Tsukuba, Japan (2010), MOP042, and references therein
 
 
THPB046 RF Setup of the MedAustron RFQ rfq, simulation, ion, pick-up 957
 
  • B. Koubek, A. Schempp, J.S. Schmidt
    IAP, Frankfurt am Main, Germany
  • J. Haeuser
    Kress GmbH, Biebergemuend, Germany
 
  A Radio Frequency Quadrupole (RFQ) was built for the injector of the cancer treatment facility MedAuston in Austria. For the RF design simulations were performed using CST Microwave Studio and the structure was manufactured by Firma Kress in Biebergemuend, Germany. The simulations and the RF setup of the delivered RFQ are presented in this paper.  
 
THPB049 Tuning Studies on 4-Rod-RFQs rfq, simulation, linac, coupling 963
 
  • J.S. Schmidt, B. Klump, B. Koubek, A. Schempp
    IAP, Frankfurt am Main, Germany
 
  A NI LabVIEW based Tuning Software has been devel- oped to structure the tuning process of 4-rod Radio Fre- quency Quadrupole s (RFQs). Its results are compared to measurement data of 4-rod RFQs in different frequency ranges. For the optimization of RFQ design parameters, a certain voltage distribution along the electrodes of an RFQ is assumed. Therefore an accurate tuning of the voltage distribution is very important for the beam dynamic prop- erties of an RFQ. A variation can lead to particle losses and reduced beam quality especially at higher frequencies. Our electrode design usually implies a constant longitudi- nal voltage distribution. For its adjustment tuning plates are used between the stems of the 4-rod-RFQ. These pre- dictions are based, in contrast to other simulations, on mea- surements to define the characteristics of the RFQ as it was build - not depending on assumptions of the design. This will lead to a totally new structured process of tuning 4- rod-RFQs in a broad range of frequencies by using the pre- dictions of a software. The results of these studies are pre- sented in this paper.  
 
THPB084 A Low-Level RF Control System for a Quarter-Wave Resonator controls, LLRF, cavity, ion 1020
 
  • J.-W. Kim, D.G. Kim
    IBS, Daejeon, Republic of Korea
  • C.K. Hwang
    KAERI, Daejon, Republic of Korea
 
  A low-level rf control system was designed and built for an rf deflector, which is a quarter wave resonator and was designed to deflect a secondary electron beam to measure the bunch length of an ion beam. The deflector has a resonance frequency at near 88 MHz, and its required phase stability is approximately ±1° and amplitude stability less than ±1%. The control system consists of analog input and output components, and a digital system based on an FPGA for signal processing. It is a cost effective system, while meeting the stability requirements. Some basic properties of the control system were measured. Then the capability of the rf control has been tested using a mechanical vibrator made of a dielectric rod attached to an audio speaker system, which can induce regulated perturbation in the electric fields of the resonator. The control system is flexible such that its parameters can be easily configured to compensate for disturbance induced in the resonator.  
 
THPB086 Precision Regulation of RF Fields with MIMO Controllers and Cavity-based Notch Filters cavity, controls, LLRF, feedback 1026
 
  • Ch. Schmidt, J. Branlard, S. Pfeiffer, H. Schlarb
    DESY, Hamburg, Germany
  • W. Jałmużna
    TUL-DMCS, Łódź, Poland
 
  The European XFEL requires a high precision control of the electron beam, generating a specific pulsed laser light demanded by user experiments. The low level radio frequency (LLRF) control system is certainly one of the key players for the regulation of accelerating RF fields. A uTCA standard LLRF system was developed and is currently under test at DESY. Its first experimental results showed the system performance capabilities. Investigation of regulation limiting factors evidenced the need for control over fundamental cavity modes, which is done using complex controller structures and filter techniques. The improvement in measurement accuracy and detection bandwidth increased the regulation performance and contributed to integration of further control subsystems.