LINAC2014 - List of Keywords (gun)

Paper	Title	Other Keywords	Page
MOIOB03	Generation and Acceleration of Low-Emittance, High-Current Electron Beams for SuperKEKB	emittance, laser, electron, wakefield	21
	M. Yoshida, N. Iida, S. Kazama, T. Natsui, Y. Ogawa, S. Ohsawa, L. Zang, X. Zhou KEK, Ibaraki, Japan
	KEK e⁻/e⁺ linac is now in a final stage of upgrade for SuperKEKB. One of the key issues is to stably generate and accelerate a low-emittance, high charge electron beam for SuperKEKB (a couple of single-bunched beams with a charge of 5 nC and a normalized emittance of 20 mm-mmrad each).
	Slides MOIOB03 [3.981 MB]

MOIOB04	Current Status of PAL-XFEL	undulator, linac, electron, experiment	26
	I.S. Ko, J.H. Han PAL, Pohang, Kyungbuk, Republic of Korea
	The PAL-XFEL project aims to produce 0.1~nm coherent X-ray laser to photon beam users. In order to produce such photons, there are 10 GeV electron linac based on S-band normal conducting accelerating structures and a 150 m long out-vacuum undulator system. The project was already started in April 2011, and the 1.1 km long building is expected to be completed by December 2014. The injector test facility (ITF) which is for a test of the first 139 MeV section of the main linac has been installed and is in normal operation at the extension of the PLS linac building. In this paper, we introduce the project in general, a brief summary of site preparation and building construction, beam test results of ITF, and test results of subsystems produced by domestic manufacturers
	Slides MOIOB04 [9.901 MB]

MOPP004	Design and Development of Pulsed Modulators for RF Electron Linacs	linac, electron, klystron, operation	55
	K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav BARC, Mumbai, India
	Pulsed Modulators required for RF sources, based on klystrons and magnetrons, for RF electron linacs have been designed and developed at Electron Beam Centre, BARC, Mumbai, India. Electron guns in these linacs have also been powered by pulsed modulators. Line-type modulators, as well as IGBT-based solid-state modulators have been developed for these applications. A 150 kV/100 A line-type modulator has been tested on klystron to generate 7 MW peak RF Power. Magnetron modulator has undergone testing up to 40 kV, 165 A on resistive load. Solid-state modulator, using fractional-turn pulse transformer has been designed, developed and tested successfully on magnetron load up to output power of 1.3 MW peak. A transformerless solid-state modulator for electron gun of 6 MeV cargo-scanning linac, uses the Marx adder configuration and has been successfully tested up to 40 kV. In addition, line-type modulators for electron guns up to 85 kV have been successfully commissioned and are in operation in the linac systems. This paper describes the salient design features of these modulators, development of pulse transformers, details of test set-up and discusses the test results of these modulators.
	Poster MOPP004 [2.343 MB]

MOPP012	Beam Commissioning of the SRF 704 MHz Photoemission Gun	cathode, SRF, cavity, electron	70
	W. Xu, S.A. Belomestnykh, I. Ben-Zvi, D.M. Gassner, H. Hahn, J.P. Jamilkowski, P. Kankiya, D. Kayran, N. Laloudakis, R.F. Lambiase, G.T. McIntyre, D. Phillips, V. Ptitsyn, K.S. Smith, R. Than, D. Weiss, A. Zaltsman BNL, Upton, Long Island, New York, USA S.A. Belomestnykh, I. Ben-Zvi, V. Ptitsyn Stony Brook University, Stony Brook, USA D. Holmes AES, Medford, New York, USA
	Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE. A 704 MHz superconducting RF photoemission electron gun for the R&D ERL project is under comissioning at BNL. Without a cathode insert, the SRF gun achieved its design goal: an accelerating voltage of 2 MV in CW mode. During commissioning with a copper cathode insert it reached 1.9 MV with 18% duty factor, which is limited by mulitpacting in a choke-joint cathode stalk. A new cathode stalk has been designed to eliminate multipacting in the choke-joint. This paper presents recent commissioning results, including cavity commissioning without the cathode stalk insert, first beam commissioning of the SRF gun in pulsed regime, and the design of a multipacting-free cathode stalk.

MOPP092	Compact Timing System with FPGA for SPring-8 Linac	timing, FPGA, linac, injection	270
	H. Dewa, H. Hanaki, S. Suzuki JASRI/SPring-8, Hyogo-ken, Japan
	Funding: This reserch was supported by TAKUMI project. A new timing system for SPring-8 linac was developed. It is a test system to confirm the possibility of replacing the current NIM module-based system. Although fast logic circuits can be made easily with NIM modules, they become complicated when they are used in a large system. The timing system for SPring-8 linac has been getting larger and larger after several improvements for injection to New SUBARU (NS), top-up injection for storage ring, low repetition operation for saving energy, fast alternative injection and so on. In order to simplify the system, we adopted FPGA technology that can run at a clock over 500 MHz. The new system has 50 NIM inputs and outputs on the front panel, which is installed in an 8U rack-mount box. It only has gun trigger parts of current system, but includes all of the circuit components used in the current system such as and/or logics, counter delay, fan in/out etc. Three clock sources for Synchrotron injection, NS injection, and linac solo use are available in the FPGA, and they can be changed rapidly according to the trigger sources. We describe here the details of test timing system, the results of timing jitter measurements.

MOPP098	Physical Starting of the First and Second Section of Accelerator Linac-800	electron, undulator, klystron, linac	288
	V. Kobets, N. Balalykin, I.N. Meshkov, V. Minashkin, G. Shirkov JINR, Dubna, Moscow Region, Russia V. Shabratov JINR/VBLHEP, Moscow, Russia
	In the report discusses the modernization of linear electron accelerator MEA (Medium Energy Accelerator). The aim is to develop a set of MEAs based free-electron lasers, imposed a number of emission wavelengths from infrared to ultraviolet. In work presents the results of the physical starting of the first and second stations accelerating electron linear accelerator LINAC-800, as well as start infrared undulator. We discuss the work program for this accelerator.

