LINAC2012 - List of Keywords (klystron)

Paper	Title	Other Keywords	Page
SUPB009	Linear Accelerator based on Parallel Coupled Accelerating Structure	cavity, electron, controls, focusing	19
	A.E. Levichev, A.M. Barnyakov, V.M. Pavlov BINP SB RAS, Novosibirsk, Russia Y.D. Chernousov ICKC, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

SUPB024	Development of Permanent Magnet Focusing System for Klystrons	focusing, permanent-magnet, cathode, simulation	62
	Y. Fuwa, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, S. Michizono KEK, Ibaraki, Japan
	The Distributed RF System (DRFS) for the International Linear Collider (ILC) requires thousands of klystrons. The failure rate of the power supply for solenoid focusing coil of each klystron may be a critical issue for a regular operation of the ILC. A permanent magnet beam focusing system can increase reliability and eliminate their power consumption. Since the required magnetic field is not high in this system, inexpensive anisotropic ferrite magnets can be used instead of magnets containing rare earth materials. In order to prove its feasibility, a test model of a permanent magnet focusing beam system is constructed and a power test of the klystron for DRFS with this model is under preparation. The results of magnetic field distribution measurement and the power test will be presented.

SUPB032	The C-band RF Pulse Compression for Soft XFEL at SINAP	cavity, coupling, simulation, free-electron-laser	83
	C.P. Wang, Q. Gu, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	A compact soft X-ray free electron laser facility is presently being constructed at shanghai institute of applied physics (SINAP), Chinese academy of science in 2012 and will be accomplished in 2014. This facility requires a compact linac with a high-gradient accelerating structure for a limited overall length less than 230 m. The c-band technology which is already used in KEK/Spring-8 linear accelerator is a good compromise for this compact facility and a c-and traveling-wave accelerating structure was already fabricated and tested at SINAP, so a c-band pulse compression will be required. AND a SLED type RF compression scheme is proposed for the C-band RF system of the soft XFEL and this scheme uses TE0.1.15 mode energy storage cavity for high Q-energy storage. The C-band pulse compression under development at SINAP has a high power gain about 3.1 and it is designed to compress the pulse width from 2.5 μs to 0.5 μs and multiply the input RF power of 50 MW to generate 160 MW peak RF power, and the coupling coefficient will be 8.5. It has three components: 3 dB coupler, mode convertors and the resonant cavities.

MO1A02	Status of the European XFEL – Constructing the 17.5 GeV Superconducting Linear Accelerator	cavity, undulator, electron, photon	105
	W. Decking DESY, Hamburg, Germany
	The European XFEL is presently under construction in Hamburg, Germany. It consists of a 1.2 km long superconducting linac serving an about 3 km long electron beam transport system. Three undulator systems of up to 200 m length each produce hard and soft x-rays via the self-amplified spontaneous emission (SASE) process. We will present the status of the civil construction and the accelerator components. The production of the 100 superconducting accelerator modules is distributed between industries and a collaboration of accelerator laboratories. We describe the carefully orchestrated production sequence, quality assurance measures and risk mitigation mechanisms. The last module is scheduled to be installed in the accelerator in spring 2015 and commissioning with beam will start in summer of that year.
	Slides MO1A02 [8.730 MB]

MOPLB01	Emittance Control for Different FACET Beam Setups in the SLAC Linac	linac, quadrupole, emittance, wakefield	138
	F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.
	Slides MOPLB01 [0.826 MB]

MOPLB04	A 10 MeV L-band Linac for Irradiation Applications in China	linac, electron, gun, simulation	147
	G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou IHEP, Beijing, People's Republic of China Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu Institute of High Energy Physics (IHEP), People's Republic of China Z. Li, X. Zhang Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China
	The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.
	Slides MOPLB04 [1.800 MB]

MOPLB09	Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector	coupling, electron, controls, FEL	162
	R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro INFN/LNF, Frascati (Roma), Italy A. Mostacci, L. Palumbo URLS, Rome, Italy
	The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.
	Slides MOPLB09 [1.061 MB]

MOPB001	Emittance Control for Different FACET Beam Setups in the SLAC Linac	linac, quadrupole, emittance, wakefield	174
	F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515. The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.

MOPB005	High Gradient Operation of 8 GeV C-Band Accelerator in SACLA	acceleration, laser, electron, free-electron-laser	186
	T. Inagaki, C. Kondo, Y. Otake, T. Sakurai RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	SACLA (SPring-8 angstrom compact free electron laser) is the X-ray free electron laser (XFEL) facility. In order to shorten the 8 GeV accelerator length, a C-band (5712 MHz) accelerator was employed. Since the accelerating gradient of C-band accelerating structure is 35 MV/m in nominal, the active accelerator length is 230 m. In total, 64 klystrons, 64 pulse compressors, and 128 accelerating structures are used. In order to withstand the high surface field (~ 100 MV/m), and to reduce the amount of dark current, which decreases the demagnetization effect of undulators, the accelerating structures are carefully fabricated in the factory.　After high power RF conditioning of 500 hours, the beam commissioning was started in February 2011. For night time of the commissioning, we continued the RF conditioning. The RF breakdown rate of the structure was steadily decreased. Now we operate the accelerator with the beam energy as much as 8.3 GeV, and the accelerating gradient of 37 MV/m in average. We found the amount of dark current is small enough. So far no trouble occurred in C-band RF components of 64 sets.

MOPB023	Progress on the Design and Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source	linac, electron, gun, neutron	222
	S. Pei, J. Cao, Y.L. Chi, B. Deng, C.D. Deng, H.S. Guo, D.Y. He, X. He, M. Hou, X.C. Kong, Q. Le, X. Li, J. Liu, R.L. Liu, W.B. Liu, K. Lv, C. Ma, H.Z. Ma, G. Pei, H. Song, L. Wang, S.H. Wang, X. Wang, Q. Yang, J. Yue, J.R. Zhang, F. Zhao, J.B. Zhao, J.X. Zhao, Z.S. Zhou IHEP, Beijing, People's Republic of China M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky NSC/KIPT, Kharkov, Ukraine Y. Gohar ANL, Argonne, USA
	IHEP in China is designing and constructing a 100 MeV / 100 kW electron linac for NSC KIPT, which will be used as the driver of a neutron source based on a subcritical assembly. Recently, the physical design has been finalized. The chicane scheme instead of the RF chopper one has been selected. The mechanical design is on-going and will be finished in the very near future. The injector part of the machine has been installed in the experimental hall #2 of IHEP and is being commissioned and tested. The progress on the machine design and construction are reported, initial testing and commissioning results of the injector are also presented. *peisl@ihep.ac.cn

MOPB046	A 10 MeV L-band Linac for Irradiation Applications in China	linac, electron, gun, simulation	276
	G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, X.W. Yang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou IHEP, Beijing, People's Republic of China Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu Institute of High Energy Physics (IHEP), People's Republic of China Z. Li, X. Zhang Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China
	The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.

