LINAC2014 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOPP010	Low Charge State Laser Ion Source for the EBIS Injector	ion, laser, target, electron	64
	M. Okamura, J.G. Alessi, E.N. Beebe, T. Kanesue, C.J. Liaw, V. LoDestro, A.I. Pikin, D. Raparia, J. Ritter BNL, Upton, Long Island, New York, USA Y. Fuwa, S. Ikeda, M. Kumaki RIKEN, Saitama, Japan
	Funding: NASA In March 2014, we have successfully commissioned a newly designed low charge high brightness laser ion source (LIS) which delivers various singly charged heavy ions to the electron beam ion source (EBIS) at Brookhaven National Laboratory. Now the LIS is used at routine operation of the RHIC-AGS accelerator complex and is providing stable less-contaminated beams. The laser power density was optimized to provide singly charged ions with low material consumption rate. The nominal laser energy on the target is around 500 mJ with 1064 nm Nd:YAG of the wave length. The induced plasma by the laser is transported through a 3 m pipe to stretch ion beam pulse length to match the EBIS’s requirement and the degradation of the beam current caused by the long drift section of the pipe can be compensated by a longitudinal magnetic filed induced by a coil surrounding the pipe. We also employed a twin laser system to extend the beam width further. At the conference, we will discuss the effect of the new LIS on the various accelerated beams through the EBIS, RFQ and IH-linac.

MOPP040	Application Investigation of High Precision Measurement for Basic Cavity Parameters at ESS	cavity, controls, operation, beam-loading	149
	R. Zeng ESS, Lund, Sweden P. Jonsson Lund University, Lund, Sweden W. Schappert Fermilab, Batavia, Illinois, USA
	The ESS cavity control and operation methods/algorithms are challenging due to the use of long pulse, higher beam intensity, high beam power, high gradient, uncertainties in spoke cavities and high demands for energy efficiency and availability. Suitable and effective solutions could make use of modern technologies (flexible FPGA, faster CPU, bigger memory, faster communication speed), novel measuring techniques, accurate system modeling, and advanced control concept. Those possible implementations are essential to a better understanding, and thus a better operation of ESS cavity especially SRF cavities. All these concepts rely on high precision measurement of basic cavity parameters and consequent high quality data with high resolution, high precision and completeness. This paper focuses on how high precision measurement will address the challenges at ESS on the following topics: long pulse lorentz force detuning, high precision phase and amplitude setting, heavy beam loading compensation and power overhead reduction.

MOPP092	Compact Timing System with FPGA for SPring-8 Linac	timing, FPGA, linac, gun	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.

MOPP094	Latest Improvements of the SPring-8 Linac for High Reliability	linac, operation, vacuum, electron	276
	S. Suzuki, H. Dewa, H. Hanaki, T. Kobayashi, T. Magome, A. Mizuno, T. Taniuchi, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan T. Asaka RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
	In order to perform stable injection to the 8GeV SPring-8 storage ring, which is performing the top-up operation, the high reliability of the linac has been advanced as follows: For reduction of phase variations caused by the waveguide deformation due to the variations of temperature or atmospheric pressure, the waveguide circuit of SF6 enclosure type, which fed RF powers to the bunching section, was replaced with that of vacuum type. And S-band 10MW circulators and isolators of vacuum type were adopted for the first time in the world. The timing system was improved so that the interval time of the beam injection into the 8GeV booster synchrotron and the 1.5 GeV NewSUBARU storage ring has been reduced to 1 sec from 15 seconds, respectively, even in the top-up operation of both storage rings. As a result, the stored current by the top-up operation were further stabilized. The stored current of the NewSUBARU storage ring was stabilized to 0.18% from 0.31%. The electron gun cathode assembly has been developed to reduce the dark emission from a grid plate by the double grid method and the electrolytic polishing.