MOPP132	Development of a Micro-Pulse Electron Gun Based Upon pi-Mode Dual-Cavity	cavity, electron, cathode, simulation	367
	L. Liao, Q. Gu, M. Zhang, M.H. Zhao SINAP, Shanghai, People's Republic of China
	The concept of a novel micro-pulse electron gun (MPG) based upon pi-mode dual-cavity is proposed and analyzed in this paper, and we termed it as dual-cavity micro-pulse electron gun (D-MPG) as compared to single-cavity standard MPG. From simulations, it is clear that the D-MPG is capable of yielding dozens of ampere peak currents and a few ps bunch length. Thought the mechanism for dual cavity is not fully understand, the D-MPG has demonstrate the potential to be the injectors for FEL and THz radiation facilities. Also it is a good candidate to replace the thermal cathode for industrial and medical accelerator system because of the cost-effective of the D-MPG.

MOPP140	Simulations for the High Gradient, Low Emittance Supergun RF Photoinjector	emittance, coupling, electron, simulation	391
	A.D. Cahill, A. Fukasawa, J.B. Rosenzweig UCLA, Los Angeles, California, USA L. Faillace RadiaBeam, Marina del Rey, California, USA B. Spataro INFN/LNF, Frascati (Roma), Italy A. Valloni CERN, Geneva, Switzerland
	A new S-Band photoinjector is being developed at UCLA that will feature a large accelerating gradient at 160 MeV/m creating a beam with approximately 6.5 MeV at the exit. Because of the large accelerating gradient and other considerations, such as cooling and manufacturing, the new Supergun will be coupled into using a coaxial method, rather than side coupling. With the large accelerating gradient we hope to create very low emittance beams on the order of 0.025 mm mrad. These beams can then be used for a number of purposes, mainly for high quality beams used in FELs. Electric simulations have been done using HFSS and Superfish. Heating and mechanical simulations were done using Ansys. Finally, beam simulations were completed with GPT.

TUIOA03	The MAX IV Linac	linac, electron, storage-ring, injection	400
	S. Thorin, J. Andersson, F. Curbis, M. Eriksson, O. Karlberg, D. Kumbaro, E. Mansten, D.F. Olsson, S. Werin MAX-lab, Lund, Sweden
	The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF). The linac has also been deigned to handle the high demands of an FEL injector. In the storage ring injection mode, the linac is operated at 10 Hz with a thermionic RF gun and the electron bunches are kicked out from the linac at either 3 GeV or 1.5 GeV to reach the respective storage ring. For the Short Pulse mode the linac will operate at 100 Hz with a high brightness photo cathode gun. Compression is done in two double achromats with positive R56 and the natural second order momentum compaction, T566, from the achromats is used together with weak sextupoles to linearise longitudinal phase space, leaving no need for a linearising harmonic cavity. The achromat design for bunch compression produces very short, high peak power electron pulses, while minimizing emittance increase. In this paper we present the MAX IV linac design and the status of commissioning which started in March 2014.
	Slides TUIOA03 [4.202 MB]

TUIOA05	High-Power Industrial Accelerator ILU-14 for E-Beam and X-Ray Processing	electron, cathode, controls, injection	409
	V.V. Bezuglov, A.A. Bryazgin, K.N. Chernov, B.L. Faktorovich, V.A. Gorbunov, E.N. Kokin, M.V. Korobeynikov, A.N. Lukin, I. Makarov, S.A. Maximov, A.D. Panfilov, V.M. Radchenko, E.A. Shtarklev, A.V. Sidorov, V.V. Tarnetsky, M.A. Tiunov, V.O. Tkachenko, A. YU. Vlasov, L.A. Voronin BINP SB RAS, Novosibirsk, Russia
	Growing interest to product irradiation by E-beams and X-rays calls for dedicated industrial electron accelerators. BINP has developed ILU-14 radio-frequency pulsed linear accelerator capable of providing 100 kW beam at 7.5-10 MeV. The accelerator has fast removable X-ray converter and can operate both in e-beam and X-ray processing modes. The machine utilizes a low frequency (176 MHz) 6-cells SW accelerating structure. BINP developed this machine as a turn-a-key equipment. Technical details and test results will be presented.
	Slides TUIOA05 [4.672 MB]

TUPP023	Testing of the First Part of Series Production 10MW MBKs for the XFEL Project.	klystron, cathode, operation, power-supply	481
	V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, J. Hartung, V.V. Kachaev, R. Wagner DESY, Hamburg, Germany
	At present more than half of 27 of 10 MW horizontal multi-beam klystrons (MBK) manufactured by two companies for the European XFEL project have been delivered to DESY. After delivery each klystron is connected to the connection module (CM), a HV oil tank with integrated HV connector, voltage and current monitors and a coaxial filament transformer, tested on the test stand and, if necessary conditioned. After this the klystrons are ready for installation in the underground linear accelerator tunnel. Two MBKs are already installed at the injector area of the XFEL. For the European XFEL project MBKs which can produce RF power of 10 MW, at RF frequency of 1.3 GHz, 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. During the incoming test the most important parameters of the MBK such as bandwidth, filament power, perveance, gain at different cathode voltage, phase stability and sensitivity to the solenoids current setting are measured and documented. In this paper we will give an overview of the test procedure, summarize the current test results and give a comparison of the most important parameters for several tubes.

