LINAC2016 - List of Keywords (quadrupole)

Paper	Title	Other Keywords	Page
MOPRC004	Beam Orbit Analysis and Correction of the FRIB Superconducting Linac	linac, simulation, operation, injection	71
	Y. Zhang, Z.Q. He FRIB, East Lansing, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Beam based alignment (BBA) techniques are important tools for precise beam orbit correction of a high power linac, and supplement to the model based or orbit response matrix (ORM) based correction methods. BBA will be applied to beam orbit analysis and correction of the FRIB linac arcs where a beam orbit offset within 0.1 mm is required to the second order achromatic beam tuning. In this paper, we first introduce the study of model based beam orbit correction of the arc, and then a more precise orbit correction with BBA. Realistic misalignment of beam elements and beam position monitors (BPMs) are included in the simulation studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC004
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MOPRC005	Beam Tuning of Achromatic Bending Areas of the FRIB Superconducting Linac	linac, sextupole, lattice, simulation	74
	Y. Zhang, C.P. Chu FRIB, East Lansing, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 To achieve the design beam power for heaviest ion species, acceleration and transport of multi charge state beams simultaneously in the FRIB superconducting linac becomes necessary, which poses a technical challenge especially to the FRIB folded lattice design. Achromatic and isochronous beam optics up to the second order must be established precisely in the linac bending areas, and as none-perfection beam elements and system errors exist in the real machine, beam tuning and beam optics corrections of the bending area are important to high power operation. In this paper, we introduce the beam tuning algorithms of the FRIB linac achromatic arcs and also discuss the simulation studies.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC005
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MOPRC006	Beam Tuning and Error Analysis of a Superconducting Linac	linac, cavity, simulation, lattice	77
	Y. Zhang FRIB, East Lansing, USA
	Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661 Beam tuning and error analysis of a superconducting linac for heavy ion beams are introduced in this paper. In simulation studies with accelerator codes, system errors to the beam tuning are analyzed numerically, which include random cavity and magnet errors and measurement errors of absolute beam phase, beam bunch length, and beam transverse profiles. Simple statistical equations are developed from the tedious and time-consuming numerical simulations, and they may provide advantage tools not only to analyze a linac beam tuning, such as phase and amplitude tuning of superconducting cavity, longitudinal and transverse beam matching, but also will be very helpful to linac design with practical beam diagnostics system and authentic accelerator lattice.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC006
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MOPRC008	Dispersion Free and Dispersion Target Steering Experience at CTF3	linac, optics, target, dipole	83
	D. Gamba, R. Corsini, T. Persson, P.K. Skowroński, F. Tecker CERN, Geneva, Switzerland P. Burrows Oxford University, Physics Department, Oxford, Oxon, United Kingdom P. Burrows JAI, Oxford, United Kingdom
	One of the goals of the CLIC Test Facility (CTF3) at CERN is to demonstrate the feasibility of the CLIC Drive Beam recombination, which takes place in the Drive Beam Recombination Complex (DBRC). The tight geometry of the DBRC together with its strong optics and the high energy-spread of the beam require a careful control of the beam size along the different sections of the DBRC. One of the main contribution to beam size is the dispersion. If uncontrolled, dispersion leads to fast increase of the beam size, hence it may affect the beam current stability of the combined beam. A tool has been implemented at CTF3 to measure and correct dispersion during and after the setup of the machine. Dispersion Free Steering (DFS) has been applied in the upstream drive beam LINAC, while Dispersion Target Steering (DTS) has been used in the rings of the DBRC. In the LINAC the weak optics and the wide dynamic aperture of the beamline allow a straightforward correction. In the DBRC the aperture is tighter, and the strong optics produce non-linear dispersion which one needs to take into account. A general overview of current status and future plans in controlling dispersion at CTF3 will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC008
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MOPRC009	Simulating Apertures in the Uniform Equivalent Beam Model	simulation, optics, space-charge, software	87
	G.H. Gillespie G.H. Gillespie Associates, Inc., Del Mar, California, USA