TUIOA03	The MAX IV Linac	linac, gun, electron, storage-ring	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, gun, controls	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]

TUIOB03	Commissioning of Energy Upgraded Linac of J-PARC	linac, klystron, operation, rfq	417
	K. Hasegawa J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	To realize a full potential of J-PARC facility (1MW at 3 GeV), the J-PARC linac is upgraded from 181 MeV to 400 MeV by using an annular-ring coupled structure linac (ACS). The ACS modules and peripheral system were installed and commissioned in summer to autumn of 2013. Beam commissioning is about to start and results will be expected.
	Slides TUIOB03 [4.905 MB]

TUPP009	Operation and Improvements of the ALBA Linac	linac, klystron, operation, booster	459
	R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Light Source pre-injector is a 100 MeV electron Linac which started operation in July 2010. Since then, several improvements have been made to the Linac system to enhance the beam stability and the operation reliability with special focus to top-up mode operation requirements. A description of the modifications applied to the RF system and an overview of the different modes of injection are presented. Also operational experience in decay mode and in the recently implemented top-up mode are reported.

TUPP105	Storage Ring as a Linac Beam Monitor – Its Operation and Contribution to the Stable Top-up Injection	linac, timing, synchrotron, storage-ring	668
	Y. Shoji LASTI, Hyogo, Japan T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, Y. Minagawa, A. Mizuno, T. Shinomoto, S. Suzuki, Y. Takemura, T. Taniuchi, K. Yanagida JASRI/SPring-8, Hyogo-ken, Japan
	We have used the electron storage ring, NewSUBARU, as a beam monitor of the SPring-8 linac. The time and transverse profiles of the injected linac beam are recorded in a frame of a dual-sweep streak camera. A measurements through synchrotron or betatron oscillation in the ring gives multi-dimensional beam structure. The system functions as a final check of the linac beam. It gives the time profile and energy profile or transverse emittance, which includes Twiss parameters. It measures parameters of one linac bunch in a long macro pulse. A shot-by-shot measurement gives beam fluctuations. We report how we use the system and its contribution to the stable top-up operation. The beam loading effect on the bunch energy was obtained by bunch-by-bunch energy profile measurements. It confirmed the optimization of the ECS (Energy Compression System) parameters. The single shot bunch-by-bunch vertical emittance measurement proved the difference between the front bunch and the following bunches. The same measurement showed a timing jitter of the electron gun pulse although the rf synchronization was perfect. This jittering had made the injection efficiency unstable.

TUPP120	Commissioning of BINP Injection Complex VEPP-5	electron, dumping, positron, closed-orbit	702
	A.A. Starostenko, A.E. Levichev, D.A. Nikiforov BINP SB RAS, Novosibirsk, Russia
	New BINP injector complex VEPP-5 consist of S-band linear accelerators (270 and 420MeV), positron converter (at 270 MeV) and damping ring. The injector complex will provide e⁺/e⁻ particles for the 2 colliders at BINP - VEPP-4M and VEPP-2000. After a long construction period the injector is in its commissioning stage now. Positron rate production of 6·10⁸ positrons/pulse and conversion yield of 0.14/GeV and stored positron beam current of 70mA were already achieved.

TUPP138	Analysis of New High-Q0 SRF Cavity Tests by Nitrogen Gas Doping at Jefferson Lab	cavity, SRF, niobium, vacuum	736
	A.D. Palczewski, R.L. Geng, C.E. Reece JLab, Newport News, Virginia, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. In order to refine systematic understanding and establish confident process control, Jefferson Lab has joined with partners to investigate and thoroughly characterize the dramatically higher Q0 of 1.3 GHz niobium cavities first reported by FNAL in 2013[1]. With partial support from the LCLS-II project, JLab has undertaken a parametric study of nitrogen doping in vacuum furnace at 800 C followed by variable depth surface removal in the 5 - 20 μm range. Q0 above 3×10¹⁰ are typical at 2.0 K and 16 MV/m accelerating field. We report observations from the single cell study and current interpretations. In addition to the parametric single cell study, we also report on the ongoing serial testing of six nitrogen-doped 9-cell cavities as baseline prototypes for LCLS-II. [1] A. Grassellino, et al., Supercon. Sci.and Tech., 2013. 26(10): p. 102001
	Poster TUPP138 [4.214 MB]