TUPP030	Design of a High Average Current Electron Source for the CLIC Drive Beam Injector	cathode, emittance, electron, simulation	493
	S. Döbert, N. Chritin CERN, Geneva, Switzerland B. Cadilhon, B. Cassany, J. Gardelle, K. Pepitone CEA, LE BARP cedex, France
	The drive beam injector for CLIC needs to deliver a 4.2 A electron beam for a duration of 140 μs with a repetition rate of 50 Hz. The shot to shot and flat top current stability has to be better than 0.1% to guarantee the beam stability required for CLIC. Based on the experience with the CTF3 injector a thermionic high voltage gun with a gridded cathode has been designed together with a sub-harmonic bunching system to achieve these requirements. The grid will allow controlling the current and eventually feedback on the flattop shape. The gun will operate at 140 kV and an emittance of 14 mm mrad can be obtained. The paper describes the design approach and the results of the systematic electromagnetic simulations to optimize the gun. Care was taken during the mechanical design of the gun to obtain a modular design allowing adjusting for different beam currents and cathode sizes.

TUPP066	Commissioning Results of the 2nd 3.5 Cell SRF Gun for ELBE	SRF, cavity, electron, solenoid	578
	A. Arnold, M. Freitag, P. Murcek, J. Teichert, H. Vennekate, R. Xiang HZDR, Dresden, Germany G. Ciovati, P. Kneisel, L. Turlington JLab, Newport News, Virginia, USA
	As in 2007 the first 3.5 cell superconducting radio frequency (SRF) gun was taken into operation at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), it turned out that the specified performance to realize an electron energy gain of 9.4 MeV (Epk=50 MV/m @ Q0=10¹⁰) has not been achieved. Instead, the resonator of the gun was limited by field emission to about one third of these values and the measured beam parameters remained significantly behind the expectations. However, to demonstrate the full potential of this new electron source for the ELBE LINAC, a second and slightly modified SRF gun was developed and built in collaboration with Thomas Jefferson National Accelerator Facility (TJNAF). We will report on commissioning and first results of this new SRF gun. This includes in particular the characterization of the most important RF properties of the cavity as well as their comparison with previous vertical test results.
	Poster TUPP066 [1.220 MB]

TUPP106	RF Characteristics of 20K Cryogenic 2.6-cell Photocathode RF-gun Test Cavity	cavity, simulation, cryogenics, database	671
	T. Sakai, M. Inagaki, K. Nakao, K. Nogami, T. Tanaka LEBRA, Funabashi, Japan M.K. Fukuda, T. Takatomi, J. Urakawa, M. Yoshida KEK, Ibaraki, Japan T.S. Shintomi Nihon University, Tokyo, Japan
	Funding: This work was supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan. The cryogenic C-band photocathode RF gun operating at 20K is under development at LEBRA in Nihon University. The RF gun is of the BNL-type 2.6-cell pillbox cavity with the resonant frequency of 5712 MHz. The 6N8 high purity OFC copper is used as the cavity material. From the theoretical evaluation of the anomalous skin effect, the quality factor Q of the cavity has been expected to be about 60000. Considering a low cooling capacity of the cryocooler system, initial operation of the RF gun is assumed at a duty factor of 0.01 %. The cavity basic design and the beam bunching simulation were carried out using SUPERFISH and General Particle Tracer (GPT). Machining of the cavity was carried out in KEK. The RF characteristics measured at room temperature and 20K will be reported.

TUPP112	Study of a C-Band TW Electron Gun for SwissFEL	cathode, emittance, klystron, cavity	686
	M. Schaer, A. Citterio, P. Craievich, L. Stingelin, R. Zennaro PSI, Villigen PSI, Switzerland
	For a future upgrade of the SwissFEL facility, the replacement of the S-band standing wave electron gun by a C-band standing wave, or traveling wave gun is investigated. The full model of the C-band TW gun is calculated with HFSS and is characterized by an almost vanishing group velocity in the first cell to increase the field at the cathode. ASTRA simulations predict that in the case of the C-band SW gun, a two times higher peak current of ~ 40 A can be generated while still preserving the low slice emittance of ~ 0.2 um at 200 pC, due to the higher electric field on cathode and improved magnetic focusing. This would help to halve the overall beam compression factor, relax the phase stability requirement of S- and X-band systems operated off-crest for compression and decrease the gain curve in theμbunch instability. Compared to the SW gun, a TW gun provides a more homogeneous acceleration and does not require any circulator. In this study, the preliminary RF design and beam performance of a C-band TW gun is presented and compared to a pure C-band SW gun presently under design at Paul Scherrer Institut and to the operating S-band SW gun.

TUPP116	Status of the FERMI II RF Gun at Sincrotrone Trieste	cathode, coupling, emittance, dipole	692
	L. Faillace, R.B. Agustsson, P. Frigola, A. Verma RadiaBeam, Santa Monica, California, USA
	Radiabeam Technologies, in collaboration with UCLA, developed a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system, termed the Fermi Gun II, for the Sincrotrone Trieste (ST) facility. The RF gun has been already in full operation since mid-2013 as the injector for the ST FEL. We report here the current status of the photoinjector system.

THIOC02	Allison Scanner Emittance Diagnostic Development at TRIUMF	emittance, electron, ion, TRIUMF	829
	A. Laxdal, F. Ames, R.A. Baartman, W.R. Rawnsley, A. Sen, V.A. Verzilov, G. Waters TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada R.V. Hariwal IUAC, New Delhi, India M. Kownacki SFU, Burnaby, BC, Canada R.F. Paris University of Ottawa, Ottawa, Ontario, Canada
	TRIUMF has developed Allison scanners to measure the transverse emittance of both low intensity hadron beams at 10⁴ pps and high intensity electron beams at 10mA for a dynamic range of more than 10¹² in intensity. The devices give high resolution transverse emittance information in a compact package that fits in a single diagnostic box. The talk will present the design and performance of the operating devices.
	Slides THIOC02 [2.349 MB]

THPP062	BERLinPro SRF Gun Notch Filter Investigations	cathode, cavity, SRF, resonance	995
	E.N. Zaplatin FZJ, Jülich, Germany J. Knobloch, A. Neumann HZB, Berlin, Germany
	BERLinPro is an approved ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity (1300 MHz, β=1) for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.8 MeV kinetic energy while limited by fundamental power coupler performance to about 230 kW forward power. The RF and beam dynamics gun cavity features 1.4 λ/2 cell resonator. To protect a cathode housing from RF power propagation from the cavity cells and to reduce its component heating a high-frequency notch filter was investigated. We present results of different schemes of choke cell combinations to optimize filter parameters. The goal for the filter design was the RF power attenuation better than -30 dB in the wide frequency range.