	The uniform equivalent beam model is useful for simulating particle beam envelopes. Beam root-mean-square (rms) sizes, divergences, and emittances of an equivalent uniform beam approximate well the rms properties of more realistic beam distributions, even in the presence of space charge. Envelope simulation codes for high current beams using the model, such as TRACE 3-D, are central to particle optics design. However, the modeling of apertures has required multi-particle simulation codes. Multi-particle codes do not typically have the fitting and optimization capabilities common to envelope codes, so the evaluation of aperture effects is often a secondary study that may result in further design iteration. To incorporate aperture effects into the optics design at the start, a method has been developed for simulating apertures in the context of a uniform equivalent beam. The method is described and its TRACE 3-D implementation is outlined. Comparisons with multi-particle simulations are used to validate the method and examine regions of applicability.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC009
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MOPRC013	Tracking Based Courant-Snyder Parameter Matching in a Linac with a Strong Space-Charge Force	linac, DTL, space-charge, emittance	93
	R. Miyamoto ESS, Lund, Sweden
	During the design of a hadron linac, matching at the interfaces of different structures or lattice periods is often performed with the linear approximation of the space-charge force. When space-charge is extremely strong, like in the low energy part of the proton linac of the European Spallation Source, such a matching method is not always good enough and could lead to a residual mismatch at the design level. To avoid this, a matching scheme based on iterations of tracking, thus including the full effect of the space-charge force, is developed. This paper presents the scheme itself as well as its application to the ESS linac.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC013
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MOPRC015	Development Status of FRIB On-line Model Based Beam Commissioning Application	cavity, solenoid, lattice, linac	100
	Z.Q. He, M.A. Davidsaver, K. Fukushima, D.G. Maxwell, G. Shen, Y. Zhang, Q. Zhao FRIB, East Lansing, USA
	Funding: The work is supported by the U.S. National Science Foundation under Grant No. PHY-11-02511, and the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661. The new software FLAME has been developed to serve as physics model used for on-line beam commissioning applications. FLAME is specially designed to cover FRIB modeling challenges to balance between speed and precision. Several on-line beam commissioning applications have been prototyped based on FLAME and tested on the physics application prototyping environment. In this paper, components of the physics application prototyping environment are firstly described. Then, the design strategy and result of the four major applications: baseline generator, cavity tuning, orbit correction, transverse matching, are discussed.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC015
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MOPRC018	Improved Beam Dynamics and Cavity RF Design for the FAIR Proton Injector	cavity, linac, proton, DTL	111
	R. Tiede, A. Almomani, M. Busch, F.D. Dziuba, U. Ratzinger IAP, Frankfurt am Main, Germany
	The FAIR facility at GSI requires a dedicated 70 MeV, 70 mA proton injector for the research program with intense antiproton beams. The main accelerator part consists of six 'Crossbar H-type' (CH) cavities operated at 325 MHz. Based on a linac layout carefully developed over several years, recently the beam dynamics has been revised with the scope of finalising the design and thus being able to start the construction of the main linac components. As compared to previous designs the MEBT behind the RFQ was slightly extended, the gap numbers per CH cavity and the voltage distributions were optimised and the layout of the intermediate diagnostics section including a rebuncher cavity at 33 MeV was redesigned. Finally, detailed machine error studies were performed in order to check the error response of the new design and the steering concept in particular. In the consequence, the final parameters obtained from the beam dynamics update are used for finalizing the CH-DTL cavity design by CST-MWS calculations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC018
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MOPLR004	Development of an High Gradient, S-band, Accelerating Structure for the FERMI Linac	linac, operation, electron, wakefield	136
	C. Serpico, I. Cudin Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy A. Grudiev CERN, Geneva, Switzerland
	The FERMI seeded free-electron laser (FEL), located at the Elettra laboratory in Trieste, is driven by a 200 meter long, S-band linac routinely operated at nearly 1.5 GeV and 10 Hz repetition rate [1]. The high energy part of the Linac is equipped with seven, 6 meter long Backward Traveling Wave (BTW) structures: those structures have small iris radius and a nose cone geometry which allows for high gradient operation [2]. Nonetheless a possible development of high-gradient, S-band accelerating struc-tures for the replacement of the actual BTW structures is under consideration. This paper investigates a possible solution for RF couplers that could be suitable for linac driven FEL where reduced wakefields effects, high oper-ating gradient and very high reliability are required.
	Poster MOPLR004 [0.947 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR004
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MOPLR008	Status Of the ILC Main Linac Design	linac, lattice, cryomodule, emittance	149
	A. Saini, V.V. Kapin, N. Solyak Fermilab, Batavia, Illinois, USA
