IPAC2017 - List of Keywords (photon)

Paper	Title	Other Keywords	Page
MOOCB3	Intensity Interferometer to Measure Bunch Length at SPEAR3	detector, optics, electron, storage-ring	60
	W.J. Corbett SLAC, Menlo Park, California, USA T.M. Mitsuhashi KEK, Ibaraki, Japan
	Electron bunch length in a storage ring is typically measured with streak cameras, electro-optic devices or non-linear cross-correlation techniques with a range of system complexity, signal-to-noise ratios and cost. Another straight-forward method is to construct an 'intensity interferometer' utilizing a coincidence detector to record simultaneous photon arrival events. In this configuration, visible SR light is passed through a narrow bandpass filter followed by a small pinhole to generate a stream of single-mode monochromatic wavepackets. As the interferometer delay is scanned across an electron bunch, two-photon events occurring within the longitudinal coherence time of the light cause a reduction in the measured coincidence rate. The resulting autocorrelation of the optical pulse duration reveals the electron bunch length, independent of synchrotron oscillation motion. In this paper we comment on the theory and report on preliminary measurements carried out at SPEAR3.
	Slides MOOCB3 [2.606 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOOCB3
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MOPAB011	Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators	proton, neutron, optics, interface	96
	A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner CERN, Geneva, Switzerland
	Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.
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MOPAB057	Analysis and Correction of Geometrical Non-Linearities of ELI-NP BPMs on Position and Current Measurements	linac, electron, laser, instrumentation	235
	G. Franzini, F. Cioeta, O. Coiro, V.L. Lollo, D. Pellegrini, S. Pioli, A. Stella, A. Variola INFN/LNF, Frascati (Roma), Italy M. Marongiu INFN-Roma, Roma, Italy A. Mostacci University of Rome La Sapienza, Rome, Italy A.A. Nosych ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain L. Sabato U. Sannio, Benevento, Italy
	The advanced source of Gamma-ray photons will be soon built near Bucharest (Romania) by an European consortium (EurogammaS) led by INFN, as part of the ELI-NP (Extreme Light Infrastructure-Nuclear Physics). It will generate photons by Compton back-scattering in the collision between a multi-bunch electron beam, at a maximum energy of 720 MeV, and a high intensity recirculated laser pulse. An S-Band photo-injector and the following C-band Linac, which are under construction, will operate at 100Hz repetition rate with macro pulses of 32 electron bunches, separated by 16ns and with 250pC nominal charge. Stripline and cavity BPMs will be installed along the linac, in order to measure both the position and charge of the electron beam. Stripline BPM response can be considered linear within a limited area around the BPM origin. In order to use the full BPM acceptance area, without accuracy losses due to non-linearities, we plan to use correction algorithms, developed on the basis of simulations and measurements of BPMs response. In particular, suitable high-order surface polynomials will be used.
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MOPAB065	Breit-Wheeler Scattering Events Produced by Two Interacting Compton Sources	scattering, electron, laser, background	261
	I. Drebot, L. Serafini Istituto Nazionale di Fisica Nucleare, Milano, Italy D. Micieli, E. Tassi UNICAL, Arcavacata di Rende, Italy E. Milotti INFN-Trieste, Trieste, Italy V. Petrillo Universita' degli Studi di Milano & INFN, Milano, Italy
	We present the dimensioning of a photon-photon collider based on conventional Compton gamma sources for the observation of Breit-Wheeler pair production and QED gamma-gamma generation. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two primary gamma rays through Compton back-scattering with two high-energy lasers. Tuning the system energy above the Breit-Wheeler cross section threshold, a flux of secondary electrons and positrons is generated. The process is analyzed by start-to-end simulations. The Monte Carlo code 'Rate Of Scattering Events' (ROSE) has been developed ad hoc for the counting of the QED events. Realistic numbers of the secondary particles yield, referring to existing or approved set-ups, a discussion of the feasibility of the experiment and the evaluation of the background are presented.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-MOPAB065
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MOPAB066	Development and Performance Test of the BPM System for the SPring-8 Upgrade	radiation, simulation, storage-ring, electron	265
	H. Maesaka RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan H. Dewa, T. Fujita, M. Masaki JASRI, Hyogo, Japan S. Takano Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan
	We are developing a stable and precise BPM system for the low-emittance upgrade of SPring-8. One of the essential requirements for the BPM is the long term stabilization of the photon beam by regulating the electron beam orbit. Both the single-pass resolution of 100 um rms for an injected beam charge of 100 pC and an accuracy of 100 um rms are also crucial for beam commissioning. Drift sources of the present BPM system have been investigated extensively, such as humidity-dependent drifts coming from the radiation damage of coaxial cables, and the results are fed back to the design of the new BPM system. We have optimized the design of the button BPM electrodes to reconcile reduction of trapped-mode heating and maximization of the signal intensity. Stringent machining tolerance is imposed on a BPM head to align the BPM electric center accurately. A few kinds of the BPM head prototypes were produced and the machining accuracy, RF characteristics etc. were confirmed to be sufficient. We have installed one of the prototypes in the present storage ring to test the performance of the new BPM system under development, and have been obtaining successful results satisfying the requirements.
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MOPAB118	Cherenkov Diffraction Radiation From Long Dielectric Material: An Intense Source of Photons in the NIR-THz Range	radiation, electron, target, storage-ring	400
	T. Lefèvre, M. Bergamaschi, O.R. Jones, R. Kieffer, S. Mazzoni CERN, Geneva, Switzerland M.G. Billing, J.V. Conway, J.P. Shanks Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA L.M. Bobb DLS, Oxfordshire, United Kingdom P. Karataev Royal Holloway, University of London, Surrey, United Kingdom
	This paper presents the design on the Cornell Electron Storage Ring (CESR) of an experimental set-up to meas-ure incoherent Diffraction Cherenkov Radiation (DChR) produced in a 2 cm long SiO2 radiator by a 2.1 GeV elec-tron beam. The electron beam is circulating at a distance of few mm from the edge of the radiator and the DChR photon output power is expected to be significantly higher than the diffraction radiation power emitted from a metal-lic slit of similar aperture. The radiator design and the detection set-up are presented in detail together with sim-ulations describing the expected properties of the emitted DChR in terms of light intensity and spectral bandwidth. Finally, potential applications of DChR are discussed.
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MOPAB125	Post-Mortem System for the Taiwan Photon Source	kicker, timing, operation, data-acquisition	422
	C.Y. Liao, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Huang, C.Y. Wu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source (TPS), a 3-GeV third-generation synchrotron light source located in Hsinchu, is available to users since 2016. During operation, it will inevitably encounter system trips caused by beam losses. Thus, a post-mortem (PM) system is an important tool to analyze the cause of such events. Main functions of the PM system are: (i) PM trigger will be generated when the stored beam is suddenly lost abnormally; (ii) storage of relevant signals when the server receives such a trigger; (iii) PM Viewer to analyze each event and understand the cause and effect of a beam trip event. The post-mortem system architecture, plans and implementation will be discussed in this report.
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MOPAB139	A Supersonic Gas-Jet Based Beam Induced Fluorescence Prototype Monitor for Transverse Profile Determination	electron, ion, experiment, gun	458
	H.D. Zhang, E. Martin, V. Tzoganis, C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom E. Barrios Diaz, N. Chritin, O.R. Jones, G. Schneider, R. Veness CERN, Geneva, Switzerland P. Forck, S. Udrea GSI, Darmstadt, Germany P. Forck IAP, Frankfurt am Main, Germany E. Martin, V. Tzoganis, C.P. Welsch, H.D. Zhang The University of Liverpool, Liverpool, United Kingdom S. Udrea TU Darmstadt, Darmstadt, Germany
	Supersonic gas jets have been used in transverse beam profile monitoring as Ionization Profile Monitors (IPMs) and Beam Induced Fluorescence (BIF) monitors. The former method images ions generated by the projectile beam, whilst the latter is based on the detection of photons. This is a promising technology for use in high energy accelerators, such as the High Luminosity Large Hadron Collider (HLLHC). In this paper, the suitability of a supersonic gas jet in combination with a BIF detection system for the measurement of the transverse beam profile of a low energy electron beam is discussed. The technical layout and experimental results from measurements at a test installation at the Cockcroft Institute are also presented.
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MOPAB146	Electron Beam Diagnosis Using K-edge Absorption of Laser-Compton Photons	electron, laser, emittance, scattering	473
	Y. Hwang, T. Tajima UCI, Irvine, California, USA C.P.J. Barty, D.J. Gibson, R.A. Marsh LLNL, Livermore, California, USA
	Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. The mean energy, energy spread and divergence of the electron beam can be deduced from laser-Compton scattered X-rays filtered by a material whose K-edge is near the energy of the X-rays. This technique, combined with a spot size measurement of the beam, can be used to measure the emittance of electron bunches, and can be especially useful in LWFA experiments where conventional methods are unavailable. The effects of the electron beam parameters on X-ray absorption images are discussed, along with experimental demonstrations of the technique using the Compact Laser-Compton X-ray Source at LLNL.
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MOPIK026	Commissioning and Operation of an Ultrafast Electron Diffraction Facility as Part of the ATF-II Upgrade at Brookhaven National Laboratory	electron, operation, laser, experiment	554
	M.G. Fedurin, M. Babzien, C. Folz, M. Fulkerson, K. Kusche, J.J. Li, R. Malone, M.A. Palmer, T.V. Shaftan, J. Skaritka, L. Snydstrup, C. Swinson, F.J. Willeke BNL, Upton, Long Island, New York, USA
	Funding: Work supported by the US DOE under contract DE-SC0012704. The Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) is presently carrying out an upgrade, ATF-II, which will provide significantly expanded experimental space and capabilities for its users. One of the new capabilities being integrated into the ATF-II program is an Ultrafast Electron Diffraction (UED) beam line, which was originally deployed in the BNL Source Development Laboratory. Inclusion of the UED in the ATF-II research portfolio will enable ongoing development and extension of the UED capabilities for use in materials research. We describe the design, operation and future plans for the UED beam line at the ATF-II.
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MOPVA001	Coherent X-Ray Radiation From Electron Beam Processed by Channeling and Emittance Exchange	electron, radiation, laser, emittance	845
	I. Lobach, A.I. Benediktovitch BSU, Minsk, Belarus
	Presented contribution theoretically studies a novel scheme of compact intense x-ray radiation source. In the scheme, longitudinally modulated electron beam emits x-rays by Inverse Compton Scattering (ICS). The setup's feature is the way how longitudinal density modulation in angstrom scale is created. There are three stages of processing of initial beam of relativistic electrons: 1. First, the electrons cross a crystal plate in channeling regime. It is shown that upon leaving the crystal, the electron beam acquires discernible transverse modulation in angstrom scale. It is taken into account that not all electrons are captured in channeling mode and that some of those that do may leave it as they travel through the crystal slab. 2. Further, the beam is transported to Emittance Exchange (EEX) line, in which the direction of modulation is tilted and the beam becomes longitudinally modulated. The scale of modulation remains the same. 3. Finally, intense quasi-coherent x-ray radiation is emitted by ICS. Numerical estimations show that coherent contribution to intensity is considerable for feasible parameters of used beam, components of EEX line and laser producing photons for ICS.
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MOPVA004	Operating Simultaneously Two In-Vacuum Canted Undulators in Synchrotron SOLEIL	undulator, vacuum, radiation, electron	851
	L.S. Nadolski, Y.-M. Abiven, P. Brunelle, N. Béchu, M.-E. Couprie, F.J. Cullinan, X. Delétoille, M. El Ajjouri, C. Herbeaux, N. Hubert, N. Jobert, M. Labat, J.-F. Lamarre, A. Lestrade, A. Loulergue, O. Marcouillé, P. Monteiro, A. Nadji, R. Nagaoka, D. Pédeau, P. Rommeluère, K.T. Tavakoli, M. Valléau, J. Vétéran SOLEIL, Gif-sur-Yvette, France C. Benabderrahmane ESRF, Grenoble, France
	Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with a minimum gap of 5.5 mm. The canted radiation sources are installed in a long straight section of the storage ring. The first closure of both undulators led to the severe damage of the downstream undulator in 2011. The reason for this incident has been investigated and clearly identified. A long-term project has enabled us to find a technical solution for a simultaneous operation of both undulators. A special angle fast interlock was designed and a dedicated photon absorber has been introduced at the entrance of the second undulator while keeping the impact on the beam performance as low as possible. The main technical steps will be reported with an interim solution put in place in spring 2015 and a final solution deployed and validated in May 2016.
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MOPVA023	Luminosity Increase in Laser-Compton Scattering by Crab Crossing Method	laser, electron, luminosity, scattering	902
	Y. Koshiba, D. Igarashi, S. Ota, T. Takahashi, M. Washio RISE, Tokyo, Japan K. Sakaue Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan J. Urakawa KEK, Ibaraki, Japan
	In collider experiments such as KEKB, crab crossing method is a promising way to increase the luminosity. We are planning to apply crab crossing to laser-Compton scattering, which is a collision of electron beam and laser, to gain a higher luminosity leading to a higher flux X-ray source. It is well known that the collision angle between electron beam and laser affects the luminosity. It is the best when the collision angle is zero, head-on collision, to get a higher luminosity but difficult to construct such system especially when using an optical cavity for laser. Concerning this difficulty, we are planning crab crossing by tilting the electron beam using an rf-deflector. Although crab crossing in laser-Compton scattering has been already proposed, nowhere has demonstrated yet. We are going to demonstrate and conduct experimental study at our compact accelerator system in Waseda University. In this conference, we will report about our compact accelerator system, laser system for laser-Compton scattering, and expected results of crab crossing laser-Compton scattering. Variola Alessandro, et al. Luminosity optimization schemes in Compton experiments based on Fabry-Perot optical resonators. Physical Review Special Topics-Accelerators and Beams 14.3 (2011): 031001.
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MOPVA026	Effects of Insertion Devices on Stored Electron Beam of High Energy Photon Source	undulator, emittance, insertion, brilliance	911
	X.Y. Li, Z. Duan, D. Ji, Y. Jiao, Y.F. Yang IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a 4th generation, 6-Gev, ultralow-emittance, photon source project in China. High brightness hard X-ray beams at the energy particularly above 10kev are provided by insertion devices installed in straight sections of the storage ring. Brightness tuning curves of 14 ID beamlines planned in HEPS first stage are obtained after designing their parameters. However the presence of these insertion devices produce several effects on the beam performances including betatron tunes, betatron amplitude functions, closed orbit, emittance and dynamic aperture etc. It is found that the vertical octupole effect due to the fourteen IDs under the present schemes produce the most significant effect on the vertical dynamic aperture reduction. The ID field error effects on close orbit can be completely compensated by two correctors adjacent the ID at the both side. The horizontal emittance reduces to 36pm.rad due to the damping wiggler effect of IDs with field error after the orbit correction is also obtained.
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MOPVA071	Press Forming Tests of Superconducting Spoke Cavity for Laser Compton Scattered Photon Sources	cavity, laser, niobium, resonance	1031
	M. Sawamura, R. Hajima QST, Tokai, Japan H. Hokonohara, Y. Iwashita, H. Tongu Kyoto ICR, Uji, Kyoto, Japan T. Kubo, T. Saeki KEK, Ibaraki, Japan
