LINAC2014 - List of Keywords (operation)

Paper	Title	Other Keywords	Page
MOIOB01	Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility	cryomodule, linac, cavity, SRF	11
	M. Spata JLab, Newport News, Virginia, USA
	Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.
	Slides MOIOB01 [2.754 MB]

MOPP004	Design and Development of Pulsed Modulators for RF Electron Linacs	linac, electron, klystron, gun	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]

MOPP007	SF6 Gas Monitoring and Safety for DC Electron Beam Accelerator at EBC, Kharghar, Navi Mumbai	electron, monitoring, high-voltage, experiment	61
	S.K. Suneet, S. Acharya, S. Banerjee, R. Barnwal, D. Bhattacharjee, N. Chaudhary, R.B. Chavan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, B.S. Israel, D. Jayaprakash, N. Lawangare, K. Mahender, R.L. Mishra, K.C. Mittal, B. Nayak, S. Nayak, R. Patel, R.N. Rajan, P.C. Saroj, D.K. Sharma, V. Sharma, M.K. Srvastava, D.P. Suryaprakash, N.T. Thakur, R. Tiwari, A. Waghmare BARC, Mumbai, India
	A 3 MeV, 30kW DC Industrial electron beam accelerator has been designed, commissioned and tested at Electron beam centre, Kharghar. The accelerator has been tested upto 5 kW power level with SF6 gas at 6 kg/cm². The accelerating column, high voltage multiplier column, electron gun and its power supply are housed in accelerator tank, which is filled with SF6 gas as gaseous insulator at 6 kg/cm². The SF6 gas is being used due to high dielectric strength and excellent heat transfer characteristics. The SF6 gas is non toxic and non carcinogenic. The SF6 gas replaces oxygen hence the TLV (threshold limiting value) is 1000 ppm for inhaled gas for persons working on the SF6 gas handling system. The SF6 gas is being green house gas, leak tightness has to monitor in the system and leak if any should be repaired. The gas should be used, recycled and reuse and thus saving the environment. This paper describes the safety and monitoring of the SF6 gas leak, quality and precautions in 3MeV accelerator.
	Poster MOPP007 [1.389 MB]

MOPP011	Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory	linac, detector, ion, target	67
	D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski BNL, Upton, Long Island, New York, USA
	Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP017	Cool Down and Flux Trapping Studies on SRF Cavities	cavity, SRF, cryomodule, linac	84
	D. Gonnella, M. Liepe Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Recent results from Cornell and FNAL have shown that cool down rate can have a strong impact on the residual resistance of a superconducting RF cavity during operation. We have studied the effect of cool down rate, gradient, and external magnetic field during cool down on the residual resistance of an EP, EP+120C baked, and nitrogen-doped cavities. For each cavity, faster cool down and large gradient resulted in lower residual resistance in vertical test. The nitrogen-doped cavities showed the largest improvement with fast cool down, while the EP+120C cavity showed the smallest. The cavities were also placed in a uniform external magnetic field and residual resistance was measured as a function of applied field and cool down rate. We show that the nitrogen-doped cavity was the most susceptible to losses from trapped flux and the EP+120C cavity was least susceptible. These measurements provide new insights into understanding the physics behind the observed impact of cool down rates and gradients on the performance of cavities with differing preparations.

MOPP023	X-band Technology for FEL Sources	FEL, linac, emittance, experiment	101
	G. D'Auria, S. Di Mitri, C. Serpico Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy E. Adli University of Oslo, Oslo, Norway A.A. Aksoy, O. Yavaş Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey D. Angal-Kalinin, J.A. Clarke STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom C.J. Bocchetta, A.I. Wawrzyniak Solaris, Kraków, Poland M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu SLSA, Clayton, Australia G. Burt Lancaster University, Lancaster, United Kingdom N. Catalán Lasheras, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland W. Fang, Q. Gu SINAP, Shanghai, People's Republic of China E.N. Gazis National Technical University of Athens, Athens, Greece M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann Uppsala University, Uppsala, Sweden X.J.A. Janssen VDL ETG, Eindhoven, The Netherlands
	As is widely recognized, fourth generation Light Sources are based on FELs driven by Linacs. Soft and hard X-ray FEL facilities are presently operational at several laboratories, SLAC (LCLS), Spring-8 (SACLA), Elettra-Sincrotrone Trieste (FERMI), DESY (FLASH), or are in the construction phase, PSI (SwissFEL), PAL (PAL-XFEL), DESY (European X-FEL), SLAC (LCLS II), or are newly proposed in many laboratories. Most of the above mentioned facilities use NC S-band (3 GHz) or C-band (6 GHz) linacs for generating a multi-GeV low emittance beam. The use of the C-band increases the linac operating gradients, with an overall reduction of the machine length and cost. These advantages, however, can be further enhanced by using X-band (12 GHz) linacs that operate with gradients twice that given by C-band technology. With the low bunch charge option, currently considered for future X-ray FELs, X-band technology offers a low cost and compact solution for generating multi-GeV, low emittance bunches. The paper reports the ongoing activities in the framework of a collaboration among several laboratories for the development and validation of X-band technology for FEL based photon sources.

MOPP024	Perspectives of the S-Band Linac of FERMI	linac, klystron, FEL, electron	105
	A. Fabris, P. Delgiusto, M. Milloch, C. Serpico Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. Grudiev CERN, Geneva, Switzerland
	The S-band linac of FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, has reached the peak on-crest electron energy of 1.55 GeV required for FEL-2 with the present layout. Different ways are being considered to extend the operating energy of the S-band linac up to 1.8 GeV. At the same time upgrades on the existing systems are investigated to address the requirements of operability of a users facility. This paper provides an overview of the developments that are under consideration and discusses the requirements and constraints for their implementation.

MOPP040	Application Investigation of High Precision Measurement for Basic Cavity Parameters at ESS	cavity, controls, beam-loading, injection	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.

MOPP041	Commissioning Plan for the FRIB Driver Linac*	linac, radiation, ion, cryomodule	152
	M. Ikegami, L.T. Hoff, S.M. Lidia, F. Marti, G. Pozdeyev, T. Russo, R.C. Webber, J. Wei, Y. Yamazaki FRIB, East Lansing, Michigan, USA
	Funding: * Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The FRIB driver linac accelerates CW beams of all stable ions up to uranium to the energy of 200 MeV/u with the beam power of 400 kW. We plan to start staged beam commissioning in December 2017 in parallel with ongoing installation activities. This allows early recognition of technical issues, which is essential for smooth commissioning and early completion of commissioning goals. As the interlaced nature of commissioning and installation poses both scheduling challenges and special safety issues, it is essential to develop a commissioning plan with focused consideration of each. In this paper, we present a commissioning plan with emphasis on its characteristic features.

MOPP053	TTF-III Coupler Modification for CW Operation	simulation, resonance, coupling, status	174
	I.V. Gonin, T.N. Khabiboulline, A. Lunin, O.V. Prokofiev, N. Solyak, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	LCLS-II linac is based on XFEL/ILC superconducting technology, but CW regime of operation requires the modification of components to satisfy LCLS-II requirements. TTF-III coupler is considered as a candidate for a fundamental power coupler for the 1.3 GHz 9-cell accelerating structure at the LCLS-II project. In this paper we discuss the results of multiphysics analysis of the coupler working at various operating regimes. Two major modifications are proposed in order to meet the LCLS-II requirements and eliminate possible overheating: reducing the length of antenna (cold part) and increasing the thickness of a cooper plating on the inner conductor of the warm part of the coupler.

MOPP055	RF Tests of Dressed 325 MHz Single-Spoke Resonators at 2 K	cavity, network, LLRF, resonance	180
	A. Hocker, E. Cullerton, B.M. Hanna, W. Schappert, A.I. Sukhanov Fermilab, Batavia, Illinois, USA
	Funding: United States Department of Energy, Contract No.DE- AC02-07CH11359 Fermilab has recently completed an upgrade to its spoke resonator test cryostat to enable testing of cavities in superfluid helium. Two single-spoke resonators with differing helium vessel designs have been tested in this new configuration. Gradient and Q0 performance was studied along with microphonics control and sensitivity of the resonant frequency to pressure variations. A description of the testing and the results obtained are presented.
	Poster MOPP055 [0.437 MB]

MOPP067	Operation of the LINAC and the LINAC RF System for the Ion-Beam Therapy Center Heidelberg	ion, linac, DTL, rfq	211
	E. Feldmeier, R. Cee, Th. Haberer HIT, Heidelberg, Germany
	The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. It is the first dedicated european particle accelerator for medical treatment. Its central location on the campus of the Heidelberg University Hospital fits perfectly in the clinical everyday life. The accelerator complex consists of a linear accelerator and a synchrotron and is designed for protons and carbon ions, but can also provide helium and oxygen ions. The LINAC, build in 2006, operates since 5 years in a 24/7 schema which leads to 60000 operating hours up to now. The performance with an availibility of better than 99% is much higher than expected and is caused by a solid design and a well planned and foresighted maintenance. Unavoidable failures during operation can be solved very fast with the on site experts for each section. The combination of personnel spare parts and permanent ongoing developments is very successful. An upgrade program for parts of the linac and also for the RF system is in planning to keep the uptime high and to improve the performance for further needs.

MOPP068	The Fast Piezo-Based Frequency Tuner for SC CH-Cavities	cavity, resonance, laser, simulation	214
	M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger IAP, Frankfurt am Main, Germany K. Aulenbacher HIM, Mainz, Germany W.A. Barth, V. Gettmann, S. Mickat GSI, Darmstadt, Germany
	Funding: Work supported by HIM, GSI, BMBF Contr. No 05P12RFRBL Superconducting structures are very susceptible to external influences due to their thin walls and their narrow bandwidth. Even small mechanical deformations caused by dynamic effects like microphonic noise, pressure fluctuations of the liquid helium bath or Lorentz-Force-Detuning can lead to resonance frequency changes of the cavity which are much larger than the bandwidth. To compensate the slow and fast resonance frequency variations during operation a compact frequency tuner prototype equipped with a stepper motor and a piezo actuator has been developed at the Institute for Applied Physics (IAP) of Frankfurt University. In this paper, the tuner design and the results of first room temperature measurements of the tuner prototype are presented.
	Poster MOPP068 [2.304 MB]

MOPP071	BESSY VSR 1.5 GHz Cavity Design and Considerations on Waveguide Damping	damping, cavity, HOM, SRF	221
	A.V. Velez, J. Knobloch, A. Neumann HZB, Berlin, Germany
	The BESSY VSR upgrade of the BESSY II light source represents a novel approach to simultaneously store long (ca. 15ps) and short (ca. 1.5ps) bunches in the storage ring with the present user optics. To this end, new high-voltage L-Band superconducting multi-cell cavities must be installed in one of the straights of the ring. These 1.5 GHz and 1.75 GHz cavities are based on 1.3 GHz systems being developed for the BERLinPro energy-recovery linac. This paper describes the baseline electromagnetic design of the first 5-cell cavity operating at 1.5 GHz.
	Poster MOPP071 [1.088 MB]

MOPP072	Present Status of J-PARC LINAC LLRF Systems	linac, controls, timing, feedback	224
	Z. Fang, Y. Fukui, K. Futatsukawa, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan E. Chishiro, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	The RF control systems have been developed for the J-PARC proton linac, which consists of 324-MHz and 972-MHz acceleration sections. From October 2006, we started the commissioning of the 324-MHz sections. Then the J-PARC 324-MHz 181-MeV proton linac had been operated nearly for 7 years, until May 2013. In the summer of 2013, we upgraded the J-PARC linac by adding 972-MHz acceleration sections. The output energy of the J-PARC linac was successfully upgraded to 400 MeV in December 2013, and then the operation of the J-PARC 400-MeV linac started. In the past 8 years of the J-PARC linac operation, no heavy troubles occurred in the RF control systems. Every year we made improvements on the RF control systems, according to the operation experiences. In this paper, the present status of the J-PARC 400-MeV linac RF control systems will be described in details, and an improvement plan for the LLRF systems in the future will also be introduced.

MOPP074	Digital Filters Used for Digital Feedback System at cERL	LLRF, controls, cavity, feedback	227
	F. Qiu, D.A. Arakawa, H. Katagiri, H. Matsumoto, S. Michizono, T. Miura KEK, Ibaraki, Japan
	As a test facility for the future KEK 3-GeV energy recovery linac (ERL) project, the compact ERL (cERL) features three two-cell cavities for the injector and two nine-cell cavities for the main linac. Digital low-level radio frequency (LLRF) systems have been developed to realize highly accurate RF control. In order to reduce the influence of clock jitter and to suppress the parasitic modes in the multi-cell cavities, we have developed several types of digital filters, including a first-order IIR filter, a fourth-order conjugate poles IIR filter and a notch filter. Furthermore, to design a more effective and robust controller (such as an H-infinite controller, or repetitive controller), we need to acquire more detailed system knowledge. This knowledge can be gained by using modern system identification methods. In this paper, we present the latest applications in the LLRF systems of the cERL. identification methods. In this paper, we have compared the performance of these different type filters in cERL. The preliminary result of the system identification will be also described.

MOPP094	Latest Improvements of the SPring-8 Linac for High Reliability	linac, vacuum, electron, injection	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.

MOPP096	Current Status of the Mainz Energy-Recovering Superconducting Accelerator Project	experiment, linac, feedback, diagnostics	282
	M. Dehn, I. Alexander, K. Aulenbacher, J. Diefenbach, R.G. Heine, C. Matejcek, F. Schlander, D. Simon IKP, Mainz, Germany
	Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA" The Mainz Energy-Recovering Superconducting Accelerator (MESA) project at Johannes Gutenberg-Universtitaet Mainz has started in 2012 and is in full swing now. This presentation shows the current status of the project with a glance on cryogenics, superconducting RF, accelerator lattice design and the normal conducting injector.

MOPP103	Fault Tolerance and Consequences in the MYRRHA Superconducting Linac	linac, cavity, cryomodule, simulation	297
	F. Bouly LPSC, Grenoble Cedex, France J.-L. Biarrotte IPN, Orsay, France D. Uriot CEA/DSM/IRFU, France
	Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project). The MYRRHA project aims at the construction of new irradiation complex in Mol (Belgium) to demonstrate the transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton flux with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable rapid failures mitigations. Beam dynamics studies on the fault tolerance capability of the MYRRHA superconducting linac will be presented. The results will be mainly focused on RF failure compensation scenarios: when one or several superconducting cavities are lost in the linac. The impact on the R&D to enable fast retuning procedures in the linac will also be discussed.

MOPP119	Measurements and High Power Test of the First C-band Accelerating Structure for SwissFEL	vacuum, FEL, klystron, linac	333
	R. Zennaro, J. Alex, A. Citterio, J.-Y. Raguin PSI, Villigen PSI, Switzerland
	The SwissFEL project is based on a 5.8 GeV C-band Linac which is composed of 10⁴ accelerating structures with a length of 2 m each. Due to the absence of dimple tuning no local frequency correction is possible and hence ultra-precise machining is required. The paper reports on both low level and high power RF test of the first nominal structure produced. The required mechanical precision has been reached and the structure has been successfully power tested to a gradient larger than 50 MV/m, well above the nominal level of 28 MV/m. The measured dark current and break down rates are well in the specifications.

MOPP124	Development of a 3 MeV Prototype RFQ Structure for High Intensity Proton Linac for ISNS	rfq, vacuum, ion, proton	345
	S.C. Joshi, A. Chaturvedi, S.K. Chauhan, K.K. Das, G.V. Kane, S.V. Kokil, B. Oraon, S. Raghvendra, N.K. Sharma RRCAT, Indore (M.P.), India
	Raja Ramanna Centre for Advanced Technology (RRCAT) has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. A 3 MeV Radio Frequency Quadrupole (RFQ) will be used as front end of the pulsed proton linac. A full scale prototype RFQ structure has been designed and fabricated to validate the physics design and manufacturing procedures. The total of 3.46 meter has been divided in three segments for ease in machining. The fabricated RFQ structure has been assembled for low power RF characterization. The RFQ frequency and field tuning exercise is being carried out using 48 stub tuners. The paper will also present the engineering design aspects and fabrication issues for the full scale RFQ structure.