	International Linear collider (ILC) is a proposed accelerator facility which is primarily based on two 11-km long superconducting main linacs. In this paper we present recent updates on the main linac design and discuss changes made in order to meet specification outlined in the technical design report (TDR).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPLR008
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TUOP11	Methods for Bunch Shape Monitor Phase Resolution Improvement	electron, linac, focusing, space-charge	408
	A. Feschenko, S.A. Gavrilov RAS/INR, Moscow, Russia
	Bunch shape monitors, based on secondary electrons emission, are widely used for measurements of longitudinal bunch profiles during a linac commissioning and initial optimization of beam dynamics. A typical phase resolution of these devices is about 1°. However it becomes insufficient for new modern linacs, which require a better resolution. Some developed methods for a phase resolution improvement are discussed.
	Slides TUOP11 [21.248 MB]
	Poster TUOP11 [1.888 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUOP11
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TUPLR020	Commissioning of the Compact 14MeV LINAC for an FEL-Based THz Source	linac, target, gun, radiation	509
	Y.J. Pei, G. Feng, X.Y. He, Y. Hong, G. Huang, D. Jia, K. Jin, J. Liu, P. Lu, L. Shang, B.G. Sun, Zh. X. Tang, W. Wei, Z. Zhao USTC/NSRL, Hefei, Anhui, People's Republic of China L. Cao, Q.S. Chen, S. Hu, T. Hu, J. Li, Y.J. Liang, B. Qin, B. Tang, T. Tang, Y.Q. Xiong, Q. Zhang HUST, Wuhan, People's Republic of China W. Chen, Y.B. Wang, J. Zha Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People's Republic of China G. Feng DESY, Hamburg, Germany Zh. X. Tang DICP, Dalian, People's Republic of China
	Commissioning the compact LINAC of 14Mev for a THz source based on FEL Y.J.Pei National Synchrotron Radiation laboratory, University of Science & Technology of China Abstract The compact LINAC of 14MeV is designed for a FEL which will produce a THz radiation through 30μm to 300μm. The LINAC was composed of a novel EC-ITC-RF gun, constant gradient travelling wave accelerator with a collinear absorbing load, focusing system, RF power system, beam diagnostic system, vacuum system, control system and so on. The LINAC was installed on November of 2014. Last year, we finished the install of the undulator and the optical resonance cavities. Now the LINAC has been testing and commissioning for THz radiation test. So far, the running beam parameters of the LINAC are as the following: Energy is of 13.58MeV macro pulse current is of 655mA macro pulse length of 1.2μsμpulse beam current is of 59A beam length of theμpulse is of 4ps energy spread of 0.33% normal beam emmitance is of 24.1mm.mrad.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR020
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TUPLR054	RFQ Vane Shapes for Efficient Acceleration	acceleration, rfq, multipole, focusing	581
	Y. Iwashita, Y. Fuwa Kyoto ICR, Uji, Kyoto, Japan R.A. Jameson IAP, Frankfurt am Main, Germany
	RFQ vane shapes for efficient acceleration are under investigation by introducing more terms in addition to the two term potential. They can incorporate with the feature of the trapezoidal shape modulation with less multipole components, while higher acceleration efficiency is expected. The simulation study will be presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR054
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TUPLR059	Asymmetric Four-Vane RFQ	dipole, impedance, rfq, simulation	592
	A.S. Plastun ANL, Argonne, Illinois, USA A. Kolomiets, D.A. Liakin ITEP, Moscow, Russia
	Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357. A four-vane resonator is widely used in Radio Frequency Quadrupole (RFQ) accelerators. The field distribution in a long four-vane resonator can be easily perturbed by nearest dipole modes which are excited due to the local geometry errors. This paper describes the electromagnetic properties of a four-vane resonator with an introduced asymmetry between neighboring chambers. The asymmetry provides necessary separation of dipole modes keeping losses and field uniformity of quadrupole mode similar to those in a conventional four-vane resonator. This feature of an asymmetric resonator is confirmed by analytical results from transmission line model as well as by CST Studio simulations.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TUPLR059
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TH2A03	Complete Transverse 4D Beam Characterization for Ions Beams at Energies of Few MeV/u	emittance, coupling, ion, vacuum	720
	M.T. Maier, X. Du, P. Gerhard, L. Groening, S. Mickat, H. Vormann GSI, Darmstadt, Germany
	Measurement of the ion beam rms-emittances is done through determination of the second order beam moments. For time being the moments quantifying the amount of inter-plane coupling, as <xy'> for instance, have been accessible to measurements just for very special cases of ions at energies below 200 keV/u using pepperpots. This talk presents successful measurements of all inter-plane coupling moments at 1 to 11 MeV/u. From first principles the used methods are applicable at all ion energies. The first campaign applied skewed quadrupoles in combination with a regular slit/grid emittance measurement device. The second campaign used a rotatable slit/grid device in combination with regular quadrupoles.