	We are developing the superconducting spoke cavity for laser Compton scattered (LCS) photon sources. We adopt the superconducting spoke cavity for electron beam drivers to realize a wide use of LCS X-ray and '-ray sources in academic and industrial applications. The spoke cavity can make the accelerator more compact than an elliptical cavity because the cavity size is small at the same frequency and the packing factor is good by installing couplers on outer conductor. Though our proposal design for the photon source consists of the 325 MHz spoke cavities in 4K operation, we are fabricating the half scale model of 650 MHz spoke cavity in order to accumulate our cavity production experience by effective utilization of our limited resources. Since the spoke has more complicated structure than an elliptical cavity, we performed press forming tests for the half spoke and estimated the formed shapes with 3-dimensional measurement.
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MOPVA076	Measurement of Thin Film Coating on Superconductors	cryogenics, controls, experiment, FPGA	1043
	Y. Iwashita, Y. Fuwa, H. Tongu Kyoto ICR, Uji, Kyoto, Japan H. Hayano, T. Kubo, T. Saeki KEK, Ibaraki, Japan M. Hino Kyoto University, Research Reactor Institute, Osaka, Japan H. Oikawa Utsunomiya University, Utsunomiya, Japan
	Funding: This research is supported by following programs: Grant-in-Aid for Exploratory Research JSPS KAKENHI Grant Number 26600142 and Photon and Quantum Basic Research Coordinated Development Program from the MEXT. Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.
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TUOAA2	A Soft X-Ray Free-Electron Laser Beamline of SACLA	FEL, electron, undulator, laser	1209
	K. Togawa, T. Asaka, N. Azumi, T. Hara, T. Hasegawa, N. Hosoda, T. Inagaki, T. Ishikawa, R. Kinjo, C. Kondo, H. Maesaka, S. Matsui, T. Ohshima, Y. Otake, S. Owada, H. Tanaka, T. Tanaka, M. Yabashi RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan T. Bizen, H. Kimura, S. Matsubara, K. Nakajima, T. Sakurai, T. Togashi, K. Tono JASRI/SPring-8, Hyogo, Japan T. Fukui RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
	At the Japanese x-ray free-electron laser (FEL) facility, SACLA, the beamline-1 has been upgraded from a spontaneous radiation to a soft x-ray FEL beamline, which generates FEL lights over a wide wavelength range from the extreme-ultraviolet to the soft x-ray regions. We started operation for users in July 2016. A dedicated accelerator, which is a refinement of the SCSS test accelerator operated in 2005-2013, was installed beside the XFEL beamlines in the SACLA undulator hall. The SCSS concept to make an FEL facility compact was continuously adopted. In the 2016 summer shutdown period, the beam energy was upgraded from 500 MeV to 800 MeV by adding two C-band rf units. The maximum K-value of the undulator magnet is 2.1. The available wavelengths of the FEL lights were extended to the range from 8 to 50 nm with pulse energies between a few to few tensμJ at an operational repetition rate of 60 Hz. In this conference, we will report an overview of the upgraded SACLA-beamline-1 and characteristics of the FEL light pulse.
	Slides TUOAA2 [15.457 MB]
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TUOAA3	Progress of Pr2Fe14B Based Hybrid Cryogenic Undulators at SOLEIL	undulator, cryogenics, radiation, electron	1213
	A.M. Ghaith, P. Berteaud, F. Blache, F. Briquez, N. Béchu, M.-E. Couprie, J. Da Silva Castro, J.M. Dubuisson, C. Herbeaux, C.A. Kitegi, A. Lestrade, O. Marcouillé, F. Marteau, M. Sebdaoui, G. Sharma, A. Somogyi, K.T. Tavakoli, M. Tilmont, M. Valléau SOLEIL, Gif-sur-Yvette, France C. Benabderrahmane ESRF, Grenoble, France
	Cryogenic Permanent Magnet Undulators (CPMUs) take advantage of the enhanced field performance of permanent magnets when cooled down to low temperature, enabling shorter period with sufficient magnetic field to achieve high brightness radiation in the X-ray domain. Several CPMUs have been manufactured at SOLEIL. The first CPMU of period 18 mm (U18), optimized with a phase error of 3.2° at temperature of 77 K, has been installed and operated for the past 5 years at SOLEIL for the NANOSCOPIUM beamline. We report on photon beam based alignment enabling for a better adjustment of the vertical position offset of the undulator with a precision of 50 μm, and on the correction of the taper with a precision of 5 μrad to enhance the radiation flux. A second U18 cryo-ready undulator, with a new mechanical and magnetic sorting of module shimming, has attained a phase error of 2.3° at CT without any further adjustments after the assembly. Currently, two more CPMUs are being built; a 2 m long U18 for the SOLEIL ANATOMIX beamline, and a 3 m long U15 undulator reaching a magnetic gap of 3 mm. The new challenges encountered with magnetic measurements and mechanical designs for U15 are presented.
	Slides TUOAA3 [3.491 MB]
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TUXB1	Non-destructive Beam Profile Monitors	ion, electron, vacuum, focusing	1234
	C.P. Welsch The University of Liverpool, Liverpool, United Kingdom C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	This paper will present an overview and comparison between beam induced fluorescence, residual gas ionization and gas jet based beam profile monitors, based on recent experimental and theoretical results at different labs. The achievable image/profile quality and resolution limits will be discussed, along with design consideration for different particle species and primary beam energies. Details may be provided about different classic and novel approaches to gas jet shaping, including nozzle-skimmer and Freznel Zone Plate configurations. Finally, particular challenges such as those arising from monitoring multiple beams in parallel (e.g. proton and electron beam in HLLHC) and solutions for targeting the energy limit within the HLLHC project will be presented.
	Slides TUXB1 [12.557 MB]
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TUOAB2	First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph	background, simulation, synchrotron, radiation	1244
	T.M. Mitsuhashi KEK, Ibaraki, Japan E. Bravin, F. Roncarolo, G. Trad CERN, Geneva, Switzerland
	A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.
	Slides TUOAB2 [8.302 MB]
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TUPAB002	Material Tests for the ILC Positron Source	target, positron, electron, operation	1293
	A. Ushakov, G.A. Moortgat-Pick University of Hamburg, Hamburg, Germany K. Aulenbacher, Th. Beiser, P. Heil, V. Tioukine IKP, Mainz, Germany A. Ignatenko, S. Riemann DESY Zeuthen, Zeuthen, Germany A.L. Prudnikava, Y. Tamashevich University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
	The positron source is a vital system of the ILC. The conversion target that yields 10¹⁴ positrons per second will undergo high peak and cyclic load during ILC operation. In order to ensure stable long term operation of the positron source the candidate material for the conversion target has to be tested. The intense electron beam at the Mainz Microtron (MAMI) provides a good opportunity for such tests. The first results for Ti6Al4V are presented which is the candidate material for the positron conversion target as well as for the exit window to the photon beam absorber.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB002
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TUPAB003	High Energy Density Irradiation With MAMI LINAC	target, positron, electron, radiation	1296
	P. Heil, K. Aulenbacher, Th. Beiser IKP, Mainz, Germany A. Ignatenko, G.A. Moortgat-Pick, A. Ushakov DESY, Hamburg, Germany S. Riemann DESY Zeuthen, Zeuthen, Germany
	In order to build a positron source for the ILC, a high energy density irradiation is needed to test the used materials. At the MAMI linear accelerator such a radiation can be provided at different electron energies. With a macro pulsed source it is possible to imitate a yearlong radiation at the ILC within several hours. Small transversal beam sizes need to be provided with the focusing system and be measured at high beam currents using transition radiation and current measurements.
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TUPAB025	Experimental Results for Multiphoton Nonlinear Photoemission Processes on Phil Test Line	laser, electron, gun, cathode	1369
	H. Purwar, C. Bruni, V. Chaumat, N. ElKamchi, V. Soskov LAL, Orsay, France D. Garzella CEA, Gif-sur-Yvette, France B. Lucas CNRS LPGP Univ Paris Sud, Orsay, France M. Pittman CLUPS, Orsay, France T. Vinatier DESY, Hamburg, Germany
	One of the prerequisites for the next generation high luminosity light sources is the availability of the short electron bunches. It also has several applications in other domains, including medical diagnostics and high-resolution imaging. In principle, using photoelectric effect a short electron bunch can initially be generated by illuminating a photocathode with an ultra-short light pulse of appropriate wavelength. Strong EM fields from a RF gun or similar accelerating structures, synchronized with the incoming laser pulses, are then used to accelerate these electron bunches initially up to an energy of tens of MeV. We present our preliminary results on the experimental investigation of two-photon nonlinear photoemission processes for the generation of picosecond, low-charge electron bunches conducted at PHIL photoinjector facility. A comparison of the emission efficiency and bunch characteristics with the single photon emission process is also made. *PHIL is an acronym for Photo-injector at Linear Accelerator Laboratory (LAL).
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB025
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TUPAB035	Field Quality of 1.5 m Long Conduction Cooled Superconducting Undulator Coils with 20 mm Period Length	undulator, multipole, synchrotron, emittance	1395
	S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui KIT, Eggenstein-Leopoldshafen, Germany C. Boffo, T.A. Gerhard, M. Turenne, W. Walter Babcock Noell GmbH, Wuerzburg, Germany
	The Institute for Beam Physics and Technology (IBPT) at the Karlsruhe Institute of Technology (KIT) and the industrial partner Babcock Noell GmbH (BNG) are col-laborating since 2007 on the development of superconducting undulators both for ANKA and low emittance light sources. The first full length device with 15 mm period length has been successfully tested in the ANKA storage ring for one year. The next superconducting undulator has 20 mm period length (SCU20) and is also planned to be installed in the accelerator test facility and synchrotron light source ANKA. The SCU20 1.5 m long coils have been characterized in a conduction cooled horizontal test facility developed at KIT IBPT. Here we present the local magnetic field and field integral measurements, as well as their analysis including the expected photon spectrum. S. Casalbuoni et al., Characterization and long term operation of a novel superconducting undulator with 15 mm period length in a synchrotron light source, Phys. Rev. ST Accel. Beams, vol. 19, p.110702, Nov. 2016.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPAB035
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TUPAB055	Development of compact magnetic field measurement system available for in-vacuum undulators	undulator, brightness, vacuum, emittance	1449
	M. Adachi, R. Kato, T. Shioya, K. Tsuchiya KEK, Ibaraki, Japan
	A low-emittance 3-GeV KEK-LS* ring has been designed at KEK. KEK-LS's undulators can produce extremely high brightness light ranging from VUV to X-ray. Brightness of undulator light strongly depends on the phase error of its periodic magnetic field. Then a precise magnetic field adjustment is required in order to prevent the reduction of the brightness performance. Generally, the adjustment is performed by the conventional field measurement system equipped with hole-probes on a huge stone table. But, for the in-vacuum undulator, the measurement must be performed without the vacuum chamber. The additional phase error caused by reattaching the chamber is not negligible for the low emittance rings. Therefore, some groups have developed measurement systems available for the direct field measurement inside the chamber,. We have started to develop a compact measurement system. Our system is compacted and stabilized by utilizing the rigid metal beam of the undulator frame instead of the stone table. In the conference, we will report the detail of the system and the present status of the development. KEK-LS HP, http://kekls.kek.jp/ T. Tanaka, et al., Physical Review ST-AB, vol.12, p.120702 (2009). * M. Musardo, et al., Proceedings of IPAC2015, Richmond, VA, USA, p.1693 (2015).
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TUPAB064	Development of a PrFeB Cryogenic Permanent Magnet Undulator (CPMU) Prototype at IHEP	vacuum, cryogenics, undulator, permanent-magnet	1469
	H.H. Lu, W. Chen, L. Gong, X.Y. Li, L.Z. Li, S.C. Sun, Y.J. Sun, Y.F. Yang, L. Zhang, X.Z. Zhang, S.T. Zhao IHEP, Beijing, People's Republic of China
	A PrFeB cryogenic permanent magnet undulator (CPMU) prototype is under construction for High Energy Photon Source Test Facility (HEPS-TF) at IHEP. The device is a full scale in-vacuum undulator with a magnetic length of 2 meters and a period of 13.5 mm, and it will work at less than 85K. The whole design scheme of prototype is presented and the specifications are given, where the consideration of in-vacuum magnetic measurement bench is also included. The development progress is introduced.
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TUPAB066	Mechanical Design of a Cryogenic Permanent Magnet Undulator at IHEP	vacuum, cryogenics, undulator, permanent-magnet	1475
	S.C. Sun, W. Chen, L. Gong, X.Y. Li, L.Z. Li, H.H. Lu, Y.J. Sun, Y.F. Yang, L. Zhang, X.Z. Zhang, S.T. Zhao IHEP, Beijing, People's Republic of China
	High Energy Photon Source (HEPS) at Institute of High energy Physics (IHEP) is a new 6 GeV third generation electron storage ring. Insertion devices play a significant role in achieving the high performance of the photon source. A 13.5mm period-length Cryogenic Permanent Magnet Undulator (CPMU) prototype is designed and under construction. The mechanical structure designed based on physical requirements will be presented. Work supported by Project of High Energy Photon Source Test Facility, email address: sunsc@ihep.ac.cn
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TUPAB067	Studies of Beam Lifetime at HEPS	scattering, lattice, electron, storage-ring	1478
	S.K. Tian, Y. Jiao, G. Xu IHEP, Beijing, People's Republic of China
	The electron storage ring's beam lifetime is determined by scattering of the electrons at the nucleus and the shell of the atoms of the residual gas (gas lifetime) and the scattering of electrons within a bunch (Touschek lifetime).Beam lifetime studies have been performed at the 6 GeV electron storage ring HEPS.
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TUPAB068	Design of the CPMU Vacuum System at the HEPS	vacuum, undulator, cryogenics, radiation	1482
	L. Zhang, H.H. Lu, S.C. Sun IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS) is a 3rd generation synchrotron radiation light source. Its beam energy is 6 GeV and its emittance is less than 60 pm'rad, which can provide high brilliance hard X-rays to several tens of experimental stations. The Cryogenic Permanent Magnet Undulator (CPMU) is one of the key components to achieve the high brilliance. And its vacuum system is necessary to provide an ultra-high vacuum environment for CPMU operation. To design the CPMU vacuum system, we do experiments to test the outgassing rate, estimate the total gas load, calculate the effective pumping speed, design the baking program and select all pumps and other vacuum equipments. This paper presents the design specifications and the assemblage status of the CPMU vacuum system.
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TUPAB103	Orbit Correction With Path Length Compensation Based on Rf Frequency Adjusments in TPS	operation, electron, feedback, site	1553
	P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.-C. Kuo, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng NSRRC, Hsinchu, Taiwan
	The 3 GeV Taiwan Photon Source has been routinely operated for public users since September 2016. Orbit reproducibility and stability are critical for the quality of user experiments. Ambient temperature variations and earth tides can cause a change in circumference, changing in turn the beam energy, and orbit drift. Therefore both, orbit correction and rf frequency adjustments are necessary to keep the ring circumference constant. A Fast Orbit Feedback (FOFB) system combined with rf frequency correction deduced from the fast corrector strengths is applied to the FOFB routine. The correlation between the measured frequency variation with ambient temperature and earth tides is also reported in this article.
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TUPAB104	Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators	polarization, optics, undulator, radiation	1556
	T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang NSRRC, Hsinchu, Taiwan H.W. Luo NTHU, Hsinchu, Taiwan
	While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.
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TUPAB107	Study of 60 Hz Beam Orbit Fluctuations in the Taiwan Photon Source	SRF, vacuum, shielding, insertion-device	1566
	C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source is a 3 GeV synchrotron light source at NSRRC. To achieve high quality experimental results, it is important to minimize beam motion. During the installation of insertion devices and front-ends, the beam motion around 60 Hz became significant. The response matrix together with singular value decomposition was used to identify the transmitter of the superconducting radio frequency system as the source for the 60 Hz perturbations. This was subsequently corrected by rerouting the grounding of the mains in the transmitters. Yet, the 60Hz orbit fluctuation became even more serious after the next shutdown. A serious of experiments are performed to dig out that the beam was disturbed by the magnetic field from newly installed fan motors. Shielding the fans with mu-metal and increasing the distance between fan and beam pipe drastically reduced the leakage field and greatly increased beam stability. These errors could be prevented at the design stage in the ideal case. However, these errors happened finally and need to be dug out and eliminated. The method and experiences are summarized in this report. These will benefit others who facing the similar problems.