MOPP127	Wakefield Effects of the Bypass Line in LCLS-II	dipole, wakefield, undulator, acceleration	355
	K.L.F. Bane, T.O. Raubenheimer SLAC, Menlo Park, California, USA
	Funding: Work supported by Department of Energy contract DE–AC02–76SF00515. In LCLS-II, after acceleration and compression and just before entering the undulator, the beam passes through roughly 2.5 km of 24.5 mm (radius) stainless steel pipe. The bunch that passes through the pipe is extremely short with an rms of 8 um for the nominal 100 pC case. Thus, even though the pipe has a large aperture, the wake that applies is the short-range resistive wall wakefield. It turns out that the wake supplies needed dechirping to the LCLS-II beam before it enters the undulator. The LCLS-II bunch distribution is approximately uniform, and therefore the wake induced voltage is characterized by a rather linear voltage chirp for short bunches. However for bunches longer than 25 um (300 pC at 1 kA) the wake starts to become nonlinear, effectively limiting the maximum charge with which the LCLS-II can operate. In this note we calculate the wake, discuss the confidence in the calculation, and investigate how to improve the induced chirp linearity and/or strength. Finally, we also study the strength and effects of the transverse (dipole) resistive wall wakefield.

MOPP128	Bridging the Gap Between Conventional RF Acceleration and Laser Driven Acceleration	electron, experiment, acceleration, cyclotron	358
	M.V. Fazio, V.A. Dolgashev, S.G. Tantawi SLAC, Menlo Park, California, USA
	For decades conventional RF accelerators have been built and operated with ever increasing capability through a few tens of gigahertz in frequency. More recent research takes advantage of the continuing development of high peak power short pulse lasers to drive accelerator structures at optical frequencies. This jump from RF to optical frequencies skips four orders of magnitude in wavelength. With recent experiments that demonstrate high gradients in metallic structures at millimeter wavelengths one is compelled to consider the viability of new approaches for acceleration in the millimeter-wave to terahertz regime. This paper will explore some of these possibilities.

TUIOA02	R&D Efforts for ERLs	linac, emittance, cavity, SRF	394
	R.G. Eichhorn Cornell University, Ithaca, New York, USA
	The last few years has seen extensive R&D for ERLs, with several prototype facilities now under construction or in operation. The Cornell ERL R&D program has reached major goals, with producing the world’s brightest beam from any photoinjector, reaching CW beam current of greaters than 75 mA, and reaching intrinsic quality factors of 10¹¹ in an SRF cavity installed in a cryomodule. The talk gives an overview of status of ERLs projects, and ERL R&D.
	Slides TUIOA02 [8.803 MB]

TUIOA04	The New LCLS-II Project : Status and Challenges	linac, cryomodule, electron, undulator	404
	J.N. Galayda SLAC, Menlo Park, California, USA
	The LCLS-II was an upgrade of the LCLS which essentially replicated the LCLS in another tunnel using the middle 1/3 of the SLAC S-band linac. In August 2013, the project was doubled in scope and redirected towards providing MHz-rate X-ray pulses from 0.2 to 5.0 keV while still supporting the ongoing program at the LCLS. The accelerator is now based on a 4.0 GeV SCRF linac installed in the front of the SLAC linac tunnel. Status and challenges of LCLS-II in context of July 2013 recommendation of DOE BESAC for a fully coherent, cw, FEL with photon energies up to ~5 keV.
	Slides TUIOA04 [6.386 MB]

TUIOB02	Beam Commissioning of the 100 MeV KOMAC Linac	proton, DTL, linac, klystron	413
	Y.-S. Cho KAERI, Daejon, Republic of Korea
	Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government. The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.
	Slides TUIOB02 [7.200 MB]

TUIOB03	Commissioning of Energy Upgraded Linac of J-PARC	linac, klystron, injection, 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]

TUPP002	Commissioning of the 72 MHz Quarter-Wave Cavity Cryomodule at ATLAS	cavity, cryomodule, SRF, ion	440
	M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Hendricks, M. Kedzie, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, T. Reid, S.I. Sharamentov, G.P. Zinkann ANL, Argonne, Illinois, USA
	Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357. A cryomodule of seven 72 MHz SC quarter-wave cavities optimized for ions with v/c=0.077 has been commissioned in the ATLAS heavy-ion accelerator at Argonne. ATLAS has a new capability for increased beam currents with low beam losses for nuclear physics experiments using stable or rare isotope beams or neutron rich beams from the Californium Rare Isotope Breeder. The main goal for the cryomodule, to provide an accelerating voltage of 17.5 MV (2.5 MV/cavity), with no detectable beam losses has been met within the first month of commissioning. Thus far, cavities and primary subsystems including high-power couplers and pneumatic tuners are operating as designed with full availability. For present levels there is practically no field emission (EPEAK=40 MV/m) and RF losses of ~5 Watts/cavity are only half of that planned. Cavity fields will continue to be gradually increased, with the limits due to cavity quench measured at VACC=3.75 MV. Due to a combination of rf design and cavity processing, effective voltages are now 2 ½ times those for any other operational cavities for this v/c. We report here on the recent online test results and technical features of the present design.

TUPP009	Operation and Improvements of the ALBA Linac	linac, klystron, injection, 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.

TUPP015	Status on Airix Restart	electron, target, induction, timing	462
	A. Georges, J. Beaubernard, V. Bernigaud, L. Buche, Y. Collet, S. Combacon, B. Gouin, G. Grandpierre, J.K. Kranzmann, L. Magnin, R. Nicolas, D. Pierre, F. Poulet, Y. Tailleur, J-L. Verstraete, J. Magnan CEA, Pontfaverger-Moronvilliers, France
	The Airix accelerator has been moved from Moronvilliers to Valduc to be part of the EPURE facility. Airix has been refurbished and restarted. This paper presents the first results and quantification of performances at its new location. M.Mouillet et al., “First results of AIRIX induction accelerator”,XXth LINAC cf.,p.491(2000) *H.Dzitko et al., "operationnal efficiency of Airix accelerator since its commissioning",IPAC2012,p.4017

TUPP019	Qualification of the Titanium Welds in the E-XFEL Cryomodule and the CE Certification	cryomodule, cavity, linac, quadrupole	468
	S. Barbanotti, H. Hintz, K. Jensch, R. Klos, W. Maschmann, A. Matheisen, A. Schmidt DESY, Hamburg, Germany C. Boulch, C. Cloué, C. Madec, J.L. Perrin, T. Trublet CEA/IRFU, Gif-sur-Yvette, France J.-P. Charrier, O. Napoly CEA/DSM/IRFU, France
	The CE stamping of the one hundred 1.3 GHz cryomodules for the XFEL Linac is a main step in the process of the certification of the entire Linac as a pressure equipment. Stringent requirements on materials and the quality of the welds of the pressurised components need to be satisfied to obtain the stamp. This paper summarizes these requirements, describes the process developed to qualify each module and summarises the rework campaign on the cavity helium vessels made necessary to obtain the required quality for a reliable and safe accelerator.

TUPP021	A New Type of Waveguide Distribution for the Accelerator Module Test Facility of the European XFEL	klystron, cryomodule, cavity, shielding	475
	V.V. Katalev, S. Choroba DESY, Hamburg, Germany E.M. Apostolov MicroPlus-Apostolov Ltd., Sofia, Bulgaria A.A. Seliverstov s.p.a. FERRITE Ltd., St.Petersburg, Russia
	In order to test 100 superconducting accelerator modules within two years three test benches have been created in the accelerator module test facility (AMTF) to achieve the rate of one cryomodule per week. Each RF station of the test facility consists of a 5 MW klystron, at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate, and a waveguide distribution system. Each waveguide distribution supplies RF power to eight cavities, four times a pair of cavities. The distribution allows for a maximum power of 1 MW per cavity when the distribution is switched to mode supplying power to only four cavities. A new type of 1 MW isolator and a new compact 5 MW power divider have been developed to achieve that goal. Several cryomodule have been already successfully tested with this setup. We present the waveguide distribution for this test stand and describe the performance of the different elements.

TUPP023	Testing of the First Part of Series Production 10MW MBKs for the XFEL Project.	klystron, cathode, gun, 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.

TUPP028	Beam Tests at the CLIC Test Facility, CTF3	experiment, emittance, linac, acceleration	487
	R. Corsini, S. Döbert, W. Farabolini, D. Gamba, J.L. Navarro Quirante, T. Persson, P.K. Skowronski, F. Tecker CERN, Geneva, Switzerland W. Farabolini CEA/DSM/IRFU, France D. Gamba JAI, Oxford, United Kingdom
	The CLIC Test Facility CTF3 has been built at CERN by the Compact Linear Collider (CLIC) International Collaboration, in order to prove the main feasibility issues of the two-beam acceleration technology on which the collider is based. After the successful completion of its initial task, CTF3 is continuing its experimental program in order to give further indications on cost and performance issues, to act as a test bed for the CLIC technology, and to conduct beam experiments aimed at mitigating technological risks. In this paper we discuss the status of the ongoing experiments and present the more recent results, including improvements in beam quality and stability.

TUPP029	Diagnostics and Analysis Techniques for High Power X-Band Accelerating Structures	diagnostics, timing, controls, klystron	490
	A. Degiovanni, S. Döbert, W. Farabolini, I. Syratchev, W. Wuensch CERN, Geneva, Switzerland J. Giner Navarro IFIC, Valencia, Spain J. Tagg National Instruments Switzerland, Ennetbaden, Switzerland B.J. Woolley Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
	The study of high gradient limitations due to RF breakdowns is extremely important for the CLIC project. A series of diagnostic tools and analysis techniques have been developed in order to monitor and characterize the behaviour of CLIC accelerating structures under high power operation in the first CERN X-band klystron-based test stand (Xbox1). The data collected during the last run on a TD26r05 structure are presented in this paper. From the analysis of the RF power and phases, the location of the breakdowns inside the structure could be determined. Other techniques based on the field emitted dark current signals collected by Faraday cups placed at the two extremities of the structure have also been investigated. The results of these analyses are reported and discussed.

TUPP052	SSR1 Tuner Mechanism: Passive and Active Device	cavity, cryomodule, alignment, SRF	541
	D. Passarelli Fermilab, Batavia, Illinois, USA
	In this paper we present the methodology adopted in designing the mechanism responsible for controlling the resonant frequency of Single Spoke Resonators of first type (SSR1). Such device is capable of compensating the effects of external perturbations, such as pressure fluctuations and microphonics, on the frequency of SSR1. The compensation is achieved through active responses via an actuation system and passive responses which are inherent to the elastic behavior of the overall system. The first experiences in the design, assembly, QA and testing are reported.
	Poster TUPP052 [2.368 MB]

TUPP056	High Current Proton Beam Operation at GSI UNILAC	proton, ion, linac, ion-source	550
	W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann GSI, Darmstadt, Germany
	A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP057	In Situ Measurement of Mechanical Vibrations of a 4-Rod RFQ at GSI	laser, rfq, vacuum, quadrupole	553
	P. Gerhard, L. Groening, K.-O. Voss GSI, Darmstadt, Germany
	A new 4-rod CW Radio Frequency Quadrupole was commissioned at the high charge state injector HLI at the UNILAC in 2009. It is in operation since 2010. At high rf amplitudes strong modulations of the rf reflection emerge, with a modulation frequency of approximately 500 Hz. They are attributed to mechanical oscillations of the rods, excited by the rf pulse. The high fraction of reflected rf power severely limits the pulse length and rf amplitude achievable. As these modulations could only be seen during the rf pulse by means of rf measurements, a direct observation of the mechanical vibrations was desirable. Such measurements have been conducted using a commercial laser vibrometer, allowing for the investigation of the mechanical behavior of the RFQ independent of the presence of rf power. After a short introduction of the method, the results will be presented and compared with rf measurements and simulations. : P. Gerhard et al., “Experience with a 4–Rod CW RFQ”, LINAC’12, Sept. 2012, Tel Aviv, THPB035

TUPP058	RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI	linac, controls, ion, LLRF	556
	B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz GSI, Darmstadt, Germany
	The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP060	Development of a 217 MHz Superconducting CH Structure	cavity, simulation, linac, accelerating-gradient	563
	M. Basten, M. Amberg, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech IAP, Frankfurt am Main, Germany M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat HIM, Mainz, Germany W.A. Barth, S. Mickat GSI, Darmstadt, Germany
	Funding: Helmholtz-Institut Mainz, Bundesministerium für Bildung und Forschung contract number 05P12RFRBL To compete in the production of Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. The baseline design consists of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently an advanced cw demonstrator is under design at the Institute for Applied Physics (IAP) at Frankfurt University. The purpose of the advanced demonstrator is to investigate a new concept for the superconducting CH structures. It is based on shorter CH-cavities with 8 equidistant gaps without girders and with stiffening brackets at the front and end cap to reduce the pressure sensitivity. One major goal of the advanced demonstrator is to show that the new design leads to higher acceleration gradients and smaller E_p/E_a values. In this contribution first simulation results and technical layouts will be presented.
	Poster TUPP060 [0.593 MB]

TUPP067	Chopper Operation for the Tandem Scrapers at the J-PARC Linac	linac, cavity, software, timing	581
	K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono KEK, Ibaraki, Japan E. Chishiro, K. Hirano, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan
	In the J-PARC linac, the energy upgrade from 181 MeV to 400 MeV by the installation of annular-ring coupled structure (ACS) cavities was successfully achieved in 2013. In the next stage, we will schedule the intensity upgrade by the increase of the beam current by improving the front-end in this summer. Then, the high heat load of the scraper, which stops the kicked-beam by the RF chopper, is predicted to damage the surface. Therefore, we prepare the tandem scrapers to suppress the heat load. The half of the kicked beam leads to a scraper and the residual is to the other. Its chopping expedient will be achieved by reversing the phase of the RF chopper on the periodic cycle at the low-level RF system. In this paper, I would like to introduce this system and present the result of the low-level test.

TUPP068	New SRF Facility at KEK for Mass-Production Study in Collaboration with Industries	cryomodule, SRF, cavity, cryogenics	584
	H. Hayano KEK, Ibaraki, Japan
	The construction of the new SRF facility next to the KEK-STF facility has started from 2014 for the mass-production study of SRF accelerators in collaboration with industries. The new building for this facility has the dimension of 80 m x 30 m, and the plan is to install clean-room for cavity-string assembly, cryomodule-assembly facility, cryogenic system, vertical test facility, cryomodule test facility, input coupler process facility, cavity Electro-Polishing (EP) facility, and control-room/office-rooms in it. The purpose of this new SRF facility is to establish a close collaboration between SRF researchers and industries in order to prepare for the upcoming large-scale future SRF project, like ILC. This paper describes the infra-structure detail and the plan to utilize for future SRF accelerators.

TUPP070	Status and Recent Modifications to 324-MHz RF Source in J-PARC LINAC	klystron, linac, high-voltage, cathode	587
	M. Kawamura, Y. Fukui, K. Futatsukawa, F. Naito KEK, Ibaraki, Japan E. Chishiro, K. Hasegawa, F. Sato, S. Shinozaki JAEA/J-PARC, Tokai-mura, Japan T. Hori JAEA, Ibaraki-ken, Japan
	This paper describes the present status of and the recent modifications to the 324-MHz RF source in the J-PARC linac. The recovery from the Great East Japan Earthquake Disaster, the status of the 324-MHz klystrons, the failure of 3 high-voltage transformers (HVTRs), and the discharge suppression for the anode-modulators are described.
	Poster TUPP070 [0.660 MB]

TUPP075	The First Beam Recirculation and Beam Tuning in the Compact ERL at KEK	linac, emittance, recirculation, quadrupole	599
	S. Sakanaka, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X. Jin, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, O.A. Konstantinova, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida KEK, Ibaraki, Japan E. Cenni Sokendai, Ibaraki, Japan R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma JAEA, Ibaraki-ken, Japan J.G. Hwang KNU, Deagu, Republic of Korea M. Kuriki, Y. Seimiya HU/AdSM, Higashi-Hiroshima, Japan A. Valloni CERN, Geneva, Switzerland
	Superconducting(SC)-linac-based light sources, which can produce ultra-brilliant photon beams in CW operation, are attracting worldwide attention. In KEK, we have been conducting R&D efforts towards the energy-recovery-linac(ERL)-based light source* since 2006. To demonstrate the key technologies for the ERL, we constructed the Compact ERL (cERL)** from 2009 to 2013. In the cERL, high-brightness CW electron beams are produced using a 500-kV photocathode DC gun. The beams are accelerated using SC cavities, transported through a recirculation loop, decelerated in the SC cavities, and dumped. In the February of 2014, we succeeded in accelerating and recirculating the CW beams of 4.5 micro-amperes in the cERL; the beams were successfully transported from the gun to the beam dump under energy recovery operation in the main linac. Then, precise tuning of beam optics and diagnostics of beam properties are under way. We report our experience on the beam commissioning, as well as the results of initial measurements of beam properties. * N. Nakamura, IPAC2012, TUXB02. ** S. Sakanaka et al., IPAC2013, WEPWA015.