	Slides TH2A03 [17.343 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-TH2A03
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THOP09	Tuning of the CERN 750 MHz RFQ for Medical Applications	rfq, linac, operation, target	763
	B. Koubek, Y. Cuvet, A. Grudiev, C. Rossi, M.A. Timmins CERN, Geneva, Switzerland
	CERN has built a compact 750 MHz RFQ as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 MeV within only 2 m length. It is divided into four segments and equipped with 32 tuners in total. The RFQ length corresponds to 5λ which is considered to be close to the limit for simple field adjustment using tuners. Nevertheless the high frequency results in a sensitive structure and requires careful tuning by means of the alignment of the pumping ports and fixed tuners. This paper gives an overview of the tuning procedure and bead pull measurements of the RFQ.
	Slides THOP09 [16.367 MB]
	Poster THOP09 [23.832 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THOP09
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THPRC031	Manufacturing of MEBT Combined Quadrupole & Steerer Magnets for the Linear IFMIF Prototype Accelerator LIPAC	radiation, factory, beam-transport, vacuum	840
	J. Castellanos, B. Brañas, J. Mollá, C. Oliver, I. Podadera, F. Toral CIEMAT, Madrid, Spain R. Iturbe, B. López ANTEC Magnets SLU, Vizcaya, Spain O. Nomen IREC, Sant Adria del Besos, Spain
	Funding: This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Agreement as published in BOE, 16/01/2013, page 1988. The Medium Energy Beam Transport line (MEBT) that is being installed on the LIPAC accelerator* will have five quadrupole and steerer magnets which have been recently manufactured and tested. The design of the magnets was done by CIEMAT** and considers a magnetic yoke made of four solid iron quadrants joined together. The yoke integrates four water-cooled coils (quadrupole) and eight air-cooled coils (steerers) made of copper wires. The manufacturing and testing (excluded magnetic measurements) of the five magnets were carried out by the Spanish company ANTECSA. This paper focuses on the technical aspects considered during the manufacturing and the assembly of the different components of the magnets. The details about the geometrical, electrical and hydraulic measurements and tests that were carried out before the magnetic measurements are also described. * A. Mosnier et al., IPAC10, MOPEC056, p.588, Kyoto, Japan (2010) ** C. Oliver et al., IPAC11, WEPO014, p. 2424, San Sebastián, Spain (2011)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPRC031
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THPLR015	Fifth-Order Moment Correction for Beam Position and Second-Order Moment Measurement	linac, simulation, experiment, factory	876
	K. Yanagida, H. Hanaki, S. Suzuki JASRI/SPring-8, Hyogo-ken, Japan
	For precise beam position measurement using a beam position monitor (BPM), a recursive correction which is expressed by the higher-order polynomials of beam positions are usually adopted. We recognized that the higher-order polynomials came from the higher-order moments and that beam position measurement is consequently influenced by a transverse beam shape. To investigate what order was required for adequate correction, we performed a successive iteration for the six-electrode BPM holding an inner radius of 16mm (circular cross-section). The successive iteration is a method to obtain a self-consistent solution for the higher-order correction. An amplitude of static electric field due to a beam charge was calculated by two-dimensional mirror charge method. As a result of the successive iteration, the convergence region was large enough for ordinary measurements (from lower than -5mm to higher than 5mm horizontally and vertically). In the convergence region the root mean square of the differences between the set and calculated vertical position were obtained as 0.487mm (without correction), 0.030mm (with third-order correction) and 0.003mm (with fifth-order correction).
	Poster THPLR015 [6.049 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR015
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THPLR032	Update on SSR2 Cavity EM Design for PIP-II	cavity, linac, simulation, acceleration	920
	P. Berrutti, T.N. Khabiboulline, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	Proton Improvement Plan II (PIP-II) is the future plan for upgrading the Fermilab proton accelerator complex to a beam power capability of at least 1 MW delivered to the neutrino production target. A room temperature section accelerates H⁻ ions to 2.1 MeV and creates the desired bunch structure for injection into the superconducting (SC) linac. SC linac using five cavity types. One 162.5 MHz half wave resonator, two 325 MHz spoke resonators and two 650 MHz elliptical 5-cell cavities, provide acceleration to 800 MeV. The EM design of the second family of spoke resonator is presented in this paper. The work reported is a thorough electromagnetic study including: the RF parameters, multipacting mitigation and transverse field asymmetry. The cavity is now ready for structural design analysis.
	Poster THPLR032 [1.947 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-THPLR032
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Paper