THPP114	The SwissFEL RF Gun: Manufacturing and Proof of Precision by Field Profile Measurements	electron, cathode, coupling, vacuum	1117
	U. Ellenberger, H. Blumer, M. Kleeb, L. Paly, M. Probst Paul Scherrer Institute, Villigen PSI, Switzerland M. Bopp, A. Citterio, H. Fitze, J.-Y. Raguin, A. Scherer, L. Stingelin PSI, Villigen PSI, Switzerland
	The high brightness electron source for SwissFEL is an in-house built 2.6 cell normal-conducting RF gun which is scaled to the RF frequency of 2'998.8 MHz. The RF gun is capable of operating at 100 Hz repetition rate and produces electron bunches at the exit of the RF gun of an energy of 7 MeV. Key features of the RF gun are described and how they have been implemented in the manufacturing process. RF field measurements of the RF gun are presented to account for the mechanical precision reached after manufacturing. The RF gun has been thoroughly tested in the SwissFEL injector test facility.

THPP123	Experience of Operation of the Electron Linear Accelerator Based on Parallel Coupled Accelerating Structure	cavity, electron, controls, multipactoring	1144
	A.E. Levichev, A.M. Barnyakov, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia Y.D. Chernousov ICKC, Novosibirsk, Russia V. Ivannikov, I.V. Shebolaev ICKC SB RAS, Novosibirsk, Russia
	An electron linear accelerator based on parallel coupled accelerating structure was developed and produced by Budker Institute of Nuclear Physics SB RAS and Institute of Chemical Kinetics and Combustion SB RAS. Short and long versions of the accelerating structure at 2450 MHz were built. For easy disassembly electrical and vacuum connections of the first (short) structure were made using indium seals. The second structure was brazed. Now the accelerator is in operation and used to study the accelerating and RF technologies. In the report the features of the accelerator are presented, including the design and characteristics of RF antenna and solid-state switch for the electron gun. Test results of the long parallel coupled accelerating structure are discussed. Observations made on the short structure surface after it had been opened are depicted. Now the short structure undergoes certain modifications in order to accelerate higher beam currents.

THPP126	Design of the High Repetition Rate Photocathode Gun for the CLARA Project	cavity, simulation, multipactoring, electron	1155
	B.L. Militsyn, L.S. Cowie, P. Goudket, J.W. McKenzie, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom G. Burt Cockcroft Institute, Lancaster University, Lancaster, United Kingdom T.J. Jones STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom V.V. Paramonov, A.K. Skasyrskaya RAS/INR, Moscow, Russia
	The CLARA injector is required to deliver ultrashort singe electron pulses with a charge of 250 pC following with a repetition rate of 100 and/or 400 Hz. It should also provide 2 us trains of twenty 25 pC pulses with a repetition rate 100 Hz. To meet this challenge, a 1.5 cell S-band photocathode gun with a field of up to 120 MV/m and coaxial coupling has been chosen. The length of the first cell of 0.5 is decided on the basis of beam dynamic simulation with the goal to obtain optimal for CLARA parameters. In order to improve amplitude and phase stability of the RF field, the gun is equipped with RF probes, which will provide feedback to the RF system. The gun and coupler were designed to accept up to 10 MW peak and 10 kW average RF powers. Cooling will be achieved by water channels cut into the bulk of the copper. The coupler will transition from waveguide to coax using an innovative H-shaped dual feed system that cancels out any dipole mode components and allows tuning of the match. The RF and mechanical design of the CLARA high brightness photocathode gun along with beam dynamics simulations are presented in this paper.

THPP136	Study of Femtosecond Electron Bunch Generation at t-ACTS, Tohoku University	electron, injection, bunching, radiation	1178
	S. Kashiwagi, H. Hama, F. Hinode, A. Lueangaramwong, T. Muto, I. Nagasawa, S. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan N.Y. Huang NSRRC, Hsinchu, Taiwan
	We are conducting a beam experiment of sub-picosecond electron bunch generation at a test accelerator as a coherent terahertz source (t-ACTS), Tohoku University. In the t-ACTS, the intense coherent terahertz radiation will be generated from an undulator and an isochronous accumulator ring based on the sub-picoseconds bunches. The accelerator is composed of a thermionic cathode rf gun, alpha magnet and 3 m-long accelerating structure. A velocity bunching scheme in accelerating structure is applied to generate the short electron bunch. The thermionic rf gun consists two independent cavities has been developed, which is capable of manipulating the beam longitudinal phase space. To produced femtosecond electron bunch, the longitudinal phase space distribution of the beam entering the accelerating structure is optimized by changing the rf gun parameters. The bunch length is measured by observing an optical tradition radiation with a streak camera. In the study of femtosecond electron bunch generation, a relation between the rf gun parameters and the bunch length after compression was investigated. The preliminary results of experiments will be described in this conference.

Paper

Title

Other Keywords

Page

MOIOB03

Generation and Acceleration of Low-Emittance, High-Current Electron Beams for SuperKEKB

emittance, laser, electron, wakefield

21

M. Yoshida, N. Iida, S. Kazama, T. Natsui, Y. Ogawa, S. Ohsawa, L. Zang, X. Zhou
KEK, Ibaraki, Japan

KEK e⁻/e⁺ linac is now in a final stage of upgrade for SuperKEKB. One of the key issues is to stably generate and accelerate a low-emittance, high charge electron beam for SuperKEKB (a couple of single-bunched beams with a charge of 5 nC and a normalized emittance of 20 mm-mmrad each).