TUPP080	Commissioning of the MAX 700 MHz Test Stand	cavity, cryomodule, controls, experiment	610
	J.-L. Biarrotte, F. Chatelet, M. El Yakoubi, N. Gandolfo, C. Joly, J. Lesrel, H. Saugnac IPN, Orsay, France A. Bosotti, R. Paparella, P. Pierini INFN/LASA, Segrate (MI), Italy F. Bouly LPSC, Grenoble Cedex, France I. Martin-Hoyo ADEX, Madrid, Spain
	The MYRRHA project aims at the construction of an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux produced thanks to a 600 MeV high intensity proton beam. This beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. Under the MAX (MYRRHA Accelerator eXperiment) program, which aims at pursuing the R&D activities on the ADS-type accelerator, a 700 MHz Cryomodule was developed. The main goal of this test stand is to dispose of a facility to carry out “real scale” reliability oriented studies on a RF Superconducting cavity of the high-energy linac section. This module holds 5-cells elliptical cavity equipped with its blade cold tuning system and its coaxial power coupler. The experimental work undertaken at IPN Orsay, has allowed to fully qualify the module in machine configuration (high RF power, at 2K), including assessment of the tuning system and measurement of microphonics spectrums. During this study the dynamic behavior of the fast tuning system of the cavity was also measured. We review here the obtained results and lessons learnt by operating this module.

TUPP092	Developmental and Operational Aspects of Nb QWR Based Heavy Ion LINAC System at IUAC Delhi	linac, controls, niobium, ion	640
	S. Ghosh, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, K.K. Mistri, A. Pandey, P. Patra, P.N. Potukuchi, A. Rai, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman IUAC, New Delhi, India A. Roy VECC, Kolkata, India
	The superconducting linac of IUAC consists of five cryostats containing 27 niobium quarter wave resonators. The prototype and the first 12 resonators were fabricated in collaboration with Argonne National Laboratory. The fabrication of the remaining resonators were carried out using in-house facilities available at IUAC. During the initial period of linac operations, problems were faced to generate higher accelerating fields in the resonators inside the linac cryostat and to reproduce the high fields at the time of beam acceleration. With systemetic efforts, all the major problems are solved and the complete linac is now operational. Since last few years, energized ion beams from linac are being delivered routinely for scheduled experiments. Among the major developmental works related to the linac operation, the vibrational damping mechansim by SS-balls, use of piezo actuator as mechanical tuner and the calculation of optimum phase focussing to control the time width of the beam bunches are noteworthy. Other two developments e.g. automatic phase locking of the resonators and auto beam tuning of the complete linac will be tested during the next beam acceleration.

TUPP094	Recent Progress of Beam Commissioning at J-PARC Linac	linac, acceleration, DTL, cavity	646
	T. Maruta J-PARC, KEK & JAEA, Ibaraki-ken, Japan K. Futatsukawa, T. Miyao KEK, Ibaraki, Japan M. Ikegami FRIB, East Lansing, Michigan, USA Y. Liu KEK/JAEA, Ibaraki-Ken, Japan A. Miura, H. Sako JAEA/J-PARC, Tokai-mura, Japan
	We installed Annular-type Coupled Structure (ACS) linac in year 2013 in present linac downstream to extend the beam energy from 181 to 400 MeV. The beam commissioning had been conducted for one month in last December to January, and then we successfully extract 400 MeV beam. Whereas, we stably operate the linac at peak current of 15 mA, which is equivalent to 300 kW at the extraction of 3 GeV RCS, we observe unexpected residual radiations in ACS section. In this presentation, we review the recent progress in beam commissioning and beam loss study.

TUPP095	High-Power Test Results of the RFQ III in J-PARC Linac	rfq, cavity, vacuum, ion	649
	T. Morishita, K. Hasegawa, K. Hirano, Y. Kondo, H. Oguri, S. Yamazaki JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Hori JAEA, Ibaraki-ken, Japan F. Naito, T. Sugimura, A. Takagi KEK, Ibaraki, Japan
	The J-PARC accelerator comprises an injector linac, a 3-GeV Rapid-Cycling Synchrotron and a 50-GeV Main Ring. The beam energy of the linac has been upgraded from 181MeV to 400MeV in 2013. For the beam current upgrade, the new frontend (RF ion source, RFQ, chopping system) installation is scheduled in summer 2014 for 1MW operation at RCS. The RFQ III, which is designed for 50mA beam acceleration from 0.05MeV to 3MeV, has been fabricated and the high-power test has started at April 2013 at the test station in the J-PARC. The test station consists of the ion source, the LEBT, the RFQ, and the diagnostics devices. The nominal RF power and RF duty of the RFQ III are 380kW and 3%(0.6ms and 50Hz), respectively. The high-power conditioning reached to the 120% of the nominal power with 1.5% (0.6ms, 25Hz) RF duty within 24 hours. Then, we performed the beam operation at the test station and measured beam parameters after the RFQ III. The results of the high-power conditioning and the stability of the RFQ operation with beam will be discussed.

TUPP100	Operation Of The Versatile Accelerator Driving the Low Power ADS GUINEVERE at SCK•CEN	neutron, target, ion, ion-source	659
	M.A. Baylac, A. Billebaud, P. Boge, D. Bondoux, J. Bouvier, S. Chabod, G. Dargaud, E. Froidefond, E. Labussière, R. Micoud, S. Rey LPSC, Grenoble Cedex, France A. Kochetkov, J. Mertens, F. Van Gestel, C. Van Grieken, B. Van Houdt, G. Vittiglio SCK•CEN, Mol, Belgium F.R. Lecolley, J.L. Lecouey, G. Lehaut, N. Marie-Nourry CNRS/IN2P3/LPC CAEN, Caen, France
	GUINEVERE provides a low power accelerator driven system (ADS) to investigate on-line reactivity monitoring and operational procedures of an ADS. It consists of a versatile neutron source, GENEPI-3C, driving the fast sub-critical core, VENUS-F, in SCK•CEN (Belgium). GENEPI-3C is an electrostatic accelerator generating 14 MeV neutrons by bombarding a 250 keV deuteron beam onto a tritium target located within the reactor core. This accelerator produces alternatively continuous beam (up to 1 mA DC), possibly chopped with fast and adjustable interruptions, or short and intense deuteron bunches (~25 mA peak, 1 μs). This paper presents the facility and assesses the 2 years of coupled operation of the accelerator to the reactor.
	Slides TUPP100 [0.969 MB]

TUPP121	Limitations for Acceleration of Intermediate Mass Particles with Traveling Wave Structure	acceleration, electron, accelerating-gradient, linac	705
	V.V. Paramonov RAS/INR, Moscow, Russia
	The Disk Loaded Waveguide (DLW) is the mostly used high frequency structure for acceleration of lightweight particles – electrons in the high energy range. DLW parameters are considered for the lower frequency range and lower particle velocity. Physical and technical restrictions for DLW application for the low particles velocity are analyzed. Basing on particularities of acceleration with traveling wave, deep optimization of DLW cells dimensions, the choice of optimal operating phase advance for each DLW section and combination of forward and backward wave modes, it looks possible to create the simple, cost effective acceleration system for intermediate particles acceleration in the moderate velocity range, in some parameters overcoming accelerating system with RF cavities in the standing wave mode.

TUPP137	High Power Solid-State Amplifiers. New Developments and Technology Comparison	controls, vacuum, power-supply, impedance	733
	G.B. Sharkov, A.I. Botyachkova, E.V. Ivanov, N.G. Kalugin, A.A. Krasnov, K.K. Naraianamurtkhi, K.I. Nikolskiy, S.A. Polikhov, I. Řežanov, A.Yu. Smirnov, P. Yazev Siemens Research Center, Moscow,, Russia A.I. Botyachkova National Research Nuclear University (MEPhI), Moscow, Russia
	Funding: Skolkovo Foundation, contract #44 from 2011.11.14 We present a newly developed compact and cost effective SSPA with megawatt range output power and scalable architecture. System components test results are discussed. A comparison of the state-of-the-art vacuum tube and solid-state technologies of RF power amplifiers for scientific accelerators is given. Solid-state microwave generator, Siemens

WEIOA05	High Power RF Sources for the ESS RF Systems	klystron, linac, DTL, rfq	756
	M. Jensen, G. Göransson, C. Marrelli, C. Martins, R. Montaño, A. Sunesson, R.A. Yogi, R. Zeng ESS, Lund, Sweden A.J. Johansson Lund University, Lund, Sweden
	The RF system for ESS will consist of around 150 high power RF sources and will deliver 125 MW peak power to the proton beam during the 2.86 ms pulse with an average power of 5 MW. The two RF frequencies, 352 and 704 MHz, the different power requirements along the linac and the sources currently available strongly influence the choice of RF technology. This talk will focus on the high power RF solutions for the main parts of the linac. We present an overview of the available technology along with the first test results of the main sources. Additionally, we will present the preliminary design of a new 1.2 MW multi-beam super power IOT being designed together with industry for the high beta section of the linac.
	Slides WEIOA05 [5.090 MB]

WEIOA06	Low Level RF for SRF Accelerators	LLRF, cavity, controls, SRF	760
	J. Branlard DESY, Hamburg, Germany
	Low level radio frequency (LLRF) systems are a fundamental component of superconducting RF accelerators. Since the release of the MicroTCA standard (MTCA.4), major developments in MTCA.4-based LLRF systems have taken place. State-of-the-art LLRF designs deliver better than 10^-4 relative amplitude and 10 mdeg phase stability for the vector sum control of SRF cavities. These developments in LLRF systems architecture and technology, driven by research institutes and supported by the industry are of highest importance for the European XFEL, but also for other SRF-based projects such as LCLS-II and the ESS, as well as for the next generation accelerators with 10-5 and mdeg regulation requirements.
	Slides WEIOA06 [5.812 MB]

WEIOB02	SARAF Phase-I Proton / Deuteron Linac Beam Operation Status	target, rfq, proton, neutron	770
	A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach Soreq NRC, Yavne, Israel
	SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.
	Slides WEIOB02 [3.027 MB]

THIOA02	Superconducting RF Development for FRIB at MSU	cavity, cryomodule, solenoid, SRF	790
	K. Saito, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S.K. Chandrasekaran, S. Chouhan, C. Compton, J.L. Crisp, K. Elliott, A. Facco, A.D. Fox, P.E. Gibson, M.J. Johnson, G. Kiupel, R.E. Laxdal, M. Leitner, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, G. Wu, X. Wu, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng FRIB, East Lansing, Michigan, USA
	Funding: *This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. FRIB is a $730M heavy ion accelerator project and a very large scale machine for many nuclear physics users. The civil construction started on March 17th 2014. The SRF system design and development have completed. The machine is to be in early completion end of 2019. FRIB accelerates ion species up to 238U with energies of no less than 200MeV/u and provides a beam power up to 400kW. Four SRF cavity families are used from β=0.041, 0.085 (QWRs) to 0.29 and 0.53 (HWRs). 8T superconducting solenoids are installed in the cryomodules for space effective strong beam focusing. The biggest challenges are in accelerating the high-power heavy ion beams from the very low energy to medium energy and the stable operation for large user community. The SRF cryomodule design addressed three critical issues: high performance, stable operation and easy maintainability, which chose several unique technical strategies, e.g.2K operation, bottom up cryomodule assembly, local magnetic shielding and so on. This talk will include high performance cavity R&D, local magnetic shielding, flux trapping by solenoid fringe field, and bottom up cryomodule assembly.
	Slides THIOA02 [5.049 MB]

THIOA05	An 800 MeV Superconducting Linac to Support Megawatt Proton Operations at Fermilab	linac, cryomodule, booster, cavity	807
	V.A. Lebedev, P. Derwent, S.D. Holmes Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy Active discussion on the high energy physics priorities in the US carried out since summer of 2013 resulted in changes in Fermilab plans for future development of the existing accelerator complex. In particular, the scope of Project X was reduced to the support of the Long Base Neutrino Facility (LBNF) at the project first stage. The name of the facility was changed to the PIP-II (Proton Improvement Plan). This new facility is a logical extension of the existing Proton Improvement Plan aimed at doubling average power of the Fermilab’s Booster and Main Injector (MI). Its design and required R&D are closely related to the Project X. The paper discusses the goals of this new facility and changes to the Project X linac introduced to support the goals.
	Slides THIOA05 [1.597 MB]

THIOB02	SPIRAL2 Cryomodule Production Result and Analysis	cryomodule, cavity, linac, cryogenics	814
	P.-E. Bernaudin, R. Ferdinand GANIL, Caen, France P. Bosland, C. Marchand CEA/IRFU, Gif-sur-Yvette, France Y. Gómez Martínez LPSC, Grenoble Cedex, France D. Longuevergne, G. Olry IPN, Orsay, France
	The production and qualification of the SPIRAL2 cryomodules are close to the end. Their performances are now well established. This paper will explain the path followed to the good achievements, and show some statistical analyses to be used for future projects. How far can we push the performances? What cryogenics consumption shall we take as design values?
	Slides THIOB02 [2.864 MB]

THPP014	Catalogue of Losses for the Linear IFMIF Prototype Accelerator	simulation, rfq, beam-losses, distributed	860
	N. Chauvin, P.A.P. Nghiem, D. Uriot CEA/IRFU, Gif-sur-Yvette, France M. Comunian INFN/LNL, Legnaro (PD), Italy C. Oliver CIEMAT, Madrid, Spain
	One of the activities of the EVEDA (Engineering Validation and Engineering Design Activities) phase of the IFMIF (International Fusion Materials Irradiation Facility) project consists in building, testing and operating, in Japan, a 125 mA/9 MeV deuteron accelerator, called LIPAc, which has been developed in Europe. For the accelerator safety aspects, a precise knowledge of beam loss location and power deposition is crucial, especially for a high intensity, high power accelerator like LIPAc. This paper presents the beam dynamics simulations allowing to estimate beam losses in different situations of the accelerator lifetime: starting from scratch, beam commissioning, tuning or exploration, routine operation, sudden failure. Some results of these studies are given and commented. Recommendations for hot point protection, beam stop velocity, beam power limitation are given accordingly.
	Slides THPP014 [4.780 MB]

THPP021	Analysis of the RF Test Results from the On-going Accelerator Cavity Production for the European XFEL	cavity, superconductivity, SRF, linac	879
	D. Reschke, S. Aderhold, V. Gubarev, J. Schaffran, N.J. Walker DESY, Hamburg, Germany L. Monaco INFN/LASA, Segrate (MI), Italy Y. Yamamoto KEK, Ibaraki, Japan
	Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP) The main Linac of the European XFEL will consist of 100 superconducting accelerator modules, operated at an average design gradient of 23.6 MV/m. The fabrication by industry (which includes chemical surface preparation) of the required 800 superconducting cavities is now in full swing, with approximately 400 cavities having been delivered to date. In this interim report, we present an analysis of the RF acceptance tests amassed so far.