WEIOA04	Phase Locked Magnetrons for Accelerators	cathode, controls, cavity, electron	751
	A.C. Dexter Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	Magnetrons offer lower capital costs and higher efficiencies than klystrons, however are natural oscillators rather than amplifiers. This paper reviews techniques and issues for applying high efficiency L band magnetrons to long pulse, high intensity proton linacs. Reference is made to a proof of principle experiment whereby the phase of an SRF cavity was accurately controlled when energised by a magnetron.
	Slides WEIOA04 [1.224 MB]

THPP005	A New High Current and Single Bunch Injector at ELSA	booster, linac, electron, timing	847
	M. Schedler, P. Hänisch, W. Hillert, D. Proft ELSA, Bonn, Germany J. Zappai Uni Bonn, Bonn, Germany
	At the Electron Stretcher Facility ELSA of Bonn University, an increase of the maximum stored beam current from 20 mA to 200 mA is planned for the stretcher ring. In order to keep the desired duty cycle of the post acceleration mode at about 80 \% a new high current injector operating at 3 GHz has been built. It provides an electron beam with an energy of 20 MeV and a beam current of 800 mA in pulsed operation. A prebuncher, travelling wave buncher system and an energy compressing system are installed in order to enhance the beam acceptance of the linac and to reduce the energy spread in order to achieve an improved injection efficiency into the booster synchrotron. For studying accelerators impedances and beam instabilities the linac is able to produce single bunches with a pulse current of 2 A which will be accumulated in the stretcher ring.

THPP073	Cavity Excitation of the Chopped Beam at the J-PARC Linac	DTL, linac, pick-up, operation	1023
	K. Futatsukawa KEK, Ibaraki, Japan
	In the J-PARC linac, the beam energy at the injection of the rapid-cycle synchrotron (RCS) was upgraded up to 400 MeV by the installation of 25 additional cavities, annular-ring coupled structure (ACS), in 2013. The initial frequency of RCS was shifted to 1.227 MHz because of the change the injection-beam velocity. At the linac, the beam is chopped as the comb-like structure with this frequency (intermediate-pulse) by the RF deflector. The component of this RCS frequency excited the PC1 mode of DTL2 and was the cause of the RF-control difficulty. Additionally, it could be confirmed that other chopping operations, which does not have specific intermediate-pulses for example, drove other modes. In this paper, I would like to introduce this phenomena and the counterplan as the RF control.

THPP090	Longitudinal Measurement of Annular-Ring Coupled Structure Linac in J-PARC	simulation, linac, distributed, rfq	1056
	T. Maruta, Y. Liu KEK/JAEA, Ibaraki-Ken, Japan A. Miura JAEA/J-PARC, Tokai-mura, Japan
	In the J-PARC linac, Annular-type Coupled Structure (ACS) linac was introduced for the beam energy extension to 400 MeV in year 2013. To measure the longitudinal property of the ACS, we measured acceptance in phase direction by synchronous phase scan method and confirm that the acceptance is consistent with that by 3D PIC simulation. Simultaneously, the output beam energy from ACS was measured by orbit displacement where the dispersion is large. In this presentation, we discuss the measurement method and results.

THPP093	Combined System of Optical Inspection and Local Grinder	cavity, brightness, controls, superconducting-cavity	1065
	Y. Iwashita Kyoto ICR, Uji, Kyoto, Japan H. Hayano, T. Kubo, K. Watanabe, Y. Yamamoto KEK, Ibaraki, Japan
	Optical inspections on superconducting accelerating tubes have been playing an important role on improving their accelerating gradients. Instead of treatments on whole cavity inner surfaces to eliminate the found defects on the surfaces, the local grinding method succeeds to remove them efficiently. A combined system of the optical inspection and the local Grinding machines are fabricated. The overview of the system will be presented.