Slides MOIOB03 [3.981 MB]

MOIOB04

Current Status of PAL-XFEL

undulator, linac, electron, experiment

26

I.S. Ko, J.H. Han
PAL, Pohang, Kyungbuk, Republic of Korea

The PAL-XFEL project aims to produce 0.1~nm coherent X-ray laser to photon beam users. In order to produce such photons, there are 10 GeV electron linac based on S-band normal conducting accelerating structures and a 150 m long out-vacuum undulator system. The project was already started in April 2011, and the 1.1 km long building is expected to be completed by December 2014. The injector test facility (ITF) which is for a test of the first 139 MeV section of the main linac has been installed and is in normal operation at the extension of the PLS linac building. In this paper, we introduce the project in general, a brief summary of site preparation and building construction, beam test results of ITF, and test results of subsystems produced by domestic manufacturers

Slides MOIOB04 [9.901 MB]

MOPP004

Design and Development of Pulsed Modulators for RF Electron Linacs

linac, electron, klystron, operation

55

K.P. Dixit, S. Chandan, N. Chaudhary, R.B. Chavan, L.M. Gantayet, S.R. Ghodke, M. Kumar, K.C. Mittal, H.E. Sarukte, A.R. Tillu, H. Tyagi, V. Yadav
BARC, Mumbai, India

Pulsed Modulators required for RF sources, based on klystrons and magnetrons, for RF electron linacs have been designed and developed at Electron Beam Centre, BARC, Mumbai, India. Electron guns in these linacs have also been powered by pulsed modulators. Line-type modulators, as well as IGBT-based solid-state modulators have been developed for these applications. A 150 kV/100 A line-type modulator has been tested on klystron to generate 7 MW peak RF Power. Magnetron modulator has undergone testing up to 40 kV, 165 A on resistive load. Solid-state modulator, using fractional-turn pulse transformer has been designed, developed and tested successfully on magnetron load up to output power of 1.3 MW peak. A transformerless solid-state modulator for electron gun of 6 MeV cargo-scanning linac, uses the Marx adder configuration and has been successfully tested up to 40 kV. In addition, line-type modulators for electron guns up to 85 kV have been successfully commissioned and are in operation in the linac systems. This paper describes the salient design features of these modulators, development of pulse transformers, details of test set-up and discusses the test results of these modulators.

Poster MOPP004 [2.343 MB]

MOPP012

Beam Commissioning of the SRF 704 MHz Photoemission Gun

cathode, SRF, cavity, electron

70

W. Xu, S.A. Belomestnykh, I. Ben-Zvi, D.M. Gassner, H. Hahn, J.P. Jamilkowski, P. Kankiya, D. Kayran, N. Laloudakis, R.F. Lambiase, G.T. McIntyre, D. Phillips, V. Ptitsyn, K.S. Smith, R. Than, D. Weiss, A. Zaltsman
BNL, Upton, Long Island, New York, USA
S.A. Belomestnykh, I. Ben-Zvi, V. Ptitsyn
Stony Brook University, Stony Brook, USA
D. Holmes
AES, Medford, New York, USA

Funding: This work is supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. DOE.
A 704 MHz superconducting RF photoemission electron gun for the R&D ERL project is under comissioning at BNL. Without a cathode insert, the SRF gun achieved its design goal: an accelerating voltage of 2 MV in CW mode. During commissioning with a copper cathode insert it reached 1.9 MV with 18% duty factor, which is limited by mulitpacting in a choke-joint cathode stalk. A new cathode stalk has been designed to eliminate multipacting in the choke-joint. This paper presents recent commissioning results, including cavity commissioning without the cathode stalk insert, first beam commissioning of the SRF gun in pulsed regime, and the design of a multipacting-free cathode stalk.

MOPP092

Compact Timing System with FPGA for SPring-8 Linac

timing, FPGA, linac, injection

270

H. Dewa, H. Hanaki, S. Suzuki
JASRI/SPring-8, Hyogo-ken, Japan

Funding: This reserch was supported by TAKUMI project.
A new timing system for SPring-8 linac was developed. It is a test system to confirm the possibility of replacing the current NIM module-based system. Although fast logic circuits can be made easily with NIM modules, they become complicated when they are used in a large system. The timing system for SPring-8 linac has been getting larger and larger after several improvements for injection to New SUBARU (NS), top-up injection for storage ring, low repetition operation for saving energy, fast alternative injection and so on. In order to simplify the system, we adopted FPGA technology that can run at a clock over 500 MHz. The new system has 50 NIM inputs and outputs on the front panel, which is installed in an 8U rack-mount box. It only has gun trigger parts of current system, but includes all of the circuit components used in the current system such as and/or logics, counter delay, fan in/out etc. Three clock sources for Synchrotron injection, NS injection, and linac solo use are available in the FPGA, and they can be changed rapidly according to the trigger sources. We describe here the details of test timing system, the results of timing jitter measurements.

MOPP098

Physical Starting of the First and Second Section of Accelerator Linac-800

electron, undulator, klystron, linac

288

V. Kobets, N. Balalykin, I.N. Meshkov, V. Minashkin, G. Shirkov
JINR, Dubna, Moscow Region, Russia
V. Shabratov
JINR/VBLHEP, Moscow, Russia

In the report discusses the modernization of linear electron accelerator MEA (Medium Energy Accelerator). The aim is to develop a set of MEAs based free-electron lasers, imposed a number of emission wavelengths from infrared to ultraviolet. In work presents the results of the physical starting of the first and second stations accelerating electron linear accelerator LINAC-800, as well as start infrared undulator. We discuss the work program for this accelerator.