THPP038	The Drift Tube Welding Assembly for the Linac4 Drift Tube Linac at CERN	linac, drift-tube-linac, electron, DTL	929
	I. Sexton, A. Cherif, Y. Cuvet, G. Favre, J.-M. Geisser, S. Ramberger, S. Sgobba, T. Tardy CERN, Geneva, Switzerland F.M. Mirapeix DMP, Mendaro, Spain
	The fabrication of the Linac4 Drift Tube Linac (DTL) required the welding assembly of 10⁸ drift tubes (DT) which has been undertaken at the CERN workshop. The design of the DTL is particular in that it was purposely simplified to avoid any position adjustment mechanism for drift tubes in the tank. In consequence, drift tubes have been designed with tight tolerances and parts have been assembled with an optimised welding procedure. Two re-machining stages have been introduced in order to compensate for welding distortions. This paper discusses the various assembly stages with a view on the final precision that has been achieved.
	Poster THPP038 [8.665 MB]

THPP041	The Accelerator Cryoplant at ESS	controls, cryogenics, cryomodule, linac	939
	P. Arnold, J. Fydrych, W. Hees, J.M. Jurns, X. Wang, J.G. Weisend ESS, Lund, Sweden
	The European Spallation Source (ESS) is a neutron science facility funded by a collaboration of 17 European countries currently under design and construction in Lund, Sweden. Cryogenic cooling is vital particularly for the linear accelerator, producing a 5 MW beam of 2.0 GeV protons to strike a rotating tungsten target. The cryogenic section of the linac comprises cryomodules with superconducting RF cavities that require helium cooling at 2.0 K, shield cooling at ~40 K and liquid helium for power coupler cooling. An extensive cryogenic distribution system connects the cryomodules with the linac cryoplant. With estimated electricity consumption of up to 3 MW this plant will be one of the major power consumers at ESS. Turndown modes and the intrinsic uncertainties regarding heat loads drive the need for high plant efficiency not only during full load operation but also at reduced performance. Together with flexibility and reliability over a long operation period these are the key challenges that will be addressed in this paper.
	Poster THPP041 [4.141 MB]

THPP048	Design of a Compact Lever Slow/Fast Tuner for 650 MHz Cavities for Project X	cavity, resonance, simulation, SRF	957
	I.V. Gonin, E. Borissov, T.N. Khabiboulline, Y.M. Pischalnikov, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Fermilab is developing 5-cell elliptical 650 MHz β=0.6 and β=0.9 cavities for Project X. A compact fast/slow lever tuner intended for both types of cavities has been developed for final tuning of the resonance frequency of the cavity after cooling down and to compensate the resonance frequency variations of the cavity during operation coming from liquid helium pressure fluctuations. The updated helium vessel (presented at this conference) is equipped with the tuner located at one of the end of the cavity. The tuner design and results of ANSYS analysis of their properties are presented.

THPP073	Cavity Excitation of the Chopped Beam at the J-PARC Linac	DTL, linac, pick-up, injection	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.

THPP077	Fast Tuner Performance for a Double Spoke Cavity	cavity, simulation, controls, SRF	1034
	N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet IPN, Orsay, France C. Darve, M. Lindroos ESS, Lund, Sweden
	IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. In order to compensate resonant frequency variations of each cavity during operation, a deformation tuner has been studied and two of them have been built. The typical perturbations are coming from LHe saturated bath pressure variations as well as microphonics and Lorentz force detuning (LFD). In this paper, the tuner performance of the double Spoke cavity is presented.

THPP089	High Power Conditioning of Annular-Ring Coupled Structures for the J-PARC Linac	vacuum, linac, cavity, coupling	1053
	H. Ao, T. Ito, Y. Nemoto, H. Oguri, N. Ouchi, J. Tamura JAEA/J-PARC, Tokai-mura, Japan H. Asano Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan Z. Fang, K. Futatsukawa, K. Nanmo, T. Sugimura KEK, Ibaraki, Japan
	The linac of Japan Proton Accelerator Research Complex (J-PARC), which is an injector to a 3-GeV synchrotron, comprised a 3-MeV RFQ, 50-MeV DTLs and 181-MeV Separated-type DTLs. From September 2013, 25 annular-ring coupled structure (ACS) cavities were additionally installed to increase the linac beam energy up to 400 MeV and achieve 1-MW beam power of the 3-GeV synchrotron. After installation work the high power conditioning was started from December 2013 and most of the ACS cavities were conditioned within three weeks. We passed through some troubles and finally finished conditioning all the cavities until the middle of January 2014. In this paper, we present the conditioning results and how to handle the issue in the conditioning process.
	Slides THPP089 [7.756 MB]

THPP091	Installation and Performance Check of Beam Monitors for Energy Upgraded J-PARC Linac	linac, quadrupole, cavity, acceleration	1059
	A. Miura, K. Hasegawa, H. Oguri, N. Ouchi JAEA/J-PARC, Tokai-mura, Japan M. Ikegami FRIB, East Lansing, Michigan, USA Y. Liu KEK/JAEA, Ibaraki-Ken, Japan T. Maruta J-PARC, KEK & JAEA, Ibaraki-ken, Japan T. Miyao KEK, Ibaraki, Japan
	An energy upgrade project has started to achieve the design beam power of 1 MW at the exit of the downstream synchrotron in the J-PARC Linac since 2009. In the upgraded project, a beam energy in the Linac has increased from present 181 MeV to 400 MeV using the additional 21 annular-ring coupled structure (ACS) cavities. The new beam monitors as the beam current monitors, the phase monitors, the beam position monitors, the transverse profile monitors (wire scanner monitors) and the longitudinal profile monitors (bunch shape monitors) for the part where the ACS cavities were installed were designed, fabricated and calibrated. Till the end of November, 2013, all beam monitors were completed to be installed. From the middle of December, we started the beam commissioning to achieve the beam energy as 400 MeV, as well as to confirm the beam monitor functioning. We achieved the 400 MeV beam acceleration at the middle of January, 2014 using newly installed beam monitors. This paper describes the beam monitor installation, calibration and the beam commissioning results of beam monitor functioning.

THPP107	Study on Polishing Method of Nb Surface by Periodic Reverse Current Electrolysis With Alkali Solution	experiment, cavity, SRF, laser	1102
	M. Umehara Nomura Plating Co, Ltd., Osaka, Japan H. Hayano, T. Saeki KEK, Ibaraki, Japan
	Currently, electropolising method is thought to be the best method for the final surface preparation of superconducting RF cavity to obtain high gradient. In this conventional electropolising method, the electrolyte is the mixture of fluoric and sulfuric acids. Therefore, the operation of this method is dangerous, and the equipment becomes expensive because all parts should be made of high density polyethylene or fluorocarbon resin to avoid metallic parts which suffers from corrosion by electrolyte. Moreover, sulfur is produced as byproduct in the electropolishing process and this causes degradation of cavity performance. In order to overcome these drawbacks, we studied new polishing method of Nb surface by periodic reverse current electrolysis with alkali solution which causes no sulfur and allows the usage of metallic parts to realize cost effective equipment. In the study, we performed experiment of Nb coupons by this new method and obtained as good surface roughness as conventional electropolishing method. In this article, we report the details of the study.

THPP108	Status of New 2.5 MeV Test Facility at SNS	rfq, ion, ion-source, neutron	1105
	A.V. Aleksandrov, M.S. Champion, M.T. Crofford, Y.W. Kang, A.A. Menshov, R.T. Roseberry, M.P. Stockli, A. Webster, R.F. Welton, A.P. Zhukov ORNL, Oak Ridge, Tennessee, USA K. Ewald Fermilab, Batavia, Illinois, USA M.E. Middendorf, S.N. Murray, R.B. Saethre ORNL RAD, Oak Ridge, Tennessee, USA
	Funding: Oak Ridge National Laboratory is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy A new 2.5Mev beam test facility is being built at SNS. It consists of a 65 keV H⁻ ion source, a 2.5MeV RFQ, a beam line with various beam diagnostics and a 6 kW beam dump. The facility is capable of producing one-ms-long pulses at 60Hz repetition rate with up to 50mA peak current. Commissioning with reduced average beam power is planned for fall 2014 to verify operation of all systems. The full power operation is scheduled to begin in 2015. Status of the facilty will be presented as well as discussion of the future R&D program.

THPP109	History of Cryomodule Repairs at SNS	cryomodule, HOM, cavity, linac	1108
	M.P. Howell, M. Doleans, D.L. Douglas, S.-H. Kim ORNL, Oak Ridge, Tennessee, USA R. Afanador, B. DeGraff, B.S. Hannah, C.J. McMahan, T.S. Neustadt, S.W. Ottaway, J. Saunders, P.V. Tyagi, D.M. Vandygriff ORNL RAD, Oak Ridge, Tennessee, USA
	The operation of the Superconducting linear accelerator (SCL) has matured and now averages less than one trip per day. The availability of the SCL including radiofrequency systems, high voltage converter modulators, controls, vacuum and other support systems over the last three years is approximately 98%. The SNS has been in operation for ten years including the commissioning period. In support of achieving the stability of operation, multiple cryomodule repairs have been performed. Repairs to cryomodules have included instruments, helium leaks, valve actuators, cavity tuners, insulating vacuum repairs and upgrades, power supplies, higher order mode (HOM) feedthroughs, coupler windows, and coupler cooling components. Performance degradation has been experienced in multiple cavities. This has been corrected by thermal cycling the cryomodules with the affected cavities. Only two cavities have displayed slight permanent degradation that could not be corrected by thermal cycling. Repairs made to the SNS cryomodule will be detailed in this paper.

THPP115	PKU 2.45 GHz Microwave Driven H⁻ Ion Source Performance Study	electron, ion, ion-source, experiment	1120
	T. Zhang, J.E. Chen, Z.Y. Guo, S.X. Peng, H.T. Ren, Y. Xu, J.F. Zhang, J. Zhao PKU, Beijing, People's Republic of China A.L. Zhang University of Chinese Academy of Sciences, Beijing, People's Republic of China
	Funding: This work is supported by the National Science Foundation of China (Grant Nos. 11175009, 91126004 and 11305004) 　　In a high intensity volume-produced H⁻ ion source, H⁻ ion production processes are great affected by electron temperature and gas pressure distribution within the discharge chamber. The H-/e ratio within an extracted H⁻ ion beam is much depended on the electron absorption within the extraction system. At Peking University (PKU), lots of experiments were carried out for better understanding H⁻ processes and electron dump on our 2.45 GHz microwave driven Cs-free permanent magnet volume-produced H⁻ source. Detail will be given in this paper. Author to whom correspondence should be addressed. Electronic mail: sxpeng@pku.edu.cn.
	Poster THPP115 [2.252 MB]

THPP116	Performance of New Injector RILAC2 for Riken Ri-Beam Factory	cyclotron, injection, ECRIS, 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.

THPP132	Warming Rate Reduction of the SARAF RF Couplers by Application of a High Voltage Dc Bias	experiment, proton, cavity, linac	1168
	B. Kaizer, Y. Ben Aliz, I. Fishman, J. Rodnizki, L. Weissman Soreq NRC, Yavne, Israel
	Warming up of the coupler region of the SARAF Half Wave Resonator (HWR) cavities was one of the main limiting factors for long operation at high RF field values. The warming effect is, most likely, associated with multipacting in the coupler region. We have tried to suppress the multipacting discharge in the couplers by application a DC bias to their inner conductors. A bias-T, element that conducts up to 4 kW of 176 MHz RF power and provides DC insulation of the coupler inner conductor, was designed and built for this purpose. First on-line operation showed that the DC bias indeed reduces dramatically the warming rates of most of the cavities by an order of magnitude. Today, coupler warming is no longer the main factor hindering accelerator operation.

THPP139	800MeV Linear Accelerator Development for HLS Upgrade	linac, electron, klystron, injection	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.

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MOIOB01

Early Commissioning Experience and Future Plans for the 12 GeV Continuous Electron Beam Accelerator Facility

cryomodule, linac, cavity, SRF

11

M. Spata
JLab, Newport News, Virginia, USA

Jefferson Lab has recently completed the accelerator portion of the 12 GeV Upgrade for the Continuous Electron Beam Accelerator Facility. All 52 SRF cryomodules have been commissioned and operated with beam. The initial beam transport goals of demonstrating 2.2 GeV per pass, greater than 6 GeV in 3 passes to an existing experimental facility and greater than 10 GeV in 5-1/2 passes have all been accomplished. These results along with future plans to commission the remaining beamlines and to increase the performance of the accelerator to achieve reliable, robust and efficient operations at 12 GeV are presented.

Slides MOIOB01 [2.754 MB]

MOPP004

Design and Development of Pulsed Modulators for RF Electron Linacs

linac, electron, klystron, gun

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]

MOPP007

SF6 Gas Monitoring and Safety for DC Electron Beam Accelerator at EBC, Kharghar, Navi Mumbai

electron, monitoring, high-voltage, experiment

61

S.K. Suneet, S. Acharya, S. Banerjee, R. Barnwal, D. Bhattacharjee, N. Chaudhary, R.B. Chavan, K.P. Dixit, S. Gade, L.M. Gantayet, S.R. Ghodke, S. Gond, B.S. Israel, D. Jayaprakash, N. Lawangare, K. Mahender, R.L. Mishra, K.C. Mittal, B. Nayak, S. Nayak, R. Patel, R.N. Rajan, P.C. Saroj, D.K. Sharma, V. Sharma, M.K. Srvastava, D.P. Suryaprakash, N.T. Thakur, R. Tiwari, A. Waghmare
BARC, Mumbai, India

A 3 MeV, 30kW DC Industrial electron beam accelerator has been designed, commissioned and tested at Electron beam centre, Kharghar. The accelerator has been tested upto 5 kW power level with SF6 gas at 6 kg/cm². The accelerating column, high voltage multiplier column, electron gun and its power supply are housed in accelerator tank, which is filled with SF6 gas as gaseous insulator at 6 kg/cm². The SF6 gas is being used due to high dielectric strength and excellent heat transfer characteristics. The SF6 gas is non toxic and non carcinogenic. The SF6 gas replaces oxygen hence the TLV (threshold limiting value) is 1000 ppm for inhaled gas for persons working on the SF6 gas handling system. The SF6 gas is being green house gas, leak tightness has to monitor in the system and leak if any should be repaired. The gas should be used, recycled and reuse and thus saving the environment. This paper describes the safety and monitoring of the SF6 gas leak, quality and precautions in 3MeV accelerator.

Poster MOPP007 [1.389 MB]

MOPP011

Reliability and Intensity Upgrade for 200 MeV Linac at Brookhaven National Laboratory

linac, detector, ion, target

67

D. Raparia, J.G. Alessi, B. Briscoe, D.M. Gassner, O. Gould, T. Lehn, V. Lo Destro, J. Ritter, W. Shaffer, A. Zelenski
BNL, Upton, Long Island, New York, USA

Brookhaven 200 MeV H⁻ linac has been operating for last 44 years and providing beam to nuclear physics program and isotope program. Two upgrade programs are in progress to make machine more reliable and to double the intensity. This paper will discuss in detail these upgrade programs.

MOPP017

Cool Down and Flux Trapping Studies on SRF Cavities

cavity, SRF, cryomodule, linac

84

D. Gonnella, M. Liepe
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Recent results from Cornell and FNAL have shown that cool down rate can have a strong impact on the residual resistance of a superconducting RF cavity during operation. We have studied the effect of cool down rate, gradient, and external magnetic field during cool down on the residual resistance of an EP, EP+120C baked, and nitrogen-doped cavities. For each cavity, faster cool down and large gradient resulted in lower residual resistance in vertical test. The nitrogen-doped cavities showed the largest improvement with fast cool down, while the EP+120C cavity showed the smallest. The cavities were also placed in a uniform external magnetic field and residual resistance was measured as a function of applied field and cool down rate. We show that the nitrogen-doped cavity was the most susceptible to losses from trapped flux and the EP+120C cavity was least susceptible. These measurements provide new insights into understanding the physics behind the observed impact of cool down rates and gradients on the performance of cavities with differing preparations.