THPP116	Performance of New Injector RILAC2 for Riken Ri-Beam Factory	cyclotron, ECRIS, operation, ion	1123
	N. Sakamoto, M. Fujimaki, N. Fukunishi, Y. Higurashi, O. Kamigaito, H. Okuno, K. Suda, T. Watanabe, Y. Watanabe, K. Yamada RIKEN Nishina Center, Wako, Japan R. Koyama SHI Accelerator Service Ltd., Tokyo, Japan
	New injector called RILAC2 was designed and constructed to provide intense uranium beams with A/q≈7 with an energy of 0.67 MeV/u which are injected to the succeeding ring cyclotron, RIKEN Ring Cyclotron, called RRC. After the last LINAC conference where the commissioning of the RILAC2 was reported, some modifications and improvements with RILAC2 have been made aiming at stable operation. Recently, transmission efficiency and stability of the beams have been improved and the average beam current more than 20 pnA for uranium 345 MeV/u acceleration has been realized. In this paper the modifications and improvements of the RILAC2 together with the present performance are reported.

THPP136	Study of Femtosecond Electron Bunch Generation at t-ACTS, Tohoku University	electron, gun, 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.

THPP139	800MeV Linear Accelerator Development for HLS Upgrade	linac, electron, klystron, operation	1189
	K. Jin, Y. Hong, G. Huang, D. Jia, S.C. Zhang USTC/NSRL, Hefei, Anhui, People's Republic of China
	Hefei Light Source (HLS) was mainly composed of an 800 MeV electron storage ring and a 200 MeV constant-impedance Linac functioning as its injector in NSRL PhaseⅠ. A new Linac has been developed successfully in view of the Full Energy Injection and the Top-up Injection scheme will be adopted in the HLS upgrade. In this paper, an 800MeV linear accelerating system construction, the constant-gradient structure with the symmetry couplers will be described in detail. The microwave system, the manufacture technology, the RF measurement, the high power testing and the accelerating system operation with beam currents are presented.

Paper

Title

Other Keywords

Page

MOPP010

Low Charge State Laser Ion Source for the EBIS Injector

ion, laser, target, electron

64

M. Okamura, J.G. Alessi, E.N. Beebe, T. Kanesue, C.J. Liaw, V. LoDestro, A.I. Pikin, D. Raparia, J. Ritter
BNL, Upton, Long Island, New York, USA
Y. Fuwa, S. Ikeda, M. Kumaki
RIKEN, Saitama, Japan

Funding: NASA
In March 2014, we have successfully commissioned a newly designed low charge high brightness laser ion source (LIS) which delivers various singly charged heavy ions to the electron beam ion source (EBIS) at Brookhaven National Laboratory. Now the LIS is used at routine operation of the RHIC-AGS accelerator complex and is providing stable less-contaminated beams. The laser power density was optimized to provide singly charged ions with low material consumption rate. The nominal laser energy on the target is around 500 mJ with 1064 nm Nd:YAG of the wave length. The induced plasma by the laser is transported through a 3 m pipe to stretch ion beam pulse length to match the EBIS’s requirement and the degradation of the beam current caused by the long drift section of the pipe can be compensated by a longitudinal magnetic filed induced by a coil surrounding the pipe. We also employed a twin laser system to extend the beam width further. At the conference, we will discuss the effect of the new LIS on the various accelerated beams through the EBIS, RFQ and IH-linac.

