LINAC2018 - List of Keywords (GUI)

Paper	Title	Other Keywords	Page
MOPO034	Dielectric Waveguide-Based THz Radiator Study for SwissFEL	electron, experiment, radiation, FEL	94
	L. Shi, S. Bettoni, M.M. Dehler, E. Ferrari, B. Hermann, R. Ischebeck, F. Marcellini, S. Reiche, V.G. Thominet PSI, Villigen PSI, Switzerland A.K. Mittelbach Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany
	Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 701647 THz pulses have many unique properties in terms of radiation matter interaction. In particular their non-ionizing excitation of phonons in matter makes them a preferred pump for pump-probe studies at free electron lasers. In order to enrich the scientific potentials at SwissFEL (Swiss Free Electron Laser), which can provide ultrashort soft and hard X-ray pulses, we plan to build an economic THz radiator in the range of 1-20 THz by passing the spent electron beam through a dielectric lined tube after the electron beam has generated X-rays. These THz pulses will be transported to the photon user station. Since SwissFEL operates with 2 bunches, serving two beamlines, THz from the first bunch can be used at the user station of the second bunch to allow for pump arrival time before the probe. The core of such a THz generation setup is the dielectric lined tube and the relativistic electron beam. This paper reports on the numerical study of these tubes, in terms of mode structure, energy, pulse length etc, which are essential parameters for the pump-probe experiments. These tubes will be fabricated and tested in the near future in the electron beam line for the soft X-ray of SwissFEL.
	Slides MOPO034 [1.471 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO034
About •	paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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MOPO035	Status of CLARA Front End Commissioning	linac, laser, cathode, MMI	98
	D. Angal-Kalinin, A.D. Brynes, S.R. Buckley, P.A. Corlett, L.S. Cowie, K.D. Dumbell, D.J. Dunning, P.C. Hornickel, F. Jackson, J.K. Jones, J.W. McKenzie, B.L. Militsyn, A.J. Moss, T.C.Q. Noakes, M.D. Roper, D.J. Scott, B.J.A. Shepherd, E.W. Snedden, N. Thompson, C. Tollervey, D.A. Walsh, T.M. Weston, A.E. Wheelhouse STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom R.J. Cash, R.F. Clarke, G. Cox, C. Hodgkinson, R.J. Smith, J.T.G. Wilson STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom K.D. Dumbell, B.J.A. Shepherd Cockcroft Institute, Warrington, Cheshire, United Kingdom
	CLARA (Compact Linear Accelerator for Research and Applications) is a Free Electron Laser (FEL) test facility under development at Daresbury Laboratory. The principal aim of CLARA is to test advanced FEL schemes which can later be implemented on existing and future short wavelength FELs. We report on the commissioning of the CLARA front end, consisting of a photoinjector and the first linac section, and merger into the existing VELA (Versatile Electron Linear Accelerator) beamline.
	Slides MOPO035 [1.870 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO035
About •	paper received ※ 11 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019
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MOPO064	O-Arm Mounted X-Band Linear Accelerator System for Radiotherapy	linac, radiation, DSL, operation	142
	S. Kim, Y.W. Choi, G.J. Kim, I.S. Kim, J.I. Kim, J.H. Lee, Y.S. Lee KERI, Changwon, Republic of Korea J.H. Hwang, Y.N. Kang, A.R. Kim, J.N. Kim, T.G. Oh, Y.A. Oh, Y. J. Seol, J.S. Shin The Catholic University of Korea, Seoul, Republic of Korea
	Current advances in radiotherapy are based on the precise imaging techniques, and there is a pressing need for the development of techniques that are capable of visualizing cancer tissues in real time in conjunction with radiotherapy. Indeed, the image-guided radiotherapy systems in which conventional diagnostic tools such as CT and MRI are combined with the linear accelerator (LINAC)-based radiotherapy have been extensively studied. In this work, we mounted 9.3GHz X-band LINAC designed by KERI on the 360 degree-rotatable O-arm system, which allows efficient integration of a diagnostic tool with a radiotherapy equipment. After mounting, the X-ray profile and percentage depth dose were measured by following the quality assurance using the AAPM TG-51,142 protocol. The beam profile symmetry was estimated to be 10².4% with ±3% tolerance. The X-ray dose was also measured by rotating the O-arm to confirm the stability of the mounted X-band LINAC. As a result, the standard deviation of the X-ray dose was shown to be 0.016 while rotating. Therefore, we demonstrate the feasibility of our O-arm X-band LINAC system for use in highly effective radiotherapy with simultaneous CT image guidance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO064
About •	paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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MOPO089	Design Details of the European Spallation Source Drift Tube LINAC	DTL, interface, vacuum, linac	190