MOPB048	Linear Accelerator Based on Parallel Coupled Accelerating Structure	cavity, electron, controls, focusing	282
	A.E. Levichev, A.M. Barnyakov, V.M. Pavlov BINP SB RAS, Novosibirsk, Russia Y.D. Chernousov ICKC, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

MOPB080	Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector	coupling, electron, controls, FEL	360
	R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro INFN/LNF, Frascati (Roma), Italy A. Mostacci, L. Palumbo URLS, Rome, Italy
	The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

MOPB083	Operational experience with the FERMI@Elettra S-band RF System	FEL, linac, gun, LLRF	369
	A. Fabris, P. Delgiusto, F. Gelmetti, M.M. Milloch, A. Milocco, F. Pribaz, C. Serpico, N. Sodomaco, R. Umer, L. Veljak ELETTRA, Basovizza, Italy
	FERMI@Elettra is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The machine is presently under commissioning and the first FEL line (FEL-1) will be opened to the users by the end of 2012. The 1.5 GeV linac is based on S-band technology. The S-band system is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, eighteen accelerating structures and the RF deflectors. The S-band system has been set into operation in different phases starting from the second half of 2009. This paper provides an overview of the performance of the system, discussing the achieved results, the strategies adopted to assure them and possible upgrade paths to increase the operability and safety margins of the system.

MOPB087	S-Band Loads for SLAC Linac	linac, vacuum, plasma, insertion	378
	A. Krasnykh, F.-J. Decker SLAC, Menlo Park, California, USA R.W. LeClair INTA, Santa Clara, USA
	Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515 and SBIR grant number DE-SC0007661 The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials. [1] “The Stanford Two-Mile Accelerator”, p. 376-381, R. B. Neal, General Editor, 1968, W. A. Benjamin, Inc., NY Amsterdam

TU1A05	Status and Commissioning Plan of the PEFP 100-MeV Linear Accelerator	linac, DTL, proton, site	422
	H.-J. Kwon, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun KAERI, Daejon, Republic of Korea
	Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government. One of the goals of the Proton Engineering Frontier Project (PEFP) is to develop a 100 MeV proton linear accelerator, which consists of 50 keV proton injector, 3 MeV radio frequency quadrupole (RFQ), 20 MeV/100 MeV drift tube linac (DTL) and 20 MeV/100 MeV beam lines. The 100 MeV linear accelerator and beam line components have been installed in the tunnel and experimental hall. After the completion of the utility commissioning, the commissioning of the accelerator starts with a goal of the beam delivery to the 100 MeV target room located at the end of the beam line in 2012. In this paper, the status and commissioning plan of the PEFP 100 MeV linear accelerator are presented.
	Slides TU1A05 [6.795 MB]

TUPLB04	Results of Testing of Multi-beam Klystrons for the European XFEL	cathode, high-voltage, vacuum, status	448
	V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung DESY, Hamburg, Germany
	For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.

TUPLB12	Development of Permanent Magnet Focusing System for Klystrons	focusing, permanent-magnet, cathode, simulation	470
	Y. Fuwa, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, S. Michizono KEK, Ibaraki, Japan
	The Distributed RF System (DRFS) for the International Linear Collider (ILC) requires thousands of klystrons. The failure rate of the power supply for solenoid focusing coil of each klystron may be a critical issue for a regular operation of the ILC. A permanent magnet beam focusing system can increase reliability and eliminate their power consumption. Since the required magnetic field is not high in this system, inexpensive anisotropic ferrite magnets can be used instead of magnets containing rare earth materials. In order to prove its feasibility, a test model of a permanent magnet focusing beam system is constructed and a power test of the klystron for DRFS with this model is under preparation. The results of magnetic field distribution measurement and the power test will be presented.
	Slides TUPLB12 [1.357 MB]

TUPB004	Results of Testing of Multi-beam Klystrons for the European XFEL	cathode, high-voltage, vacuum, status	479
	V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung DESY, Hamburg, Germany
	For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.

TUPB009	C-Band Accelerating Structure Development and Tests for the SwissFEL	impedance, controls, FEL, linac	492
	R. Zennaro, J. Alex, H. Blumer, M. Bopp, A. Citterio, T. Kleeb, L. Paly, J.-Y. Raguin PSI, Villigen, Switzerland
	SwissFEL requires a 5.8 GeV beam provided by a C-band linac consisting of 104 two-meter accelerating structures. Each structure is of the constant gradient type and is composed of 113 cups. The cup shape is double-rounded to increase the quality factor. No tuning feature is implemented. For this reason ultra-precise turning is exploited. A strong R&D program has been launched on structure fabrication, which will be followed by a future technology transfer to a commercial company. The program includes the production and test of short structures that can be brazed in the existing PSI vacuum oven and will be completed with the production of the full two-meter prototype once the new full scale brazing oven, presently under construction, is operational. The status of the R&D program, including the production and power test results of the first two test structures, is reported here.

TUPB012	The Swiss FEL C-Band Accelerating Structure: RF Design and Thermal Analysis	accelerating-gradient, linac, FEL, impedance	501
	J.-Y. Raguin, M. Bopp PSI, Villigen, Switzerland
	The Swiss FEL accelerator concept consists of a 450 MeV S-band injector linac followed by the main linac in C-band aiming at a final energy of 5.8 GeV. The two-meter long C-band accelerating structures have 113 cells, including the two coupler cells, and operate with a 2π/3 phase advance. The structure is of the constant-gradient type with rounded wall cells and has an average iris radius of 6.44 mm, a radius compatible with the impact of the short-range wakefields on the whole linac beam dynamics. The cell irises have an elliptical profile to minimize the peak surface electric fields and the coupler cells are of the J-type. We report here on the RF design of the structure, as well as on its thermal analysis, to target operational conditions with an accelerating gradient of about 28 MV/m and a repetition rate of 100 Hz.

TUPB015	Warm Beamlines and Infrastructure in the European XFEL	linac, shielding, diagnostics, radiation	510
	M. Hüning DESY, Hamburg, Germany
	The European XFEL is driven by a superconducting linear accelerator. In the main accelerator tunnel the accelerator modules will be suspended from the tunnel ceiling. The warm sections like bunch compressors will be installed on girders supported from the floor. The accelerator infrastructure like klystrons and electronic racks will be installed in the accelerator tunnel in close proximity to the electron beamline.