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TUPAB117	Conceptual Design of a Novel SCAPE Undulator	undulator, simulation, lattice, vacuum	1596
	Y. Ivanyushenkov, J.F. Fuerst, E. Gluskin, Q.B. Hasse, M. Kasa, Y. Shiroyanagi, E. Trakhtenberg ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. A concept of a novel SuperConducting Arbitrarily Polarizing Emitter, or SCAPE, has recently been suggested at the Advanced Photon Source. It consists of two pairs - both vertical and horizontal - of superconducting planar magnets assembled around a beam vacuum chamber. Such a device will be capable of generating either planar or circularly polarized photons, depending on which pair of magnets is energized. The magnetic simulation suggests that due to the employment of superconducting technology, the expected magnetic field is higher than that of the APPLE undulators. The SCAPE undulators could be useful for the fourth generation of storage rings with a multi-bend achromat lattice, as well as for the FELs where utilization of round beam vacuum chambers becomes possible. The results of magnetic modelling, as well as the design concept of the SCAPE, are presented.
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TUPAB122	Engineering Optimization of The Support Structure and Drive System for the LCLS-II Soft X-Ray Undulator Segments	undulator, simulation, experiment, laser	1602
	A.J. DeMello, D. Arbelaez, D. Bianculli, A.P. Brown, J.N. Corlett, J.R. Dougherty, D.E. Humphries, J.-Y. Jung, M. Leitner, S. Marks, K.A. McCombs, K.L. Ray, D.A. Sadlier, D. Schlueter, E.J. Wallén LBNL, Berkeley, California, USA
	Funding: Work supported by the Director, O'ce of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. The Linear Coherent Light Source II (LCLS-II) project, an upgrade to the free-electron laser facility at SLAC, is replacing the undulator system from a fixed gap to a variable gap system to enable tuning of the photon energy range. The LCLS-II project will include a soft x-ray (SXR) beam line and a hard x-ray (HXR) beam line. The SXR undulators are conventional vertical-gap horizontally-polarizing devices while the HXR undulators are novel horizontal-gap vertically-polarizing devices. This paper describes in detail the development of the SXR mechanical support structure and drive system. The effort has included extensive analysis of the various components to ensure that the undulators will perform within the design specifications. Engineering simulations undertaken and experiments performed to validate the computer modeling are presented together with measurement results from prototype and pre-production undulators.
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TUPAB123	Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project	undulator, linac, FEL, electron	1605
	M. Leitner, D. Arbelaez, A.J. Band, D. Bianculli, A.P. Brown, J.N. Corlett, A.J. DeMello, J.R. Dougherty, L. Garcia Fajardo, K. Hanzel, M. Hoyt, D.E. Humphries, D. Jacobs, C. Joiner, J.-Y. Jung, D. Leitner, S. Marks, K.A. McCombs, D.V. Munson, K.L. Ray, D.A. Sadlier, J.J. Savino, D. Schlueter, E.J. Wallén, V. Waring, A. Zikmund LBNL, Berkeley, California, USA C.J. Andrews, D.E. Bruch, A.L. Callen, G. Janša, S. Jansson, K.R. Lauer, Yu.I. Levashov, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, Â. Oven, M. Rowen, Z.R. Wolf SLAC, Menlo Park, California, USA
	Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Stanford Linear Accelerator Laboratory is currently constructing the Linear Coherent Light Source II (LCLS-II), a free-electron laser (FEL) which will deliver x-rays at an energy range between 0.2 keV and 5 keV at high repetition rate of up to ~1 MHz using a new 4 GeV superconducting RF linac, and at and an energy range between 1 keV and 25 keV when driven by an existing copper linac at up to 120 Hz repetition rate. To cover the full photon energy range, LCLS-II includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator (SXR) line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV plus a hard x-ray undulator (HXR) line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. Lawrence Berkeley National Laboratory is responsible for fabricating the 53 undulator segments. This paper summarizes the main parameters and design attributes for both LCLS-II undulator segment types.
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TUPAB125	Magnetic Field Measurements at LBNL on Soft X-Ray and Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project	undulator, linac, software, alignment	1612
	E.J. Wallén, D. Arbelaez, J.N. Corlett, L. Fajrado, H.W. Kim, M. Leitner, S. Marks, D. Schlueter, A. Zikmund LBNL, Berkeley, California, USA Yu.I. Levashov, H.-D. Nuhn, Z.R. Wolf SLAC, Menlo Park, California, USA
	Funding: Work supported by the Director, O'ce of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Stanford Linear Accelerator Laboratory is currently constructing the Linear Coherent Light Source II (LCLS-II), a FEL which will deliver x-rays at an energy range 0.2-5 keV at high repetition rate of up to 1 MHz using a new 4 GeV superconducting linac, and at an energy range 1-25 keV when using the existing copper linac at up to 120 Hz. To cover the full photon energy range, LCLS-II includes two variable-gap, hybrid-type permanent magnet undulator lines: A soft x-ray undulator (SXR) line with 21 undulator segments for the photon energy range 0.2-1.3 keV plus a hard x-ray undulator (HXR) line with 32 undulator segments designed for a photon energy range from 1-5 keV when using the superconducting linac. The HXR line is also designed to support 25 keV and higher photon energies when using the existing copper linac. Lawrence Berkeley National Laboratory (LBNL) is responsible for fabricating the undulators and tuning 23 of the HXR undulators. This paper summarizes the magnetic field measurements carried out on the pre-production undulators and describes the plans at LBNL for the magnetic measurements on the HXR undulators in series production.
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TUPIK055	Target Investigation Driven by a 10 MeV Electron Linac for Bremsstrahlung Production	target, electron, linac, radiation	1819
	M. Yarmohammadi Satri, M. Lamehi, H. Shaker IPM, Tehran, Iran F. Ghasemi NSTRI, Tehran, Iran
	IPM E-Linac is a 10 MeV electron linear accelerator presently under construction at Institute for Research in Fundamental Sciences (IPM). It will accelerate electron from 45 keV to 10 MeV along the 160 cm accelerating tube. One of the beam energy measurement devices is designed based on the production of bremsstrahlung radiation. Target of the electron linac presents a key role in the production of bremsstrahlung. In this paper, we present the simulation results for an investigation on the bremsstrahlung radiation production based on target thickness, radius and atomic number, Z. We have applied Fluka Monte Carlo code for collecting the dose equiva-lent of generated bremsstrahlung along the target central axis at 30cm located downstream the target.
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TUPIK075	ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs	collimation, wakefield, background, simulation	1864
	N. Fuster-Martínez, A. Faus-Golfe IFIC, Valencia, Spain P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang LAL, Orsay, France K. Kubo, T. Okugi, T. Tauchi, N. Terunuma Sokendai, Ibaraki, Japan S. Kuroda KEK, Ibaraki, Japan I. Podadera, F. Toral CIEMAT, Madrid, Spain G.R. White SLAC, Menlo Park, California, USA
	A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.
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TUPIK101	Development and Construction of Safety and Control Systems for the TPS Front End Interlock	controls, vacuum, status, radiation	1947
	J. -Y. Chuang, C.K. Chan, Y.M. Hsiao, C.K. Kuan, Y.Z. Lin, I.C. Sheng, Y.C. Yang NSRRC, Hsinchu, Taiwan C.S. Lin NPUST, Pingtung, Taiwan
	The Taiwan photon source (TPS) at NSRRC (National Taiwan Photon Source) is a 3rd generation, 3 GeV storage ring with designed current of 500 mA. In phase-I, six insertion device beamlines have been available to users after the safety interlock systems were commissioned and reviewed. National Instrument (NI) compact RIO 9030 is used for the front end interlock control system, and both scan and FPGA modes are activated in a hybrid mode to enhance the safety reliability. The personnel and machine protection system as well as EPICS communications of the TPS control system are presented in this paper as well.
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TUPIK106	Analysis of the Synchrotron Radiation from Segmented Undulator in Double-Mini Beta Function	undulator, radiation, brilliance, electron	1964
	H.W. Luo, C.H. Lee NTHU, Hsinchu, Taiwan T.Y. Chung, C.-S. Hwang NSRRC, Hsinchu, Taiwan C.-S. Hwang NCTU, Hsinchu, Taiwan
	Three long straight sections with double-mini beta-y lattice were created in the Taiwan Photon Source (TPS) for which the effects of focusing elements and phase shifters between the collinear undulators result in incorrect calculations of the brilliance while assuming a Gaussian-approximation. Therefore, an on-axis Wigner distribution function (WDF), which includes effects of wave phenomena, is a natural way to measure the intensity of synchrotron radiation and is used in this article as the definition of brilliance.
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TUPVA004	Synchrotron Radiation Backgrounds for the FCC-hh Experiments	simulation, radiation, optics, collider	2031
	F. Collamati INFN-Roma1, Rome, Italy M. Boscolo INFN/LNF, Frascati (Roma), Italy H. Burkhardt, R. Kersevan CERN, Geneva, Switzerland
	Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305. We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.
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TUPVA011	Comparing Behaviour of Simulated Proton Synchrotron Radiation in the Arcs of the LHC with Measurements	simulation, synchrotron, synchrotron-radiation, radiation	2059
	G. Guillermo Cantón, M. Ady, R. Kersevan, F. Zimmermann CERN, Geneva, Switzerland M. Angelucci, R. Cimino, E. La Francesca INFN/LNF, Frascati (Roma), Italy D. Sagan Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: EuCARD2 CONACyT In previous work it was shown that at high proton-beam energies, synchrotron radiation is an important source of beam-screen heating, of beam-related vacuum pressure increase, and of primary photoelectrons, which can contribute to electron cloud formation. We have used the Synrad3D code developed at Cornell to simulate the photon distributions in the arcs of the LHC, HL-LHC, and FCC-hh. Specifically, for the LHC we studied the effect of the sawtooth chamber. In this paper specific results of the Synrad3D simulations are compared with simulations in Synrad+, developed at CERN; and later on compared with experimental data for actual LHC vacuum-chamber samples.
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TUPVA118	Particle Accelerators for Humanity: Resources for Public Engagement with Particle Accelerators	proton, survey, quadrupole, neutron	2369
	S.L. Sheehy JAI, Oxford, United Kingdom
	To those who work in the accelerator field, it is obvious that there are many applications of accelerators beyond particle physics. Yet the public remains largely unaware of the far reaching uses of accelerators, or the scientific and engineering challenges that lay behind them. A recent project Particle Accelerators for Humanity has addressed this gap by creating a series of video resources, based on a programme of live events, short films and a specially commissioned animation. The project captured the dedication and diversity of those who design, operate and work with accelerators and highlights the varied ways in which their work is impacting on our lives. Here we overview the project and the resources, available under Creative Commons license, and discuss the impact of the project so far. We encourage the accelerator community to use the resources in their teaching and public engagement activities.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2017-TUPVA118
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WEOCA1	Performance of SOLARIS Storage Ring	storage-ring, injection, electron, closed-orbit	2490
	A.I. Wawrzyniak, P.B. Borowiec, M.B. Jaglarz, A. Kisiel, P.M. Klimczyk, M.A. Knafel, M.P. Kopeć, A.M. Marendziak, S. Piela, P. Sagało, M.J. Stankiewicz, K. Wawrzyniak, M. Zając Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	After one year of the Solaris storage ring commission-ing excellent performance has been achieved. The optics was corrected close to the design values. However, some minor adjustments are still needed. The commissioning of the Solaris 1.5 GeV storage ring required a big effort in machine parameters optimization. Performance of posi-tion monitoring devices has proven essential for the suc-cessful optimization of beam parameters such as: closed orbit, tune, chromaticity, and dispersion. Now, the effort is focused on fine-tuning the machine by implementing the linear optics from orbit correction (LOCO) and reduc-ing the disparity between model and measured results revealed by the phase advance analysis and dispersion measurement. Moreover, during daily operation the main task is to maintain long-term stability of the circulating electron beam allowing for beamlines commissioning. Within this presentation the current status of the Solaris facility and the commissioning results will be reported.
	Slides WEOCA1 [13.180 MB]
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WEOCA3	Status of the Development of Superconducting Undulators at the Advanced Photon Source	undulator, vacuum, FEL, storage-ring	2499
	Y. Ivanyushenkov, C.L. Doose, J.F. Fuerst, E. Gluskin, Q.B. Hasse, M. Kasa, Y. Shiroyanagi ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357 Superconducting planar undulator (SCU) technology has been developed and is currently in use at the Advanced Photon Source (APS). The experience of building and operating the first short-length, 16-mm period superconducting undulator, SCU0, paved the way for two 1-m long, 18-mm period devices, SCU18-1 and SCU18-2. The first of those undulators has been in operation since May 2015, while the second one replaced SCU0 in September 2016. The possibility of building planar SCUs with a high quality field has been demonstrated at the APS. The measured phase errors of SCU18-2 at the design operational current are only 2 degrees rms, for example. An FEL SCU prototype - a 1.5-m long, 21-mm period undulator - was also built and tested as part of an LCLS SCU R&D program. This undulator successfully achieved all LCLS-II undulator requirements including a phase error of 5 degrees rms. The superconducting undulator technology also allows the fabrication of circular polarizing devices. Currently, a new helical SCU is under construction at the APS. In addition, the concept of a novel Superconducting Arbitrarily Polarizing Emitter, or SCAPE, has been suggested and is now under development.
	Slides WEOCA3 [2.826 MB]
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WEOBB1	Recirculated Electron Beam Photo-Converter for Rare Isotope Production	target, electron, TRIUMF, isotope-production	2526
	A. Laxdal, R.A. Baartman, I.V. Bylinskii, S. Ganesh, A. Gottberg, F.W. Jones, P. Kunz, L.A. Lopera, T. Planche, A. Sen TRIUMF, Vancouver, Canada
	The TRIUMF 50 MeV electron linac has the potential to drive cw beams of up to 0.5 MW to the ARIEL photo-fission facility for rare isotope science. Due to the cooling requirements, the use of a thick Bremsstrahlung target for electron to photon conversion is a difficult technical challenge in this intensity regime. Here we present a different concept in which electrons are injected into a small storage ring to make multiple passes through a thin internal photo-conversion target, eventually depositing their remaining energy in a cooled central core absorber. We discuss the design requirements and propose a set of design parameters for the Fixed Field Alternating Gradient (FFAG) ring. Using particle simulation models, we estimate various beam properties, as well as the MPS for the electron loss.
	Slides WEOBB1 [4.650 MB]
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WEPAB014	PETRA III Operation	operation, timing, experiment, optics	2589
	M. Bieler, I.V. Agapov, H. Ehrlichmann, J. Keil, G.K. Sahoo, R. Wanzenberg DESY, Hamburg, Germany
	At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the challenges of daily operation, including different bunch patterns and their side effects, a procedure to clear spurious bunches, the operational statistics and the main contributions to down time.
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WEPAB016	Experience in Operating sFLASH With High-Gain Harmonic Generation	FEL, laser, electron, radiation	2596
	J. Bödewadt, R.W. Aßmann, N. Ekanayake, B. Faatz, I. Hartl, T. Laarmann, C. Lechner, M.M. Mohammad Kazemi, A. Przystawik DESY, Hamburg, Germany Ph. Amstutz, A. Azima, M. Drescher, W. Hillert, L.L. Lazzarino, Th. Maltezopoulos, V. Miltchev, T. Plath, J. Roßbach University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany K.E. Hacker, S. Khan, N.M. Lockmann, R. Molo DELTA, Dortmund, Germany
	sFLASH, the experimental setup for external seeding of free-electron lasers (FEL) at FLASH, has been operated in the high-gain harmonic generation (HGHG) mode. A detailed characterization of the laser-induced energy modulation, as well as the temporal characterization of the seeded FEL pulses is possible by using a transverse deflecting structure and an electron spectrometer. FEL saturation was reached for the 7th harmonic of the 266 nm seed laser. In this contribution, we present the latest experimental results.