	P. Mereu, M. Mezzano, C. Mingioni, M. Nenni INFN-Torino, Torino, Italy G. Cibinetto INFN-Ferrara, Ferrara, Italy F. Grespan, A. Pisent INFN/LNL, Legnaro (PD), Italy
	The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is designed to operate at 352.2MHz with a duty cycle of 4% (3 ms pulse length, 14 Hz repetition period) and will accelerate a proton beam of 62.5mA pulse peak current from 3.62 to 90 MeV. This paper gives a detailed overview of the ESS-DTL current mechanical design, and the related driving criteria. It presents also an outlook of the main aspects of the assembly and installation, with related equipments, toolings and procedures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO089
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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MOPO095	A Risk Based Approach to Improving Beam Availability at an Accelerator Facility	operation, experiment, factory, proton	207
	W.C. Barkley, M.J. Borden, R.W. Garnett, M.S. Gulley, E.L. Kerstiens, M. Pieck, D. Rees, F.E. Shelley, B.G. Smith LANL, Los Alamos, New Mexico, USA
	Funding: United States Department of Energy This paper describes a risk-based approach to improving beam availability at an accelerator facility. Los Alamos Neutron Science Center (LANSCE), like many other accelerator facilities, was built many years ago and has been re-purposed when new missions were adopted. Many of the upgrades to the accelerator and beamlines allowed improvements in the general area of the upgrade but large-scale, system-wide improvements were never accomplished. Because of this, the facility operates with a mix of old and new equipment of varying condition. Limited budgets have constrained spending for spares procurement making it vital to prioritize those items predicted to have the highest impact to availability, should they fail. A systematic approach is described where equipment is inventoried, condition assessed, rated for potential failure and finally compiled into a risk-based priority list.
	Poster MOPO095 [0.332 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO095
About •	paper received ※ 21 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019
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MOPO101	LINAC-multitool - an Open Source Java-toolkit	linac, cavity, simulation, MMI	217
	M. Schwarz, D. Bade, J. Corbet, H. Podlech IAP, Frankfurt am Main, Germany
	Funding: Work supported by BMBF contr. No. 05P15RFRBA and HIC for FAIR Dedicating more precious time to advanced research instead of spending it towards timeconsuming routine tasks is a desirable goal in particle accelerator simulation and development. Requirements engineering was started at IAP in order to identify routine processes at our institute’s R&D that can be automated or simplified. Results indicated that there were several areas to consider: Bead pull measurements, data processing and visualization for the beam dynamics code LORASR, CST field map processing for the use with TraceWin, conversion between different particle distribution data formats and more. Subsequently development of the LINAC-Multitool started to rationalize these processes and replace preexisting scripts also to ensure consistency of results and increase transparency and reliability of computation. In order to guarantee maintainability, expandability and platform independence, LINAC-Multitool is programmed using Java and will be open source. This contribution presents the current state of development.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO101
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TUPO022	Manufacturing of X-band Accelerating Structures: Metrology Analysis and Process Capability	controls, collider, linac, linear-collider	374
	J. Sauza-Bedolla, S. Atieh, N. Catalán Lasheras CERN, Geneva, Switzerland
	The fabrication tolerances of RF components are essential for CLIC X-band accelerating structures to perform efficiently. On one hand, the capability of high power accelerating structures depends on the shape accuracy and the asperity of the inner surfaces, when microwaves pass through the cavity. On the other hand, surface flatness and dimensional tolerances are necessary to guarantee a correct assembly process. Hence, the discs that build up the structure require sub-micrometre specifications and, in order to meet all the needs, ultra-precision machining using single crystal diamond tools is mandatory. This paper shows the analysis of the metrology results of the fabrication of 118 discs (4 accelerating structures). Dimensional and form tolerances are studied following the production order to find drifts in the production and to predict the impact on the assembly process. Finally, process capability is evaluated.
	Poster TUPO022 [2.987 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO022