TUPB090	Development of Permanent Magnet Focusing System for Klystrons	focusing, permanent-magnet, cathode, simulation	669
	Y. Fuwa, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan S. Fukuda, S. Michizono KEK, Ibaraki, Japan
	A permanent magnet focusing system for klystrons is under development to improve reliability of RF supply system and reduce power consumption. To save production cost, anisotropic ferrite magnets are used in this system. A test model has been fabricated and the power test of a 750 kW klystron with this focusing magnet is carried out. 60 % of the nominal output power has been achieved at a preliminary power test so far

TUPB094	High Power Tests of TRASCO RFQ Couplers	vacuum, cavity, rfq, simulation	681
	E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri, F. Scarpa INFN/LNL, Legnaro (PD), Italy O. Brunasso Cattarello, R. Panero INFN-Torino, Torino, Italy M. Desmons CEA/DSM/IRFU, France
	The 352.2 MHz 7.13 m long TRASCO RFQ requires an overall amount of 900 kW CW RF power in order to deliver the 40 mA proton beam from the initial energy of 80 keV to the final energy of 5 MeV. For such a purpose a system of eight compact (ϕext=38 mm, ϕint=19.4 mm) loop-based couplers was designed. In a first phase, only the first two (out of six) modules of the RFQ were tested at full power. Therefore only two (out of eight) couplers were used. In order to completely characterize these couplers, a dedicated test bench was prepared, consisting of a bridge waveguide and diagnostics (reflected power, vacuum, arc detectors etc.), onto which a couple of couplers was connected for transmission measurements. Each coupler was tested with a forward power of up to 140 kW. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.

TUPB097	The C-band RF Pulse Compression for Soft XFEL at SINAP	cavity, coupling, simulation, free-electron-laser	687
	C.P. Wang, Q. Gu, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	A compact soft X-ray free electron laser facility is presently being constructed at shanghai institute of applied physics (SINAP), Chinese academy of science in 2012 and will be accomplished in 2014. This facility requires a compact linac with a high-gradient accelerating structure for a limited overall length less than 230 m. The c-band technology which is already used in KEK/Spring-8 linear accelerator is a good compromise for this compact facility and a c-and traveling-wave accelerating structure was already fabricated and tested at SINAP, so a c-band pulse compression will be required. AND a SLED type RF compression scheme is proposed for the C-band RF system of the soft XFEL and this scheme uses TE0.1.15 mode energy storage cavity for high Q-energy storage. The C-band pulse compression under development at SINAP has a high power gain about 3.1 and it is designed to compress the pulse width from 2.5 μs to 0.5 μs and multiply the input RF power of 50 MW to generate 160 MW peak RF power, and the coupling coefficient will be 8.5. It has three components: 3 dB coupler, mode convertors and the resonant cavities.

WE2A02	Solid State Marx Modulators for Emerging Applications	linac, high-voltage, diagnostics, linear-collider	743
	M.A. Kemp SLAC, Menlo Park, California, USA
	A class of intelligent, Marx-topology modulators are under development at SLAC. These modulators combine numerous advanced features that could be employed in any significant new HPRF installation. The talk will describe the design features and operational experience.
	Slides WE2A02 [1.117 MB]

TH2A01	The ESS Linac Design	linac, cryomodule, cavity, proton	768
	M. Lindroos, H. Danared, C. Darve, D.P. McGinnis, S. Molloy ESS, Lund, Sweden
	The European Spallation Source (ESS) is a 5 MW, 2.5 MeV long pulse proton machine. It represents a big jump in power compare to the existing spallation facilities. The design phase is well under way, with the delivery of a Conceptual Design Report expected in 2012, and a Technical Design Report in 2013. Why and how the 5 MW goal influences the parameter choice will be describe.
	Slides TH2A01 [5.667 MB]

THPLB02	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, controls, rfq, LLRF	810
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.
	Slides THPLB02 [1.610 MB]

THPB010	Progress in the Construction of Linac4 at CERN	linac, injection, rfq, DTL	864
	M. Vretenar, L. Arnaudon, P. Baudrenghien, G. Bellodi, C. Bertone, Y. Body, J.C. Broere, O. Brunner, M.C.L. Buzio, C. Carli, J.-P. Corso, J. Coupard, A. Dallocchio, N. Dos Santos, J.-F. Fuchs, A. Funken, R. Garoby, F. Gerigk, L. Hammouti, K. Hanke, J. Hansen, I. Kozsar, J.-B. Lallement, J. Lettry, A.M. Lombardi, L.A. Lopez Hernandez, C. Maglioni, S.J. Mathot, B. Mikulec, D. Nisbet, M.M. Paoluzzi, B. Puccio, U. Raich, S. Ramberger, F. Roncarolo, C. Rossi, N. Schwerg, R. Scrivens, G. Vandoni, J. Vollaire, R. Wegner, S. Weisz, Th. Zickler CERN, Geneva, Switzerland
	As first step of the LHC luminosity upgrade program CERN is building a new 160 MeV H¯ linear accelerator, Linac4, to replace the ageing 50 MeV Linac2 as injector to the PS Booster (PSB). Linac4 is an 86-m long normal-conducting linac made of a 3 MeV injector followed by 22 accelerating cavities of three different types. The general service infrastructure has been installed in the new tunnel and surface building and its commissioning is progressing; high power RF equipment is being installed in the hall and installations in the tunnel will start soon. Construction of the accelerator parts is in full swing involving industry, the CERN workshops and a network of international collaborations. The injector section including a newly designed and built H¯ source, a 3-m long RFQ and a chopping line is being commissioned in a dedicated test stand. Beam commissioning of the linac will take place in steps of increasing energy between 2013 and 2014. From end of 2014 Linac4 could deliver 50 MeV protons in case of Linac2 failure, while 160 MeV H¯ could be injected into the PSB from end of 2015; the exact start of the LHC shut-down required for connection will be coordinated with its experiments.