Title

Other Keywords

Page

MOPRC004

Beam Orbit Analysis and Correction of the FRIB Superconducting Linac

linac, simulation, operation, injection

71

Y. Zhang, Z.Q. He
FRIB, East Lansing, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Beam based alignment (BBA) techniques are important tools for precise beam orbit correction of a high power linac, and supplement to the model based or orbit response matrix (ORM) based correction methods. BBA will be applied to beam orbit analysis and correction of the FRIB linac arcs where a beam orbit offset within 0.1 mm is required to the second order achromatic beam tuning. In this paper, we first introduce the study of model based beam orbit correction of the arc, and then a more precise orbit correction with BBA. Realistic misalignment of beam elements and beam position monitors (BPMs) are included in the simulation studies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC004

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MOPRC005

Beam Tuning of Achromatic Bending Areas of the FRIB Superconducting Linac

linac, sextupole, lattice, simulation

74

Y. Zhang, C.P. Chu
FRIB, East Lansing, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
To achieve the design beam power for heaviest ion species, acceleration and transport of multi charge state beams simultaneously in the FRIB superconducting linac becomes necessary, which poses a technical challenge especially to the FRIB folded lattice design. Achromatic and isochronous beam optics up to the second order must be established precisely in the linac bending areas, and as none-perfection beam elements and system errors exist in the real machine, beam tuning and beam optics corrections of the bending area are important to high power operation. In this paper, we introduce the beam tuning algorithms of the FRIB linac achromatic arcs and also discuss the simulation studies.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC005

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MOPRC006

Beam Tuning and Error Analysis of a Superconducting Linac

linac, cavity, simulation, lattice

77

Y. Zhang
FRIB, East Lansing, USA

Funding: Work supported by the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661
Beam tuning and error analysis of a superconducting linac for heavy ion beams are introduced in this paper. In simulation studies with accelerator codes, system errors to the beam tuning are analyzed numerically, which include random cavity and magnet errors and measurement errors of absolute beam phase, beam bunch length, and beam transverse profiles. Simple statistical equations are developed from the tedious and time-consuming numerical simulations, and they may provide advantage tools not only to analyze a linac beam tuning, such as phase and amplitude tuning of superconducting cavity, longitudinal and transverse beam matching, but also will be very helpful to linac design with practical beam diagnostics system and authentic accelerator lattice.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC006

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MOPRC008

Dispersion Free and Dispersion Target Steering Experience at CTF3

linac, optics, target, dipole

83

D. Gamba, R. Corsini, T. Persson, P.K. Skowroński, F. Tecker
CERN, Geneva, Switzerland
P. Burrows
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
P. Burrows
JAI, Oxford, United Kingdom

One of the goals of the CLIC Test Facility (CTF3) at CERN is to demonstrate the feasibility of the CLIC Drive Beam recombination, which takes place in the Drive Beam Recombination Complex (DBRC). The tight geometry of the DBRC together with its strong optics and the high energy-spread of the beam require a careful control of the beam size along the different sections of the DBRC. One of the main contribution to beam size is the dispersion. If uncontrolled, dispersion leads to fast increase of the beam size, hence it may affect the beam current stability of the combined beam. A tool has been implemented at CTF3 to measure and correct dispersion during and after the setup of the machine. Dispersion Free Steering (DFS) has been applied in the upstream drive beam LINAC, while Dispersion Target Steering (DTS) has been used in the rings of the DBRC. In the LINAC the weak optics and the wide dynamic aperture of the beamline allow a straightforward correction. In the DBRC the aperture is tighter, and the strong optics produce non-linear dispersion which one needs to take into account. A general overview of current status and future plans in controlling dispersion at CTF3 will be presented.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC008

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MOPRC009

Simulating Apertures in the Uniform Equivalent Beam Model

simulation, optics, space-charge, software

87

G.H. Gillespie
G.H. Gillespie Associates, Inc., Del Mar, California, USA

The uniform equivalent beam model is useful for simulating particle beam envelopes. Beam root-mean-square (rms) sizes, divergences, and emittances of an equivalent uniform beam approximate well the rms properties of more realistic beam distributions, even in the presence of space charge. Envelope simulation codes for high current beams using the model, such as TRACE 3-D, are central to particle optics design. However, the modeling of apertures has required multi-particle simulation codes. Multi-particle codes do not typically have the fitting and optimization capabilities common to envelope codes, so the evaluation of aperture effects is often a secondary study that may result in further design iteration. To incorporate aperture effects into the optics design at the start, a method has been developed for simulating apertures in the context of a uniform equivalent beam. The method is described and its TRACE 3-D implementation is outlined. Comparisons with multi-particle simulations are used to validate the method and examine regions of applicability.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC009