About •	paper received ※ 10 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TUPO027	Series Production of the Specific Waveguide Distribution for the European XFEL at DESY	cavity, cryomodule, FEL, LLRF	380
	B. Yildirim, S. Choroba, V.V. Katalev, P. Morozov, Y. Nachtigal DESY, Hamburg, Germany E.M. Apostolov Technical University of Sofia, Sofia, Bulgaria
	Series Production of the Specific Waveguide Distribution for the European XFEL at DESY B.Yildirim, S.Choroba, V.Katalev, P.Morozov, Y.Nachtigal, E.Apostolov The European XFEL uses 100 accelerating cryomodules. One RF station with 10 MW klystron supplies four cryomodules, each with eight cavities, through a waveguide distribution system. The RF station operates at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate. The results of the cryomodule test have shown however different maximum gradients for each cavity. The maximum gradient has been measured between 11 MV/m and 31 MV/m, which requires the cavity power from 29 kW to 230 kW. To operate with the maximum energy for every cryomodule, it is necessary to supply individual power to the cavity. In this case the weakest cavity problem can be avoided. For this goal a specific waveguide distribution has been developed. 100 waveguide distributions have been successfully tailored, produced and tested at the Waveguide Assembly Test Facility (WATF) at DESY and finally assembled to the cryomodules. We present the series production of the specific waveguide distributions at the WATF.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO027
About •	paper received ※ 06 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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TUPO057	Low-temperature Baking and Infusion Studies for High-gradient ILC SRF Cavities	cavity, SRF, collider, linear-collider	466
	M. Ge, P.N. Koufalis, G. Kulina, M. Liepe, J.T. Maniscalco Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Low-temperature infusion has become a hot-topic in SRF researches recently. Past results show that low-temperature infusion can produce high quality factor at medium accelerating fields. Also, 75°C baking recently has been shown to improve accelerating gradients of SRF cavities. Hence these treatments are very promising for reducing cost of the ILC. In this work, we present latest results of low temperature infusion and baking, showing that these treatments can improve SRF cavities performance.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO057
About •	paper received ※ 19 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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TUPO113	Beam Dynamics Studies Through Dielectric THz Accelerating Structures	simulation, vacuum, accelerating-gradient, linac	569
	R. Apsimon, G. Burt, A.L. Healy, S.P. Jamison Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R.B. Appleby, E.J.H. Smith UMAN, Manchester, United Kingdom A. Latina CERN, Geneva, Switzerland
	As conventional RF accelerating schemes approach the physical limit of accelerating gradient, the accelerator community is increasingly looking at novel accelerating techniques to overcome these limitations. Moving from the RF to the THz frequency range, higher acceleration gradients of high energy beams can be achieved in compact structures. Beam dynamics studies are crucial as part of the design of novel accelerating structures to maximise the output beam current as well as the accelerating gradient. In this paper we present beam dynamics simulations through dielectric lined waveguide structures using novel techniques to simulate broadband signals for particle tracking studies in RF-Track. The beam parameters through the structure are optimised and we study the dynamics of general broadband accelerating structures.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO113
About •	paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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WE1A04	The High Power RF System for the European XFEL	klystron, FEL, cavity, gun	601
	S. Choroba DESY, Hamburg, Germany
	The presentation will be on the design, construction and commissioning of the high power RF system for the European XFEL. The RF system consists of 26 high power RF stations each capable of 10MW RF pulse power. It will report on the overall system layout, cover RF system components e.g. klystrons, modulators and high power RF waveguide distribution. It will also cover system modifications during construction phase and report on commissioning results.
	Slides WE1A04 [12.620 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A04
About •	paper received ※ 17 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO016	Investigation of 2D PBG Waveguides for THz Driven Acceleration	acceleration, impedance, photon, electron	714
	A. Vint, R. Letizia Cockcroft Institute, Lancaster University, Lancaster, United Kingdom R. Letizia Lancaster University, Lancaster, United Kingdom