THPB015	Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test	cavity, controls, rfq, LLRF	879
	P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan Fermilab, Batavia, USA
	The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB044	Plans for an Integrated Front-End Test Stand at the Spallation Neutron Source	rfq, ion, ion-source, controls	954
	M.S. Champion, A.V. Aleksandrov, M.T. Crofford, D. Heidenreich, Y.W. Kang, J. Moss, R.T. Roseberry, J.P. Schubert ORNL, Oak Ridge, Tennessee, USA
	Funding: Work performed at Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy. A spare Radio-Frequency Quadrupole (RFQ) is presently being fabricated by industry with delivery to Oak Ridge National Laboratory planned in late 2012. The establishment of a test stand at the Spallation Neutron Source site is underway so that complete acceptance testing can be performed during the winter of 2012-2013. This activity is the first step in the establishment of an integrated front-end test stand that will include an ion source, low-energy beam transport (LEBT), RFQ, medium-energy beam transport, diagnostics, and a beam dump. The test stand will be capable of delivering an H⁻ ion beam of up to 50 mA with a pulse length of 1 ms and a repetition rate of 60 Hz or a proton beam of up to 50 mA, 100 μs, 1 Hz. The test stand will enable the following activities: complete ion source characterization; development of a magnetic LEBT chopper; development of a two-source layout; development of beam diagnostics; and study of beam dynamics of high intensity beam.

THPB092	Recent Improvements in SPring-8 Linac for Early Recovery from Beam Interruption	gun, linac, electron, power-supply	1035
	S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan
	The 1GeV SPring-8 linac is an injector for the SPring-8 synchrotron radiation storage ring with 8GeV booster synchrotron. In recent years, backup systems were installed to eliminate long-time interruption of the beam injections: The main gun system is usually operated, and the second gun is always pre-heated and can inject electron beams into a buncher section with an interval of several minutes in case the main gun failed. The first klystron, that feeds RF powers to the buncher system and the downstream klystrons, can be relieved by the next klystron with an interval of about 20 minutes by switching the waveguide circuit. When one of the eleven working klystrons faults, one of standby klystrons, which are kept for hot spares on line, is automatically activated to accelerate beams instead of the failed one without beam interruption. The total downtime in FY2012 was 0.12% in top-up operation user time. The averaged fault frequency was 0.2 times per day.

THPB096	High-power Sources of RF Radiation Driven by Periodic Laser Pulses	laser, cavity, electron, radiation	1044
	S.V. Kuzikov, A.V. Savilov IAP/RAS, Nizhny Novgorod, Russia S.V. Kuzikov Omega-P, Inc., New Haven, USA
	Funding: Supported in part by DoE USA. A fast, periodic modulation of electron RF sources can be carried out in a form of Q-factor switching by means of fast RF switches, or in a form of I-switching by means of the bunched electron beam. If modulation frequency equals to time which is necessary for RF radiation to travel along the cavity and to come back, the RF oscillator can produce periodic, giant, short pulses which are desirable for many applications in order to avoid a breakdown. The produced RF pulses are phase and frequency locked by modulation shape. The mentioned effects of the phase and frequency locking remain also possible for RF sources operated in a single-mode regime. In last case the modulation frequency should be close to natural single-mode oscillation frequency. For example, one might control operation of a BWO by means of a small periodical modulation of the electron voltage in a drift section in-between a cathode and the corrugated interaction section. The necessary voltage modulation can be provided by means of a DC generator those voltage due to a photoconductivity is externally modulated with definite frequency by laser which irradiates GaAs isolator inserted in-between the electrodes.

Paper

Title

Other Keywords

Page

SUPB009

Linear Accelerator based on Parallel Coupled Accelerating Structure

cavity, electron, controls, focusing

19

A.E. Levichev, A.M. Barnyakov, V.M. Pavlov
BINP SB RAS, Novosibirsk, Russia
Y.D. Chernousov
ICKC, Novosibirsk, Russia
V. Ivannikov, I.V. Shebolaev
ICKC SB RAS, Novosibirsk, Russia

Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

SUPB024

Development of Permanent Magnet Focusing System for Klystrons

focusing, permanent-magnet, cathode, simulation

62

Y. Fuwa, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
S. Fukuda, S. Michizono
KEK, Ibaraki, Japan

The Distributed RF System (DRFS) for the International Linear Collider (ILC) requires thousands of klystrons. The failure rate of the power supply for solenoid focusing coil of each klystron may be a critical issue for a regular operation of the ILC. A permanent magnet beam focusing system can increase reliability and eliminate their power consumption. Since the required magnetic field is not high in this system, inexpensive anisotropic ferrite magnets can be used instead of magnets containing rare earth materials. In order to prove its feasibility, a test model of a permanent magnet focusing beam system is constructed and a power test of the klystron for DRFS with this model is under preparation. The results of magnetic field distribution measurement and the power test will be presented.

SUPB032

The C-band RF Pulse Compression for Soft XFEL at SINAP

cavity, coupling, simulation, free-electron-laser

83

C.P. Wang, Q. Gu, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

A compact soft X-ray free electron laser facility is presently being constructed at shanghai institute of applied physics (SINAP), Chinese academy of science in 2012 and will be accomplished in 2014. This facility requires a compact linac with a high-gradient accelerating structure for a limited overall length less than 230 m. The c-band technology which is already used in KEK/Spring-8 linear accelerator is a good compromise for this compact facility and a c-and traveling-wave accelerating structure was already fabricated and tested at SINAP, so a c-band pulse compression will be required. AND a SLED type RF compression scheme is proposed for the C-band RF system of the soft XFEL and this scheme uses TE0.1.15 mode energy storage cavity for high Q-energy storage. The C-band pulse compression under development at SINAP has a high power gain about 3.1 and it is designed to compress the pulse width from 2.5 μs to 0.5 μs and multiply the input RF power of 50 MW to generate 160 MW peak RF power, and the coupling coefficient will be 8.5. It has three components: 3 dB coupler, mode convertors and the resonant cavities.

MO1A02

Status of the European XFEL – Constructing the 17.5 GeV Superconducting Linear Accelerator

cavity, undulator, electron, photon

105

W. Decking
DESY, Hamburg, Germany

The European XFEL is presently under construction in Hamburg, Germany. It consists of a 1.2 km long superconducting linac serving an about 3 km long electron beam transport system. Three undulator systems of up to 200 m length each produce hard and soft x-rays via the self-amplified spontaneous emission (SASE) process. We will present the status of the civil construction and the accelerator components. The production of the 100 superconducting accelerator modules is distributed between industries and a collaboration of accelerator laboratories. We describe the carefully orchestrated production sequence, quality assurance measures and risk mitigation mechanisms. The last module is scheduled to be installed in the accelerator in spring 2015 and commissioning with beam will start in summer of that year.

Slides MO1A02 [8.730 MB]

MOPLB01

Emittance Control for Different FACET Beam Setups in the SLAC Linac

linac, quadrupole, emittance, wakefield

138

F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.

Slides MOPLB01 [0.826 MB]

MOPLB04

A 10 MeV L-band Linac for Irradiation Applications in China

linac, electron, gun, simulation

147

G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou
IHEP, Beijing, People's Republic of China
Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu
Institute of High Energy Physics (IHEP), People's Republic of China
Z. Li, X. Zhang
Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China

The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.