MOPP040

Application Investigation of High Precision Measurement for Basic Cavity Parameters at ESS

cavity, controls, operation, beam-loading

149

R. Zeng
ESS, Lund, Sweden
P. Jonsson
Lund University, Lund, Sweden
W. Schappert
Fermilab, Batavia, Illinois, USA

The ESS cavity control and operation methods/algorithms are challenging due to the use of long pulse, higher beam intensity, high beam power, high gradient, uncertainties in spoke cavities and high demands for energy efficiency and availability. Suitable and effective solutions could make use of modern technologies (flexible FPGA, faster CPU, bigger memory, faster communication speed), novel measuring techniques, accurate system modeling, and advanced control concept. Those possible implementations are essential to a better understanding, and thus a better operation of ESS cavity especially SRF cavities. All these concepts rely on high precision measurement of basic cavity parameters and consequent high quality data with high resolution, high precision and completeness. This paper focuses on how high precision measurement will address the challenges at ESS on the following topics: long pulse lorentz force detuning, high precision phase and amplitude setting, heavy beam loading compensation and power overhead reduction.

MOPP092

Compact Timing System with FPGA for SPring-8 Linac

timing, FPGA, linac, gun

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.

MOPP094

Latest Improvements of the SPring-8 Linac for High Reliability

linac, operation, vacuum, electron

276

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

In order to perform stable injection to the 8GeV SPring-8 storage ring, which is performing the top-up operation, the high reliability of the linac has been advanced as follows: For reduction of phase variations caused by the waveguide deformation due to the variations of temperature or atmospheric pressure, the waveguide circuit of SF6 enclosure type, which fed RF powers to the bunching section, was replaced with that of vacuum type. And S-band 10MW circulators and isolators of vacuum type were adopted for the first time in the world. The timing system was improved so that the interval time of the beam injection into the 8GeV booster synchrotron and the 1.5 GeV NewSUBARU storage ring has been reduced to 1 sec from 15 seconds, respectively, even in the top-up operation of both storage rings. As a result, the stored current by the top-up operation were further stabilized. The stored current of the NewSUBARU storage ring was stabilized to 0.18% from 0.31%. The electron gun cathode assembly has been developed to reduce the dark emission from a grid plate by the double grid method and the electrolytic polishing.

TUIOA03

The MAX IV Linac

linac, gun, electron, storage-ring

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, gun, controls

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]

TUIOB03

Commissioning of Energy Upgraded Linac of J-PARC

linac, klystron, operation, rfq

417

K. Hasegawa
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

To realize a full potential of J-PARC facility (1MW at 3 GeV), the J-PARC linac is upgraded from 181 MeV to 400 MeV by using an annular-ring coupled structure linac (ACS). The ACS modules and peripheral system were installed and commissioned in summer to autumn of 2013. Beam commissioning is about to start and results will be expected.

Slides TUIOB03 [4.905 MB]

TUPP009

Operation and Improvements of the ALBA Linac

linac, klystron, operation, booster

459

R. Muñoz Horta, J.M. Gómez Cordero, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Light Source pre-injector is a 100 MeV electron Linac which started operation in July 2010. Since then, several improvements have been made to the Linac system to enhance the beam stability and the operation reliability with special focus to top-up mode operation requirements. A description of the modifications applied to the RF system and an overview of the different modes of injection are presented. Also operational experience in decay mode and in the recently implemented top-up mode are reported.

TUPP105

Storage Ring as a Linac Beam Monitor – Its Operation and Contribution to the Stable Top-up Injection

linac, timing, synchrotron, storage-ring

668

Y. Shoji
LASTI, Hyogo, Japan
T. Asaka, H. Dewa, H. Hanaki, T. Kobayashi, Y. Minagawa, A. Mizuno, T. Shinomoto, S. Suzuki, Y. Takemura, T. Taniuchi, K. Yanagida
JASRI/SPring-8, Hyogo-ken, Japan

We have used the electron storage ring, NewSUBARU, as a beam monitor of the SPring-8 linac. The time and transverse profiles of the injected linac beam are recorded in a frame of a dual-sweep streak camera. A measurements through synchrotron or betatron oscillation in the ring gives multi-dimensional beam structure. The system functions as a final check of the linac beam. It gives the time profile and energy profile or transverse emittance, which includes Twiss parameters. It measures parameters of one linac bunch in a long macro pulse. A shot-by-shot measurement gives beam fluctuations. We report how we use the system and its contribution to the stable top-up operation. The beam loading effect on the bunch energy was obtained by bunch-by-bunch energy profile measurements. It confirmed the optimization of the ECS (Energy Compression System) parameters. The single shot bunch-by-bunch vertical emittance measurement proved the difference between the front bunch and the following bunches. The same measurement showed a timing jitter of the electron gun pulse although the rf synchronization was perfect. This jittering had made the injection efficiency unstable.