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WEPAB025	Status of the Soft X-Ray Free Electron Laser FLASH	laser, FEL, experiment, operation	2628
	M. Vogt, B. Faatz, K. Honkavaara, M. Kuhlmann, J. Rönsch-Schulenburg, S. Schreiber, R. Treusch DESY, Hamburg, Germany
	The superconducting free-electron laser user facility FLASH at DESY in Hamburg, routinely produces several thousand photon pulses per second. The operational parameters cover a wavelength range from 90 nm down to 4 nm with pulse energies from several uJ up to 1 mJ and with pulse durations of several hundred fs down to a few fs. The FLASH injector and linac drives two undulator beam lines (FLASH1, FLASH2) and therefore FLASH is capable of serving 2 independent experiments with photon pulse (sub-) trains of several 100 bunches at the full train repetition frequency of 10 Hz. We summarize here the highlights of the user operation at FLASH1/2 and the study program (machine development and FEL optimization) of the FLASH facility.
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WEPAB032	A Novel Optical Beam Concept for Producing Coherent Synchrotron Radiation with Large Energy Spread Beams	undulator, radiation, laser, electron	2646
	R. Rossmanith, A. Bernhard, V. Saile, P. Wesolowski KIT, Karlsruhe, Germany R.W. Aßmann, U. Dorda, B. Marchetti DESY, Hamburg, Germany
	Up to now two FEL concepts are known in conventional accelerators: 1.) In THz lasers an off-crest cavity adds a chirp to the bunch followed by a bunch compressor. Particles with different energies travel on different trajectories to the radiator. 2.) For EUV and X-ray FELs the beam enters an undulator which produces microbunches which then radiate. In this paper it is proposed to copy the THz laser scheme for EUV lasers. The incoming beam is chirped and a dogleg forces afterwards the particles with different energies to move on different parallel trajectories. Considering a detector plane perpendicular to the trajectories the particles with different energies arrive in general at different times. When in this plane for instance a TGU (Transverse Gradient Undulator) is positioned the emitted radiation in the TGU is monochromatic. If in addition chirp and dogleg are selected in such a way that the particles with different energies arrive at the same time at the entrance of the TGU the radiation is monochromatic and coherent similar to the THz laser concept.
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WEPAB035	Elettra Status Present Upgrades and Plans	undulator, operation, controls, storage-ring	2657
	E. Karantzoulis, A. Carniel, M. Cautero, B. Diviacco, S. Krecic, R. Visintini Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with an account of some present upgrades and plans for the near future.
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WEPAB041	Status Report of Hiroshima Synchrotron Radiation Center Hiroshima University	undulator, synchrotron, synchrotron-radiation, radiation	2672
	S. Matsuba, K. Goto, K. Kawase HSRC, Higashi-Hiroshima, Japan
	The Hiroshima Synchrotron Radiation Center (HSRC) at Hiroshima University was established in 1996 for the research of solid state physics. The HSRC equips a 700 MeV electron storage ring nicknamed HiSOR. Recently, we are considering upgrade of the instrumentation beamline for the optical monitoring. In this paper, we report the present status of HSRC.
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WEPAB085	Siam Photon Source: Present Machine Status and Future Upgrades	storage-ring, injection, electron, operation	2770
	P. Klysubun, S. Boonsuya, N. Juntong, K. Kittimanapun, S. Kongtawong, S. Krainara, A. Kwankasem, T. Pulampong, P. Sudmuang, N. Suradet SLRI, Nakhon Ratchasima, Thailand
	Siam Photon Source, the Thailand synchrotron light source, has received several upgrades in recent years. Most important of which are the improvement of the positional stability of the stored electron beam, and the installation of 2 IDs, i.e. a 2.2 T hybrid multipole wiggler and a 6.5 T superconducting wavelength shifter, to extend the available SR spectrum into hard x-ray region. The beam stability improvement was achieved through several activities, including improving the BPM system, upgrading the existing corrector power supplies, and implementing global orbit feedback. The two new IDs provide higher-intensity and higher-energy (up to 25 keV) synchrotron light, which will be utilized for MX, high-energy SAXS, WAXS, XAS, and microtomography. Ongoing machine upgrades include increasing the energy of the booster and transport line to 1.2 GeV for full-energy injection and eventual top-up operation. Utilization of the electron beam is also being explored. A beam test facility, which extracts electron beam in the booster for characterizing high-energy particle sensors, as well as calibrating other beam diagnostic instruments, has been constructed and is now in operation.
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WEPAB098	Dielectrically-Loaded Waveguide as a Microwave Undulator for High Brillance X-Rays at 45 - 90 Kev	undulator, brightness, operation, coupling	2812
	R. Kustom, A. Nassiri, G.J. Waldschmidt ANL, Argonne, Illinois, USA
	The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. This structure, operating near the cutoff frequency of the HEM12 mode, spans a frequency range where the wavelength and phase velocity vary significantly. This property can be exploited to generate undulator action with short periods for the generation of high brightness x-rays. The frequency range of interest would be from 18 to 34.5-GHz. The goal would be to generate x-rays on the fundamental mode over a range of 45 to 90-kev. The tunability would be achieved by changing the source frequency while maintaining a constant on-axis equivalent undulator field strength of 0.5-T.
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WEPAB115	Normal Conducting CW Transverse Crab Cavity For Producing Short Pulses In SPEAR3	cavity, HOM, impedance, damping	2840
	Z. Li, V.A. Dolgashev, M. Dunham, K.J. Gaffney, R.O. Hettel, X. Huang, N. Kurita, J.A. Safranek, J.J. Sebek, K. Tian SLAC, Menlo Park, California, USA
	Funding: This work was supported by DOE Contract No. DE-AC02-76SF00515. The ability to produce short pulse X-rays on the scale of 1-10 ps fwhm in the SPEAR3 storage ring light source would enable enhanced timing mode studies of dynamic processes in materials as they occur. The crab cavity approach appears to be optimal for SPEAR3 to produce short pulse X-rays. Furthermore, by using a two-frequency crabbing scheme, SPEAR3 would be able to produce short-pulse bunches while supplying the high average flux needed for regular users. While supercon-ducting RF (SCRF) technology could be a natural choice for the CW crab cavity, the deflecting voltage for SPEAR3 crabbing appears to be within reach of more affordable normal conducting RF (NCRF). In this paper, we present a preliminary NCRF CW crab cavity design for SPEAR3.
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WEPAB118	High Power Sub-Femtosecond X-Ray Pulse Study for the LCLS	undulator, electron, simulation, space-charge	2848
	J.P. MacArthur Stanford University, Stanford, California, USA J.P. Duris, Z. Huang, A. Marinelli SLAC, Menlo Park, California, USA
	The desire to resolve sub-femtosecond electron dynamics has pushed FEL facilities to shorter pulse lengths. However, current short-pulse schemes provide low pulse energy and a gain-length limited lower bound on the pulse duration. The X-ray Laser-Enhanced Attosecond Pulses (XLEAP) project at SLAC is designed implement an Enhanced Self Amplified Spontaneous Emission (ESASE) scheme, which produces sub-fs current spikes by modulating and compressing the electron beam. We show through a series of Genesis simulations that the current spike is capable of producing sub-fs pulses with a peak power well above 100 GW. Space-charge induced beam chirp can decrease pulse lengths below 400 as, and multi-stage schemes can increase peak x-ray powers to around 1 TW.
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WEPAB124	Study of Hadron-Photon Colliders for Secondary Beam Generation	proton, collider, hadron, secondary-beams	2865
	L. Serafini, C. Curatolo Istituto Nazionale di Fisica Nucleare, Milano, Italy F. Broggi INFN/LASA, Segrate (MI), Italy
	We summarize the potentialities of combining two well developed technologies, which are advancing the frontiers of hadron colliders and of light sources, namely the hadron colliders for high energy physics, and the FELs for applied and fundamental science with light, towards the generation of secondary beams with unprecedented characteristics. The collision between their typical pulses of high energy protons and X-ray photons opens a collider scenario with potentials for luminosities in excess of 10³⁸ s^-1cm^-2, adequate to generate TeV-class pion, muon, neutrino and photon beams with very high phase space densities. We report results based on Monte Carlo simulations of such a hadron-photon collider, aiming at qualifying the features of these secondary beams in view of experiments to be performed directly, or towards the design of a new kind of muon collider. C. Curatolo, et al., Nuclear Instruments & Methods in Physics Research A (2016), http://dx.doi.org/10.1016/j. nima.2016.09.002i
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WEPIK002	Experimental Activities on High Intensity Positron Sources Using Channeling	positron, target, electron, experiment	2910
	I. Chaikovska, R. Chehab, H. Guler, V. Kubytskyi LAL, Orsay, France X. Artru IN2P3 IPNL, Villeurbanne, France K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada KEK, Ibaraki, Japan V. Rodin National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine P. Sievers CERN, Geneva, Switzerland
	The positron source under investigation is using channeling radiation of multi-GeV electrons in a tungsten crystal. The radiated photons are impinging on the amorphous targets creating e⁺e⁻ pairs. A dipole magnet between the crystal-radiator and the amorphous-converter allows the charged particles to be swept off and only emitted photons to generate e⁺e⁻ pairs in the converter. Granular targets of different thicknesses, made of small tungsten spheres, have been recently investigated as a target-converter. This paper is describing the experimental studies conducted at the KEKB linac with such device. After the description of the experimental set-up and beam parameters, the measurement methods and preliminary results are presented.
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WEPIK004	Luminosity- and Beam- Induced Backgrounds for the FCC-ee Interaction Region Design	detector, background, luminosity, interaction-region	2914
	G.G. Voutsinas, P. Janot, A.M. Kolano, E. Perez, N.A. Tehrani CERN, Geneva, Switzerland N. Bacchetta INFN- Sez. di Padova, Padova, Italy M. Boscolo INFN/LNF, Frascati (Roma), Italy M.K. Sullivan SLAC, Menlo Park, California, USA
	A preliminary study on machine induced backgrounds has been performed for the proposed FCC-ee interaction region (IR) and proto-detector. Synchrotron radiation has the strongest impact on the present design of the IR and both radiation from dipoles and quadrupoles have been taken into account. The effect of luminosity backgrounds like gamma gamma to hadrons and pair production have also been studied. The impact of background particles on the detector occupancy has also been studied in full simulation.
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WEPIK008	Problems in SuperKEKB Vacuum System During the Phase-1 Commissioning and Their Mitigation Measures	wiggler, vacuum, electron, positron	2925
	Y. Suetsugu, H. Hisamatsu, T. Ishibashi, K. Kanazawa, K. Shibata, M. Shirai, S. Terui KEK, Ibaraki, Japan
	The first (Phase-1) commissioning of the SuperKEKB, an energy-asymmetric electron-positron collider in KEK, Japan, started in February and ended in June, 2016. The vacuum system of the main ring worked well through the commissioning period as a whole, but experienced several problems, such as the electron cloud effect (ECE) in the positron ring, the pressure bursts accompanying beam losses due to dust particles in the beam pipe, an air leak at a connection flange due to the direct hitting of synchrotron radiation (SR), and so on. Towards the next (Phase-2) commissioning, countermeasures to these problems are taken during the shutdown period. For example, permanent magnets generating axial magnetic fields are attached to beam pipes at drift spaces for the suppression of the ECE. Knockers, which can artificially drop dust particles attached to the top surface in beam pipes by continuous impacts, are prepared to the beam pipes at which the pressure bursts had been frequently observed. Bellows chambers with masks are installed to protect the leaked flange from SR. The problems and their mitigation measures will be summarized in the presentation.
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WEPIK048	Evaluation and Mitigation of Synchrotron Radiation Background in the eRHIC Ring-Ring Interaction Region	detector, electron, radiation, quadrupole	3032
	C. Montag BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Synchrotron radiation is a potential source of background in the detector of any future electron-ion collider. In the case of the eRHIC ring-ring design, a 22mrad crossing angle eliminates the need for a separator dipole, which would otherwise be a major source of synchrotron radiation. However, electrons in the transverse tails experience strong magnetic fields in the low-beta quadrupoles near the interaction point. Despite the low electron density in the tails the resulting hard radiation generated in these strong fields is a major concern, and a set of masks needs to be in place to shield the detector from these photons. We present simulation studies and a first design of a synchrotron radiation masking scheme.
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WEPIK065	Research Activities Towards a Conversion of PETRA III Into a Diffraction Limited Synchrotron Light Source	lattice, emittance, sextupole, synchrotron	3077
	R. Wanzenberg, I.V. Agapov, K. Balewski, M. Bieler, W. Brefeld, R. Brinkmann, M. Dohlus, H. Ehrlichmann, X.N. Gavaldà, J. Keil, M. Körfer, G.K. Sahoo, C.G. Schroer, E. Weckert DESY, Hamburg, Germany M. Eriksson MAX IV Laboratory, Lund University, Lund, Sweden
	At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. Research activities have been started towards a future upgrade scenario of PETRA III which envisions the conversion of the PETRA ring into a ultra-low emittance hard X-ray radiation source: PETRA IV. The lattice design is aiming for a horizontal emittance in the range between 10 pm rad and 30 pm rad at a beam energy of 6 GeV. Two different approaches have been considered for the lattice design: a design based on a hybrid multibend achromat with an interleaved sextupole configuration based on the ESRF design, and a lattice with a non-interleaved sextupole configuration with a special phase space exchange configuration. We are reporting the current status of the design activities including studies related to the injector.
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WEPVA058	Development of HOM Absorber for SuperKEKB	electron, HOM, vacuum, plasma	3394
	S. Terui, T. Ishibashi, Y. Suetsugu, Y. Takeuchi, K. Watanabe KEK, Ibaraki, Japan H. Ishizaki, A. Kimura, T. Sawhata Metal Technology Co. Ltd., Ibaraki, Japan
	Higher-order modes (HOM) absorbers are necessary components for recent high-power accelerators in order to prevent beam instabilities (e.g. HOM- Beam Break Up instabilities) or the overheating of vacuum components. Several kinds of absorber materials, such as SiC, ferrite and Kanthal, have been investigated and applied in accelerators. Among these materials, ferrite has been found to be superior to others because of its higher HOM absorbing efficiency. However, because of its low tensile strength and small thermal expansion rate, it cannot be easily bonded to other metals thus limiting its use as a HOM absorber. We reported the success of the fabrication of ferrite-copper-blocks using the spark plasma sintering (SPS)-technique last year. This year we report testing with a high-power RF source and measuring gas desorption rate after baking and secondary electron yield.
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WEPVA127	Design of a 3.5 T Superconducting Multipole Wiggler	vacuum, radiation, wiggler, simulation	3564
	J.C. Jan, C.-H. Chang, H.-H. Chen, S.D. Chen, T.Y. Chung, C.-S. Hwang, F.-Y. Lin, G.-H. Luo NSRRC, Hsinchu, Taiwan
	A 3.5 T superconducting multipole wiggler (SMPW) has been designed through the collaboration of National Synchrotron Radiation Research Center (NSRRC) and Synchrotron Light Research Institute (SLRI). The SMPW will support the hard X-ray source for the X-ray absorption spectroscopy (XAS) beamline in SLRI. The design concept of the SMPW follows from, and improves on, the operating experience of the superconducting magnet in NSRRC. An improvement of the operation and compatible with the cooling capacity of the cryogenic system, is the design goal. A quick and easy recovery of the magnet from a quench event is also required. The design of the magnet circuit and the mechanical of the SMPW are also discussed herein.
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WEPVA129	Arc-Flash Hazard and Protection for Electric Switchboard at NSRRC	detector, site, power-supply, impedance	3571
	T.-S. Ueng, Y.F. Chiu, C.K. Kuan, K.C. Kuo, Y.-C. Lin NSRRC, Hsinchu, Taiwan
	During the operation of electrical equipment the arc-flash accident could damage the equipment and endanger the working personnel. In order to prevent this type of accidents from happening and to minimize the damages, a delicate setup is being installed inside the electric switchboard for suppressing the accidents at the initial stage of arcing at NSRRC's power system. The installed device includes the arc sensor, the smoke detector, the high rupturing capacity fuse, the circuit breaker and the protection relay. Further improvement on preventing the arc-flash accidents is also under study.