Slides MOPLB04 [1.800 MB]

MOPLB09

Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector

coupling, electron, controls, FEL

162

R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro
INFN/LNF, Frascati (Roma), Italy
A. Mostacci, L. Palumbo
URLS, Rome, Italy

The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

Slides MOPLB09 [1.061 MB]

MOPB001

Emittance Control for Different FACET Beam Setups in the SLAC Linac

linac, quadrupole, emittance, wakefield

174

F.-J. Decker, W.S. Colocho, N. Lipkowitz, Y. Nosochkov, J. Sheppard, H. Smith, Y. Sun, M.-H. Wang, G.R. White, U. Wienands, M. Woodley, G. Yocky
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy, Contract DE-AC02-76SF00515.
The linac beam at SLAC requires different setups for different users at FACET (Facility for Advanced aCcelerator Experimental Tests) area, like highly compressed, intense bunches, or lower charge, long bunches. These require typically a lengthy tuning effort since with a energy-time correlation ("chirp") bunch transverse wakefield kicks can be compensated with dispersive trajectory oscillations and vice versa. Lowering the charge or changing the bunch length will destroy this delicate balance. Besides the typical steering to minimize BPMs (Beam Position Monitors) with correctors, we applied different techniques to try to localize beam disturbances like dispersion with phase changes, RF-kicks and RF quadrupole fields turning a klystron off and on, or varying the phase, and finally wakefield kicks with different beam intensities. It is also important to quantify BPM to quadrupole offsets with "bow-tie" plot and that the correctors give the expected kicks with orbit response matrix measurements.

MOPB005

High Gradient Operation of 8 GeV C-Band Accelerator in SACLA

acceleration, laser, electron, free-electron-laser

186

T. Inagaki, C. Kondo, Y. Otake, T. Sakurai
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

SACLA (SPring-8 angstrom compact free electron laser) is the X-ray free electron laser (XFEL) facility. In order to shorten the 8 GeV accelerator length, a C-band (5712 MHz) accelerator was employed. Since the accelerating gradient of C-band accelerating structure is 35 MV/m in nominal, the active accelerator length is 230 m. In total, 64 klystrons, 64 pulse compressors, and 128 accelerating structures are used. In order to withstand the high surface field (~ 100 MV/m), and to reduce the amount of dark current, which decreases the demagnetization effect of undulators, the accelerating structures are carefully fabricated in the factory.　After high power RF conditioning of 500 hours, the beam commissioning was started in February 2011. For night time of the commissioning, we continued the RF conditioning. The RF breakdown rate of the structure was steadily decreased. Now we operate the accelerator with the beam energy as much as 8.3 GeV, and the accelerating gradient of 37 MV/m in average. We found the amount of dark current is small enough. So far no trouble occurred in C-band RF components of 64 sets.

MOPB023

Progress on the Design and Construction of the 100 MeV / 100 kW Electron Linac for the NSC KIPT Neutron Source

linac, electron, gun, neutron

222

S. Pei, J. Cao, Y.L. Chi, B. Deng, C.D. Deng, H.S. Guo, D.Y. He, X. He, M. Hou, X.C. Kong, Q. Le, X. Li, J. Liu, R.L. Liu, W.B. Liu, K. Lv, C. Ma, H.Z. Ma, G. Pei, H. Song, L. Wang, S.H. Wang, X. Wang, Q. Yang, J. Yue, J.R. Zhang, F. Zhao, J.B. Zhao, J.X. Zhao, Z.S. Zhou
IHEP, Beijing, People's Republic of China
M.I. Ayzatskiy, I.M. Karnaukhov, V.A. Kushnir, V.V. Mytrochenko, A.Y. Zelinsky
NSC/KIPT, Kharkov, Ukraine
Y. Gohar
ANL, Argonne, USA

IHEP in China is designing and constructing a 100 MeV / 100 kW electron linac for NSC KIPT, which will be used as the driver of a neutron source based on a subcritical assembly. Recently, the physical design has been finalized. The chicane scheme instead of the RF chopper one has been selected. The mechanical design is on-going and will be finished in the very near future. The injector part of the machine has been installed in the experimental hall #2 of IHEP and is being commissioned and tested. The progress on the machine design and construction are reported, initial testing and commissioning results of the injector are also presented.
*peisl@ihep.ac.cn

MOPB046

A 10 MeV L-band Linac for Irradiation Applications in China

linac, electron, gun, simulation

276

G. Pei, Y.L. Chi, M.H. Dai, D.Y. He, X. He, X. Li, J. Liu, C. Ma, X. Wang, X.W. Yang, C.H. Yu, F. Zhao, J. Zhao, Z.S. Zhou
IHEP, Beijing, People's Republic of China
Y. Feng, H. Huang, S. Shi, E. Tang, X. Yang, Q. Yuan, Z. Zhu
Institute of High Energy Physics (IHEP), People's Republic of China
Z. Li, X. Zhang
Wuxi EL PONT Radiation Technology Ltd, Wuxi, People's Republic of China

The electron linear accelerator has wide applications, and the demands are keeping growing for the irradiation applications in China. A high beam power 10 MeV L-band Linac has been developed recently as a joint venture of Institute of High Energy Physics and EL-PONT Company. The Thales TH2104U klystron, 3 A thermionic electron gun and three meter L-band disk-loaded constant impedance RF structure are adopted. A stable electron beam of 10 MeV, 40 kW has been obtained in the last May with a microwave to beam efficiency of about 65%. In this paper we will present the detailed design issues and beam commissioning.

MOPB048

Linear Accelerator Based on Parallel Coupled Accelerating Structure

cavity, electron, controls, focusing

282

A.E. Levichev, A.M. Barnyakov, V.M. Pavlov
BINP SB RAS, Novosibirsk, Russia
Y.D. Chernousov
ICKC, Novosibirsk, Russia
V. Ivannikov, I.V. Shebolaev
ICKC SB RAS, Novosibirsk, Russia

Accelerating stand based on parallel coupled accelerating structure and electron gun is developed and produced. The structure consists of five accelerating cavities. The RF power feeding of accelerating cavities is provided by common exciting cavity which is performed from rectangular waveguide loaded by reactive pins. Operating frequency is 2450 MHz. Electron gun is made on the basis of RF triode. Linear accelerator was tested with different working regimes. The obtained results are following: energy is up to 4 MeV, accelerating current is up to 300 mA with pulse duration of 2.5 ns on the half of the width; energy is up to 2.5 MeV, accelerating current is up to 100 mA with pulse duration of 5 μs; energy is up to 2.5 MeV, accelerating current is up to 120 mA with pulse duration of 5 μs and beam capture of 100%. The descriptions of the accelerator elements are given in the report. The features of the parallel coupled accelerating structure are discussed. The results of the measuring accelerator’s parameters are presented.