	Funding: Work supported by the STFC PhD Studentship Novel accelerating techniques that overcome the limitations of conventional RF technology are receiving significant interest. Moving from RF to the THz frequency range, higher gradient of acceleration of high energy beams can be achieved in miniaturised structures. Moreover, with respect to the optical frequency range, the THz regime allows for larger structures and better beam quality to be obtained. In this paper, we investigate the use of a 2D photonic bandgap (PBG) waveguide for THz driven electron acceleration. In accelerator applications, the properties of PBG waveguides can be exploited to damp higher order modes and offer low-loss dielectric confinement at high frequency. In particular, 2D PBG waveguides offer a good compromise between manufacturability, total photonic bandgap confinement, and ease of parallel illumination. The structure here proposed is optimised for maximum bandgap and single mode operation. Dispersion characteristics of the accelerating mode are studied to achieve the best compromise between high accelerating field and effective accelerating bandwidth, given a ~10% bandwidth of the THz driving pulse.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO016
About •	paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019
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THPO020	Dynamic Behavior of Electron Beam under Rf Field and Static Magnetic Field in Cyclotron Auto-resonance Accelerator	electron, SRF, resonance, acceleration	725
	Y.T. Yuan HUST, Wuhan, People’s Republic of China K. Fan Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China Y. Jiang Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA
	Funding: the National Natural Science Foundation of China The cyclotron auto-resonance accelerator (CARA) is a novel concept of accelerating continuous gyrating charged-particle beams to moderately or highly relativistic energies, which can be used as the high power microwave source and applied in environment improvement area, particularly in the flue gas pollution remediation. In CARA, the continuous-wave (CW) electron beam follows a gyrating trajectory while undergoing the interaction with the rotating TE-mode rf field and tapered static magnetic field. In the process of gyrating acceleration, the phase synchronization with the rf field is automatically maintained, so to speak, with auto-resonance. Simulation models are constructed to study the effect of rf field and static magnetic field on electron beam in CARA, where the beam energy, trajectory and velocity component are analysed. The simulation results match reasonably well with theoretical predication, which sets up a solid foundation for future designs of CARA.
	Poster THPO020 [1.448 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO020
About •	paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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THPO109	A New Spherical Pulse Compressor Working with Degenerated "Whispering Gallery" Mode	cavity, coupling, simulation, collider	928
	Z.B. Li, W. Fang, Q. Gu, Z.T. Zhao SINAP, Shanghai, People’s Republic of China A. Grudiev CERN, Geneva, Switzerland
	CLIC is focusing on the Compact Linear Collider. To obtain a relatively high accelerating gradient, CLIC utilizes Pulse Compressors to increase the input power of accelerators. This work is to make an alternative design for CLIC pulse compression scheme. There are several kinds of pulse compressor: SLED, BOC, SLED-Ⅱ, spherical pulse compressor and so on. Usually, a spherical cavity, including BOC, can offer a higher Q factor compared with a cylindrical cavity. This design utilizes a spherical cavity working with degenerated Whispering Gallery mode.
	Slides THPO109 [1.738 MB]
	Poster THPO109 [1.913 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO109
About •	paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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THPO126	Compact H⁺ ECR Ion Source with Pulse Gas Valve	ion-source, plasma, ECR, extraction	955
	Y. Takeuchi, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan
	We are developing a compact ECR H⁺ ion source with pulse gas valve. In the case of high current ion linac, the distance between the ion source and the first accelerating tube such as RFQ must be as short as possible to reduce the space charge effect, while operating in a high electric field a good vacuum condition is desirable. Since hydrogen gas always flows out from ion sources if the plasma chamber is filled with the gas, vacuum pumping systems have to evacuate the gas enough before the first accelerating tube. The pulse gas injection system achieved by a fast piezo gas valve can reduce the gas load on the vacuum evacuation system and is suitable for installing the ion source close to the RFQ.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO126
About •	paper received ※ 19 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019
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Paper