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WEPVA132	Switching Power Supply Automatic Test System in Taiwan Photon Source	radiation, power-supply, synchrotron, simulation	3580
	Y.S. Wong, C.Y. Liu, K.-B. Liu, B.S. Wang NSRRC, Hsinchu, Taiwan
	This paper studies the use of a novel switching power supply automatic test system used in Taiwan photon source, Model 8000 is the ultimate solution for power electronic testing, the system includes a wide range of hardware choice such as AC/DC source, electronic loads, DMM, oscillate scope, noise analyzer and short/OVP tester. The ATS 8000 system uses a unique test command optimazation technology to prevent repetitive control commands from being sent to system hardware devices. This improve test speed dramatically and makes ideal choice for both high speed production applications as well as design verification.
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WEPVA134	Impedance Measurement of Vacuum Chamber Components for the Advance Photon Source (APS) Upgrade	impedance, simulation, cavity, vacuum	3583
	M.P. Sangroula IIT, Chicago, Illinois, USA R.M. Lill, R.R. Lindberg, X. Sun ANL, Argonne, Illinois, USA
	Funding: U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC0206CH11357. The proposed Advance Photon Source Upgrade (APS-U) employs a multi-bend achromat (MBA) lattice to increase the photon brightness by two to three orders of magnitude. One of the main design challenges of the upgrade is to minimize rf heating and collective instabilities associated with the impedance of small-aperture vacuum components. As part of this effort, my research focuses on impedance measurement and simulation of various MBA vacuum components. Here, we present the summary of the impedance contributions for the APS-U and describe our planned impedance measurement technique, including some measurement results for the non-evaporative getter (NEG)-coated copper chamber and simulation results for other critical components using a novel Goubau line (G-line) set up.
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WEPVA136	Vacuum System for the Diamond Light Source DDBA Upgrade	vacuum, dipole, simulation, electron	3587
	M.P. Cox, M.J. Duignan, R. Howard, S.C. Lay, A.G. Miller, H.S. Shiers, A. Wolfenden DLS, Oxfordshire, United Kingdom
	One cell of the Diamond Light Source (Diamond) storage ring was upgraded in late 2016 to a Double Double Bend Achromat (DDBA) configuration to provide an additional mid-achromat insertion device straight. For practical reasons it was decided to use discrete non-evaporable getter (NEG) pumps rather than NEG coatings. This paper outlines the vacuum design of the up-grade, the reasons for the choices made and the vacuum simulation tools used as well as describing the vacuum system engineering, assembly, installation and commissioning. The measured vacuum performance is found to be in close agreement with the simulations and a simple expression is derived for the beam gas lifetime.
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WEPVA137	Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project	vacuum, storage-ring, lattice, radiation	3590
	B.K. Stillwell, B. Billett, B. Brajuskovic, J.A. Carter, E.S. Kirkus, M.A. Lale, J.E. Lerch, J. R. Noonan, M.M. O'Neill, B.G. Rocke, K.J. Suthar, D.R. Walters, G.E. Wiemerslage, J. Zientek ANL, Argonne, Illinois, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction, and rf cavity straight sections. An overview of progress in these areas is presented.
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WEPVA148	Dynamics of Target Motion Under Exposure of Hard Gamma Undulator Radiation	target, positron, electron, undulator	3618
	A.A. Mikhailichenko Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	We describe time dependent dynamics of the target motion under exposure by undulator radiation in a system for positron production. We took into account inertia of material of target. Calculations carried with help of FlexPDE code.
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THOBA1	Studies of the Micro-Bunching Instability in Multi-Bunch Operation at the ANKA Storage Ring	synchrotron, bunching, radiation, storage-ring	3645
	M. Brosi, E. Blomley, E. Bründermann, M. Caselle, B. Kehrer, A. Kopmann, A.-S. Müller, L. Rota, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber KIT, Eggenstein-Leopoldshafen, Germany
	Funding: Supported by the German Federal Ministry of Education and Research (05K13VKA & 05K16VKA), the Helmholtz Association (VH-NG-320) and the Helmholtz International Research School for Teratronics (HIRST) The test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and can generate brilliant coherent synchrotron radiation (CSR) in the THz range employing a dedicated bunch length-reducing optic at 1.3 GeV beam energy. The high degree of spatial compression leads to complex longitudinal dynamics and to time evolving sub-structures in the longitudinal phase space of the electron bunches. The results of the micro-bunching instability are time-dependent fluctuations and strong bursts in the radiated THz power. To study these fluctuations in the emitted THz radiation simultaneously for each individual bunch in a multi-bunch environment, fast THz detectors are combined with KAPTURE, the dedicated KArlsruhe Pulse Taking and Ultrafast Readout Electronics system, developed at KIT. In this contribution we present measurements conducted to study possible multi-bunch effects on the characteristic bursting behavior of the micro-bunch instability.
	Slides THOBA1 [12.910 MB]
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THPAB029	Simulation of the Single Bunch Instabilities for the High Energy Photon Source	impedance, injection, simulation, operation	3760
	Z. Duan, N. Wang, H.S. Xu IHEP, Beijing, People's Republic of China
	Funding: Work supported by Natural Science Foundation of China (No.11605212). Timing modes pursing a large single bunch charge will be important operation modes for the green-field High Energy Photon Source (HEPS). The single bunch instabilities are simulated with the elegant tracking code, based on the current impedance budget. In particular, a novel on-axis accumulation scheme* based on the RF gymnastics of an active double-RF system was proposed as a candidate injection scheme for HEPS, while the zero-current rms bunch length dramatically decreases during the injection, from 32 mm to 3 mm, over a time duration of about 200 ms. The single bunch instabilities are evaluated for both the operation mode with optimal bunch lengthening as well as the injection mode with the very short bunch length, as a first step in understanding the possible beam instability for this injection scheme. * G. Xu, et al., in Proc. IPAC'16, pp. 2886-2888. Z. Duan, et al., in Proc. eeFACT 2016.
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THPAB066	Modeling Cathode Roughness, Work Function, and Field Enhancement Effects on Electron Emission	electron, emittance, simulation, scattering	3869
	D.A. Dimitrov, G.I. Bell, D.N. Smithe, S.A. Veitzer Tech-X, Boulder, Colorado, USA I. Ben-Zvi, J. Smedley BNL, Upton, Long Island, New York, USA J. Feng, S.S. Karkare, H.A. Padmore LBNL, Berkeley, California, USA
	Funding: This work is supported by the US DOE Office of Science, department of Basic Energy Sciences under grant DE-SC0013190. Recent developments in material design and growth have resulted in photocathodes that can deliver high quantum efficiency and are sufficiently robust to use in high electric field gradient photoinjectors and free electron lasers. The growth process usually produces photoemissive material layers with rough surface profiles that lead to transverse accelerating fields and possible work function variation resulting in emittance growth. To better understand the effects of surface roughness on emitted electron beams, we have developed realistic three-dimensional models for photocathode materials with grated surface structures. They include general modeling of electron excitation due to photon absorption, charge transport and emission from rough surfaces taking into account image charge and field enhancement effects. We implemented these models in the VSim particle-in-cell code. We report results from simulations using different photocathode materials with grated and flat surfaces to investigate how controlled roughness, work function variation, and field enhancement affect emission properties.
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THPAB132	MCP Based Detectors Installation in European XFEL	detector, ion, radiation, laser	4031
	E. Syresin, O.I. Brovko, A.Yu. Grebentsov JINR, Dubna, Moscow Region, Russia W. Freund XFEL. EU, Hamburg, Germany J. Grünert European XFEL, Schenefeld, Germany M.V. Yurkov DESY, Hamburg, Germany
	An important task of the photon beam diagnostics at the European XFEL is providing reliable tools for measurements aiming at the search for and fine tuning of the amplification process in the SASE FEL. Radiation detectors based onμchannel plates (MCP) were prepared for such measurements. These detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ to 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 5.1 nm for SASE3. Photon pulse energies are measured at the MCP anode and with a photodiode. The transverse photon beam profile is measured by an MCP imager with phosphor screen anode. Three MCP devices are being installed, one in each of the three FEL beamlines (SASE1, SASE2, and SASE3). The units for SASE1 and SASE3 were already installed in the XFEL tunnel, and the technical commissioning of the MCP detectors and their electronics is progressing. Calibration and acceptance test experiments with beam are scheduled for early 2017.
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THPAB154	Mechanical Design of Compact Vertical and Horizontal Linear Nanopositioning Flexure Stages With Centimeter-Level Travel Range for X-Ray Beamline Instrumentation	controls, laser, instrumentation, synchrotron	4096
	D. Shu, J.W.J. Anton, S.P. Kearney, B. Lai, W. Liu, J. Maser, C. Roehrig, J.Z. Tischler ANL, Argonne, Illinois, USA J.W.J. Anton University of Illinois at Chicago, Chicago, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357. Nanopositioning techniques present an important capability to support the state-of-the-art x-ray instrumentation research for the APS operations and upgrade project. To overcome the performance limitations of precision ball-bearing-based or roller-bearing-based linear stage systems, compact vertical and horizontal linear nanopositioning flexure stages have been designed and developed at the APS with centimeter-level travel range and nanometer-level resolution for x-ray beamline instrumentation. Using improved deformation compensated linear guiding mechanisms [,], the APS T8-55 vertical linear flexure stage and T8-56 horizontal linear flexure stage are initially designed as a pair of sample scanning stages for a hard x-ray scanning microscope at the APS sector 2. Due to their unique repeatable nanopositioning performance over the centimeter-level travel range, these stages are also suitable for many photon beam lines optics with repeatable and stable nanopositioning requirements. The mechanical design and finite element analyses of the APS T8-55 and T8-56 flexural stages, as well as its initial mechanical test results with laser interferometer are described in this paper. D. Shu, W. Liu, S. Kearney, J. Anton, B. Lai, J. Maser, C. Roehrig, and J. Z. Tischler, Proceedings of MEDSI-2016, Sept. 11-16, 2016, Barcelona, Spain. ** U.S. Patent granted No. 8,957, 567, D. Shu, S. Kearney, and C. Preissner, 2015.
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THPVA040	Magnetic Field Computation for PMTs Shielding Optimization	shielding, simulation, experiment, quadrupole	4522
	E. Bouquerel, O. Dorvaux, S. Kihel, M. Krauth, P. Peaupardin IPHC, Strasbourg Cedex 2, France C. Ciemala IFJ-PAN, Kraków, Poland
	The Photon Array for the studies of Radioactive and Ion Stable beams (PARIS) is a multidetector of clusters. Each cluster is composed of 9 units of two-shells phoswiches of LaBr3/NaI scintillators optically coupled to one photomultiplier tube. PARIS will be used in combination with the VAMOS spectrometer at GANIL. During the experiment, PMTs will be exposed to the constant magnetic fringe fields produced by a quadrupole. Magnetic shielding is essential to efficiently lower the magnetic field inside the PMTs. The design and the optimization of this shield is presented. A comparison is done between the simulated and the experimental values.
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THPVA045	Telecommunication Concepts for Compact, Electro-Optical and Frequency Tunable Sensors for Accelerator Diagnostics	laser, electron, diagnostics, synchrotron	4534
	E. Bründermann, A.-S. Müller KIT, Karlsruhe, Germany I. Hosako, I. Morohashi, S. Nakajima, S. Saito, N. Sekine NICT, Tokyo, Japan
	Funding: Supported by Invitation Fellowship for Research ID No. S16704 of Japan Society for the Promotion of Science (JSPS) awarded to E.B. hosted by I.H. Terahertz diagnostics* for investigating the properties of electron and photon beams, especially the investigation of electron bunch instabilities, accompanied by terahertz photon bursts is increasingly employed to monitor and investigate electron bunch dynamics. Recent advances in information and communications technology promise compact sensors based on telecom and thus industry standards. We present potential applications of such technology concepts for accelerators, including a miniature probe for electro-optical sampling, which could be employed for electron bunch electrical near-field studies, and laser sources with widely tunable pulse repetition rates adaptable for pulsed diagnostics*. E. Bründermann, H.-W. Hübers, M.F. Kimmitt, Terahertz Techniques, Springer-Verlag (2012). J.L. Steinmann et al., Phys. Rev. Lett. 117, 174802, 2016. * M. Brosi et al., Phys. Rev. Accel. Beams 19, 110701, 2016. **** I. Morohashi et al., Nano Commun Netw 10, 79, 2016.
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THPVA050	Latest Progress of Magnet Girder Prototypes for HEPS-TF	controls, alignment, target, interface	4551
	H. Wang, C. H. Li, S.J. Li, H. Qu, Z. Wang, L. Wu IHEP, Beijing, People's Republic of China
	The magnet girder technology is one of the key tech-nologies which should be overcome in the stage of HEPS-TF (Test Facility of High Energy Photon Source). The girder should be beam-based aligned, and must has high adjusting precision and high stability as well. For these issues, two girder systems are designed and developed. This paper will describe the latest progress of the girder prototypes, including structure design updates, control system progress, and processing and assembling of Girder I prototype.
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THPVA051	Vibration Study of Magnet Girder of the HEPS-TF	experiment, factory, quadrupole, emittance	4554
	Z. Wang, C. H. Li, H. Qu, H. Wang IHEP, Beijing, People's Republic of China
	Abstract: There are stringent requirements on beam stability in the High Energy Photon Source (HEPS). The stability of the magnet girder is an extremely important factor for the beam stability. This paper will discuss the influence of ground vibration to the beam stability. This influence will determine the scope of the vibration magnification of the magnet girder. By improving the stiffness of the magnet girder, the influence will be reduced and the beam stability shall be improved. Besides, the progress of the HEPS-TF girder prototype and the vibration test will be described.
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THPVA053	Design of the Girder Control System for HEPS-TF	controls, hardware, interface, status	4560
	S.J. Li, C. H. Li, J. Liu, H. Wang, Z. Wang IHEP, Beijing, People's Republic of China
	To make the alignment become easier, the HEPS-TF (High Energy Photon Source-Test Facility) magnet girder, which is different from the conventional one, is designed to achieve the goal of adjusting the girder's position and orientation online. The control system is one of the key sub-part. This Paper will describe the control system design, especially on the hardware configuration, software programming as well as user interface design.
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THPVA068	General Design of ID Front Ends in the TPS	radiation, vacuum, synchrotron, storage-ring	4601
	C.K. Kuan, C.K. Chan, Y.T. Cheng, J. -Y. Chuang, Y.M. Hsiao, I.C. Sheng, C. Shueh, H.Y. Yan NSRRC, Hsinchu, Taiwan
	The Taiwan Photon Source is a 3 GeV, 3rd generation synchrotron radiation source at the NSRRC. Phase-I commissioning includes seven Insertion Device (ID) Front Ends which are built to transmit intense synchro-tron radiation generated by In-vacuum Undulators and Elliptically Polarizing Undulators in the storage ring to the Photon Beamline. The total power and power distri-bution on Front End components is calculated and ana-lysed and Finite Element Analysis is used to verify the thermal performance under high heat loads while Monte-Carlo methods are utilized to simulate the vacuum pres-sure distribution. All apertures of the components are the same to simplify and standardize the design of the Front Ends. This paper describes main design considerations, especially the high heat load and vacuum pressure distri-bution.
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THPVA072	Travelling Laser Focus System for the Particles Acceleration	laser, acceleration, radiation, emittance	4613
	A.A. Mikhailichenko Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	We describe the result of the wake-fields calculation in a device for acceleration of particles in the micro-structures illuminated by the swept laser bust. Calculations carried with help of FlexPDE code.
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Paper