TUPP120

Commissioning of BINP Injection Complex VEPP-5

electron, dumping, positron, closed-orbit

702

A.A. Starostenko, A.E. Levichev, D.A. Nikiforov
BINP SB RAS, Novosibirsk, Russia

New BINP injector complex VEPP-5 consist of S-band linear accelerators (270 and 420MeV), positron converter (at 270 MeV) and damping ring. The injector complex will provide e⁺/e⁻ particles for the 2 colliders at BINP - VEPP-4M and VEPP-2000. After a long construction period the injector is in its commissioning stage now. Positron rate production of 6·10⁸ positrons/pulse and conversion yield of 0.14/GeV and stored positron beam current of 70mA were already achieved.

TUPP138

Analysis of New High-Q0 SRF Cavity Tests by Nitrogen Gas Doping at Jefferson Lab

cavity, SRF, niobium, vacuum

736

A.D. Palczewski, R.L. Geng, C.E. Reece
JLab, Newport News, Virginia, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177.
In order to refine systematic understanding and establish confident process control, Jefferson Lab has joined with partners to investigate and thoroughly characterize the dramatically higher Q0 of 1.3 GHz niobium cavities first reported by FNAL in 2013[1]. With partial support from the LCLS-II project, JLab has undertaken a parametric study of nitrogen doping in vacuum furnace at 800 C followed by variable depth surface removal in the 5 - 20 μm range. Q0 above 3×10¹⁰ are typical at 2.0 K and 16 MV/m accelerating field. We report observations from the single cell study and current interpretations. In addition to the parametric single cell study, we also report on the ongoing serial testing of six nitrogen-doped 9-cell cavities as baseline prototypes for LCLS-II.
[1] A. Grassellino, et al., Supercon. Sci.and Tech., 2013. 26(10): p. 102001

Poster TUPP138 [4.214 MB]

WEIOA04

Phase Locked Magnetrons for Accelerators

cathode, controls, cavity, electron

751

A.C. Dexter
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

Magnetrons offer lower capital costs and higher efficiencies than klystrons, however are natural oscillators rather than amplifiers. This paper reviews techniques and issues for applying high efficiency L band magnetrons to long pulse, high intensity proton linacs. Reference is made to a proof of principle experiment whereby the phase of an SRF cavity was accurately controlled when energised by a magnetron.

Slides WEIOA04 [1.224 MB]

THPP005

A New High Current and Single Bunch Injector at ELSA

booster, linac, electron, timing

847

M. Schedler, P. Hänisch, W. Hillert, D. Proft
ELSA, Bonn, Germany
J. Zappai
Uni Bonn, Bonn, Germany

At the Electron Stretcher Facility ELSA of Bonn University, an increase of the maximum stored beam current from 20 mA to 200 mA is planned for the stretcher ring. In order to keep the desired duty cycle of the post acceleration mode at about 80 \% a new high current injector operating at 3 GHz has been built. It provides an electron beam with an energy of 20 MeV and a beam current of 800 mA in pulsed operation. A prebuncher, travelling wave buncher system and an energy compressing system are installed in order to enhance the beam acceptance of the linac and to reduce the energy spread in order to achieve an improved injection efficiency into the booster synchrotron. For studying accelerators impedances and beam instabilities the linac is able to produce single bunches with a pulse current of 2 A which will be accumulated in the stretcher ring.