Title

Other Keywords

Page

MOPO034

Dielectric Waveguide-Based THz Radiator Study for SwissFEL

electron, experiment, radiation, FEL

94

L. Shi, S. Bettoni, M.M. Dehler, E. Ferrari, B. Hermann, R. Ischebeck, F. Marcellini, S. Reiche, V.G. Thominet
PSI, Villigen PSI, Switzerland
A.K. Mittelbach
Friedrich-Alexander Universität Erlangen-Nuernberg, University Erlangen-Nuernberg LFTE, Erlangen, Germany

Funding: This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 701647
THz pulses have many unique properties in terms of radiation matter interaction. In particular their non-ionizing excitation of phonons in matter makes them a preferred pump for pump-probe studies at free electron lasers. In order to enrich the scientific potentials at SwissFEL (Swiss Free Electron Laser), which can provide ultrashort soft and hard X-ray pulses, we plan to build an economic THz radiator in the range of 1-20 THz by passing the spent electron beam through a dielectric lined tube after the electron beam has generated X-rays. These THz pulses will be transported to the photon user station. Since SwissFEL operates with 2 bunches, serving two beamlines, THz from the first bunch can be used at the user station of the second bunch to allow for pump arrival time before the probe. The core of such a THz generation setup is the dielectric lined tube and the relativistic electron beam. This paper reports on the numerical study of these tubes, in terms of mode structure, energy, pulse length etc, which are essential parameters for the pump-probe experiments. These tubes will be fabricated and tested in the near future in the electron beam line for the soft X-ray of SwissFEL.

Slides MOPO034 [1.471 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO034

About •

paper received ※ 12 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO035

Status of CLARA Front End Commissioning

linac, laser, cathode, MMI

98

D. Angal-Kalinin, A.D. Brynes, S.R. Buckley, P.A. Corlett, L.S. Cowie, K.D. Dumbell, D.J. Dunning, P.C. Hornickel, F. Jackson, J.K. Jones, J.W. McKenzie, B.L. Militsyn, A.J. Moss, T.C.Q. Noakes, M.D. Roper, D.J. Scott, B.J.A. Shepherd, E.W. Snedden, N. Thompson, C. Tollervey, D.A. Walsh, T.M. Weston, A.E. Wheelhouse
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
R.J. Cash, R.F. Clarke, G. Cox, C. Hodgkinson, R.J. Smith, J.T.G. Wilson
STFC/DL, Daresbury, Warrington, Cheshire, United Kingdom
K.D. Dumbell, B.J.A. Shepherd
Cockcroft Institute, Warrington, Cheshire, United Kingdom

CLARA (Compact Linear Accelerator for Research and Applications) is a Free Electron Laser (FEL) test facility under development at Daresbury Laboratory. The principal aim of CLARA is to test advanced FEL schemes which can later be implemented on existing and future short wavelength FELs. We report on the commissioning of the CLARA front end, consisting of a photoinjector and the first linac section, and merger into the existing VELA (Versatile Electron Linear Accelerator) beamline.

Slides MOPO035 [1.870 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO035

About •

paper received ※ 11 September 2018 paper accepted ※ 19 September 2018 issue date ※ 18 January 2019

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MOPO064

O-Arm Mounted X-Band Linear Accelerator System for Radiotherapy

linac, radiation, DSL, operation

142

S. Kim, Y.W. Choi, G.J. Kim, I.S. Kim, J.I. Kim, J.H. Lee, Y.S. Lee
KERI, Changwon, Republic of Korea
J.H. Hwang, Y.N. Kang, A.R. Kim, J.N. Kim, T.G. Oh, Y.A. Oh, Y. J. Seol, J.S. Shin
The Catholic University of Korea, Seoul, Republic of Korea

Current advances in radiotherapy are based on the precise imaging techniques, and there is a pressing need for the development of techniques that are capable of visualizing cancer tissues in real time in conjunction with radiotherapy. Indeed, the image-guided radiotherapy systems in which conventional diagnostic tools such as CT and MRI are combined with the linear accelerator (LINAC)-based radiotherapy have been extensively studied. In this work, we mounted 9.3GHz X-band LINAC designed by KERI on the 360 degree-rotatable O-arm system, which allows efficient integration of a diagnostic tool with a radiotherapy equipment. After mounting, the X-ray profile and percentage depth dose were measured by following the quality assurance using the AAPM TG-51,142 protocol. The beam profile symmetry was estimated to be 10².4% with ±3% tolerance. The X-ray dose was also measured by rotating the O-arm to confirm the stability of the mounted X-band LINAC. As a result, the standard deviation of the X-ray dose was shown to be 0.016 while rotating. Therefore, we demonstrate the feasibility of our O-arm X-band LINAC system for use in highly effective radiotherapy with simultaneous CT image guidance.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO064