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MOOCB3

Intensity Interferometer to Measure Bunch Length at SPEAR3

detector, optics, electron, storage-ring

60

W.J. Corbett
SLAC, Menlo Park, California, USA
T.M. Mitsuhashi
KEK, Ibaraki, Japan

Electron bunch length in a storage ring is typically measured with streak cameras, electro-optic devices or non-linear cross-correlation techniques with a range of system complexity, signal-to-noise ratios and cost. Another straight-forward method is to construct an 'intensity interferometer' utilizing a coincidence detector to record simultaneous photon arrival events. In this configuration, visible SR light is passed through a narrow bandpass filter followed by a small pinhole to generate a stream of single-mode monochromatic wavepackets. As the interferometer delay is scanned across an electron bunch, two-photon events occurring within the longitudinal coherence time of the light cause a reduction in the measured coincidence rate. The resulting autocorrelation of the optical pulse duration reveals the electron bunch length, independent of synchrotron oscillation motion. In this paper we comment on the theory and report on preliminary measurements carried out at SPEAR3.

Slides MOOCB3 [2.606 MB]

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MOPAB011

Impact on the HL-LHC Triplet Region and Experiments From Asynchronous Beam Dumps on Tertiary Collimators

proton, neutron, optics, interface

96

A. Tsinganis, R. Bruce, F. Cerutti, A. Lechner
CERN, Geneva, Switzerland

Accidental beam impacts on the tertiary collimators (TCTs) can lead to significant energy deposition in the triplet region and to leakage of the induced particle shower towards the experimental cavern. In this work, carried out in the context of the planned High Luminosity Upgrade of the LHC, severe impacts from asynchronous beam dumps on the horizontal tertiary collimators in cells 4 and 6 of the CMS insertion were studied, with half or a full proton bunch impacting on a collimator jaw. The choice of jaw material is shown to be of great importance, with over a factor of 10 increase in peak energy density values in the triplet coils moving from tungsten (Inermet) to molybdenum graphite jaws. Nevertheless, although the quench limit is exceeded in at least one or more triplet magnets in all the evaluated scenarios, values remain well below the damage limit. Energy spectra of particles leaking into the experimental cavern have also been estimated and are presented here.

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MOPAB057

Analysis and Correction of Geometrical Non-Linearities of ELI-NP BPMs on Position and Current Measurements

linac, electron, laser, instrumentation

235

G. Franzini, F. Cioeta, O. Coiro, V.L. Lollo, D. Pellegrini, S. Pioli, A. Stella, A. Variola
INFN/LNF, Frascati (Roma), Italy
M. Marongiu
INFN-Roma, Roma, Italy
A. Mostacci
University of Rome La Sapienza, Rome, Italy
A.A. Nosych
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
L. Sabato
U. Sannio, Benevento, Italy

The advanced source of Gamma-ray photons will be soon built near Bucharest (Romania) by an European consortium (EurogammaS) led by INFN, as part of the ELI-NP (Extreme Light Infrastructure-Nuclear Physics). It will generate photons by Compton back-scattering in the collision between a multi-bunch electron beam, at a maximum energy of 720 MeV, and a high intensity recirculated laser pulse. An S-Band photo-injector and the following C-band Linac, which are under construction, will operate at 100Hz repetition rate with macro pulses of 32 electron bunches, separated by 16ns and with 250pC nominal charge. Stripline and cavity BPMs will be installed along the linac, in order to measure both the position and charge of the electron beam. Stripline BPM response can be considered linear within a limited area around the BPM origin. In order to use the full BPM acceptance area, without accuracy losses due to non-linearities, we plan to use correction algorithms, developed on the basis of simulations and measurements of BPMs response. In particular, suitable high-order surface polynomials will be used.

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MOPAB065

Breit-Wheeler Scattering Events Produced by Two Interacting Compton Sources

scattering, electron, laser, background

261

I. Drebot, L. Serafini
Istituto Nazionale di Fisica Nucleare, Milano, Italy
D. Micieli, E. Tassi
UNICAL, Arcavacata di Rende, Italy
E. Milotti
INFN-Trieste, Trieste, Italy
V. Petrillo
Universita' degli Studi di Milano & INFN, Milano, Italy

We present the dimensioning of a photon-photon collider based on conventional Compton gamma sources for the observation of Breit-Wheeler pair production and QED gamma-gamma generation. Two symmetric electron beams, generated by photocathodes and accelerated in linacs, produce two primary gamma rays through Compton back-scattering with two high-energy lasers. Tuning the system energy above the Breit-Wheeler cross section threshold, a flux of secondary electrons and positrons is generated. The process is analyzed by start-to-end simulations. The Monte Carlo code 'Rate Of Scattering Events' (ROSE) has been developed ad hoc for the counting of the QED events. Realistic numbers of the secondary particles yield, referring to existing or approved set-ups, a discussion of the feasibility of the experiment and the evaluation of the background are presented.

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MOPAB066

Development and Performance Test of the BPM System for the SPring-8 Upgrade

radiation, simulation, storage-ring, electron

265

H. Maesaka
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan
H. Dewa, T. Fujita, M. Masaki
JASRI, Hyogo, Japan
S. Takano
Japan Synchrotron Radiation Research Institute (JASRI), RIKEN SPring-8 Center, Hyogo, Japan

We are developing a stable and precise BPM system for the low-emittance upgrade of SPring-8. One of the essential requirements for the BPM is the long term stabilization of the photon beam by regulating the electron beam orbit. Both the single-pass resolution of 100 um rms for an injected beam charge of 100 pC and an accuracy of 100 um rms are also crucial for beam commissioning. Drift sources of the present BPM system have been investigated extensively, such as humidity-dependent drifts coming from the radiation damage of coaxial cables, and the results are fed back to the design of the new BPM system. We have optimized the design of the button BPM electrodes to reconcile reduction of trapped-mode heating and maximization of the signal intensity. Stringent machining tolerance is imposed on a BPM head to align the BPM electric center accurately. A few kinds of the BPM head prototypes were produced and the machining accuracy, RF characteristics etc. were confirmed to be sufficient. We have installed one of the prototypes in the present storage ring to test the performance of the new BPM system under development, and have been obtaining successful results satisfying the requirements.

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MOPAB118

Cherenkov Diffraction Radiation From Long Dielectric Material: An Intense Source of Photons in the NIR-THz Range

radiation, electron, target, storage-ring

400

T. Lefèvre, M. Bergamaschi, O.R. Jones, R. Kieffer, S. Mazzoni
CERN, Geneva, Switzerland
M.G. Billing, J.V. Conway, J.P. Shanks
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
L.M. Bobb
DLS, Oxfordshire, United Kingdom
P. Karataev
Royal Holloway, University of London, Surrey, United Kingdom

This paper presents the design on the Cornell Electron Storage Ring (CESR) of an experimental set-up to meas-ure incoherent Diffraction Cherenkov Radiation (DChR) produced in a 2 cm long SiO2 radiator by a 2.1 GeV elec-tron beam. The electron beam is circulating at a distance of few mm from the edge of the radiator and the DChR photon output power is expected to be significantly higher than the diffraction radiation power emitted from a metal-lic slit of similar aperture. The radiator design and the detection set-up are presented in detail together with sim-ulations describing the expected properties of the emitted DChR in terms of light intensity and spectral bandwidth. Finally, potential applications of DChR are discussed.

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MOPAB125

Post-Mortem System for the Taiwan Photon Source

kicker, timing, operation, data-acquisition

422

C.Y. Liao, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.H. Huang, C.Y. Wu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source (TPS), a 3-GeV third-generation synchrotron light source located in Hsinchu, is available to users since 2016. During operation, it will inevitably encounter system trips caused by beam losses. Thus, a post-mortem (PM) system is an important tool to analyze the cause of such events. Main functions of the PM system are: (i) PM trigger will be generated when the stored beam is suddenly lost abnormally; (ii) storage of relevant signals when the server receives such a trigger; (iii) PM Viewer to analyze each event and understand the cause and effect of a beam trip event. The post-mortem system architecture, plans and implementation will be discussed in this report.

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MOPAB139

A Supersonic Gas-Jet Based Beam Induced Fluorescence Prototype Monitor for Transverse Profile Determination

electron, ion, experiment, gun

458

H.D. Zhang, E. Martin, V. Tzoganis, C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom
E. Barrios Diaz, N. Chritin, O.R. Jones, G. Schneider, R. Veness
CERN, Geneva, Switzerland
P. Forck, S. Udrea
GSI, Darmstadt, Germany
P. Forck
IAP, Frankfurt am Main, Germany
E. Martin, V. Tzoganis, C.P. Welsch, H.D. Zhang
The University of Liverpool, Liverpool, United Kingdom
S. Udrea
TU Darmstadt, Darmstadt, Germany

Supersonic gas jets have been used in transverse beam profile monitoring as Ionization Profile Monitors (IPMs) and Beam Induced Fluorescence (BIF) monitors. The former method images ions generated by the projectile beam, whilst the latter is based on the detection of photons. This is a promising technology for use in high energy accelerators, such as the High Luminosity Large Hadron Collider (HLLHC). In this paper, the suitability of a supersonic gas jet in combination with a BIF detection system for the measurement of the transverse beam profile of a low energy electron beam is discussed. The technical layout and experimental results from measurements at a test installation at the Cockcroft Institute are also presented.

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MOPAB146

Electron Beam Diagnosis Using K-edge Absorption of Laser-Compton Photons

electron, laser, emittance, scattering

473

Y. Hwang, T. Tajima
UCI, Irvine, California, USA
C.P.J. Barty, D.J. Gibson, R.A. Marsh
LLNL, Livermore, California, USA

Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
The mean energy, energy spread and divergence of the electron beam can be deduced from laser-Compton scattered X-rays filtered by a material whose K-edge is near the energy of the X-rays. This technique, combined with a spot size measurement of the beam, can be used to measure the emittance of electron bunches, and can be especially useful in LWFA experiments where conventional methods are unavailable. The effects of the electron beam parameters on X-ray absorption images are discussed, along with experimental demonstrations of the technique using the Compact Laser-Compton X-ray Source at LLNL.

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MOPIK026

Commissioning and Operation of an Ultrafast Electron Diffraction Facility as Part of the ATF-II Upgrade at Brookhaven National Laboratory

electron, operation, laser, experiment

554

M.G. Fedurin, M. Babzien, C. Folz, M. Fulkerson, K. Kusche, J.J. Li, R. Malone, M.A. Palmer, T.V. Shaftan, J. Skaritka, L. Snydstrup, C. Swinson, F.J. Willeke
BNL, Upton, Long Island, New York, USA

Funding: Work supported by the US DOE under contract DE-SC0012704.
The Accelerator Test Facility (ATF) at Brookhaven National Laboratory (BNL) is presently carrying out an upgrade, ATF-II, which will provide significantly expanded experimental space and capabilities for its users. One of the new capabilities being integrated into the ATF-II program is an Ultrafast Electron Diffraction (UED) beam line, which was originally deployed in the BNL Source Development Laboratory. Inclusion of the UED in the ATF-II research portfolio will enable ongoing development and extension of the UED capabilities for use in materials research. We describe the design, operation and future plans for the UED beam line at the ATF-II.

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MOPVA001

Coherent X-Ray Radiation From Electron Beam Processed by Channeling and Emittance Exchange

electron, radiation, laser, emittance

845

I. Lobach, A.I. Benediktovitch
BSU, Minsk, Belarus

Presented contribution theoretically studies a novel scheme of compact intense x-ray radiation source. In the scheme, longitudinally modulated electron beam emits x-rays by Inverse Compton Scattering (ICS). The setup's feature is the way how longitudinal density modulation in angstrom scale is created. There are three stages of processing of initial beam of relativistic electrons: 1. First, the electrons cross a crystal plate in channeling regime. It is shown that upon leaving the crystal, the electron beam acquires discernible transverse modulation in angstrom scale. It is taken into account that not all electrons are captured in channeling mode and that some of those that do may leave it as they travel through the crystal slab. 2. Further, the beam is transported to Emittance Exchange (EEX) line, in which the direction of modulation is tilted and the beam becomes longitudinally modulated. The scale of modulation remains the same. 3. Finally, intense quasi-coherent x-ray radiation is emitted by ICS. Numerical estimations show that coherent contribution to intensity is considerable for feasible parameters of used beam, components of EEX line and laser producing photons for ICS.

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MOPVA004

Operating Simultaneously Two In-Vacuum Canted Undulators in Synchrotron SOLEIL

undulator, vacuum, radiation, electron

851

L.S. Nadolski, Y.-M. Abiven, P. Brunelle, N. Béchu, M.-E. Couprie, F.J. Cullinan, X. Delétoille, M. El Ajjouri, C. Herbeaux, N. Hubert, N. Jobert, M. Labat, J.-F. Lamarre, A. Lestrade, A. Loulergue, O. Marcouillé, P. Monteiro, A. Nadji, R. Nagaoka, D. Pédeau, P. Rommeluère, K.T. Tavakoli, M. Valléau, J. Vétéran
SOLEIL, Gif-sur-Yvette, France
C. Benabderrahmane
ESRF, Grenoble, France

Each long SOLEIL beamline, ANATOMIX and Nanoscopium, takes a photon beam from an in-vacuum undulator with a minimum gap of 5.5 mm. The canted radiation sources are installed in a long straight section of the storage ring. The first closure of both undulators led to the severe damage of the downstream undulator in 2011. The reason for this incident has been investigated and clearly identified. A long-term project has enabled us to find a technical solution for a simultaneous operation of both undulators. A special angle fast interlock was designed and a dedicated photon absorber has been introduced at the entrance of the second undulator while keeping the impact on the beam performance as low as possible. The main technical steps will be reported with an interim solution put in place in spring 2015 and a final solution deployed and validated in May 2016.

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MOPVA023

Luminosity Increase in Laser-Compton Scattering by Crab Crossing Method

laser, electron, luminosity, scattering

902

Y. Koshiba, D. Igarashi, S. Ota, T. Takahashi, M. Washio
RISE, Tokyo, Japan
K. Sakaue
Waseda University, Waseda Institute for Advanced Study, Tokyo, Japan
J. Urakawa
KEK, Ibaraki, Japan

In collider experiments such as KEKB, crab crossing method is a promising way to increase the luminosity. We are planning to apply crab crossing to laser-Compton scattering, which is a collision of electron beam and laser, to gain a higher luminosity leading to a higher flux X-ray source. It is well known that the collision angle between electron beam and laser affects the luminosity. It is the best when the collision angle is zero, head-on collision, to get a higher luminosity but difficult to construct such system especially when using an optical cavity for laser. Concerning this difficulty, we are planning crab crossing by tilting the electron beam using an rf-deflector. Although crab crossing in laser-Compton scattering has been already proposed*, nowhere has demonstrated yet. We are going to demonstrate and conduct experimental study at our compact accelerator system in Waseda University. In this conference, we will report about our compact accelerator system, laser system for laser-Compton scattering, and expected results of crab crossing laser-Compton scattering.
*Variola Alessandro, et al. Luminosity optimization schemes in Compton experiments based on Fabry-Perot optical resonators. Physical Review Special Topics-Accelerators and Beams 14.3 (2011): 031001.

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MOPVA026

Effects of Insertion Devices on Stored Electron Beam of High Energy Photon Source

undulator, emittance, insertion, brilliance

911

X.Y. Li, Z. Duan, D. Ji, Y. Jiao, Y.F. Yang
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a 4th generation, 6-Gev, ultralow-emittance, photon source project in China. High brightness hard X-ray beams at the energy particularly above 10kev are provided by insertion devices installed in straight sections of the storage ring. Brightness tuning curves of 14 ID beamlines planned in HEPS first stage are obtained after designing their parameters. However the presence of these insertion devices produce several effects on the beam performances including betatron tunes, betatron amplitude functions, closed orbit, emittance and dynamic aperture etc. It is found that the vertical octupole effect due to the fourteen IDs under the present schemes produce the most significant effect on the vertical dynamic aperture reduction. The ID field error effects on close orbit can be completely compensated by two correctors adjacent the ID at the both side. The horizontal emittance reduces to 36pm.rad due to the damping wiggler effect of IDs with field error after the orbit correction is also obtained.