MOPP023

X-band Technology for FEL Sources

FEL, linac, emittance, experiment

101

G. D'Auria, S. Di Mitri, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
E. Adli
University of Oslo, Oslo, Norway
A.A. Aksoy, O. Yavaş
Ankara University, Accelerator Technologies Institute, Golbasi / Ankara, Turkey
D. Angal-Kalinin, J.A. Clarke
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
C.J. Bocchetta, A.I. Wawrzyniak
Solaris, Kraków, Poland
M.J. Boland, T.K. Charles, R.T. Dowd, G. LeBlanc, Y.E. Tan, K.P. Wootton, D. Zhu
SLSA, Clayton, Australia
G. Burt
Lancaster University, Lancaster, United Kingdom
N. Catalán Lasheras, A. Grudiev, A. Latina, D. Schulte, S. Stapnes, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
W. Fang, Q. Gu
SINAP, Shanghai, People's Republic of China
E.N. Gazis
National Technical University of Athens, Athens, Greece
M. Jacewicz, R.J.M.Y. Ruber, V.G. Ziemann
Uppsala University, Uppsala, Sweden
X.J.A. Janssen
VDL ETG, Eindhoven, The Netherlands

As is widely recognized, fourth generation Light Sources are based on FELs driven by Linacs. Soft and hard X-ray FEL facilities are presently operational at several laboratories, SLAC (LCLS), Spring-8 (SACLA), Elettra-Sincrotrone Trieste (FERMI), DESY (FLASH), or are in the construction phase, PSI (SwissFEL), PAL (PAL-XFEL), DESY (European X-FEL), SLAC (LCLS II), or are newly proposed in many laboratories. Most of the above mentioned facilities use NC S-band (3 GHz) or C-band (6 GHz) linacs for generating a multi-GeV low emittance beam. The use of the C-band increases the linac operating gradients, with an overall reduction of the machine length and cost. These advantages, however, can be further enhanced by using X-band (12 GHz) linacs that operate with gradients twice that given by C-band technology. With the low bunch charge option, currently considered for future X-ray FELs, X-band technology offers a low cost and compact solution for generating multi-GeV, low emittance bunches. The paper reports the ongoing activities in the framework of a collaboration among several laboratories for the development and validation of X-band technology for FEL based photon sources.

MOPP024

Perspectives of the S-Band Linac of FERMI

linac, klystron, FEL, electron

105

A. Fabris, P. Delgiusto, M. Milloch, C. Serpico
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. Grudiev
CERN, Geneva, Switzerland

The S-band linac of FERMI, the seeded Free Electron Laser (FEL) located at the Elettra laboratory in Trieste, has reached the peak on-crest electron energy of 1.55 GeV required for FEL-2 with the present layout. Different ways are being considered to extend the operating energy of the S-band linac up to 1.8 GeV. At the same time upgrades on the existing systems are investigated to address the requirements of operability of a users facility. This paper provides an overview of the developments that are under consideration and discusses the requirements and constraints for their implementation.

MOPP040

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

cavity, controls, beam-loading, injection

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.

MOPP041

Commissioning Plan for the FRIB Driver Linac*

linac, radiation, ion, cryomodule

152

M. Ikegami, L.T. Hoff, S.M. Lidia, F. Marti, G. Pozdeyev, T. Russo, R.C. Webber, J. Wei, Y. Yamazaki
FRIB, East Lansing, Michigan, USA

Funding: * Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The FRIB driver linac accelerates CW beams of all stable ions up to uranium to the energy of 200 MeV/u with the beam power of 400 kW. We plan to start staged beam commissioning in December 2017 in parallel with ongoing installation activities. This allows early recognition of technical issues, which is essential for smooth commissioning and early completion of commissioning goals. As the interlaced nature of commissioning and installation poses both scheduling challenges and special safety issues, it is essential to develop a commissioning plan with focused consideration of each. In this paper, we present a commissioning plan with emphasis on its characteristic features.

MOPP053

TTF-III Coupler Modification for CW Operation

simulation, resonance, coupling, status

174

I.V. Gonin, T.N. Khabiboulline, A. Lunin, O.V. Prokofiev, N. Solyak, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

LCLS-II linac is based on XFEL/ILC superconducting technology, but CW regime of operation requires the modification of components to satisfy LCLS-II requirements. TTF-III coupler is considered as a candidate for a fundamental power coupler for the 1.3 GHz 9-cell accelerating structure at the LCLS-II project. In this paper we discuss the results of multiphysics analysis of the coupler working at various operating regimes. Two major modifications are proposed in order to meet the LCLS-II requirements and eliminate possible overheating: reducing the length of antenna (cold part) and increasing the thickness of a cooper plating on the inner conductor of the warm part of the coupler.

MOPP055

RF Tests of Dressed 325 MHz Single-Spoke Resonators at 2 K

cavity, network, LLRF, resonance

180

A. Hocker, E. Cullerton, B.M. Hanna, W. Schappert, A.I. Sukhanov
Fermilab, Batavia, Illinois, USA

Funding: United States Department of Energy, Contract No.DE- AC02-07CH11359
Fermilab has recently completed an upgrade to its spoke resonator test cryostat to enable testing of cavities in superfluid helium. Two single-spoke resonators with differing helium vessel designs have been tested in this new configuration. Gradient and Q0 performance was studied along with microphonics control and sensitivity of the resonant frequency to pressure variations. A description of the testing and the results obtained are presented.

Poster MOPP055 [0.437 MB]

MOPP067

Operation of the LINAC and the LINAC RF System for the Ion-Beam Therapy Center Heidelberg

ion, linac, DTL, rfq

211

E. Feldmeier, R. Cee, Th. Haberer
HIT, Heidelberg, Germany

The Heidelberg Ion Therapy Center HIT is in clinical operation since 2009. It is the first dedicated european particle accelerator for medical treatment. Its central location on the campus of the Heidelberg University Hospital fits perfectly in the clinical everyday life. The accelerator complex consists of a linear accelerator and a synchrotron and is designed for protons and carbon ions, but can also provide helium and oxygen ions. The LINAC, build in 2006, operates since 5 years in a 24/7 schema which leads to 60000 operating hours up to now. The performance with an availibility of better than 99% is much higher than expected and is caused by a solid design and a well planned and foresighted maintenance. Unavoidable failures during operation can be solved very fast with the on site experts for each section. The combination of personnel spare parts and permanent ongoing developments is very successful. An upgrade program for parts of the linac and also for the RF system is in planning to keep the uptime high and to improve the performance for further needs.

MOPP068

The Fast Piezo-Based Frequency Tuner for SC CH-Cavities

cavity, resonance, laser, simulation

214

M. Amberg, M. Busch, F.D. Dziuba, H. Podlech, U. Ratzinger
IAP, Frankfurt am Main, Germany
K. Aulenbacher
HIM, Mainz, Germany
W.A. Barth, V. Gettmann, S. Mickat
GSI, Darmstadt, Germany

Funding: Work supported by HIM, GSI, BMBF Contr. No 05P12RFRBL
Superconducting structures are very susceptible to external influences due to their thin walls and their narrow bandwidth. Even small mechanical deformations caused by dynamic effects like microphonic noise, pressure fluctuations of the liquid helium bath or Lorentz-Force-Detuning can lead to resonance frequency changes of the cavity which are much larger than the bandwidth. To compensate the slow and fast resonance frequency variations during operation a compact frequency tuner prototype equipped with a stepper motor and a piezo actuator has been developed at the Institute for Applied Physics (IAP) of Frankfurt University. In this paper, the tuner design and the results of first room temperature measurements of the tuner prototype are presented.

Poster MOPP068 [2.304 MB]

MOPP071

BESSY VSR 1.5 GHz Cavity Design and Considerations on Waveguide Damping

damping, cavity, HOM, SRF

221

A.V. Velez, J. Knobloch, A. Neumann
HZB, Berlin, Germany

The BESSY VSR upgrade of the BESSY II light source represents a novel approach to simultaneously store long (ca. 15ps) and short (ca. 1.5ps) bunches in the storage ring with the present user optics. To this end, new high-voltage L-Band superconducting multi-cell cavities must be installed in one of the straights of the ring. These 1.5 GHz and 1.75 GHz cavities are based on 1.3 GHz systems being developed for the BERLinPro energy-recovery linac. This paper describes the baseline electromagnetic design of the first 5-cell cavity operating at 1.5 GHz.

Poster MOPP071 [1.088 MB]

MOPP072

Present Status of J-PARC LINAC LLRF Systems

linac, controls, timing, feedback

224

Z. Fang, Y. Fukui, K. Futatsukawa, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
E. Chishiro, F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

The RF control systems have been developed for the J-PARC proton linac, which consists of 324-MHz and 972-MHz acceleration sections. From October 2006, we started the commissioning of the 324-MHz sections. Then the J-PARC 324-MHz 181-MeV proton linac had been operated nearly for 7 years, until May 2013. In the summer of 2013, we upgraded the J-PARC linac by adding 972-MHz acceleration sections. The output energy of the J-PARC linac was successfully upgraded to 400 MeV in December 2013, and then the operation of the J-PARC 400-MeV linac started. In the past 8 years of the J-PARC linac operation, no heavy troubles occurred in the RF control systems. Every year we made improvements on the RF control systems, according to the operation experiences. In this paper, the present status of the J-PARC 400-MeV linac RF control systems will be described in details, and an improvement plan for the LLRF systems in the future will also be introduced.

MOPP074

Digital Filters Used for Digital Feedback System at cERL

LLRF, controls, cavity, feedback

227

F. Qiu, D.A. Arakawa, H. Katagiri, H. Matsumoto, S. Michizono, T. Miura
KEK, Ibaraki, Japan

As a test facility for the future KEK 3-GeV energy recovery linac (ERL) project, the compact ERL (cERL) features three two-cell cavities for the injector and two nine-cell cavities for the main linac. Digital low-level radio frequency (LLRF) systems have been developed to realize highly accurate RF control. In order to reduce the influence of clock jitter and to suppress the parasitic modes in the multi-cell cavities, we have developed several types of digital filters, including a first-order IIR filter, a fourth-order conjugate poles IIR filter and a notch filter. Furthermore, to design a more effective and robust controller (such as an H-infinite controller, or repetitive controller), we need to acquire more detailed system knowledge. This knowledge can be gained by using modern system identification methods. In this paper, we present the latest applications in the LLRF systems of the cERL. identification methods. In this paper, we have compared the performance of these different type filters in cERL. The preliminary result of the system identification will be also described.

MOPP094

Latest Improvements of the SPring-8 Linac for High Reliability

linac, vacuum, electron, injection

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.

MOPP096

Current Status of the Mainz Energy-Recovering Superconducting Accelerator Project

experiment, linac, feedback, diagnostics

282

M. Dehn, I. Alexander, K. Aulenbacher, J. Diefenbach, R.G. Heine, C. Matejcek, F. Schlander, D. Simon
IKP, Mainz, Germany

Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA"
The Mainz Energy-Recovering Superconducting Accelerator (MESA) project at Johannes Gutenberg-Universtitaet Mainz has started in 2012 and is in full swing now. This presentation shows the current status of the project with a glance on cryogenics, superconducting RF, accelerator lattice design and the normal conducting injector.

MOPP103

Fault Tolerance and Consequences in the MYRRHA Superconducting Linac

linac, cavity, cryomodule, simulation

297

F. Bouly
LPSC, Grenoble Cedex, France
J.-L. Biarrotte
IPN, Orsay, France
D. Uriot
CEA/DSM/IRFU, France

Funding: This work is being supported by the European Atomic Energy Community’s EURATOM) Seventh Framework Programme under grant agreement n°269565(MAX project).
The MYRRHA project aims at the construction of new irradiation complex in Mol (Belgium) to demonstrate the transmutation feasibility with an Accelerator Driven System (ADS). In its subcritical configuration, the MYRRHA facility requires a proton flux with a maximum power of 2.4 MW (600 MeV - 4 mA). Such a continuous wave beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements to ensure the safe ADS operation with a high level of availability. In this purpose, the accelerator design is based on a redundant and fault-tolerant scheme to enable rapid failures mitigations. Beam dynamics studies on the fault tolerance capability of the MYRRHA superconducting linac will be presented. The results will be mainly focused on RF failure compensation scenarios: when one or several superconducting cavities are lost in the linac. The impact on the R&D to enable fast retuning procedures in the linac will also be discussed.

MOPP119

Measurements and High Power Test of the First C-band Accelerating Structure for SwissFEL

vacuum, FEL, klystron, linac

333

R. Zennaro, J. Alex, A. Citterio, J.-Y. Raguin
PSI, Villigen PSI, Switzerland

The SwissFEL project is based on a 5.8 GeV C-band Linac which is composed of 10⁴ accelerating structures with a length of 2 m each. Due to the absence of dimple tuning no local frequency correction is possible and hence ultra-precise machining is required. The paper reports on both low level and high power RF test of the first nominal structure produced. The required mechanical precision has been reached and the structure has been successfully power tested to a gradient larger than 50 MV/m, well above the nominal level of 28 MV/m. The measured dark current and break down rates are well in the specifications.

MOPP124

Development of a 3 MeV Prototype RFQ Structure for High Intensity Proton Linac for ISNS

rfq, vacuum, ion, proton

345

S.C. Joshi, A. Chaturvedi, S.K. Chauhan, K.K. Das, G.V. Kane, S.V. Kokil, B. Oraon, S. Raghvendra, N.K. Sharma
RRCAT, Indore (M.P.), India

Raja Ramanna Centre for Advanced Technology (RRCAT) has taken up a program on R&D activities of a 1 GeV, high intensity superconducting proton linac for a spallation neutron source. A 3 MeV Radio Frequency Quadrupole (RFQ) will be used as front end of the pulsed proton linac. A full scale prototype RFQ structure has been designed and fabricated to validate the physics design and manufacturing procedures. The total of 3.46 meter has been divided in three segments for ease in machining. The fabricated RFQ structure has been assembled for low power RF characterization. The RFQ frequency and field tuning exercise is being carried out using 48 stub tuners. The paper will also present the engineering design aspects and fabrication issues for the full scale RFQ structure.

MOPP127

Wakefield Effects of the Bypass Line in LCLS-II

dipole, wakefield, undulator, acceleration

355

K.L.F. Bane, T.O. Raubenheimer
SLAC, Menlo Park, California, USA

Funding: Work supported by Department of Energy contract DE–AC02–76SF00515.
In LCLS-II, after acceleration and compression and just before entering the undulator, the beam passes through roughly 2.5 km of 24.5 mm (radius) stainless steel pipe. The bunch that passes through the pipe is extremely short with an rms of 8 um for the nominal 100 pC case. Thus, even though the pipe has a large aperture, the wake that applies is the short-range resistive wall wakefield. It turns out that the wake supplies needed dechirping to the LCLS-II beam before it enters the undulator. The LCLS-II bunch distribution is approximately uniform, and therefore the wake induced voltage is characterized by a rather linear voltage chirp for short bunches. However for bunches longer than 25 um (300 pC at 1 kA) the wake starts to become nonlinear, effectively limiting the maximum charge with which the LCLS-II can operate. In this note we calculate the wake, discuss the confidence in the calculation, and investigate how to improve the induced chirp linearity and/or strength. Finally, we also study the strength and effects of the transverse (dipole) resistive wall wakefield.

MOPP128

Bridging the Gap Between Conventional RF Acceleration and Laser Driven Acceleration

electron, experiment, acceleration, cyclotron

358

M.V. Fazio, V.A. Dolgashev, S.G. Tantawi
SLAC, Menlo Park, California, USA

For decades conventional RF accelerators have been built and operated with ever increasing capability through a few tens of gigahertz in frequency. More recent research takes advantage of the continuing development of high peak power short pulse lasers to drive accelerator structures at optical frequencies. This jump from RF to optical frequencies skips four orders of magnitude in wavelength. With recent experiments that demonstrate high gradients in metallic structures at millimeter wavelengths one is compelled to consider the viability of new approaches for acceleration in the millimeter-wave to terahertz regime. This paper will explore some of these possibilities.

TUIOA02

R&D Efforts for ERLs

linac, emittance, cavity, SRF

394

R.G. Eichhorn
Cornell University, Ithaca, New York, USA

The last few years has seen extensive R&D for ERLs, with several prototype facilities now under construction or in operation. The Cornell ERL R&D program has reached major goals, with producing the world’s brightest beam from any photoinjector, reaching CW beam current of greaters than 75 mA, and reaching intrinsic quality factors of 10¹¹ in an SRF cavity installed in a cryomodule. The talk gives an overview of status of ERLs projects, and ERL R&D.