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paper received ※ 11 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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MOPO089

Design Details of the European Spallation Source Drift Tube LINAC

DTL, interface, vacuum, linac

190

P. Mereu, M. Mezzano, C. Mingioni, M. Nenni
INFN-Torino, Torino, Italy
G. Cibinetto
INFN-Ferrara, Ferrara, Italy
F. Grespan, A. Pisent
INFN/LNL, Legnaro (PD), Italy

The Drift Tube Linac (DTL) of the European Spallation Source (ESS) is designed to operate at 352.2MHz with a duty cycle of 4% (3 ms pulse length, 14 Hz repetition period) and will accelerate a proton beam of 62.5mA pulse peak current from 3.62 to 90 MeV. This paper gives a detailed overview of the ESS-DTL current mechanical design, and the related driving criteria. It presents also an outlook of the main aspects of the assembly and installation, with related equipments, toolings and procedures.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO089

About •

paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

MOPO095

A Risk Based Approach to Improving Beam Availability at an Accelerator Facility

operation, experiment, factory, proton

207

W.C. Barkley, M.J. Borden, R.W. Garnett, M.S. Gulley, E.L. Kerstiens, M. Pieck, D. Rees, F.E. Shelley, B.G. Smith
LANL, Los Alamos, New Mexico, USA

Funding: United States Department of Energy
This paper describes a risk-based approach to improving beam availability at an accelerator facility. Los Alamos Neutron Science Center (LANSCE), like many other accelerator facilities, was built many years ago and has been re-purposed when new missions were adopted. Many of the upgrades to the accelerator and beamlines allowed improvements in the general area of the upgrade but large-scale, system-wide improvements were never accomplished. Because of this, the facility operates with a mix of old and new equipment of varying condition. Limited budgets have constrained spending for spares procurement making it vital to prioritize those items predicted to have the highest impact to availability, should they fail. A systematic approach is described where equipment is inventoried, condition assessed, rated for potential failure and finally compiled into a risk-based priority list.

Poster MOPO095 [0.332 MB]

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO095

About •

paper received ※ 21 September 2018 paper accepted ※ 08 October 2018 issue date ※ 18 January 2019

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MOPO101

LINAC-multitool - an Open Source Java-toolkit

linac, cavity, simulation, MMI

217

M. Schwarz, D. Bade, J. Corbet, H. Podlech
IAP, Frankfurt am Main, Germany

Funding: Work supported by BMBF contr. No. 05P15RFRBA and HIC for FAIR
Dedicating more precious time to advanced research instead of spending it towards timeconsuming routine tasks is a desirable goal in particle accelerator simulation and development. Requirements engineering was started at IAP in order to identify routine processes at our institute’s R&D that can be automated or simplified. Results indicated that there were several areas to consider: Bead pull measurements, data processing and visualization for the beam dynamics code LORASR, CST field map processing for the use with TraceWin, conversion between different particle distribution data formats and more. Subsequently development of the LINAC-Multitool started to rationalize these processes and replace preexisting scripts also to ensure consistency of results and increase transparency and reliability of computation. In order to guarantee maintainability, expandability and platform independence, LINAC-Multitool is programmed using Java and will be open source. This contribution presents the current state of development.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-MOPO101

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paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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TUPO022

Manufacturing of X-band Accelerating Structures: Metrology Analysis and Process Capability

controls, collider, linac, linear-collider

374

J. Sauza-Bedolla, S. Atieh, N. Catalán Lasheras
CERN, Geneva, Switzerland

The fabrication tolerances of RF components are essential for CLIC X-band accelerating structures to perform efficiently. On one hand, the capability of high power accelerating structures depends on the shape accuracy and the asperity of the inner surfaces, when microwaves pass through the cavity. On the other hand, surface flatness and dimensional tolerances are necessary to guarantee a correct assembly process. Hence, the discs that build up the structure require sub-micrometre specifications and, in order to meet all the needs, ultra-precision machining using single crystal diamond tools is mandatory. This paper shows the analysis of the metrology results of the fabrication of 118 discs (4 accelerating structures). Dimensional and form tolerances are studied following the production order to find drifts in the production and to predict the impact on the assembly process. Finally, process capability is evaluated.