MOPB080

Status of the C-Band RF System for the SPARC-LAB High Brightness Photoinjector

coupling, electron, controls, FEL

360

R. Boni, D. Alesini, M. Bellaveglia, G. Di Pirro, M. Ferrario, A. Gallo, B. Spataro
INFN/LNF, Frascati (Roma), Italy
A. Mostacci, L. Palumbo
URLS, Rome, Italy

The high brightness photoinjector in operation at the SPARC-LAB facility of the INFN-LNF, Italy, consists of a 150 MeV S-band electron accelerator aiming to explore the physics of low emittance high peak current electron beams and the related technology. Velocity bunching techniques, SASE and Seeded FEL experiments have been carried out successfully. To increase the beam energy and improve the performances of the experiments, it was decided to replace one S-band travelling wave accelerating cavity, with two C-band cavities that allow to reach higher energy gain per meter. The new C-band system is in a well advanced development phase and will be in operation early in 2013. The main technical issues of the C-band system and the R&D activities carried out till now are illustrated in detail in this paper.

MOPB083

Operational experience with the FERMI@Elettra S-band RF System

FEL, linac, gun, LLRF

369

A. Fabris, P. Delgiusto, F. Gelmetti, M.M. Milloch, A. Milocco, F. Pribaz, C. Serpico, N. Sodomaco, R. Umer, L. Veljak
ELETTRA, Basovizza, Italy

FERMI@Elettra is a single-pass linac-based FEL user-facility covering the wavelength range from 100 nm (12 eV) to 4 nm (310 eV) and is located next to the third generation synchrotron radiation facility Elettra in Trieste, Italy. The machine is presently under commissioning and the first FEL line (FEL-1) will be opened to the users by the end of 2012. The 1.5 GeV linac is based on S-band technology. The S-band system is composed of fifteen 3 GHz 45 MW peak RF power plants powering the gun, eighteen accelerating structures and the RF deflectors. The S-band system has been set into operation in different phases starting from the second half of 2009. This paper provides an overview of the performance of the system, discussing the achieved results, the strategies adopted to assure them and possible upgrade paths to increase the operability and safety margins of the system.

MOPB087

S-Band Loads for SLAC Linac

linac, vacuum, plasma, insertion

378

A. Krasnykh, F.-J. Decker
SLAC, Menlo Park, California, USA
R.W. LeClair
INTA, Santa Clara, USA

Funding: Work supported by the U.S. Department of Energy under contract number DE-AC02-76SF00515 and SBIR grant number DE-SC0007661
The S-Band loads on the current SLAC linac RF system were designed, in some cases, 40+ years ago to terminate 2-3 MW peak power into a thin layer of coated Kanthal material as the high power absorber [1]. The technology of the load design was based on a flame-sprayed Kanthal wire method onto a base material. During SLAC linac upgrades, the 24 MW peak klystrons were replaced by 5045 klystrons with 65+ MW peak output power. Additionally, SLED cavities were introduced and as a result, the peak power in the current RF setup has increased up to 240 MW peak. The problem of reliable RF peak power termination and RF load lifetime required a careful study and adequate solution. Results of our studies and three designs of S-Band RF load for the present SLAC RF linac system is discussed. These designs are based on the use of low conductivity materials.
[1] “The Stanford Two-Mile Accelerator”, p. 376-381, R. B. Neal, General Editor, 1968, W. A. Benjamin, Inc., NY Amsterdam

TU1A05

Status and Commissioning Plan of the PEFP 100-MeV Linear Accelerator

linac, DTL, proton, site

422

H.-J. Kwon, Y.-S. Cho, J.-H. Jang, D.I. Kim, H.S. Kim, B.-S. Park, J.Y. Ryu, K.T. Seol, Y.-G. Song, S.P. Yun
KAERI, Daejon, Republic of Korea

Funding: Works supported by the Ministry of Education, Science and Technology of Korean Government.
One of the goals of the Proton Engineering Frontier Project (PEFP) is to develop a 100 MeV proton linear accelerator, which consists of 50 keV proton injector, 3 MeV radio frequency quadrupole (RFQ), 20 MeV/100 MeV drift tube linac (DTL) and 20 MeV/100 MeV beam lines. The 100 MeV linear accelerator and beam line components have been installed in the tunnel and experimental hall. After the completion of the utility commissioning, the commissioning of the accelerator starts with a goal of the beam delivery to the 100 MeV target room located at the end of the beam line in 2012. In this paper, the status and commissioning plan of the PEFP 100 MeV linear accelerator are presented.

Slides TU1A05 [6.795 MB]

TUPLB04

Results of Testing of Multi-beam Klystrons for the European XFEL

cathode, high-voltage, vacuum, status

448

V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung
DESY, Hamburg, Germany

For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.

TUPLB12

Development of Permanent Magnet Focusing System for Klystrons

focusing, permanent-magnet, cathode, simulation

470

Y. Fuwa, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
S. Fukuda, S. Michizono
KEK, Ibaraki, Japan

The Distributed RF System (DRFS) for the International Linear Collider (ILC) requires thousands of klystrons. The failure rate of the power supply for solenoid focusing coil of each klystron may be a critical issue for a regular operation of the ILC. A permanent magnet beam focusing system can increase reliability and eliminate their power consumption. Since the required magnetic field is not high in this system, inexpensive anisotropic ferrite magnets can be used instead of magnets containing rare earth materials. In order to prove its feasibility, a test model of a permanent magnet focusing beam system is constructed and a power test of the klystron for DRFS with this model is under preparation. The results of magnetic field distribution measurement and the power test will be presented.

Slides TUPLB12 [1.357 MB]

TUPB004

Results of Testing of Multi-beam Klystrons for the European XFEL

cathode, high-voltage, vacuum, status

479

V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, I. Harders, J. Hartung
DESY, Hamburg, Germany

For the European XFEL multi-beam klystrons, which can produce RF power of 10 MW at an RF frequency of 1.3 GHz, at 1.5ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. Twenty-seven of horizontal multi-beam klystrons (MBK) together with connection modules (CM) will be installed in the XFEL underground tunnel. The CM will be installed on the MBK and connects the MBK to the pulse transformer with only one HV cable, because the CM has a filament transformer inside as well as all diagnostics for HV and cathode current measurements. MBK prototypes together with CM prototypes have been tested for long time at a test stand at DESY, about 3000 hours of operation for each of horizontal MBK with full RF output power, full pulse length and repetition rate of 10 Hz. Testing of first MBKs from series production has been started. In this paper we will give an overview of the test procedure, summarize the current test results and we will give a comparison of the most important parameters.