MOPP132

Development of a Micro-Pulse Electron Gun Based Upon pi-Mode Dual-Cavity

cavity, electron, cathode, simulation

367

L. Liao, Q. Gu, M. Zhang, M.H. Zhao
SINAP, Shanghai, People's Republic of China

The concept of a novel micro-pulse electron gun (MPG) based upon pi-mode dual-cavity is proposed and analyzed in this paper, and we termed it as dual-cavity micro-pulse electron gun (D-MPG) as compared to single-cavity standard MPG. From simulations, it is clear that the D-MPG is capable of yielding dozens of ampere peak currents and a few ps bunch length. Thought the mechanism for dual cavity is not fully understand, the D-MPG has demonstrate the potential to be the injectors for FEL and THz radiation facilities. Also it is a good candidate to replace the thermal cathode for industrial and medical accelerator system because of the cost-effective of the D-MPG.

MOPP140

Simulations for the High Gradient, Low Emittance Supergun RF Photoinjector

emittance, coupling, electron, simulation

391

A.D. Cahill, A. Fukasawa, J.B. Rosenzweig
UCLA, Los Angeles, California, USA
L. Faillace
RadiaBeam, Marina del Rey, California, USA
B. Spataro
INFN/LNF, Frascati (Roma), Italy
A. Valloni
CERN, Geneva, Switzerland

A new S-Band photoinjector is being developed at UCLA that will feature a large accelerating gradient at 160 MeV/m creating a beam with approximately 6.5 MeV at the exit. Because of the large accelerating gradient and other considerations, such as cooling and manufacturing, the new Supergun will be coupled into using a coaxial method, rather than side coupling. With the large accelerating gradient we hope to create very low emittance beams on the order of 0.025 mm mrad. These beams can then be used for a number of purposes, mainly for high quality beams used in FELs. Electric simulations have been done using HFSS and Superfish. Heating and mechanical simulations were done using Ansys. Finally, beam simulations were completed with GPT.

TUIOA03

The MAX IV Linac

linac, electron, storage-ring, injection

400

S. Thorin, J. Andersson, F. Curbis, M. Eriksson, O. Karlberg, D. Kumbaro, E. Mansten, D.F. Olsson, S. Werin
MAX-lab, Lund, Sweden

The MAX IV linac will be used both for injection and top up into two storage rings, and as a high brightness injector for a Short Pulse Facility (SPF). The linac has also been deigned to handle the high demands of an FEL injector. In the storage ring injection mode, the linac is operated at 10 Hz with a thermionic RF gun and the electron bunches are kicked out from the linac at either 3 GeV or 1.5 GeV to reach the respective storage ring. For the Short Pulse mode the linac will operate at 100 Hz with a high brightness photo cathode gun. Compression is done in two double achromats with positive R56 and the natural second order momentum compaction, T566, from the achromats is used together with weak sextupoles to linearise longitudinal phase space, leaving no need for a linearising harmonic cavity. The achromat design for bunch compression produces very short, high peak power electron pulses, while minimizing emittance increase. In this paper we present the MAX IV linac design and the status of commissioning which started in March 2014.

Slides TUIOA03 [4.202 MB]

TUIOA05

High-Power Industrial Accelerator ILU-14 for E-Beam and X-Ray Processing

electron, cathode, controls, injection

409

V.V. Bezuglov, A.A. Bryazgin, K.N. Chernov, B.L. Faktorovich, V.A. Gorbunov, E.N. Kokin, M.V. Korobeynikov, A.N. Lukin, I. Makarov, S.A. Maximov, A.D. Panfilov, V.M. Radchenko, E.A. Shtarklev, A.V. Sidorov, V.V. Tarnetsky, M.A. Tiunov, V.O. Tkachenko, A. YU. Vlasov, L.A. Voronin
BINP SB RAS, Novosibirsk, Russia

Growing interest to product irradiation by E-beams and X-rays calls for dedicated industrial electron accelerators. BINP has developed ILU-14 radio-frequency pulsed linear accelerator capable of providing 100 kW beam at 7.5-10 MeV. The accelerator has fast removable X-ray converter and can operate both in e-beam and X-ray processing modes. The machine utilizes a low frequency (176 MHz) 6-cells SW accelerating structure. BINP developed this machine as a turn-a-key equipment. Technical details and test results will be presented.

Slides TUIOA05 [4.672 MB]

TUPP023

Testing of the First Part of Series Production 10MW MBKs for the XFEL Project.

klystron, cathode, operation, power-supply

481

V. Vogel, L. Butkowski, A. Cherepenko, S. Choroba, J. Hartung, V.V. Kachaev, R. Wagner
DESY, Hamburg, Germany

At present more than half of 27 of 10 MW horizontal multi-beam klystrons (MBK) manufactured by two companies for the European XFEL project have been delivered to DESY. After delivery each klystron is connected to the connection module (CM), a HV oil tank with integrated HV connector, voltage and current monitors and a coaxial filament transformer, tested on the test stand and, if necessary conditioned. After this the klystrons are ready for installation in the underground linear accelerator tunnel. Two MBKs are already installed at the injector area of the XFEL. For the European XFEL project MBKs which can produce RF power of 10 MW, at RF frequency of 1.3 GHz, 1.5 ms pulse length and 10 Hz repetition rate, were chosen as RF power sources. During the incoming test the most important parameters of the MBK such as bandwidth, filament power, perveance, gain at different cathode voltage, phase stability and sensitivity to the solenoids current setting are measured and documented. In this paper we will give an overview of the test procedure, summarize the current test results and give a comparison of the most important parameters for several tubes.