Slides TUIOA02 [8.803 MB]

TUIOA04

The New LCLS-II Project : Status and Challenges

linac, cryomodule, electron, undulator

404

J.N. Galayda
SLAC, Menlo Park, California, USA

The LCLS-II was an upgrade of the LCLS which essentially replicated the LCLS in another tunnel using the middle 1/3 of the SLAC S-band linac. In August 2013, the project was doubled in scope and redirected towards providing MHz-rate X-ray pulses from 0.2 to 5.0 keV while still supporting the ongoing program at the LCLS. The accelerator is now based on a 4.0 GeV SCRF linac installed in the front of the SLAC linac tunnel. Status and challenges of LCLS-II in context of July 2013 recommendation of DOE BESAC for a fully coherent, cw, FEL with photon energies up to ~5 keV.

Slides TUIOA04 [6.386 MB]

TUIOB02

Beam Commissioning of the 100 MeV KOMAC Linac

proton, DTL, linac, klystron

413

Y.-S. Cho
KAERI, Daejon, Republic of Korea

Funding: This work was supported by the Ministry of Science, ICT & Future Planning of the Korean Government.
The operation of the 100MeV proton linear accelerator for multipurpose application started in July, 2013 at KOMAC (Korea Multipurpose Accelerator Complex), KAERI (Korea Atomic Energy Research Institute). Also, the operation of the two beam lines, one is for 20MeV beam and the other for 100MeV beam, started in order to supply proton beams to users. The accumulated operation time was 2,290 hours and the proton beam was supplied to 937 samples in 2013. In addition to the beam service, the effort to increase the beam power is continuing in 2014. Beam commissioning and operation status of the linac will be presented in this talk.

Slides TUIOB02 [7.200 MB]

TUIOB03

Commissioning of Energy Upgraded Linac of J-PARC

linac, klystron, injection, 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]

TUPP002

Commissioning of the 72 MHz Quarter-Wave Cavity Cryomodule at ATLAS

cavity, cryomodule, SRF, ion

440

M.P. Kelly, Z.A. Conway, S.M. Gerbick, M. Hendricks, M. Kedzie, S.H. Kim, S.W.T. MacDonald, R.C. Murphy, P.N. Ostroumov, T. Reid, S.I. Sharamentov, G.P. Zinkann
ANL, Argonne, Illinois, USA

Funding: This material is based upon work supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under contract number DE-AC02-06CH11357.
A cryomodule of seven 72 MHz SC quarter-wave cavities optimized for ions with v/c=0.077 has been commissioned in the ATLAS heavy-ion accelerator at Argonne. ATLAS has a new capability for increased beam currents with low beam losses for nuclear physics experiments using stable or rare isotope beams or neutron rich beams from the Californium Rare Isotope Breeder. The main goal for the cryomodule, to provide an accelerating voltage of 17.5 MV (2.5 MV/cavity), with no detectable beam losses has been met within the first month of commissioning. Thus far, cavities and primary subsystems including high-power couplers and pneumatic tuners are operating as designed with full availability. For present levels there is practically no field emission (EPEAK=40 MV/m) and RF losses of ~5 Watts/cavity are only half of that planned. Cavity fields will continue to be gradually increased, with the limits due to cavity quench measured at VACC=3.75 MV. Due to a combination of rf design and cavity processing, effective voltages are now 2 ½ times those for any other operational cavities for this v/c. We report here on the recent online test results and technical features of the present design.

TUPP009

Operation and Improvements of the ALBA Linac

linac, klystron, injection, 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.

TUPP015

Status on Airix Restart

electron, target, induction, timing

462

A. Georges, J. Beaubernard, V. Bernigaud, L. Buche, Y. Collet, S. Combacon, B. Gouin, G. Grandpierre, J.K. Kranzmann, L. Magnin, R. Nicolas, D. Pierre, F. Poulet, Y. Tailleur, J-L. Verstraete, J. Magnan
CEA, Pontfaverger-Moronvilliers, France

The Airix accelerator has been moved from Moronvilliers to Valduc to be part of the EPURE facility. Airix has been refurbished and restarted. This paper presents the first results and quantification of performances at its new location.
*M.Mouillet et al., “First results of AIRIX induction accelerator”,XXth LINAC cf.,p.491(2000)
**H.Dzitko et al., "operationnal efficiency of Airix accelerator since its commissioning",IPAC2012,p.4017

TUPP019

Qualification of the Titanium Welds in the E-XFEL Cryomodule and the CE Certification

cryomodule, cavity, linac, quadrupole

468

S. Barbanotti, H. Hintz, K. Jensch, R. Klos, W. Maschmann, A. Matheisen, A. Schmidt
DESY, Hamburg, Germany
C. Boulch, C. Cloué, C. Madec, J.L. Perrin, T. Trublet
CEA/IRFU, Gif-sur-Yvette, France
J.-P. Charrier, O. Napoly
CEA/DSM/IRFU, France

The CE stamping of the one hundred 1.3 GHz cryomodules for the XFEL Linac is a main step in the process of the certification of the entire Linac as a pressure equipment. Stringent requirements on materials and the quality of the welds of the pressurised components need to be satisfied to obtain the stamp. This paper summarizes these requirements, describes the process developed to qualify each module and summarises the rework campaign on the cavity helium vessels made necessary to obtain the required quality for a reliable and safe accelerator.

TUPP021

A New Type of Waveguide Distribution for the Accelerator Module Test Facility of the European XFEL

klystron, cryomodule, cavity, shielding

475

V.V. Katalev, S. Choroba
DESY, Hamburg, Germany
E.M. Apostolov
MicroPlus-Apostolov Ltd., Sofia, Bulgaria
A.A. Seliverstov
s.p.a. FERRITE Ltd., St.Petersburg, Russia

In order to test 100 superconducting accelerator modules within two years three test benches have been created in the accelerator module test facility (AMTF) to achieve the rate of one cryomodule per week. Each RF station of the test facility consists of a 5 MW klystron, at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate, and a waveguide distribution system. Each waveguide distribution supplies RF power to eight cavities, four times a pair of cavities. The distribution allows for a maximum power of 1 MW per cavity when the distribution is switched to mode supplying power to only four cavities. A new type of 1 MW isolator and a new compact 5 MW power divider have been developed to achieve that goal. Several cryomodule have been already successfully tested with this setup. We present the waveguide distribution for this test stand and describe the performance of the different elements.

TUPP023

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

klystron, cathode, gun, 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.

TUPP028

Beam Tests at the CLIC Test Facility, CTF3

experiment, emittance, linac, acceleration

487

R. Corsini, S. Döbert, W. Farabolini, D. Gamba, J.L. Navarro Quirante, T. Persson, P.K. Skowronski, F. Tecker
CERN, Geneva, Switzerland
W. Farabolini
CEA/DSM/IRFU, France
D. Gamba
JAI, Oxford, United Kingdom

The CLIC Test Facility CTF3 has been built at CERN by the Compact Linear Collider (CLIC) International Collaboration, in order to prove the main feasibility issues of the two-beam acceleration technology on which the collider is based. After the successful completion of its initial task, CTF3 is continuing its experimental program in order to give further indications on cost and performance issues, to act as a test bed for the CLIC technology, and to conduct beam experiments aimed at mitigating technological risks. In this paper we discuss the status of the ongoing experiments and present the more recent results, including improvements in beam quality and stability.

TUPP029

Diagnostics and Analysis Techniques for High Power X-Band Accelerating Structures

diagnostics, timing, controls, klystron

490

A. Degiovanni, S. Döbert, W. Farabolini, I. Syratchev, W. Wuensch
CERN, Geneva, Switzerland
J. Giner Navarro
IFIC, Valencia, Spain
J. Tagg
National Instruments Switzerland, Ennetbaden, Switzerland
B.J. Woolley
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom

The study of high gradient limitations due to RF breakdowns is extremely important for the CLIC project. A series of diagnostic tools and analysis techniques have been developed in order to monitor and characterize the behaviour of CLIC accelerating structures under high power operation in the first CERN X-band klystron-based test stand (Xbox1). The data collected during the last run on a TD26r05 structure are presented in this paper. From the analysis of the RF power and phases, the location of the breakdowns inside the structure could be determined. Other techniques based on the field emitted dark current signals collected by Faraday cups placed at the two extremities of the structure have also been investigated. The results of these analyses are reported and discussed.

TUPP052

SSR1 Tuner Mechanism: Passive and Active Device

cavity, cryomodule, alignment, SRF

541

D. Passarelli
Fermilab, Batavia, Illinois, USA

In this paper we present the methodology adopted in designing the mechanism responsible for controlling the resonant frequency of Single Spoke Resonators of first type (SSR1). Such device is capable of compensating the effects of external perturbations, such as pressure fluctuations and microphonics, on the frequency of SSR1. The compensation is achieved through active responses via an actuation system and passive responses which are inherent to the elastic behavior of the overall system. The first experiences in the design, assembly, QA and testing are reported.

Poster TUPP052 [2.368 MB]

TUPP056

High Current Proton Beam Operation at GSI UNILAC

proton, ion, linac, ion-source

550

W.A. Barth, A. Adonin, P. Gerhard, M. Heilmann, R. Hollinger, W. Vinzenz, H. Vormann
GSI, Darmstadt, Germany

A significant part of the experimental program at FAIR is dedicated to pbar physics requiring a high number of cooled pbars per hour. The primary proton beam has to be provided by a 70 MeV proton linac followed by two synchrotrons. The new FAIR Proton LINAC will deliver a pulsed proton beam of up to 35 mA of 36 μs duration at a repetition rate of 4 Hz. The current GSI heavy ion linac (UNILAC) is able to deliver world record uranium beam intensities for injection into the synchrotrons, but it is not dedicated for FAIR relevant proton beam operation. In an advanced machine investigation program it could be shown, that the UNILAC is able to provide for sufficient high intensities of CH3-beam, cracked (and stripped) in a supersonic nitrogen gas jet into protons and carbon ions. This advanced operational approach results in up to 2 mA of proton intensity at a maximum beam energy of 20 MeV, 100 μs pulse duration and a rep. rate of 4 Hz. Recent linac beam measurements will be presented, showing that the UNILAC is able to serve as a proton FAIR injector for the first time, while the performance is limited to 17% of the FAIR requirements.

TUPP057

In Situ Measurement of Mechanical Vibrations of a 4-Rod RFQ at GSI

laser, rfq, vacuum, quadrupole

553

P. Gerhard, L. Groening, K.-O. Voss
GSI, Darmstadt, Germany

A new 4-rod CW Radio Frequency Quadrupole was commissioned at the high charge state injector HLI at the UNILAC in 2009. It is in operation since 2010*. At high rf amplitudes strong modulations of the rf reflection emerge, with a modulation frequency of approximately 500 Hz. They are attributed to mechanical oscillations of the rods, excited by the rf pulse. The high fraction of reflected rf power severely limits the pulse length and rf amplitude achievable. As these modulations could only be seen during the rf pulse by means of rf measurements, a direct observation of the mechanical vibrations was desirable. Such measurements have been conducted using a commercial laser vibrometer, allowing for the investigation of the mechanical behavior of the RFQ independent of the presence of rf power. After a short introduction of the method, the results will be presented and compared with rf measurements and simulations.
*: P. Gerhard et al., “Experience with a 4–Rod CW RFQ”, LINAC’12, Sept. 2012, Tel Aviv, THPB035

TUPP058

RF System Development for the New 10⁸ MHz Heavy Ion High-Energy Linac at GSI

linac, controls, ion, LLRF

556

B. Schlitt, M. Hoerr, A. Schnase, G. Schreiber, W. Vinzenz
GSI, Darmstadt, Germany

The GSI UNILAC is in operation successfully since about 40 years. A replacement of the post stripper section is proposed to provide heavy ion beams for the future FAIR facility. Design studies for a new 10⁸ MHz high-energy (HE) linac optimized to accelerate high brilliance and high current ion beams up to U²⁸⁺ for synchrotron injection are in progress. Thus, the UNILAC will be converted into a short-pulse accelerator, the RF duty cycle being reduced from around 30 % to <2 %. To feed the future HE linac and to prepare for the FAIR commissioning, a major modernisation of the existing post stripper RF systems is planned from 2015 to 2017. Besides, the development of a new 1.8 MW cavity amplifier prototype was started recently, based on the widely-used THALES tetrode TH558SC promising an availability for at least 25 years. New 120 - 150 kW solid state driver amplifiers will replace the existing tube drivers. A digital LLRF system designed by industry was integrated into an existing amplifier driving a single gap resonator and was tested including ion beam tests. An overview of the RF system design and of the planned upgrades will be reported including some results of the LLRF tests.

TUPP060

Development of a 217 MHz Superconducting CH Structure

cavity, simulation, linac, accelerating-gradient

563

M. Basten, M. Amberg, M. Busch, F.D. Dziuba, D. Mäder, H. Podlech
IAP, Frankfurt am Main, Germany
M. Amberg, K. Aulenbacher, W.A. Barth, S. Mickat
HIM, Mainz, Germany
W.A. Barth, S. Mickat
GSI, Darmstadt, Germany

Funding: Helmholtz-Institut Mainz, Bundesministerium für Bildung und Forschung contract number 05P12RFRBL
To compete in the production of Super Heavy Elements (SHE) in the future a 7.3 AMeV superconducting (sc) continuous wave (cw) LINAC is planned at GSI. The baseline design consists of 9 sc Crossbar-H-mode (CH) cavities operated at 217 MHz. Currently an advanced cw demonstrator is under design at the Institute for Applied Physics (IAP) at Frankfurt University. The purpose of the advanced demonstrator is to investigate a new concept for the superconducting CH structures. It is based on shorter CH-cavities with 8 equidistant gaps without girders and with stiffening brackets at the front and end cap to reduce the pressure sensitivity. One major goal of the advanced demonstrator is to show that the new design leads to higher acceleration gradients and smaller E_p/E_a values. In this contribution first simulation results and technical layouts will be presented.

Poster TUPP060 [0.593 MB]

TUPP067

Chopper Operation for the Tandem Scrapers at the J-PARC Linac

linac, cavity, software, timing

581

K. Futatsukawa, Z. Fang, Y. Fukui, T. Kobayashi, S. Michizono
KEK, Ibaraki, Japan
E. Chishiro, K. Hirano, F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan

In the J-PARC linac, the energy upgrade from 181 MeV to 400 MeV by the installation of annular-ring coupled structure (ACS) cavities was successfully achieved in 2013. In the next stage, we will schedule the intensity upgrade by the increase of the beam current by improving the front-end in this summer. Then, the high heat load of the scraper, which stops the kicked-beam by the RF chopper, is predicted to damage the surface. Therefore, we prepare the tandem scrapers to suppress the heat load. The half of the kicked beam leads to a scraper and the residual is to the other. Its chopping expedient will be achieved by reversing the phase of the RF chopper on the periodic cycle at the low-level RF system. In this paper, I would like to introduce this system and present the result of the low-level test.

TUPP068

New SRF Facility at KEK for Mass-Production Study in Collaboration with Industries

cryomodule, SRF, cavity, cryogenics

584

H. Hayano
KEK, Ibaraki, Japan

The construction of the new SRF facility next to the KEK-STF facility has started from 2014 for the mass-production study of SRF accelerators in collaboration with industries. The new building for this facility has the dimension of 80 m x 30 m, and the plan is to install clean-room for cavity-string assembly, cryomodule-assembly facility, cryogenic system, vertical test facility, cryomodule test facility, input coupler process facility, cavity Electro-Polishing (EP) facility, and control-room/office-rooms in it. The purpose of this new SRF facility is to establish a close collaboration between SRF researchers and industries in order to prepare for the upcoming large-scale future SRF project, like ILC. This paper describes the infra-structure detail and the plan to utilize for future SRF accelerators.

TUPP070

Status and Recent Modifications to 324-MHz RF Source in J-PARC LINAC

klystron, linac, high-voltage, cathode

587

M. Kawamura, Y. Fukui, K. Futatsukawa, F. Naito
KEK, Ibaraki, Japan
E. Chishiro, K. Hasegawa, F. Sato, S. Shinozaki
JAEA/J-PARC, Tokai-mura, Japan
T. Hori
JAEA, Ibaraki-ken, Japan

This paper describes the present status of and the recent modifications to the 324-MHz RF source in the J-PARC linac. The recovery from the Great East Japan Earthquake Disaster, the status of the 324-MHz klystrons, the failure of 3 high-voltage transformers (HVTRs), and the discharge suppression for the anode-modulators are described.