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MOPVA071

Press Forming Tests of Superconducting Spoke Cavity for Laser Compton Scattered Photon Sources

cavity, laser, niobium, resonance

1031

M. Sawamura, R. Hajima
QST, Tokai, Japan
H. Hokonohara, Y. Iwashita, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
T. Kubo, T. Saeki
KEK, Ibaraki, Japan

We are developing the superconducting spoke cavity for laser Compton scattered (LCS) photon sources. We adopt the superconducting spoke cavity for electron beam drivers to realize a wide use of LCS X-ray and '-ray sources in academic and industrial applications. The spoke cavity can make the accelerator more compact than an elliptical cavity because the cavity size is small at the same frequency and the packing factor is good by installing couplers on outer conductor. Though our proposal design for the photon source consists of the 325 MHz spoke cavities in 4K operation, we are fabricating the half scale model of 650 MHz spoke cavity in order to accumulate our cavity production experience by effective utilization of our limited resources. Since the spoke has more complicated structure than an elliptical cavity, we performed press forming tests for the half spoke and estimated the formed shapes with 3-dimensional measurement.

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MOPVA076

Measurement of Thin Film Coating on Superconductors

cryogenics, controls, experiment, FPGA

1043

Y. Iwashita, Y. Fuwa, H. Tongu
Kyoto ICR, Uji, Kyoto, Japan
H. Hayano, T. Kubo, T. Saeki
KEK, Ibaraki, Japan
M. Hino
Kyoto University, Research Reactor Institute, Osaka, Japan
H. Oikawa
Utsunomiya University, Utsunomiya, Japan

Funding: This research is supported by following programs: Grant-in-Aid for Exploratory Research JSPS KAKENHI Grant Number 26600142 and Photon and Quantum Basic Research Coordinated Development Program from the MEXT.
Multilayer thin film coating is a promising technology to enhance performance of superconducting cavities. Until recently, principal parameters to achieve the sufficient performance had not been known, such as the thickness of each layer. We proposed a method to deduce a set of the parameters to exhibit a good performances. In order to verify the scheme, we are trying to make some experiments on the subject at Kyoto. The sample preparation and the test setup for the measurement apparatus will be discussed.

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TUOAA2

A Soft X-Ray Free-Electron Laser Beamline of SACLA

FEL, electron, undulator, laser

1209

K. Togawa, T. Asaka, N. Azumi, T. Hara, T. Hasegawa, N. Hosoda, T. Inagaki, T. Ishikawa, R. Kinjo, C. Kondo, H. Maesaka, S. Matsui, T. Ohshima, Y. Otake, S. Owada, H. Tanaka, T. Tanaka, M. Yabashi
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
T. Bizen, H. Kimura, S. Matsubara, K. Nakajima, T. Sakurai, T. Togashi, K. Tono
JASRI/SPring-8, Hyogo, Japan
T. Fukui
RIKEN SPring-8 Center, Innovative Light Sources Division, Hyogo, Japan

At the Japanese x-ray free-electron laser (FEL) facility, SACLA, the beamline-1 has been upgraded from a spontaneous radiation to a soft x-ray FEL beamline, which generates FEL lights over a wide wavelength range from the extreme-ultraviolet to the soft x-ray regions. We started operation for users in July 2016. A dedicated accelerator, which is a refinement of the SCSS test accelerator operated in 2005-2013, was installed beside the XFEL beamlines in the SACLA undulator hall. The SCSS concept to make an FEL facility compact was continuously adopted. In the 2016 summer shutdown period, the beam energy was upgraded from 500 MeV to 800 MeV by adding two C-band rf units. The maximum K-value of the undulator magnet is 2.1. The available wavelengths of the FEL lights were extended to the range from 8 to 50 nm with pulse energies between a few to few tensμJ at an operational repetition rate of 60 Hz. In this conference, we will report an overview of the upgraded SACLA-beamline-1 and characteristics of the FEL light pulse.

Slides TUOAA2 [15.457 MB]

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TUOAA3

Progress of Pr2Fe14B Based Hybrid Cryogenic Undulators at SOLEIL

undulator, cryogenics, radiation, electron

1213

A.M. Ghaith, P. Berteaud, F. Blache, F. Briquez, N. Béchu, M.-E. Couprie, J. Da Silva Castro, J.M. Dubuisson, C. Herbeaux, C.A. Kitegi, A. Lestrade, O. Marcouillé, F. Marteau, M. Sebdaoui, G. Sharma, A. Somogyi, K.T. Tavakoli, M. Tilmont, M. Valléau
SOLEIL, Gif-sur-Yvette, France
C. Benabderrahmane
ESRF, Grenoble, France

Cryogenic Permanent Magnet Undulators (CPMUs) take advantage of the enhanced field performance of permanent magnets when cooled down to low temperature, enabling shorter period with sufficient magnetic field to achieve high brightness radiation in the X-ray domain. Several CPMUs have been manufactured at SOLEIL. The first CPMU of period 18 mm (U18), optimized with a phase error of 3.2° at temperature of 77 K, has been installed and operated for the past 5 years at SOLEIL for the NANOSCOPIUM beamline. We report on photon beam based alignment enabling for a better adjustment of the vertical position offset of the undulator with a precision of 50 μm, and on the correction of the taper with a precision of 5 μrad to enhance the radiation flux. A second U18 cryo-ready undulator, with a new mechanical and magnetic sorting of module shimming, has attained a phase error of 2.3° at CT without any further adjustments after the assembly. Currently, two more CPMUs are being built; a 2 m long U18 for the SOLEIL ANATOMIX beamline, and a 3 m long U15 undulator reaching a magnetic gap of 3 mm. The new challenges encountered with magnetic measurements and mechanical designs for U15 are presented.

Slides TUOAA3 [3.491 MB]

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TUXB1

Non-destructive Beam Profile Monitors

ion, electron, vacuum, focusing

1234

C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

This paper will present an overview and comparison between beam induced fluorescence, residual gas ionization and gas jet based beam profile monitors, based on recent experimental and theoretical results at different labs. The achievable image/profile quality and resolution limits will be discussed, along with design consideration for different particle species and primary beam energies. Details may be provided about different classic and novel approaches to gas jet shaping, including nozzle-skimmer and Freznel Zone Plate configurations. Finally, particular challenges such as those arising from monitoring multiple beams in parallel (e.g. proton and electron beam in HLLHC) and solutions for targeting the energy limit within the HLLHC project will be presented.

Slides TUXB1 [12.557 MB]

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TUOAB2

First Observation of the LHC Beam Halo Using a Synchrotron Radiation Coronagraph

background, simulation, synchrotron, radiation

1244

T.M. Mitsuhashi
KEK, Ibaraki, Japan
E. Bravin, F. Roncarolo, G. Trad
CERN, Geneva, Switzerland

A test coronagraph for the observation of beam halo has been installed in the Synchrotron radiation monitor line LHCB2 in 2015. This coronagraph is commissioned with LHC operation at 450GeV (injection energy). After some optical testing of the coronagraph with visible Synchrotron radiation in B2, we try to observe artificially-made beam halo. The beam halo of 10^-3 order of magnitude against the beam core is excited by the kicker of the transverse damper. We have succeeded to observe a diffraction noise free image of beam halo. The effect of beam collimator is also observed. Reduction of beam halo intensity was found nicely proportional to the simultaneously-recorded beam loss.

Slides TUOAB2 [8.302 MB]

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TUPAB002

Material Tests for the ILC Positron Source

target, positron, electron, operation

1293

A. Ushakov, G.A. Moortgat-Pick
University of Hamburg, Hamburg, Germany
K. Aulenbacher, Th. Beiser, P. Heil, V. Tioukine
IKP, Mainz, Germany
A. Ignatenko, S. Riemann
DESY Zeuthen, Zeuthen, Germany
A.L. Prudnikava, Y. Tamashevich
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

The positron source is a vital system of the ILC. The conversion target that yields 10¹⁴ positrons per second will undergo high peak and cyclic load during ILC operation. In order to ensure stable long term operation of the positron source the candidate material for the conversion target has to be tested. The intense electron beam at the Mainz Microtron (MAMI) provides a good opportunity for such tests. The first results for Ti6Al4V are presented which is the candidate material for the positron conversion target as well as for the exit window to the photon beam absorber.

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TUPAB003

High Energy Density Irradiation With MAMI LINAC

target, positron, electron, radiation

1296

P. Heil, K. Aulenbacher, Th. Beiser
IKP, Mainz, Germany
A. Ignatenko, G.A. Moortgat-Pick, A. Ushakov
DESY, Hamburg, Germany
S. Riemann
DESY Zeuthen, Zeuthen, Germany

In order to build a positron source for the ILC, a high energy density irradiation is needed to test the used materials. At the MAMI linear accelerator such a radiation can be provided at different electron energies. With a macro pulsed source it is possible to imitate a yearlong radiation at the ILC within several hours. Small transversal beam sizes need to be provided with the focusing system and be measured at high beam currents using transition radiation and current measurements.

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TUPAB025

Experimental Results for Multiphoton Nonlinear Photoemission Processes on Phil Test Line

laser, electron, gun, cathode

1369

H. Purwar, C. Bruni, V. Chaumat, N. ElKamchi, V. Soskov
LAL, Orsay, France
D. Garzella
CEA, Gif-sur-Yvette, France
B. Lucas
CNRS LPGP Univ Paris Sud, Orsay, France
M. Pittman
CLUPS, Orsay, France
T. Vinatier
DESY, Hamburg, Germany

One of the prerequisites for the next generation high luminosity light sources is the availability of the short electron bunches. It also has several applications in other domains, including medical diagnostics and high-resolution imaging. In principle, using photoelectric effect a short electron bunch can initially be generated by illuminating a photocathode with an ultra-short light pulse of appropriate wavelength. Strong EM fields from a RF gun or similar accelerating structures, synchronized with the incoming laser pulses, are then used to accelerate these electron bunches initially up to an energy of tens of MeV. We present our preliminary results on the experimental investigation of two-photon nonlinear photoemission processes for the generation of picosecond, low-charge electron bunches conducted at PHIL photoinjector facility. A comparison of the emission efficiency and bunch characteristics with the single photon emission process is also made.
*PHIL is an acronym for Photo-injector at Linear Accelerator Laboratory (LAL).

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TUPAB035

Field Quality of 1.5 m Long Conduction Cooled Superconducting Undulator Coils with 20 mm Period Length

undulator, multipole, synchrotron, emittance

1395

S. Casalbuoni, N. Glamann, A.W. Grau, T. Holubek, D. Saez de Jauregui
KIT, Eggenstein-Leopoldshafen, Germany
C. Boffo, T.A. Gerhard, M. Turenne, W. Walter
Babcock Noell GmbH, Wuerzburg, Germany

The Institute for Beam Physics and Technology (IBPT) at the Karlsruhe Institute of Technology (KIT) and the industrial partner Babcock Noell GmbH (BNG) are col-laborating since 2007 on the development of superconducting undulators both for ANKA and low emittance light sources. The first full length device with 15 mm period length has been successfully tested in the ANKA storage ring for one year*. The next superconducting undulator has 20 mm period length (SCU20) and is also planned to be installed in the accelerator test facility and synchrotron light source ANKA. The SCU20 1.5 m long coils have been characterized in a conduction cooled horizontal test facility developed at KIT IBPT. Here we present the local magnetic field and field integral measurements, as well as their analysis including the expected photon spectrum.
*S. Casalbuoni et al., Characterization and long term operation of a novel superconducting undulator with 15 mm period length in a synchrotron light source, Phys. Rev. ST Accel. Beams, vol. 19, p.110702, Nov. 2016.

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TUPAB055

Development of compact magnetic field measurement system available for in-vacuum undulators

undulator, brightness, vacuum, emittance

1449

M. Adachi, R. Kato, T. Shioya, K. Tsuchiya
KEK, Ibaraki, Japan

A low-emittance 3-GeV KEK-LS* ring has been designed at KEK. KEK-LS's undulators can produce extremely high brightness light ranging from VUV to X-ray. Brightness of undulator light strongly depends on the phase error of its periodic magnetic field. Then a precise magnetic field adjustment is required in order to prevent the reduction of the brightness performance. Generally, the adjustment is performed by the conventional field measurement system equipped with hole-probes on a huge stone table. But, for the in-vacuum undulator, the measurement must be performed without the vacuum chamber. The additional phase error caused by reattaching the chamber is not negligible for the low emittance rings. Therefore, some groups have developed measurement systems available for the direct field measurement inside the chamber**,***. We have started to develop a compact measurement system. Our system is compacted and stabilized by utilizing the rigid metal beam of the undulator frame instead of the stone table. In the conference, we will report the detail of the system and the present status of the development.
* KEK-LS HP, http://kekls.kek.jp/
** T. Tanaka, et al., Physical Review ST-AB, vol.12, p.120702 (2009).
*** M. Musardo, et al., Proceedings of IPAC2015, Richmond, VA, USA, p.1693 (2015).

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TUPAB064

Development of a PrFeB Cryogenic Permanent Magnet Undulator (CPMU) Prototype at IHEP

vacuum, cryogenics, undulator, permanent-magnet

1469

H.H. Lu, W. Chen, L. Gong, X.Y. Li, L.Z. Li, S.C. Sun, Y.J. Sun, Y.F. Yang, L. Zhang, X.Z. Zhang, S.T. Zhao
IHEP, Beijing, People's Republic of China

A PrFeB cryogenic permanent magnet undulator (CPMU) prototype is under construction for High Energy Photon Source Test Facility (HEPS-TF) at IHEP. The device is a full scale in-vacuum undulator with a magnetic length of 2 meters and a period of 13.5 mm, and it will work at less than 85K. The whole design scheme of prototype is presented and the specifications are given, where the consideration of in-vacuum magnetic measurement bench is also included. The development progress is introduced.

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TUPAB066

Mechanical Design of a Cryogenic Permanent Magnet Undulator at IHEP

vacuum, cryogenics, undulator, permanent-magnet

1475

S.C. Sun, W. Chen, L. Gong, X.Y. Li, L.Z. Li, H.H. Lu, Y.J. Sun, Y.F. Yang, L. Zhang, X.Z. Zhang, S.T. Zhao
IHEP, Beijing, People's Republic of China

High Energy Photon Source (HEPS) at Institute of High energy Physics (IHEP) is a new 6 GeV third generation electron storage ring. Insertion devices play a significant role in achieving the high performance of the photon source. A 13.5mm period-length Cryogenic Permanent Magnet Undulator (CPMU) prototype is designed and under construction. The mechanical structure designed based on physical requirements will be presented.
Work supported by Project of High Energy Photon Source Test Facility,
email address: sunsc@ihep.ac.cn

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TUPAB067

Studies of Beam Lifetime at HEPS

scattering, lattice, electron, storage-ring

1478

S.K. Tian, Y. Jiao, G. Xu
IHEP, Beijing, People's Republic of China

The electron storage ring's beam lifetime is determined by scattering of the electrons at the nucleus and the shell of the atoms of the residual gas (gas lifetime) and the scattering of electrons within a bunch (Touschek lifetime).Beam lifetime studies have been performed at the 6 GeV electron storage ring HEPS.

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TUPAB068

Design of the CPMU Vacuum System at the HEPS

vacuum, undulator, cryogenics, radiation

1482

L. Zhang, H.H. Lu, S.C. Sun
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS) is a 3rd generation synchrotron radiation light source. Its beam energy is 6 GeV and its emittance is less than 60 pm'rad, which can provide high brilliance hard X-rays to several tens of experimental stations. The Cryogenic Permanent Magnet Undulator (CPMU) is one of the key components to achieve the high brilliance. And its vacuum system is necessary to provide an ultra-high vacuum environment for CPMU operation. To design the CPMU vacuum system, we do experiments to test the outgassing rate, estimate the total gas load, calculate the effective pumping speed, design the baking program and select all pumps and other vacuum equipments. This paper presents the design specifications and the assemblage status of the CPMU vacuum system.