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MOPRC013

Tracking Based Courant-Snyder Parameter Matching in a Linac with a Strong Space-Charge Force

linac, DTL, space-charge, emittance

93

R. Miyamoto
ESS, Lund, Sweden

During the design of a hadron linac, matching at the interfaces of different structures or lattice periods is often performed with the linear approximation of the space-charge force. When space-charge is extremely strong, like in the low energy part of the proton linac of the European Spallation Source, such a matching method is not always good enough and could lead to a residual mismatch at the design level. To avoid this, a matching scheme based on iterations of tracking, thus including the full effect of the space-charge force, is developed. This paper presents the scheme itself as well as its application to the ESS linac.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-LINAC2016-MOPRC013

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MOPRC015

Development Status of FRIB On-line Model Based Beam Commissioning Application

cavity, solenoid, lattice, linac

100

Z.Q. He, M.A. Davidsaver, K. Fukushima, D.G. Maxwell, G. Shen, Y. Zhang, Q. Zhao
FRIB, East Lansing, USA

Funding: The work is supported by the U.S. National Science Foundation under Grant No. PHY-11-02511, and the U.S. Department of Energy Office of Science under Cooperative Agreement DE-SC0000661.
The new software FLAME has been developed to serve as physics model used for on-line beam commissioning applications. FLAME is specially designed to cover FRIB modeling challenges to balance between speed and precision. Several on-line beam commissioning applications have been prototyped based on FLAME and tested on the physics application prototyping environment. In this paper, components of the physics application prototyping environment are firstly described. Then, the design strategy and result of the four major applications: baseline generator, cavity tuning, orbit correction, transverse matching, are discussed.

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MOPRC018

Improved Beam Dynamics and Cavity RF Design for the FAIR Proton Injector

cavity, linac, proton, DTL

111

R. Tiede, A. Almomani, M. Busch, F.D. Dziuba, U. Ratzinger
IAP, Frankfurt am Main, Germany

The FAIR facility at GSI requires a dedicated 70 MeV, 70 mA proton injector for the research program with intense antiproton beams. The main accelerator part consists of six 'Crossbar H-type' (CH) cavities operated at 325 MHz. Based on a linac layout carefully developed over several years, recently the beam dynamics has been revised with the scope of finalising the design and thus being able to start the construction of the main linac components. As compared to previous designs the MEBT behind the RFQ was slightly extended, the gap numbers per CH cavity and the voltage distributions were optimised and the layout of the intermediate diagnostics section including a rebuncher cavity at 33 MeV was redesigned. Finally, detailed machine error studies were performed in order to check the error response of the new design and the steering concept in particular. In the consequence, the final parameters obtained from the beam dynamics update are used for finalizing the CH-DTL cavity design by CST-MWS calculations.

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MOPLR004

Development of an High Gradient, S-band, Accelerating Structure for the FERMI Linac

linac, operation, electron, wakefield

136

C. Serpico, I. Cudin
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
A. Grudiev
CERN, Geneva, Switzerland

The FERMI seeded free-electron laser (FEL), located at the Elettra laboratory in Trieste, is driven by a 200 meter long, S-band linac routinely operated at nearly 1.5 GeV and 10 Hz repetition rate [1]. The high energy part of the Linac is equipped with seven, 6 meter long Backward Traveling Wave (BTW) structures: those structures have small iris radius and a nose cone geometry which allows for high gradient operation [2]. Nonetheless a possible development of high-gradient, S-band accelerating struc-tures for the replacement of the actual BTW structures is under consideration. This paper investigates a possible solution for RF couplers that could be suitable for linac driven FEL where reduced wakefields effects, high oper-ating gradient and very high reliability are required.

Poster MOPLR004 [0.947 MB]

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MOPLR008

Status Of the ILC Main Linac Design

linac, lattice, cryomodule, emittance

149

A. Saini, V.V. Kapin, N. Solyak
Fermilab, Batavia, Illinois, USA

International Linear collider (ILC) is a proposed accelerator facility which is primarily based on two 11-km long superconducting main linacs. In this paper we present recent updates on the main linac design and discuss changes made in order to meet specification outlined in the technical design report (TDR).