Poster TUPP070 [0.660 MB]

TUPP075

The First Beam Recirculation and Beam Tuning in the Compact ERL at KEK

linac, emittance, recirculation, quadrupole

599

S. Sakanaka, M. Adachi, S. Adachi, M. Akemoto, D.A. Arakawa, S. Asaoka, K. Enami, K. Endo, S. Fukuda, T. Furuya, K. Haga, K. Hara, K. Harada, T. Honda, Y. Honda, H. Honma, T. Honma, K. Hosoyama, K. Hozumi, A. Ishii, X. Jin, E. Kako, Y. Kamiya, H. Katagiri, H. Kawata, Y. Kobayashi, Y. Kojima, Y. Kondou, O.A. Konstantinova, T. Kume, T. Matsumoto, H. Matsumura, H. Matsushita, S. Michizono, T. Miura, T. Miyajima, H. Miyauchi, S. Nagahashi, H. Nakai, H. Nakajima, N. Nakamura, K. Nakanishi, K. Nakao, K.N. Nigorikawa, T. Nogami, S. Noguchi, S. Nozawa, T. Obina, T. Ozaki, F. Qiu, H. Sagehashi, H. Sakai, S. Sasaki, K. Satoh, M. Satoh, T. Shidara, M. Shimada, K. Shinoe, T. Shioya, T. Shishido, M. Tadano, T. Tahara, T. Takahashi, R. Takai, H. Takaki, T. Takenaka, Y. Tanimoto, M. Tobiyama, K. Tsuchiya, T. Uchiyama, A. Ueda, K. Umemori, K. Watanabe, M. Yamamoto, Y. Yamamoto, Y. Yano, M. Yoshida
KEK, Ibaraki, Japan
E. Cenni
Sokendai, Ibaraki, Japan
R. Hajima, S. Matsuba, R. Nagai, N. Nishimori, M. Sawamura, T. Shizuma
JAEA, Ibaraki-ken, Japan
J.G. Hwang
KNU, Deagu, Republic of Korea
M. Kuriki, Y. Seimiya
HU/AdSM, Higashi-Hiroshima, Japan
A. Valloni
CERN, Geneva, Switzerland

Superconducting(SC)-linac-based light sources, which can produce ultra-brilliant photon beams in CW operation, are attracting worldwide attention. In KEK, we have been conducting R&D efforts towards the energy-recovery-linac(ERL)-based light source* since 2006. To demonstrate the key technologies for the ERL, we constructed the Compact ERL (cERL)** from 2009 to 2013. In the cERL, high-brightness CW electron beams are produced using a 500-kV photocathode DC gun. The beams are accelerated using SC cavities, transported through a recirculation loop, decelerated in the SC cavities, and dumped. In the February of 2014, we succeeded in accelerating and recirculating the CW beams of 4.5 micro-amperes in the cERL; the beams were successfully transported from the gun to the beam dump under energy recovery operation in the main linac. Then, precise tuning of beam optics and diagnostics of beam properties are under way. We report our experience on the beam commissioning, as well as the results of initial measurements of beam properties.
* N. Nakamura, IPAC2012, TUXB02.
** S. Sakanaka et al., IPAC2013, WEPWA015.

TUPP080

Commissioning of the MAX 700 MHz Test Stand

cavity, cryomodule, controls, experiment

610

J.-L. Biarrotte, F. Chatelet, M. El Yakoubi, N. Gandolfo, C. Joly, J. Lesrel, H. Saugnac
IPN, Orsay, France
A. Bosotti, R. Paparella, P. Pierini
INFN/LASA, Segrate (MI), Italy
F. Bouly
LPSC, Grenoble Cedex, France
I. Martin-Hoyo
ADEX, Madrid, Spain

The MYRRHA project aims at the construction of an Accelerator Driven System demonstrator. The criticality will be sustained by an external spallation neutron flux produced thanks to a 600 MeV high intensity proton beam. This beam will be delivered by a superconducting linac which must fulfil very stringent reliability requirements. Under the MAX (MYRRHA Accelerator eXperiment) program, which aims at pursuing the R&D activities on the ADS-type accelerator, a 700 MHz Cryomodule was developed. The main goal of this test stand is to dispose of a facility to carry out “real scale” reliability oriented studies on a RF Superconducting cavity of the high-energy linac section. This module holds 5-cells elliptical cavity equipped with its blade cold tuning system and its coaxial power coupler. The experimental work undertaken at IPN Orsay, has allowed to fully qualify the module in machine configuration (high RF power, at 2K), including assessment of the tuning system and measurement of microphonics spectrums. During this study the dynamic behavior of the fast tuning system of the cavity was also measured. We review here the obtained results and lessons learnt by operating this module.

TUPP092

Developmental and Operational Aspects of Nb QWR Based Heavy Ion LINAC System at IUAC Delhi

linac, controls, niobium, ion

640

S. Ghosh, R. Ahuja, J. Antony, S. Babu, J. Chacko, G.K. Chaudhari, A. Chaudhary, T.S. Datta, R.N. Dutt, R. Joshi, D. Kanjilal, S. Kar, J. Karmakar, M. Kumar, R. Kumar, D.S. Mathuria, K.K. Mistri, A. Pandey, P. Patra, P.N. Potukuchi, A. Rai, J. Sacharias, B.K. Sahu, A. Sarkar, S.S.K. Sonti, S. K. Suman
IUAC, New Delhi, India
A. Roy
VECC, Kolkata, India

The superconducting linac of IUAC consists of five cryostats containing 27 niobium quarter wave resonators. The prototype and the first 12 resonators were fabricated in collaboration with Argonne National Laboratory. The fabrication of the remaining resonators were carried out using in-house facilities available at IUAC. During the initial period of linac operations, problems were faced to generate higher accelerating fields in the resonators inside the linac cryostat and to reproduce the high fields at the time of beam acceleration. With systemetic efforts, all the major problems are solved and the complete linac is now operational. Since last few years, energized ion beams from linac are being delivered routinely for scheduled experiments. Among the major developmental works related to the linac operation, the vibrational damping mechansim by SS-balls, use of piezo actuator as mechanical tuner and the calculation of optimum phase focussing to control the time width of the beam bunches are noteworthy. Other two developments e.g. automatic phase locking of the resonators and auto beam tuning of the complete linac will be tested during the next beam acceleration.

TUPP094

Recent Progress of Beam Commissioning at J-PARC Linac

linac, acceleration, DTL, cavity

646

T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
K. Futatsukawa, T. Miyao
KEK, Ibaraki, Japan
M. Ikegami
FRIB, East Lansing, Michigan, USA
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
A. Miura, H. Sako
JAEA/J-PARC, Tokai-mura, Japan

We installed Annular-type Coupled Structure (ACS) linac in year 2013 in present linac downstream to extend the beam energy from 181 to 400 MeV. The beam commissioning had been conducted for one month in last December to January, and then we successfully extract 400 MeV beam. Whereas, we stably operate the linac at peak current of 15 mA, which is equivalent to 300 kW at the extraction of 3 GeV RCS, we observe unexpected residual radiations in ACS section. In this presentation, we review the recent progress in beam commissioning and beam loss study.

TUPP095

High-Power Test Results of the RFQ III in J-PARC Linac

rfq, cavity, vacuum, ion

649

T. Morishita, K. Hasegawa, K. Hirano, Y. Kondo, H. Oguri, S. Yamazaki
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Hori
JAEA, Ibaraki-ken, Japan
F. Naito, T. Sugimura, A. Takagi
KEK, Ibaraki, Japan

The J-PARC accelerator comprises an injector linac, a 3-GeV Rapid-Cycling Synchrotron and a 50-GeV Main Ring. The beam energy of the linac has been upgraded from 181MeV to 400MeV in 2013. For the beam current upgrade, the new frontend (RF ion source, RFQ, chopping system) installation is scheduled in summer 2014 for 1MW operation at RCS. The RFQ III, which is designed for 50mA beam acceleration from 0.05MeV to 3MeV, has been fabricated and the high-power test has started at April 2013 at the test station in the J-PARC. The test station consists of the ion source, the LEBT, the RFQ, and the diagnostics devices. The nominal RF power and RF duty of the RFQ III are 380kW and 3%(0.6ms and 50Hz), respectively. The high-power conditioning reached to the 120% of the nominal power with 1.5% (0.6ms, 25Hz) RF duty within 24 hours. Then, we performed the beam operation at the test station and measured beam parameters after the RFQ III. The results of the high-power conditioning and the stability of the RFQ operation with beam will be discussed.

TUPP100

Operation Of The Versatile Accelerator Driving the Low Power ADS GUINEVERE at SCK•CEN

neutron, target, ion, ion-source

659

M.A. Baylac, A. Billebaud, P. Boge, D. Bondoux, J. Bouvier, S. Chabod, G. Dargaud, E. Froidefond, E. Labussière, R. Micoud, S. Rey
LPSC, Grenoble Cedex, France
A. Kochetkov, J. Mertens, F. Van Gestel, C. Van Grieken, B. Van Houdt, G. Vittiglio
SCK•CEN, Mol, Belgium
F.R. Lecolley, J.L. Lecouey, G. Lehaut, N. Marie-Nourry
CNRS/IN2P3/LPC CAEN, Caen, France

GUINEVERE provides a low power accelerator driven system (ADS) to investigate on-line reactivity monitoring and operational procedures of an ADS. It consists of a versatile neutron source, GENEPI-3C, driving the fast sub-critical core, VENUS-F, in SCK•CEN (Belgium). GENEPI-3C is an electrostatic accelerator generating 14 MeV neutrons by bombarding a 250 keV deuteron beam onto a tritium target located within the reactor core. This accelerator produces alternatively continuous beam (up to 1 mA DC), possibly chopped with fast and adjustable interruptions, or short and intense deuteron bunches (~25 mA peak, 1 μs). This paper presents the facility and assesses the 2 years of coupled operation of the accelerator to the reactor.

Slides TUPP100 [0.969 MB]

TUPP121

Limitations for Acceleration of Intermediate Mass Particles with Traveling Wave Structure

acceleration, electron, accelerating-gradient, linac

705

V.V. Paramonov
RAS/INR, Moscow, Russia

The Disk Loaded Waveguide (DLW) is the mostly used high frequency structure for acceleration of lightweight particles – electrons in the high energy range. DLW parameters are considered for the lower frequency range and lower particle velocity. Physical and technical restrictions for DLW application for the low particles velocity are analyzed. Basing on particularities of acceleration with traveling wave, deep optimization of DLW cells dimensions, the choice of optimal operating phase advance for each DLW section and combination of forward and backward wave modes, it looks possible to create the simple, cost effective acceleration system for intermediate particles acceleration in the moderate velocity range, in some parameters overcoming accelerating system with RF cavities in the standing wave mode.

TUPP137

High Power Solid-State Amplifiers. New Developments and Technology Comparison

controls, vacuum, power-supply, impedance

733

G.B. Sharkov, A.I. Botyachkova, E.V. Ivanov, N.G. Kalugin, A.A. Krasnov, K.K. Naraianamurtkhi, K.I. Nikolskiy, S.A. Polikhov, I. Řežanov, A.Yu. Smirnov, P. Yazev
Siemens Research Center, Moscow,, Russia
A.I. Botyachkova
National Research Nuclear University (MEPhI), Moscow, Russia

Funding: Skolkovo Foundation, contract #44 from 2011.11.14
We present a newly developed compact and cost effective SSPA with megawatt range output power and scalable architecture. System components test results are discussed. A comparison of the state-of-the-art vacuum tube and solid-state technologies of RF power amplifiers for scientific accelerators is given.
Solid-state microwave generator, Siemens

WEIOA05

High Power RF Sources for the ESS RF Systems

klystron, linac, DTL, rfq

756

M. Jensen, G. Göransson, C. Marrelli, C. Martins, R. Montaño, A. Sunesson, R.A. Yogi, R. Zeng
ESS, Lund, Sweden
A.J. Johansson
Lund University, Lund, Sweden

The RF system for ESS will consist of around 150 high power RF sources and will deliver 125 MW peak power to the proton beam during the 2.86 ms pulse with an average power of 5 MW. The two RF frequencies, 352 and 704 MHz, the different power requirements along the linac and the sources currently available strongly influence the choice of RF technology. This talk will focus on the high power RF solutions for the main parts of the linac. We present an overview of the available technology along with the first test results of the main sources. Additionally, we will present the preliminary design of a new 1.2 MW multi-beam super power IOT being designed together with industry for the high beta section of the linac.

Slides WEIOA05 [5.090 MB]

WEIOA06

Low Level RF for SRF Accelerators

LLRF, cavity, controls, SRF

760

J. Branlard
DESY, Hamburg, Germany

Low level radio frequency (LLRF) systems are a fundamental component of superconducting RF accelerators. Since the release of the MicroTCA standard (MTCA.4), major developments in MTCA.4-based LLRF systems have taken place. State-of-the-art LLRF designs deliver better than 10^-4 relative amplitude and 10 mdeg phase stability for the vector sum control of SRF cavities. These developments in LLRF systems architecture and technology, driven by research institutes and supported by the industry are of highest importance for the European XFEL, but also for other SRF-based projects such as LCLS-II and the ESS, as well as for the next generation accelerators with 10-5 and mdeg regulation requirements.

Slides WEIOA06 [5.812 MB]

WEIOB02

SARAF Phase-I Proton / Deuteron Linac Beam Operation Status

target, rfq, proton, neutron

770

A. Kreisel, A. Arenshtam, Y. Ben Aliz, D. Berkovits, Y. Buzaglo, O. Dudovich, Y. Eisen, I. Eliyahu, G. Feinberg, I. Fishman, I.G. Gertz, A. Grin, S. Halfon, Y.F. Haruvy, T. Hirsch, D. Hirschmann, Z. Horvitz, B. Kaizer, D. Kijel, J. Luner, I. Mor, J. Rodnizki, G. Shimel, A. Shor, I. Silverman, D. Vartsky, L. Weissman, E. Zemach
Soreq NRC, Yavne, Israel

SARAF Phase-I linac is the first accelerator to demonstrate acceleration of variable energy 2 mA CW proton beam. Such intense beam is used in SARAF Phase-I to irradiate a liquid lithium jet target for nuclear astrophysics studies. Several improvements were necessary to allow beam operation with such high current. The improvements include a DC bias that was introduced on the cavity RF coupler to reduce coupler heating. A new slow chopper was commissioned to enable increase the current by increasing the duty cycle with fewer changes in the beam optics. A beam dump was developed to allow beam studies of a 2 mA CW proton beam. The beam dump is based on tungsten pins which distributes, by radiation, the high beam power over a large area which is then easily water cooled. While most of beam tuning is done using a low intensity pilot beam, some nondestructive methods were studied to monitor the high intensity beam. These include a current transformer and a residual gas monitor (RGM) to monitor beam transverse distribution. Additional valuable information about the beam current and energy is gained from measurements of the nuclear reaction products of the proton on lithium targets.

Slides WEIOB02 [3.027 MB]

THIOA02

Superconducting RF Development for FRIB at MSU

cavity, cryomodule, solenoid, SRF

790

K. Saito, N.K. Bultman, E.E. Burkhardt, F. Casagrande, S.K. Chandrasekaran, S. Chouhan, C. Compton, J.L. Crisp, K. Elliott, A. Facco, A.D. Fox, P.E. Gibson, M.J. Johnson, G. Kiupel, R.E. Laxdal, M. Leitner, S.M. Lidia, I.M. Malloch, D. Miller, S.J. Miller, D. Morris, D. Norton, R. Oweiss, J.P. Ozelis, J. Popielarski, L. Popielarski, A.P. Rauch, R.J. Rose, T. Russo, S. Shanab, M. Shuptar, S. Stark, N.R. Usher, G.J. Velianoff, D.R. Victory, J. Wei, G. Wu, X. Wu, T. Xu, T. Xu, Y. Yamazaki, Q. Zhao, Z. Zheng
FRIB, East Lansing, Michigan, USA

Funding: *This material is based upon work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
FRIB is a $730M heavy ion accelerator project and a very large scale machine for many nuclear physics users. The civil construction started on March 17th 2014. The SRF system design and development have completed. The machine is to be in early completion end of 2019. FRIB accelerates ion species up to 238U with energies of no less than 200MeV/u and provides a beam power up to 400kW. Four SRF cavity families are used from β=0.041, 0.085 (QWRs) to 0.29 and 0.53 (HWRs). 8T superconducting solenoids are installed in the cryomodules for space effective strong beam focusing. The biggest challenges are in accelerating the high-power heavy ion beams from the very low energy to medium energy and the stable operation for large user community. The SRF cryomodule design addressed three critical issues: high performance, stable operation and easy maintainability, which chose several unique technical strategies, e.g.2K operation, bottom up cryomodule assembly, local magnetic shielding and so on. This talk will include high performance cavity R&D, local magnetic shielding, flux trapping by solenoid fringe field, and bottom up cryomodule assembly.