TUPB009

C-Band Accelerating Structure Development and Tests for the SwissFEL

impedance, controls, FEL, linac

492

R. Zennaro, J. Alex, H. Blumer, M. Bopp, A. Citterio, T. Kleeb, L. Paly, J.-Y. Raguin
PSI, Villigen, Switzerland

SwissFEL requires a 5.8 GeV beam provided by a C-band linac consisting of 104 two-meter accelerating structures. Each structure is of the constant gradient type and is composed of 113 cups. The cup shape is double-rounded to increase the quality factor. No tuning feature is implemented. For this reason ultra-precise turning is exploited. A strong R&D program has been launched on structure fabrication, which will be followed by a future technology transfer to a commercial company. The program includes the production and test of short structures that can be brazed in the existing PSI vacuum oven and will be completed with the production of the full two-meter prototype once the new full scale brazing oven, presently under construction, is operational. The status of the R&D program, including the production and power test results of the first two test structures, is reported here.

TUPB012

The Swiss FEL C-Band Accelerating Structure: RF Design and Thermal Analysis

accelerating-gradient, linac, FEL, impedance

501

J.-Y. Raguin, M. Bopp
PSI, Villigen, Switzerland

The Swiss FEL accelerator concept consists of a 450 MeV S-band injector linac followed by the main linac in C-band aiming at a final energy of 5.8 GeV. The two-meter long C-band accelerating structures have 113 cells, including the two coupler cells, and operate with a 2π/3 phase advance. The structure is of the constant-gradient type with rounded wall cells and has an average iris radius of 6.44 mm, a radius compatible with the impact of the short-range wakefields on the whole linac beam dynamics. The cell irises have an elliptical profile to minimize the peak surface electric fields and the coupler cells are of the J-type. We report here on the RF design of the structure, as well as on its thermal analysis, to target operational conditions with an accelerating gradient of about 28 MV/m and a repetition rate of 100 Hz.

TUPB015

Warm Beamlines and Infrastructure in the European XFEL

linac, shielding, diagnostics, radiation

510

M. Hüning
DESY, Hamburg, Germany

The European XFEL is driven by a superconducting linear accelerator. In the main accelerator tunnel the accelerator modules will be suspended from the tunnel ceiling. The warm sections like bunch compressors will be installed on girders supported from the floor. The accelerator infrastructure like klystrons and electronic racks will be installed in the accelerator tunnel in close proximity to the electron beamline.

TUPB090

Development of Permanent Magnet Focusing System for Klystrons

focusing, permanent-magnet, cathode, simulation

669

Y. Fuwa, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
S. Fukuda, S. Michizono
KEK, Ibaraki, Japan

A permanent magnet focusing system for klystrons is under development to improve reliability of RF supply system and reduce power consumption. To save production cost, anisotropic ferrite magnets are used in this system. A test model has been fabricated and the power test of a 750 kW klystron with this focusing magnet is carried out. 60 % of the nominal output power has been achieved at a preliminary power test so far

TUPB094

High Power Tests of TRASCO RFQ Couplers

vacuum, cavity, rfq, simulation

681

E. Fagotti, L. Antoniazzi, F. Grespan, A. Palmieri, F. Scarpa
INFN/LNL, Legnaro (PD), Italy
O. Brunasso Cattarello, R. Panero
INFN-Torino, Torino, Italy
M. Desmons
CEA/DSM/IRFU, France

The 352.2 MHz 7.13 m long TRASCO RFQ requires an overall amount of 900 kW CW RF power in order to deliver the 40 mA proton beam from the initial energy of 80 keV to the final energy of 5 MeV. For such a purpose a system of eight compact (ϕext=38 mm, ϕint=19.4 mm) loop-based couplers was designed. In a first phase, only the first two (out of six) modules of the RFQ were tested at full power. Therefore only two (out of eight) couplers were used. In order to completely characterize these couplers, a dedicated test bench was prepared, consisting of a bridge waveguide and diagnostics (reflected power, vacuum, arc detectors etc.), onto which a couple of couplers was connected for transmission measurements. Each coupler was tested with a forward power of up to 140 kW. The description of the experimental setup and procedure, as well as the main results of the conditioning procedure will be reported in this paper.

TUPB097

The C-band RF Pulse Compression for Soft XFEL at SINAP

cavity, coupling, simulation, free-electron-laser

687

C.P. Wang, Q. Gu, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

A compact soft X-ray free electron laser facility is presently being constructed at shanghai institute of applied physics (SINAP), Chinese academy of science in 2012 and will be accomplished in 2014. This facility requires a compact linac with a high-gradient accelerating structure for a limited overall length less than 230 m. The c-band technology which is already used in KEK/Spring-8 linear accelerator is a good compromise for this compact facility and a c-and traveling-wave accelerating structure was already fabricated and tested at SINAP, so a c-band pulse compression will be required. AND a SLED type RF compression scheme is proposed for the C-band RF system of the soft XFEL and this scheme uses TE0.1.15 mode energy storage cavity for high Q-energy storage. The C-band pulse compression under development at SINAP has a high power gain about 3.1 and it is designed to compress the pulse width from 2.5 μs to 0.5 μs and multiply the input RF power of 50 MW to generate 160 MW peak RF power, and the coupling coefficient will be 8.5. It has three components: 3 dB coupler, mode convertors and the resonant cavities.

WE2A02

Solid State Marx Modulators for Emerging Applications

linac, high-voltage, diagnostics, linear-collider

743

M.A. Kemp
SLAC, Menlo Park, California, USA

A class of intelligent, Marx-topology modulators are under development at SLAC. These modulators combine numerous advanced features that could be employed in any significant new HPRF installation. The talk will describe the design features and operational experience.

Slides WE2A02 [1.117 MB]

TH2A01

The ESS Linac Design

linac, cryomodule, cavity, proton

768

M. Lindroos, H. Danared, C. Darve, D.P. McGinnis, S. Molloy
ESS, Lund, Sweden

The European Spallation Source (ESS) is a 5 MW, 2.5 MeV long pulse proton machine. It represents a big jump in power compare to the existing spallation facilities. The design phase is well under way, with the delivery of a Conceptual Design Report expected in 2012, and a Technical Design Report in 2013. Why and how the 5 MW goal influences the parameter choice will be describe.