TUPP030

Design of a High Average Current Electron Source for the CLIC Drive Beam Injector

cathode, emittance, electron, simulation

493

S. Döbert, N. Chritin
CERN, Geneva, Switzerland
B. Cadilhon, B. Cassany, J. Gardelle, K. Pepitone
CEA, LE BARP cedex, France

The drive beam injector for CLIC needs to deliver a 4.2 A electron beam for a duration of 140 μs with a repetition rate of 50 Hz. The shot to shot and flat top current stability has to be better than 0.1% to guarantee the beam stability required for CLIC. Based on the experience with the CTF3 injector a thermionic high voltage gun with a gridded cathode has been designed together with a sub-harmonic bunching system to achieve these requirements. The grid will allow controlling the current and eventually feedback on the flattop shape. The gun will operate at 140 kV and an emittance of 14 mm mrad can be obtained. The paper describes the design approach and the results of the systematic electromagnetic simulations to optimize the gun. Care was taken during the mechanical design of the gun to obtain a modular design allowing adjusting for different beam currents and cathode sizes.

TUPP066

Commissioning Results of the 2nd 3.5 Cell SRF Gun for ELBE

SRF, cavity, electron, solenoid

578

A. Arnold, M. Freitag, P. Murcek, J. Teichert, H. Vennekate, R. Xiang
HZDR, Dresden, Germany
G. Ciovati, P. Kneisel, L. Turlington
JLab, Newport News, Virginia, USA

As in 2007 the first 3.5 cell superconducting radio frequency (SRF) gun was taken into operation at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), it turned out that the specified performance to realize an electron energy gain of 9.4 MeV (Epk=50 MV/m @ Q0=10¹⁰) has not been achieved. Instead, the resonator of the gun was limited by field emission to about one third of these values and the measured beam parameters remained significantly behind the expectations. However, to demonstrate the full potential of this new electron source for the ELBE LINAC, a second and slightly modified SRF gun was developed and built in collaboration with Thomas Jefferson National Accelerator Facility (TJNAF). We will report on commissioning and first results of this new SRF gun. This includes in particular the characterization of the most important RF properties of the cavity as well as their comparison with previous vertical test results.

Poster TUPP066 [1.220 MB]

TUPP106

RF Characteristics of 20K Cryogenic 2.6-cell Photocathode RF-gun Test Cavity

cavity, simulation, cryogenics, database

671

T. Sakai, M. Inagaki, K. Nakao, K. Nogami, T. Tanaka
LEBRA, Funabashi, Japan
M.K. Fukuda, T. Takatomi, J. Urakawa, M. Yoshida
KEK, Ibaraki, Japan
T.S. Shintomi
Nihon University, Tokyo, Japan

Funding: This work was supported by Photon and Quantum Basic Research Coordinated Development Program from the Ministry of Education, Culture, Sports, Science and Technology, Japan.
The cryogenic C-band photocathode RF gun operating at 20K is under development at LEBRA in Nihon University. The RF gun is of the BNL-type 2.6-cell pillbox cavity with the resonant frequency of 5712 MHz. The 6N8 high purity OFC copper is used as the cavity material. From the theoretical evaluation of the anomalous skin effect, the quality factor Q of the cavity has been expected to be about 60000. Considering a low cooling capacity of the cryocooler system, initial operation of the RF gun is assumed at a duty factor of 0.01 %. The cavity basic design and the beam bunching simulation were carried out using SUPERFISH and General Particle Tracer (GPT). Machining of the cavity was carried out in KEK. The RF characteristics measured at room temperature and 20K will be reported.

TUPP112

Study of a C-Band TW Electron Gun for SwissFEL

cathode, emittance, klystron, cavity

686

M. Schaer, A. Citterio, P. Craievich, L. Stingelin, R. Zennaro
PSI, Villigen PSI, Switzerland

For a future upgrade of the SwissFEL facility, the replacement of the S-band standing wave electron gun by a C-band standing wave, or traveling wave gun is investigated. The full model of the C-band TW gun is calculated with HFSS and is characterized by an almost vanishing group velocity in the first cell to increase the field at the cathode. ASTRA simulations predict that in the case of the C-band SW gun, a two times higher peak current of ~ 40 A can be generated while still preserving the low slice emittance of ~ 0.2 um at 200 pC, due to the higher electric field on cathode and improved magnetic focusing. This would help to halve the overall beam compression factor, relax the phase stability requirement of S- and X-band systems operated off-crest for compression and decrease the gain curve in theμbunch instability. Compared to the SW gun, a TW gun provides a more homogeneous acceleration and does not require any circulator. In this study, the preliminary RF design and beam performance of a C-band TW gun is presented and compared to a pure C-band SW gun presently under design at Paul Scherrer Institut and to the operating S-band SW gun.

TUPP116

Status of the FERMI II RF Gun at Sincrotrone Trieste

cathode, coupling, emittance, dipole

692

L. Faillace, R.B. Agustsson, P. Frigola, A. Verma
RadiaBeam, Santa Monica, California, USA

Radiabeam Technologies, in collaboration with UCLA, developed a high gradient normal conducting radio frequency (NCRF) 1.6 cell photoinjector system, termed the Fermi Gun II, for the Sincrotrone Trieste (ST) facility. The RF gun has been already in full operation since mid-2013 as the injector for the ST FEL. We report here the current status of the photoinjector system.

THIOC02

Allison Scanner Emittance Diagnostic Development at TRIUMF

emittance, electron, ion, TRIUMF

829

A. Laxdal, F. Ames, R.A. Baartman, W.R. Rawnsley, A. Sen, V.A. Verzilov, G. Waters
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
R.V. Hariwal
IUAC, New Delhi, India
M. Kownacki
SFU, Burnaby, BC, Canada
R.F. Paris
University of Ottawa, Ottawa, Ontario, Canada

TRIUMF has developed Allison scanners to measure the transverse emittance of both low intensity hadron beams at 10⁴ pps and high intensity electron beams at 10mA for a dynamic range of more than 10¹² in intensity. The devices give high resolution transverse emittance information in a compact package that fits in a single diagnostic box. The talk will present the design and performance of the operating devices.