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TUOP11

Methods for Bunch Shape Monitor Phase Resolution Improvement

electron, linac, focusing, space-charge

408

A. Feschenko, S.A. Gavrilov
RAS/INR, Moscow, Russia

Bunch shape monitors, based on secondary electrons emission, are widely used for measurements of longitudinal bunch profiles during a linac commissioning and initial optimization of beam dynamics. A typical phase resolution of these devices is about 1°. However it becomes insufficient for new modern linacs, which require a better resolution. Some developed methods for a phase resolution improvement are discussed.

Slides TUOP11 [21.248 MB]

Poster TUOP11 [1.888 MB]

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TUPLR020

Commissioning of the Compact 14MeV LINAC for an FEL-Based THz Source

linac, target, gun, radiation

509

Y.J. Pei, G. Feng, X.Y. He, Y. Hong, G. Huang, D. Jia, K. Jin, J. Liu, P. Lu, L. Shang, B.G. Sun, Zh. X. Tang, W. Wei, Z. Zhao
USTC/NSRL, Hefei, Anhui, People's Republic of China
L. Cao, Q.S. Chen, S. Hu, T. Hu, J. Li, Y.J. Liang, B. Qin, B. Tang, T. Tang, Y.Q. Xiong, Q. Zhang
HUST, Wuhan, People's Republic of China
W. Chen, Y.B. Wang, J. Zha
Huazhong University of Science and Technology, State Key Laboratory of Advanced Electromagnetic Engineering and Technology,, Hubei, People's Republic of China
G. Feng
DESY, Hamburg, Germany
Zh. X. Tang
DICP, Dalian, People's Republic of China

Commissioning the compact LINAC of 14Mev for a THz source based on FEL Y.J.Pei National Synchrotron Radiation laboratory, University of Science & Technology of China Abstract The compact LINAC of 14MeV is designed for a FEL which will produce a THz radiation through 30μm to 300μm. The LINAC was composed of a novel EC-ITC-RF gun, constant gradient travelling wave accelerator with a collinear absorbing load, focusing system, RF power system, beam diagnostic system, vacuum system, control system and so on. The LINAC was installed on November of 2014. Last year, we finished the install of the undulator and the optical resonance cavities. Now the LINAC has been testing and commissioning for THz radiation test. So far, the running beam parameters of the LINAC are as the following: Energy is of 13.58MeV macro pulse current is of 655mA macro pulse length of 1.2μsμpulse beam current is of 59A beam length of theμpulse is of 4ps energy spread of 0.33% normal beam emmitance is of 24.1mm.mrad.

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TUPLR054

RFQ Vane Shapes for Efficient Acceleration

acceleration, rfq, multipole, focusing

581

Y. Iwashita, Y. Fuwa
Kyoto ICR, Uji, Kyoto, Japan
R.A. Jameson
IAP, Frankfurt am Main, Germany

RFQ vane shapes for efficient acceleration are under investigation by introducing more terms in addition to the two term potential. They can incorporate with the feature of the trapezoidal shape modulation with less multipole components, while higher acceleration efficiency is expected. The simulation study will be presented.

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TUPLR059

Asymmetric Four-Vane RFQ

dipole, impedance, rfq, simulation

592

A.S. Plastun
ANL, Argonne, Illinois, USA
A. Kolomiets, D.A. Liakin
ITEP, Moscow, Russia

Funding: This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.
A four-vane resonator is widely used in Radio Frequency Quadrupole (RFQ) accelerators. The field distribution in a long four-vane resonator can be easily perturbed by nearest dipole modes which are excited due to the local geometry errors. This paper describes the electromagnetic properties of a four-vane resonator with an introduced asymmetry between neighboring chambers. The asymmetry provides necessary separation of dipole modes keeping losses and field uniformity of quadrupole mode similar to those in a conventional four-vane resonator. This feature of an asymmetric resonator is confirmed by analytical results from transmission line model as well as by CST Studio simulations.

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TH2A03

Complete Transverse 4D Beam Characterization for Ions Beams at Energies of Few MeV/u

emittance, coupling, ion, vacuum

720

M.T. Maier, X. Du, P. Gerhard, L. Groening, S. Mickat, H. Vormann
GSI, Darmstadt, Germany

Measurement of the ion beam rms-emittances is done through determination of the second order beam moments. For time being the moments quantifying the amount of inter-plane coupling, as <xy'> for instance, have been accessible to measurements just for very special cases of ions at energies below 200 keV/u using pepperpots. This talk presents successful measurements of all inter-plane coupling moments at 1 to 11 MeV/u. From first principles the used methods are applicable at all ion energies. The first campaign applied skewed quadrupoles in combination with a regular slit/grid emittance measurement device. The second campaign used a rotatable slit/grid device in combination with regular quadrupoles.