Slides TH2A01 [5.667 MB]

THPLB02

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, controls, rfq, LLRF

810

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

Slides THPLB02 [1.610 MB]

THPB010

Progress in the Construction of Linac4 at CERN

linac, injection, rfq, DTL

864

M. Vretenar, L. Arnaudon, P. Baudrenghien, G. Bellodi, C. Bertone, Y. Body, J.C. Broere, O. Brunner, M.C.L. Buzio, C. Carli, J.-P. Corso, J. Coupard, A. Dallocchio, N. Dos Santos, J.-F. Fuchs, A. Funken, R. Garoby, F. Gerigk, L. Hammouti, K. Hanke, J. Hansen, I. Kozsar, J.-B. Lallement, J. Lettry, A.M. Lombardi, L.A. Lopez Hernandez, C. Maglioni, S.J. Mathot, B. Mikulec, D. Nisbet, M.M. Paoluzzi, B. Puccio, U. Raich, S. Ramberger, F. Roncarolo, C. Rossi, N. Schwerg, R. Scrivens, G. Vandoni, J. Vollaire, R. Wegner, S. Weisz, Th. Zickler
CERN, Geneva, Switzerland

As first step of the LHC luminosity upgrade program CERN is building a new 160 MeV H¯ linear accelerator, Linac4, to replace the ageing 50 MeV Linac2 as injector to the PS Booster (PSB). Linac4 is an 86-m long normal-conducting linac made of a 3 MeV injector followed by 22 accelerating cavities of three different types. The general service infrastructure has been installed in the new tunnel and surface building and its commissioning is progressing; high power RF equipment is being installed in the hall and installations in the tunnel will start soon. Construction of the accelerator parts is in full swing involving industry, the CERN workshops and a network of international collaborations. The injector section including a newly designed and built H¯ source, a 3-m long RFQ and a chopping line is being commissioned in a dedicated test stand. Beam commissioning of the linac will take place in steps of increasing energy between 2013 and 2014. From end of 2014 Linac4 could deliver 50 MeV protons in case of Linac2 failure, while 160 MeV H¯ could be injected into the PSB from end of 2015; the exact start of the LHC shut-down required for connection will be coordinated with its experiments.

THPB015

Performance of Ferrite Vector Modulators in the LLRF system of the Fermilab HINS 6-Cavity Test

cavity, controls, rfq, LLRF

879

P. Varghese, B.W. Barnes, B. Chase, E. Cullerton, C.C. Tan
Fermilab, Batavia, USA

The High Intensity Neutrino Source (HINS) 6-cavity test is a part of the Fermilab HINS Linac R&D program for a low energy, high intensity proton/H⁻ linear accelerator. One of the objectives of the 6-cavity test is to demonstrate the use of high power RF Ferrite Vector Modulators(FVM) for independent control of multiple cavities driven by a single klystron. The beamline includes an RFQ and six cavities. The LLRF system provides a primary feedback loop around the RFQ and the distribution of the regulated klystron output is controlled by secondary learning feed-forward loops on the FVMs for each of the six cavities. The feed-forward loops provide pulse to pulse correction to the current waveform profiles of the FVM power supplies to compensate for beam-loading and other disturbances. The learning feed-forward loops are shown to successfully control the amplitude and phase settings for the cavities well within the 1 % and 1 degree requirements specified for the system.

THPB044

Plans for an Integrated Front-End Test Stand at the Spallation Neutron Source

rfq, ion, ion-source, controls

954

M.S. Champion, A.V. Aleksandrov, M.T. Crofford, D. Heidenreich, Y.W. Kang, J. Moss, R.T. Roseberry, J.P. Schubert
ORNL, Oak Ridge, Tennessee, USA

Funding: Work performed at Oak Ridge National Laboratory, which is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy.
A spare Radio-Frequency Quadrupole (RFQ) is presently being fabricated by industry with delivery to Oak Ridge National Laboratory planned in late 2012. The establishment of a test stand at the Spallation Neutron Source site is underway so that complete acceptance testing can be performed during the winter of 2012-2013. This activity is the first step in the establishment of an integrated front-end test stand that will include an ion source, low-energy beam transport (LEBT), RFQ, medium-energy beam transport, diagnostics, and a beam dump. The test stand will be capable of delivering an H⁻ ion beam of up to 50 mA with a pulse length of 1 ms and a repetition rate of 60 Hz or a proton beam of up to 50 mA, 100 μs, 1 Hz. The test stand will enable the following activities: complete ion source characterization; development of a magnetic LEBT chopper; development of a two-source layout; development of beam diagnostics; and study of beam dynamics of high intensity beam.

THPB092

Recent Improvements in SPring-8 Linac for Early Recovery from Beam Interruption

gun, linac, electron, power-supply

1035

S. Suzuki, T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, H. Tomizawa, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan

The 1GeV SPring-8 linac is an injector for the SPring-8 synchrotron radiation storage ring with 8GeV booster synchrotron. In recent years, backup systems were installed to eliminate long-time interruption of the beam injections: The main gun system is usually operated, and the second gun is always pre-heated and can inject electron beams into a buncher section with an interval of several minutes in case the main gun failed. The first klystron, that feeds RF powers to the buncher system and the downstream klystrons, can be relieved by the next klystron with an interval of about 20 minutes by switching the waveguide circuit. When one of the eleven working klystrons faults, one of standby klystrons, which are kept for hot spares on line, is automatically activated to accelerate beams instead of the failed one without beam interruption. The total downtime in FY2012 was 0.12% in top-up operation user time. The averaged fault frequency was 0.2 times per day.

THPB096

High-power Sources of RF Radiation Driven by Periodic Laser Pulses

laser, cavity, electron, radiation

1044

S.V. Kuzikov, A.V. Savilov
IAP/RAS, Nizhny Novgorod, Russia
S.V. Kuzikov
Omega-P, Inc., New Haven, USA

Funding: Supported in part by DoE USA.
A fast, periodic modulation of electron RF sources can be carried out in a form of Q-factor switching by means of fast RF switches, or in a form of I-switching by means of the bunched electron beam. If modulation frequency equals to time which is necessary for RF radiation to travel along the cavity and to come back, the RF oscillator can produce periodic, giant, short pulses which are desirable for many applications in order to avoid a breakdown. The produced RF pulses are phase and frequency locked by modulation shape. The mentioned effects of the phase and frequency locking remain also possible for RF sources operated in a single-mode regime. In last case the modulation frequency should be close to natural single-mode oscillation frequency. For example, one might control operation of a BWO by means of a small periodical modulation of the electron voltage in a drift section in-between a cathode and the corrugated interaction section. The necessary voltage modulation can be provided by means of a DC generator those voltage due to a photoconductivity is externally modulated with definite frequency by laser which irradiates GaAs isolator inserted in-between the electrodes.