Slides THIOC02 [2.349 MB]

THPP062

BERLinPro SRF Gun Notch Filter Investigations

cathode, cavity, SRF, resonance

995

E.N. Zaplatin
FZJ, Jülich, Germany
J. Knobloch, A. Neumann
HZB, Berlin, Germany

BERLinPro is an approved ERL project to demonstrate energy recovery at 100 mA beam current by pertaining a high quality beam. These goals place stringent requirements on the SRF cavity (1300 MHz, β=1) for the photoinjector which has to deliver a small emittance 100 mA beam with at least 1.8 MeV kinetic energy while limited by fundamental power coupler performance to about 230 kW forward power. The RF and beam dynamics gun cavity features 1.4 λ/2 cell resonator. To protect a cathode housing from RF power propagation from the cavity cells and to reduce its component heating a high-frequency notch filter was investigated. We present results of different schemes of choke cell combinations to optimize filter parameters. The goal for the filter design was the RF power attenuation better than -30 dB in the wide frequency range.

THPP114

The SwissFEL RF Gun: Manufacturing and Proof of Precision by Field Profile Measurements

electron, cathode, coupling, vacuum

1117

U. Ellenberger, H. Blumer, M. Kleeb, L. Paly, M. Probst
Paul Scherrer Institute, Villigen PSI, Switzerland
M. Bopp, A. Citterio, H. Fitze, J.-Y. Raguin, A. Scherer, L. Stingelin
PSI, Villigen PSI, Switzerland

The high brightness electron source for SwissFEL is an in-house built 2.6 cell normal-conducting RF gun which is scaled to the RF frequency of 2'998.8 MHz. The RF gun is capable of operating at 100 Hz repetition rate and produces electron bunches at the exit of the RF gun of an energy of 7 MeV. Key features of the RF gun are described and how they have been implemented in the manufacturing process. RF field measurements of the RF gun are presented to account for the mechanical precision reached after manufacturing. The RF gun has been thoroughly tested in the SwissFEL injector test facility.

THPP123

Experience of Operation of the Electron Linear Accelerator Based on Parallel Coupled Accelerating Structure

cavity, electron, controls, multipactoring

1144

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

An electron linear accelerator based on parallel coupled accelerating structure was developed and produced by Budker Institute of Nuclear Physics SB RAS and Institute of Chemical Kinetics and Combustion SB RAS. Short and long versions of the accelerating structure at 2450 MHz were built. For easy disassembly electrical and vacuum connections of the first (short) structure were made using indium seals. The second structure was brazed. Now the accelerator is in operation and used to study the accelerating and RF technologies. In the report the features of the accelerator are presented, including the design and characteristics of RF antenna and solid-state switch for the electron gun. Test results of the long parallel coupled accelerating structure are discussed. Observations made on the short structure surface after it had been opened are depicted. Now the short structure undergoes certain modifications in order to accelerate higher beam currents.

THPP126

Design of the High Repetition Rate Photocathode Gun for the CLARA Project

cavity, simulation, multipactoring, electron

1155

B.L. Militsyn, L.S. Cowie, P. Goudket, J.W. McKenzie, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
G. Burt
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
T.J. Jones
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
V.V. Paramonov, A.K. Skasyrskaya
RAS/INR, Moscow, Russia

The CLARA injector is required to deliver ultrashort singe electron pulses with a charge of 250 pC following with a repetition rate of 100 and/or 400 Hz. It should also provide 2 us trains of twenty 25 pC pulses with a repetition rate 100 Hz. To meet this challenge, a 1.5 cell S-band photocathode gun with a field of up to 120 MV/m and coaxial coupling has been chosen. The length of the first cell of 0.5 is decided on the basis of beam dynamic simulation with the goal to obtain optimal for CLARA parameters. In order to improve amplitude and phase stability of the RF field, the gun is equipped with RF probes, which will provide feedback to the RF system. The gun and coupler were designed to accept up to 10 MW peak and 10 kW average RF powers. Cooling will be achieved by water channels cut into the bulk of the copper. The coupler will transition from waveguide to coax using an innovative H-shaped dual feed system that cancels out any dipole mode components and allows tuning of the match. The RF and mechanical design of the CLARA high brightness photocathode gun along with beam dynamics simulations are presented in this paper.

THPP136

Study of Femtosecond Electron Bunch Generation at t-ACTS, Tohoku University

electron, injection, bunching, radiation

1178

S. Kashiwagi, H. Hama, F. Hinode, A. Lueangaramwong, T. Muto, I. Nagasawa, S. Nagasawa, K. Nanbu, Y. Shibasaki, K. Takahashi, C. Tokoku
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
N.Y. Huang
NSRRC, Hsinchu, Taiwan

We are conducting a beam experiment of sub-picosecond electron bunch generation at a test accelerator as a coherent terahertz source (t-ACTS), Tohoku University. In the t-ACTS, the intense coherent terahertz radiation will be generated from an undulator and an isochronous accumulator ring based on the sub-picoseconds bunches. The accelerator is composed of a thermionic cathode rf gun, alpha magnet and 3 m-long accelerating structure. A velocity bunching scheme in accelerating structure is applied to generate the short electron bunch. The thermionic rf gun consists two independent cavities has been developed, which is capable of manipulating the beam longitudinal phase space. To produced femtosecond electron bunch, the longitudinal phase space distribution of the beam entering the accelerating structure is optimized by changing the rf gun parameters. The bunch length is measured by observing an optical tradition radiation with a streak camera. In the study of femtosecond electron bunch generation, a relation between the rf gun parameters and the bunch length after compression was investigated. The preliminary results of experiments will be described in this conference.