Slides THIOA02 [5.049 MB]

THIOA05

An 800 MeV Superconducting Linac to Support Megawatt Proton Operations at Fermilab

linac, cryomodule, booster, cavity

807

V.A. Lebedev, P. Derwent, S.D. Holmes
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy
Active discussion on the high energy physics priorities in the US carried out since summer of 2013 resulted in changes in Fermilab plans for future development of the existing accelerator complex. In particular, the scope of Project X was reduced to the support of the Long Base Neutrino Facility (LBNF) at the project first stage. The name of the facility was changed to the PIP-II (Proton Improvement Plan). This new facility is a logical extension of the existing Proton Improvement Plan aimed at doubling average power of the Fermilab’s Booster and Main Injector (MI). Its design and required R&D are closely related to the Project X. The paper discusses the goals of this new facility and changes to the Project X linac introduced to support the goals.

Slides THIOA05 [1.597 MB]

THIOB02

SPIRAL2 Cryomodule Production Result and Analysis

cryomodule, cavity, linac, cryogenics

814

P.-E. Bernaudin, R. Ferdinand
GANIL, Caen, France
P. Bosland, C. Marchand
CEA/IRFU, Gif-sur-Yvette, France
Y. Gómez Martínez
LPSC, Grenoble Cedex, France
D. Longuevergne, G. Olry
IPN, Orsay, France

The production and qualification of the SPIRAL2 cryomodules are close to the end. Their performances are now well established. This paper will explain the path followed to the good achievements, and show some statistical analyses to be used for future projects. How far can we push the performances? What cryogenics consumption shall we take as design values?

Slides THIOB02 [2.864 MB]

THPP014

Catalogue of Losses for the Linear IFMIF Prototype Accelerator

simulation, rfq, beam-losses, distributed

860

N. Chauvin, P.A.P. Nghiem, D. Uriot
CEA/IRFU, Gif-sur-Yvette, France
M. Comunian
INFN/LNL, Legnaro (PD), Italy
C. Oliver
CIEMAT, Madrid, Spain

One of the activities of the EVEDA (Engineering Validation and Engineering Design Activities) phase of the IFMIF (International Fusion Materials Irradiation Facility) project consists in building, testing and operating, in Japan, a 125 mA/9 MeV deuteron accelerator, called LIPAc, which has been developed in Europe. For the accelerator safety aspects, a precise knowledge of beam loss location and power deposition is crucial, especially for a high intensity, high power accelerator like LIPAc. This paper presents the beam dynamics simulations allowing to estimate beam losses in different situations of the accelerator lifetime: starting from scratch, beam commissioning, tuning or exploration, routine operation, sudden failure. Some results of these studies are given and commented. Recommendations for hot point protection, beam stop velocity, beam power limitation are given accordingly.

Slides THPP014 [4.780 MB]

THPP021

Analysis of the RF Test Results from the On-going Accelerator Cavity Production for the European XFEL

cavity, superconductivity, SRF, linac

879

D. Reschke, S. Aderhold, V. Gubarev, J. Schaffran, N.J. Walker
DESY, Hamburg, Germany
L. Monaco
INFN/LASA, Segrate (MI), Italy
Y. Yamamoto
KEK, Ibaraki, Japan

Funding: The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007-2013) under grant agreement no 283745 (CRISP)
The main Linac of the European XFEL will consist of 100 superconducting accelerator modules, operated at an average design gradient of 23.6 MV/m. The fabrication by industry (which includes chemical surface preparation) of the required 800 superconducting cavities is now in full swing, with approximately 400 cavities having been delivered to date. In this interim report, we present an analysis of the RF acceptance tests amassed so far.

THPP038

The Drift Tube Welding Assembly for the Linac4 Drift Tube Linac at CERN

linac, drift-tube-linac, electron, DTL

929

I. Sexton, A. Cherif, Y. Cuvet, G. Favre, J.-M. Geisser, S. Ramberger, S. Sgobba, T. Tardy
CERN, Geneva, Switzerland
F.M. Mirapeix
DMP, Mendaro, Spain

The fabrication of the Linac4 Drift Tube Linac (DTL) required the welding assembly of 10⁸ drift tubes (DT) which has been undertaken at the CERN workshop. The design of the DTL is particular in that it was purposely simplified to avoid any position adjustment mechanism for drift tubes in the tank. In consequence, drift tubes have been designed with tight tolerances and parts have been assembled with an optimised welding procedure. Two re-machining stages have been introduced in order to compensate for welding distortions. This paper discusses the various assembly stages with a view on the final precision that has been achieved.

Poster THPP038 [8.665 MB]

THPP041

The Accelerator Cryoplant at ESS

controls, cryogenics, cryomodule, linac

939

P. Arnold, J. Fydrych, W. Hees, J.M. Jurns, X. Wang, J.G. Weisend
ESS, Lund, Sweden

The European Spallation Source (ESS) is a neutron science facility funded by a collaboration of 17 European countries currently under design and construction in Lund, Sweden. Cryogenic cooling is vital particularly for the linear accelerator, producing a 5 MW beam of 2.0 GeV protons to strike a rotating tungsten target. The cryogenic section of the linac comprises cryomodules with superconducting RF cavities that require helium cooling at 2.0 K, shield cooling at ~40 K and liquid helium for power coupler cooling. An extensive cryogenic distribution system connects the cryomodules with the linac cryoplant. With estimated electricity consumption of up to 3 MW this plant will be one of the major power consumers at ESS. Turndown modes and the intrinsic uncertainties regarding heat loads drive the need for high plant efficiency not only during full load operation but also at reduced performance. Together with flexibility and reliability over a long operation period these are the key challenges that will be addressed in this paper.

Poster THPP041 [4.141 MB]

THPP048

Design of a Compact Lever Slow/Fast Tuner for 650 MHz Cavities for Project X

cavity, resonance, simulation, SRF

957

I.V. Gonin, E. Borissov, T.N. Khabiboulline, Y.M. Pischalnikov, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Fermilab is developing 5-cell elliptical 650 MHz β=0.6 and β=0.9 cavities for Project X. A compact fast/slow lever tuner intended for both types of cavities has been developed for final tuning of the resonance frequency of the cavity after cooling down and to compensate the resonance frequency variations of the cavity during operation coming from liquid helium pressure fluctuations. The updated helium vessel (presented at this conference) is equipped with the tuner located at one of the end of the cavity. The tuner design and results of ANSYS analysis of their properties are presented.

THPP073

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

DTL, linac, pick-up, injection

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.

THPP077

Fast Tuner Performance for a Double Spoke Cavity

cavity, simulation, controls, SRF

1034

N. Gandolfo, S. Bousson, S. Brault, P. Duchesne, P. Duthil, G. Olry, D. Reynet
IPN, Orsay, France
C. Darve, M. Lindroos
ESS, Lund, Sweden

IPN Orsay is developing the low-beta double Spoke cavities cryomodule for the ESS. In order to compensate resonant frequency variations of each cavity during operation, a deformation tuner has been studied and two of them have been built. The typical perturbations are coming from LHe saturated bath pressure variations as well as microphonics and Lorentz force detuning (LFD). In this paper, the tuner performance of the double Spoke cavity is presented.

THPP089

High Power Conditioning of Annular-Ring Coupled Structures for the J-PARC Linac

vacuum, linac, cavity, coupling

1053

H. Ao, T. Ito, Y. Nemoto, H. Oguri, N. Ouchi, J. Tamura
JAEA/J-PARC, Tokai-mura, Japan
H. Asano
Nippon Advanced Technology Co. Ltd., Ibaraki-prefecture, Japan
Z. Fang, K. Futatsukawa, K. Nanmo, T. Sugimura
KEK, Ibaraki, Japan

The linac of Japan Proton Accelerator Research Complex (J-PARC), which is an injector to a 3-GeV synchrotron, comprised a 3-MeV RFQ, 50-MeV DTLs and 181-MeV Separated-type DTLs. From September 2013, 25 annular-ring coupled structure (ACS) cavities were additionally installed to increase the linac beam energy up to 400 MeV and achieve 1-MW beam power of the 3-GeV synchrotron. After installation work the high power conditioning was started from December 2013 and most of the ACS cavities were conditioned within three weeks. We passed through some troubles and finally finished conditioning all the cavities until the middle of January 2014. In this paper, we present the conditioning results and how to handle the issue in the conditioning process.

Slides THPP089 [7.756 MB]

THPP091

Installation and Performance Check of Beam Monitors for Energy Upgraded J-PARC Linac

linac, quadrupole, cavity, acceleration

1059

A. Miura, K. Hasegawa, H. Oguri, N. Ouchi
JAEA/J-PARC, Tokai-mura, Japan
M. Ikegami
FRIB, East Lansing, Michigan, USA
Y. Liu
KEK/JAEA, Ibaraki-Ken, Japan
T. Maruta
J-PARC, KEK & JAEA, Ibaraki-ken, Japan
T. Miyao
KEK, Ibaraki, Japan

An energy upgrade project has started to achieve the design beam power of 1 MW at the exit of the downstream synchrotron in the J-PARC Linac since 2009. In the upgraded project, a beam energy in the Linac has increased from present 181 MeV to 400 MeV using the additional 21 annular-ring coupled structure (ACS) cavities. The new beam monitors as the beam current monitors, the phase monitors, the beam position monitors, the transverse profile monitors (wire scanner monitors) and the longitudinal profile monitors (bunch shape monitors) for the part where the ACS cavities were installed were designed, fabricated and calibrated. Till the end of November, 2013, all beam monitors were completed to be installed. From the middle of December, we started the beam commissioning to achieve the beam energy as 400 MeV, as well as to confirm the beam monitor functioning. We achieved the 400 MeV beam acceleration at the middle of January, 2014 using newly installed beam monitors. This paper describes the beam monitor installation, calibration and the beam commissioning results of beam monitor functioning.

THPP107

Study on Polishing Method of Nb Surface by Periodic Reverse Current Electrolysis With Alkali Solution

experiment, cavity, SRF, laser

1102

M. Umehara
Nomura Plating Co, Ltd., Osaka, Japan
H. Hayano, T. Saeki
KEK, Ibaraki, Japan

Currently, electropolising method is thought to be the best method for the final surface preparation of superconducting RF cavity to obtain high gradient. In this conventional electropolising method, the electrolyte is the mixture of fluoric and sulfuric acids. Therefore, the operation of this method is dangerous, and the equipment becomes expensive because all parts should be made of high density polyethylene or fluorocarbon resin to avoid metallic parts which suffers from corrosion by electrolyte. Moreover, sulfur is produced as byproduct in the electropolishing process and this causes degradation of cavity performance. In order to overcome these drawbacks, we studied new polishing method of Nb surface by periodic reverse current electrolysis with alkali solution which causes no sulfur and allows the usage of metallic parts to realize cost effective equipment. In the study, we performed experiment of Nb coupons by this new method and obtained as good surface roughness as conventional electropolishing method. In this article, we report the details of the study.

THPP108

Status of New 2.5 MeV Test Facility at SNS

rfq, ion, ion-source, neutron

1105

A.V. Aleksandrov, M.S. Champion, M.T. Crofford, Y.W. Kang, A.A. Menshov, R.T. Roseberry, M.P. Stockli, A. Webster, R.F. Welton, A.P. Zhukov
ORNL, Oak Ridge, Tennessee, USA
K. Ewald
Fermilab, Batavia, Illinois, USA
M.E. Middendorf, S.N. Murray, R.B. Saethre
ORNL RAD, Oak Ridge, Tennessee, USA

Funding: Oak Ridge National Laboratory is managed by UT-Battelle, LLC, under contract DE-AC05-00OR22725 for the U.S. Department of Energy
A new 2.5Mev beam test facility is being built at SNS. It consists of a 65 keV H⁻ ion source, a 2.5MeV RFQ, a beam line with various beam diagnostics and a 6 kW beam dump. The facility is capable of producing one-ms-long pulses at 60Hz repetition rate with up to 50mA peak current. Commissioning with reduced average beam power is planned for fall 2014 to verify operation of all systems. The full power operation is scheduled to begin in 2015. Status of the facilty will be presented as well as discussion of the future R&D program.

THPP109

History of Cryomodule Repairs at SNS

cryomodule, HOM, cavity, linac

1108

M.P. Howell, M. Doleans, D.L. Douglas, S.-H. Kim
ORNL, Oak Ridge, Tennessee, USA
R. Afanador, B. DeGraff, B.S. Hannah, C.J. McMahan, T.S. Neustadt, S.W. Ottaway, J. Saunders, P.V. Tyagi, D.M. Vandygriff
ORNL RAD, Oak Ridge, Tennessee, USA

The operation of the Superconducting linear accelerator (SCL) has matured and now averages less than one trip per day. The availability of the SCL including radiofrequency systems, high voltage converter modulators, controls, vacuum and other support systems over the last three years is approximately 98%. The SNS has been in operation for ten years including the commissioning period. In support of achieving the stability of operation, multiple cryomodule repairs have been performed. Repairs to cryomodules have included instruments, helium leaks, valve actuators, cavity tuners, insulating vacuum repairs and upgrades, power supplies, higher order mode (HOM) feedthroughs, coupler windows, and coupler cooling components. Performance degradation has been experienced in multiple cavities. This has been corrected by thermal cycling the cryomodules with the affected cavities. Only two cavities have displayed slight permanent degradation that could not be corrected by thermal cycling. Repairs made to the SNS cryomodule will be detailed in this paper.

THPP115

PKU 2.45 GHz Microwave Driven H⁻ Ion Source Performance Study

electron, ion, ion-source, experiment

1120

T. Zhang, J.E. Chen, Z.Y. Guo, S.X. Peng, H.T. Ren, Y. Xu, J.F. Zhang, J. Zhao
PKU, Beijing, People's Republic of China
A.L. Zhang
University of Chinese Academy of Sciences, Beijing, People's Republic of China

Funding: This work is supported by the National Science Foundation of China (Grant Nos. 11175009, 91126004 and 11305004)
　　In a high intensity volume-produced H⁻ ion source, H⁻ ion production processes are great affected by electron temperature and gas pressure distribution within the discharge chamber. The H-/e ratio within an extracted H⁻ ion beam is much depended on the electron absorption within the extraction system. At Peking University (PKU), lots of experiments were carried out for better understanding H⁻ processes and electron dump on our 2.45 GHz microwave driven Cs-free permanent magnet volume-produced H⁻ source. Detail will be given in this paper.
Author to whom correspondence should be addressed. Electronic mail:
sxpeng@pku.edu.cn.

Poster THPP115 [2.252 MB]

THPP116

Performance of New Injector RILAC2 for Riken Ri-Beam Factory

cyclotron, injection, ECRIS, 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.

THPP132

Warming Rate Reduction of the SARAF RF Couplers by Application of a High Voltage Dc Bias

experiment, proton, cavity, linac

1168

B. Kaizer, Y. Ben Aliz, I. Fishman, J. Rodnizki, L. Weissman
Soreq NRC, Yavne, Israel

Warming up of the coupler region of the SARAF Half Wave Resonator (HWR) cavities was one of the main limiting factors for long operation at high RF field values. The warming effect is, most likely, associated with multipacting in the coupler region. We have tried to suppress the multipacting discharge in the couplers by application a DC bias to their inner conductors. A bias-T, element that conducts up to 4 kW of 176 MHz RF power and provides DC insulation of the coupler inner conductor, was designed and built for this purpose. First on-line operation showed that the DC bias indeed reduces dramatically the warming rates of most of the cavities by an order of magnitude. Today, coupler warming is no longer the main factor hindering accelerator operation.

THPP139

800MeV Linear Accelerator Development for HLS Upgrade

linac, electron, klystron, injection

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.