Poster TUPO022 [2.987 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO022

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paper received ※ 10 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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TUPO027

Series Production of the Specific Waveguide Distribution for the European XFEL at DESY

cavity, cryomodule, FEL, LLRF

380

B. Yildirim, S. Choroba, V.V. Katalev, P. Morozov, Y. Nachtigal
DESY, Hamburg, Germany
E.M. Apostolov
Technical University of Sofia, Sofia, Bulgaria

Series Production of the Specific Waveguide Distribution for the European XFEL at DESY B.Yildirim, S.Choroba, V.Katalev, P.Morozov, Y.Nachtigal, E.Apostolov The European XFEL uses 100 accelerating cryomodules. One RF station with 10 MW klystron supplies four cryomodules, each with eight cavities, through a waveguide distribution system. The RF station operates at 1.3 GHz, 1.37 ms pulse width and 10 Hz repetition rate. The results of the cryomodule test have shown however different maximum gradients for each cavity. The maximum gradient has been measured between 11 MV/m and 31 MV/m, which requires the cavity power from 29 kW to 230 kW. To operate with the maximum energy for every cryomodule, it is necessary to supply individual power to the cavity. In this case the weakest cavity problem can be avoided. For this goal a specific waveguide distribution has been developed. 100 waveguide distributions have been successfully tailored, produced and tested at the Waveguide Assembly Test Facility (WATF) at DESY and finally assembled to the cryomodules. We present the series production of the specific waveguide distributions at the WATF.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO027

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paper received ※ 06 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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TUPO057

Low-temperature Baking and Infusion Studies for High-gradient ILC SRF Cavities

cavity, SRF, collider, linear-collider

466

M. Ge, P.N. Koufalis, G. Kulina, M. Liepe, J.T. Maniscalco
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Low-temperature infusion has become a hot-topic in SRF researches recently. Past results show that low-temperature infusion can produce high quality factor at medium accelerating fields. Also, 75°C baking recently has been shown to improve accelerating gradients of SRF cavities. Hence these treatments are very promising for reducing cost of the ILC. In this work, we present latest results of low temperature infusion and baking, showing that these treatments can improve SRF cavities performance.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO057

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paper received ※ 19 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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TUPO113

Beam Dynamics Studies Through Dielectric THz Accelerating Structures

simulation, vacuum, accelerating-gradient, linac

569

R. Apsimon, G. Burt, A.L. Healy, S.P. Jamison
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R.B. Appleby, E.J.H. Smith
UMAN, Manchester, United Kingdom
A. Latina
CERN, Geneva, Switzerland

As conventional RF accelerating schemes approach the physical limit of accelerating gradient, the accelerator community is increasingly looking at novel accelerating techniques to overcome these limitations. Moving from the RF to the THz frequency range, higher acceleration gradients of high energy beams can be achieved in compact structures. Beam dynamics studies are crucial as part of the design of novel accelerating structures to maximise the output beam current as well as the accelerating gradient. In this paper we present beam dynamics simulations through dielectric lined waveguide structures using novel techniques to simulate broadband signals for particle tracking studies in RF-Track. The beam parameters through the structure are optimised and we study the dynamics of general broadband accelerating structures.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-TUPO113

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paper received ※ 13 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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WE1A04

The High Power RF System for the European XFEL

klystron, FEL, cavity, gun

601

S. Choroba
DESY, Hamburg, Germany

The presentation will be on the design, construction and commissioning of the high power RF system for the European XFEL. The RF system consists of 26 high power RF stations each capable of 10MW RF pulse power. It will report on the overall system layout, cover RF system components e.g. klystrons, modulators and high power RF waveguide distribution. It will also cover system modifications during construction phase and report on commissioning results.