Slides TH2A03 [17.343 MB]

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THOP09

Tuning of the CERN 750 MHz RFQ for Medical Applications

rfq, linac, operation, target

763

B. Koubek, Y. Cuvet, A. Grudiev, C. Rossi, M.A. Timmins
CERN, Geneva, Switzerland

CERN has built a compact 750 MHz RFQ as an injector for a hadron therapy linac. This RFQ was designed to accelerate protons to an energy of 5 MeV within only 2 m length. It is divided into four segments and equipped with 32 tuners in total. The RFQ length corresponds to 5λ which is considered to be close to the limit for simple field adjustment using tuners. Nevertheless the high frequency results in a sensitive structure and requires careful tuning by means of the alignment of the pumping ports and fixed tuners. This paper gives an overview of the tuning procedure and bead pull measurements of the RFQ.

Slides THOP09 [16.367 MB]

Poster THOP09 [23.832 MB]

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THPRC031

Manufacturing of MEBT Combined Quadrupole & Steerer Magnets for the Linear IFMIF Prototype Accelerator LIPAC

radiation, factory, beam-transport, vacuum

840

J. Castellanos, B. Brañas, J. Mollá, C. Oliver, I. Podadera, F. Toral
CIEMAT, Madrid, Spain
R. Iturbe, B. López
ANTEC Magnets SLU, Vizcaya, Spain
O. Nomen
IREC, Sant Adria del Besos, Spain

Funding: This work has been funded by the Spanish Ministry of Economy and Competitiveness under the Agreement as published in BOE, 16/01/2013, page 1988.
The Medium Energy Beam Transport line (MEBT) that is being installed on the LIPAC accelerator* will have five quadrupole and steerer magnets which have been recently manufactured and tested. The design of the magnets was done by CIEMAT** and considers a magnetic yoke made of four solid iron quadrants joined together. The yoke integrates four water-cooled coils (quadrupole) and eight air-cooled coils (steerers) made of copper wires. The manufacturing and testing (excluded magnetic measurements) of the five magnets were carried out by the Spanish company ANTECSA. This paper focuses on the technical aspects considered during the manufacturing and the assembly of the different components of the magnets. The details about the geometrical, electrical and hydraulic measurements and tests that were carried out before the magnetic measurements are also described.
* A. Mosnier et al., IPAC10, MOPEC056, p.588, Kyoto, Japan (2010)
** C. Oliver et al., IPAC11, WEPO014, p. 2424, San Sebastián, Spain (2011)

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THPLR015

Fifth-Order Moment Correction for Beam Position and Second-Order Moment Measurement

linac, simulation, experiment, factory

876

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

For precise beam position measurement using a beam position monitor (BPM), a recursive correction which is expressed by the higher-order polynomials of beam positions are usually adopted. We recognized that the higher-order polynomials came from the higher-order moments and that beam position measurement is consequently influenced by a transverse beam shape. To investigate what order was required for adequate correction, we performed a successive iteration for the six-electrode BPM holding an inner radius of 16mm (circular cross-section). The successive iteration is a method to obtain a self-consistent solution for the higher-order correction. An amplitude of static electric field due to a beam charge was calculated by two-dimensional mirror charge method. As a result of the successive iteration, the convergence region was large enough for ordinary measurements (from lower than -5mm to higher than 5mm horizontally and vertically). In the convergence region the root mean square of the differences between the set and calculated vertical position were obtained as 0.487mm (without correction), 0.030mm (with third-order correction) and 0.003mm (with fifth-order correction).

Poster THPLR015 [6.049 MB]

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THPLR032

Update on SSR2 Cavity EM Design for PIP-II

cavity, linac, simulation, acceleration

920

P. Berrutti, T.N. Khabiboulline, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

Proton Improvement Plan II (PIP-II) is the future plan for upgrading the Fermilab proton accelerator complex to a beam power capability of at least 1 MW delivered to the neutrino production target. A room temperature section accelerates H⁻ ions to 2.1 MeV and creates the desired bunch structure for injection into the superconducting (SC) linac. SC linac using five cavity types. One 162.5 MHz half wave resonator, two 325 MHz spoke resonators and two 650 MHz elliptical 5-cell cavities, provide acceleration to 800 MeV. The EM design of the second family of spoke resonator is presented in this paper. The work reported is a thorough electromagnetic study including: the RF parameters, multipacting mitigation and transverse field asymmetry. The cavity is now ready for structural design analysis.

Poster THPLR032 [1.947 MB]

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