THPP073

Cavity Excitation of the Chopped Beam at the J-PARC Linac

DTL, linac, pick-up, operation

1023

K. Futatsukawa
KEK, Ibaraki, Japan

In the J-PARC linac, the beam energy at the injection of the rapid-cycle synchrotron (RCS) was upgraded up to 400 MeV by the installation of 25 additional cavities, annular-ring coupled structure (ACS), in 2013. The initial frequency of RCS was shifted to 1.227 MHz because of the change the injection-beam velocity. At the linac, the beam is chopped as the comb-like structure with this frequency (intermediate-pulse) by the RF deflector. The component of this RCS frequency excited the PC1 mode of DTL2 and was the cause of the RF-control difficulty. Additionally, it could be confirmed that other chopping operations, which does not have specific intermediate-pulses for example, drove other modes. In this paper, I would like to introduce this phenomena and the counterplan as the RF control.

THPP090

Longitudinal Measurement of Annular-Ring Coupled Structure Linac in J-PARC

simulation, linac, distributed, rfq

1056

T. Maruta, Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
A. Miura
JAEA/J-PARC, Tokai-mura, Japan

In the J-PARC linac, Annular-type Coupled Structure (ACS) linac was introduced for the beam energy extension to 400 MeV in year 2013. To measure the longitudinal property of the ACS, we measured acceptance in phase direction by synchronous phase scan method and confirm that the acceptance is consistent with that by 3D PIC simulation. Simultaneously, the output beam energy from ACS was measured by orbit displacement where the dispersion is large. In this presentation, we discuss the measurement method and results.

THPP093

Combined System of Optical Inspection and Local Grinder

cavity, brightness, controls, superconducting-cavity

1065

Y. Iwashita
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, T. Kubo, K. Watanabe, Y. Yamamoto
KEK, Ibaraki, Japan

Optical inspections on superconducting accelerating tubes have been playing an important role on improving their accelerating gradients. Instead of treatments on whole cavity inner surfaces to eliminate the found defects on the surfaces, the local grinding method succeeds to remove them efficiently. A combined system of the optical inspection and the local Grinding machines are fabricated. The overview of the system will be presented.

THPP116

Performance of New Injector RILAC2 for Riken Ri-Beam Factory

cyclotron, ECRIS, operation, ion

1123

N. Sakamoto, M. Fujimaki, N. Fukunishi, Y. Higurashi, O. Kamigaito, H. Okuno, K. Suda, T. Watanabe, Y. Watanabe, K. Yamada
RIKEN Nishina Center, Wako, Japan
R. Koyama
SHI Accelerator Service Ltd., Tokyo, Japan

New injector called RILAC2 was designed and constructed to provide intense uranium beams with A/q≈7 with an energy of 0.67 MeV/u which are injected to the succeeding ring cyclotron, RIKEN Ring Cyclotron, called RRC. After the last LINAC conference where the commissioning of the RILAC2 was reported, some modifications and improvements with RILAC2 have been made aiming at stable operation. Recently, transmission efficiency and stability of the beams have been improved and the average beam current more than 20 pnA for uranium 345 MeV/u acceleration has been realized. In this paper the modifications and improvements of the RILAC2 together with the present performance are reported.

THPP136

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

electron, gun, 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.

THPP139

800MeV Linear Accelerator Development for HLS Upgrade

linac, electron, klystron, operation

1189

K. Jin, Y. Hong, G. Huang, D. Jia, S.C. Zhang
USTC/NSRL, Hefei, Anhui, People's Republic of China

Hefei Light Source (HLS) was mainly composed of an 800 MeV electron storage ring and a 200 MeV constant-impedance Linac functioning as its injector in NSRL PhaseⅠ. A new Linac has been developed successfully in view of the Full Energy Injection and the Top-up Injection scheme will be adopted in the HLS upgrade. In this paper, an 800MeV linear accelerating system construction, the constant-gradient structure with the symmetry couplers will be described in detail. The microwave system, the manufacture technology, the RF measurement, the high power testing and the accelerating system operation with beam currents are presented.