Slides WE1A04 [12.620 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-WE1A04

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paper received ※ 17 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO016

Investigation of 2D PBG Waveguides for THz Driven Acceleration

acceleration, impedance, photon, electron

714

A. Vint, R. Letizia
Cockcroft Institute, Lancaster University, Lancaster, United Kingdom
R. Letizia
Lancaster University, Lancaster, United Kingdom

Funding: Work supported by the STFC PhD Studentship
Novel accelerating techniques that overcome the limitations of conventional RF technology are receiving significant interest. Moving from RF to the THz frequency range, higher gradient of acceleration of high energy beams can be achieved in miniaturised structures. Moreover, with respect to the optical frequency range, the THz regime allows for larger structures and better beam quality to be obtained. In this paper, we investigate the use of a 2D photonic bandgap (PBG) waveguide for THz driven electron acceleration. In accelerator applications, the properties of PBG waveguides can be exploited to damp higher order modes and offer low-loss dielectric confinement at high frequency. In particular, 2D PBG waveguides offer a good compromise between manufacturability, total photonic bandgap confinement, and ease of parallel illumination. The structure here proposed is optimised for maximum bandgap and single mode operation. Dispersion characteristics of the accelerating mode are studied to achieve the best compromise between high accelerating field and effective accelerating bandwidth, given a ~10% bandwidth of the THz driving pulse.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO016

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paper received ※ 12 September 2018 paper accepted ※ 20 September 2018 issue date ※ 18 January 2019

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THPO020

Dynamic Behavior of Electron Beam under Rf Field and Static Magnetic Field in Cyclotron Auto-resonance Accelerator

electron, SRF, resonance, acceleration

725

Y.T. Yuan
HUST, Wuhan, People’s Republic of China
K. Fan
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People’s Republic of China
Y. Jiang
Yale University, Beam Physics Laboratory, New Haven, Connecticut, USA

Funding: the National Natural Science Foundation of China
The cyclotron auto-resonance accelerator (CARA) is a novel concept of accelerating continuous gyrating charged-particle beams to moderately or highly relativistic energies, which can be used as the high power microwave source and applied in environment improvement area, particularly in the flue gas pollution remediation. In CARA, the continuous-wave (CW) electron beam follows a gyrating trajectory while undergoing the interaction with the rotating TE-mode rf field and tapered static magnetic field. In the process of gyrating acceleration, the phase synchronization with the rf field is automatically maintained, so to speak, with auto-resonance. Simulation models are constructed to study the effect of rf field and static magnetic field on electron beam in CARA, where the beam energy, trajectory and velocity component are analysed. The simulation results match reasonably well with theoretical predication, which sets up a solid foundation for future designs of CARA.

Poster THPO020 [1.448 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO020

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paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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THPO109

A New Spherical Pulse Compressor Working with Degenerated "Whispering Gallery" Mode

cavity, coupling, simulation, collider

928

Z.B. Li, W. Fang, Q. Gu, Z.T. Zhao
SINAP, Shanghai, People’s Republic of China
A. Grudiev
CERN, Geneva, Switzerland

CLIC is focusing on the Compact Linear Collider. To obtain a relatively high accelerating gradient, CLIC utilizes Pulse Compressors to increase the input power of accelerators. This work is to make an alternative design for CLIC pulse compression scheme. There are several kinds of pulse compressor: SLED, BOC, SLED-Ⅱ, spherical pulse compressor and so on. Usually, a spherical cavity, including BOC, can offer a higher Q factor compared with a cylindrical cavity. This design utilizes a spherical cavity working with degenerated Whispering Gallery mode.

Slides THPO109 [1.738 MB]

Poster THPO109 [1.913 MB]

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO109

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paper received ※ 11 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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THPO126

Compact H⁺ ECR Ion Source with Pulse Gas Valve

ion-source, plasma, ECR, extraction

955

Y. Takeuchi, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan

We are developing a compact ECR H⁺ ion source with pulse gas valve. In the case of high current ion linac, the distance between the ion source and the first accelerating tube such as RFQ must be as short as possible to reduce the space charge effect, while operating in a high electric field a good vacuum condition is desirable. Since hydrogen gas always flows out from ion sources if the plasma chamber is filled with the gas, vacuum pumping systems have to evacuate the gas enough before the first accelerating tube. The pulse gas injection system achieved by a fast piezo gas valve can reduce the gas load on the vacuum evacuation system and is suitable for installing the ion source close to the RFQ.

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reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2018-THPO126

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paper received ※ 19 September 2018 paper accepted ※ 21 September 2018 issue date ※ 18 January 2019

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