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TUPAB103

Orbit Correction With Path Length Compensation Based on Rf Frequency Adjusments in TPS

operation, electron, feedback, site

1553

P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Huang, C.-C. Kuo, C.C. Liang, Y.-C. Liu, H.-J. Tsai, F.H. Tseng
NSRRC, Hsinchu, Taiwan

The 3 GeV Taiwan Photon Source has been routinely operated for public users since September 2016. Orbit reproducibility and stability are critical for the quality of user experiments. Ambient temperature variations and earth tides can cause a change in circumference, changing in turn the beam energy, and orbit drift. Therefore both, orbit correction and rf frequency adjustments are necessary to keep the ring circumference constant. A Fast Orbit Feedback (FOFB) system combined with rf frequency correction deduced from the fast corrector strengths is applied to the FOFB routine. The correlation between the measured frequency variation with ambient temperature and earth tides is also reported in this article.

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TUPAB104

Optimized Undulator to Generate Low Energy Photons From Medium to High Energy Accelerators

polarization, optics, undulator, radiation

1556

T.Y. Chung, M.-S. Chiu, J.C. Huang, C.-S. Hwang, J.C. Jan, C.K. Yang
NSRRC, Hsinchu, Taiwan
H.W. Luo
NTHU, Hsinchu, Taiwan

While emitting low energy photons from a medium or high energy storage ring, the on-axis heat load on the beam line optics can become a critical issue. In addition, the heat load in the bending magnet chamber, especially in the vertical and circular polarization mode of operation may cause some concern. In this work, we compare the heat loads for the APPLE-II and the Knot-APPLE, both optimized to emit 10 eV photons from the 3 GeV TPS. Under this constraint the heat load analysis, synchrotron radiation performance and features in various polarization modes are presented. Additional consideration is given to beam dynamics effect.

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TUPAB107

Study of 60 Hz Beam Orbit Fluctuations in the Taiwan Photon Source

SRF, vacuum, shielding, insertion-device

1566

C.H. Huang, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source is a 3 GeV synchrotron light source at NSRRC. To achieve high quality experimental results, it is important to minimize beam motion. During the installation of insertion devices and front-ends, the beam motion around 60 Hz became significant. The response matrix together with singular value decomposition was used to identify the transmitter of the superconducting radio frequency system as the source for the 60 Hz perturbations. This was subsequently corrected by rerouting the grounding of the mains in the transmitters. Yet, the 60Hz orbit fluctuation became even more serious after the next shutdown. A serious of experiments are performed to dig out that the beam was disturbed by the magnetic field from newly installed fan motors. Shielding the fans with mu-metal and increasing the distance between fan and beam pipe drastically reduced the leakage field and greatly increased beam stability. These errors could be prevented at the design stage in the ideal case. However, these errors happened finally and need to be dug out and eliminated. The method and experiences are summarized in this report. These will benefit others who facing the similar problems.

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TUPAB117

Conceptual Design of a Novel SCAPE Undulator

undulator, simulation, lattice, vacuum

1596

Y. Ivanyushenkov, J.F. Fuerst, E. Gluskin, Q.B. Hasse, M. Kasa, Y. Shiroyanagi, E. Trakhtenberg
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
A concept of a novel SuperConducting Arbitrarily Polarizing Emitter, or SCAPE, has recently been suggested at the Advanced Photon Source. It consists of two pairs - both vertical and horizontal - of superconducting planar magnets assembled around a beam vacuum chamber. Such a device will be capable of generating either planar or circularly polarized photons, depending on which pair of magnets is energized. The magnetic simulation suggests that due to the employment of superconducting technology, the expected magnetic field is higher than that of the APPLE undulators. The SCAPE undulators could be useful for the fourth generation of storage rings with a multi-bend achromat lattice, as well as for the FELs where utilization of round beam vacuum chambers becomes possible. The results of magnetic modelling, as well as the design concept of the SCAPE, are presented.

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TUPAB122

Engineering Optimization of The Support Structure and Drive System for the LCLS-II Soft X-Ray Undulator Segments

undulator, simulation, experiment, laser

1602

A.J. DeMello, D. Arbelaez, D. Bianculli, A.P. Brown, J.N. Corlett, J.R. Dougherty, D.E. Humphries, J.-Y. Jung, M. Leitner, S. Marks, K.A. McCombs, K.L. Ray, D.A. Sadlier, D. Schlueter, E.J. Wallén
LBNL, Berkeley, California, USA

Funding: Work supported by the Director, O'ce of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
The Linear Coherent Light Source II (LCLS-II) project, an upgrade to the free-electron laser facility at SLAC, is replacing the undulator system from a fixed gap to a variable gap system to enable tuning of the photon energy range. The LCLS-II project will include a soft x-ray (SXR) beam line and a hard x-ray (HXR) beam line. The SXR undulators are conventional vertical-gap horizontally-polarizing devices while the HXR undulators are novel horizontal-gap vertically-polarizing devices. This paper describes in detail the development of the SXR mechanical support structure and drive system. The effort has included extensive analysis of the various components to ensure that the undulators will perform within the design specifications. Engineering simulations undertaken and experiments performed to validate the computer modeling are presented together with measurement results from prototype and pre-production undulators.

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TUPAB123

Hard X-Ray and Soft X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project

undulator, linac, FEL, electron

1605

M. Leitner, D. Arbelaez, A.J. Band, D. Bianculli, A.P. Brown, J.N. Corlett, A.J. DeMello, J.R. Dougherty, L. Garcia Fajardo, K. Hanzel, M. Hoyt, D.E. Humphries, D. Jacobs, C. Joiner, J.-Y. Jung, D. Leitner, S. Marks, K.A. McCombs, D.V. Munson, K.L. Ray, D.A. Sadlier, J.J. Savino, D. Schlueter, E.J. Wallén, V. Waring, A. Zikmund
LBNL, Berkeley, California, USA
C.J. Andrews, D.E. Bruch, A.L. Callen, G. Janša, S. Jansson, K.R. Lauer, Yu.I. Levashov, D.S. Martinez-Galarce, B.D. McKee, H.-D. Nuhn, Â. Oven, M. Rowen, Z.R. Wolf
SLAC, Menlo Park, California, USA

Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Stanford Linear Accelerator Laboratory is currently constructing the Linear Coherent Light Source II (LCLS-II), a free-electron laser (FEL) which will deliver x-rays at an energy range between 0.2 keV and 5 keV at high repetition rate of up to ~1 MHz using a new 4 GeV superconducting RF linac, and at and an energy range between 1 keV and 25 keV when driven by an existing copper linac at up to 120 Hz repetition rate. To cover the full photon energy range, LCLS-II includes two variable-gap, hybrid-permanent-magnet undulator lines: A soft x-ray undulator (SXR) line with 21 undulator segments optimized for a photon energy range from 0.2 keV to 1.3 keV plus a hard x-ray undulator (HXR) line with 32 undulator segments designed for a photon energy range from 1.0 keV to 25.0 keV. Lawrence Berkeley National Laboratory is responsible for fabricating the 53 undulator segments. This paper summarizes the main parameters and design attributes for both LCLS-II undulator segment types.

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TUPAB125

Magnetic Field Measurements at LBNL on Soft X-Ray and Hard X-Ray Undulator Segments for the Linear Coherent Light Source Upgrade (LCLS-II) Project

undulator, linac, software, alignment

1612

E.J. Wallén, D. Arbelaez, J.N. Corlett, L. Fajrado, H.W. Kim, M. Leitner, S. Marks, D. Schlueter, A. Zikmund
LBNL, Berkeley, California, USA
Yu.I. Levashov, H.-D. Nuhn, Z.R. Wolf
SLAC, Menlo Park, California, USA

Funding: Work supported by the Director, O'ce of Science, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.
Stanford Linear Accelerator Laboratory is currently constructing the Linear Coherent Light Source II (LCLS-II), a FEL which will deliver x-rays at an energy range 0.2-5 keV at high repetition rate of up to 1 MHz using a new 4 GeV superconducting linac, and at an energy range 1-25 keV when using the existing copper linac at up to 120 Hz. To cover the full photon energy range, LCLS-II includes two variable-gap, hybrid-type permanent magnet undulator lines: A soft x-ray undulator (SXR) line with 21 undulator segments for the photon energy range 0.2-1.3 keV plus a hard x-ray undulator (HXR) line with 32 undulator segments designed for a photon energy range from 1-5 keV when using the superconducting linac. The HXR line is also designed to support 25 keV and higher photon energies when using the existing copper linac. Lawrence Berkeley National Laboratory (LBNL) is responsible for fabricating the undulators and tuning 23 of the HXR undulators. This paper summarizes the magnetic field measurements carried out on the pre-production undulators and describes the plans at LBNL for the magnetic measurements on the HXR undulators in series production.

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TUPIK055

Target Investigation Driven by a 10 MeV Electron Linac for Bremsstrahlung Production

target, electron, linac, radiation

1819

M. Yarmohammadi Satri, M. Lamehi, H. Shaker
IPM, Tehran, Iran
F. Ghasemi
NSTRI, Tehran, Iran

IPM E-Linac is a 10 MeV electron linear accelerator presently under construction at Institute for Research in Fundamental Sciences (IPM). It will accelerate electron from 45 keV to 10 MeV along the 160 cm accelerating tube. One of the beam energy measurement devices is designed based on the production of bremsstrahlung radiation. Target of the electron linac presents a key role in the production of bremsstrahlung. In this paper, we present the simulation results for an investigation on the bremsstrahlung radiation production based on target thickness, radius and atomic number, Z. We have applied Fluka Monte Carlo code for collecting the dose equiva-lent of generated bremsstrahlung along the target central axis at 30cm located downstream the target.

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TUPIK075

ATF2 Beam Halo Collimation System Background and Wakefield Measurements in the 2016 Runs

collimation, wakefield, background, simulation

1864

N. Fuster-Martínez, A. Faus-Golfe
IFIC, Valencia, Spain
P. Bambade, A. Faus-Golfe, S. Wallon, R.J. Yang
LAL, Orsay, France
K. Kubo, T. Okugi, T. Tauchi, N. Terunuma
Sokendai, Ibaraki, Japan
S. Kuroda
KEK, Ibaraki, Japan
I. Podadera, F. Toral
CIEMAT, Madrid, Spain
G.R. White
SLAC, Menlo Park, California, USA

A single vertical beam halo collimation system has been installed in ATF2 in March 2016 to reduce the background in the IP and Post-IP region. In this paper, we present the results of an experimental program carried out during 2016 in order to demonstrate the efficiency of the vertical collimation system and measure the wakefields induced by such a system. Furthermore, a comparison of the measurements of the collimation system wakefield impact with CST PS numerical simulations and analytical calculations is also presented.

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TUPIK101

Development and Construction of Safety and Control Systems for the TPS Front End Interlock

controls, vacuum, status, radiation

1947

J. -Y. Chuang, C.K. Chan, Y.M. Hsiao, C.K. Kuan, Y.Z. Lin, I.C. Sheng, Y.C. Yang
NSRRC, Hsinchu, Taiwan
C.S. Lin
NPUST, Pingtung, Taiwan

The Taiwan photon source (TPS) at NSRRC (National Taiwan Photon Source) is a 3rd generation, 3 GeV storage ring with designed current of 500 mA. In phase-I, six insertion device beamlines have been available to users after the safety interlock systems were commissioned and reviewed. National Instrument (NI) compact RIO 9030 is used for the front end interlock control system, and both scan and FPGA modes are activated in a hybrid mode to enhance the safety reliability. The personnel and machine protection system as well as EPICS communications of the TPS control system are presented in this paper as well.

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TUPIK106

Analysis of the Synchrotron Radiation from Segmented Undulator in Double-Mini Beta Function

undulator, radiation, brilliance, electron

1964

H.W. Luo, C.H. Lee
NTHU, Hsinchu, Taiwan
T.Y. Chung, C.-S. Hwang
NSRRC, Hsinchu, Taiwan
C.-S. Hwang
NCTU, Hsinchu, Taiwan

Three long straight sections with double-mini beta-y lattice were created in the Taiwan Photon Source (TPS) for which the effects of focusing elements and phase shifters between the collinear undulators result in incorrect calculations of the brilliance while assuming a Gaussian-approximation. Therefore, an on-axis Wigner distribution function (WDF), which includes effects of wave phenomena, is a natural way to measure the intensity of synchrotron radiation and is used in this article as the definition of brilliance.

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TUPVA004

Synchrotron Radiation Backgrounds for the FCC-hh Experiments

simulation, radiation, optics, collider

2031

F. Collamati
INFN-Roma1, Rome, Italy
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
H. Burkhardt, R. Kersevan
CERN, Geneva, Switzerland

Funding: This work was supported by the HORIZON 2020 project EuroCirCol, grant agreement 654305.
We present in this paper a detailed analysis of the synchrotron radiation emitted by the 50 TeV protons of the FCC-hh in the last bending and quadrupole magnets upstream the interaction region. We discuss the characteristics of this radiation in terms of power, flux, photon spectrum and fans in different running conditions such as, for example, with and without crossing angle. We mainly focus our study on the fraction of photons that may hit the detector, with a full tracking into GEANT4 that simulates their interaction within the central beam pipe.

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TUPVA011

Comparing Behaviour of Simulated Proton Synchrotron Radiation in the Arcs of the LHC with Measurements

simulation, synchrotron, synchrotron-radiation, radiation

2059

G. Guillermo Cantón, M. Ady, R. Kersevan, F. Zimmermann
CERN, Geneva, Switzerland
M. Angelucci, R. Cimino, E. La Francesca
INFN/LNF, Frascati (Roma), Italy
D. Sagan
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: EuCARD2 CONACyT
In previous work it was shown that at high proton-beam energies, synchrotron radiation is an important source of beam-screen heating, of beam-related vacuum pressure increase, and of primary photoelectrons, which can contribute to electron cloud formation. We have used the Synrad3D code developed at Cornell to simulate the photon distributions in the arcs of the LHC, HL-LHC, and FCC-hh. Specifically, for the LHC we studied the effect of the sawtooth chamber. In this paper specific results of the Synrad3D simulations are compared with simulations in Synrad+, developed at CERN; and later on compared with experimental data for actual LHC vacuum-chamber samples.

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TUPVA118

Particle Accelerators for Humanity: Resources for Public Engagement with Particle Accelerators

proton, survey, quadrupole, neutron

2369

S.L. Sheehy
JAI, Oxford, United Kingdom

To those who work in the accelerator field, it is obvious that there are many applications of accelerators beyond particle physics. Yet the public remains largely unaware of the far reaching uses of accelerators, or the scientific and engineering challenges that lay behind them. A recent project Particle Accelerators for Humanity has addressed this gap by creating a series of video resources, based on a programme of live events, short films and a specially commissioned animation. The project captured the dedication and diversity of those who design, operate and work with accelerators and highlights the varied ways in which their work is impacting on our lives. Here we overview the project and the resources, available under Creative Commons license, and discuss the impact of the project so far. We encourage the accelerator community to use the resources in their teaching and public engagement activities.

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WEOCA1

Performance of SOLARIS Storage Ring

storage-ring, injection, electron, closed-orbit

2490

A.I. Wawrzyniak, P.B. Borowiec, M.B. Jaglarz, A. Kisiel, P.M. Klimczyk, M.A. Knafel, M.P. Kopeć, A.M. Marendziak, S. Piela, P. Sagało, M.J. Stankiewicz, K. Wawrzyniak, M. Zając
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

After one year of the Solaris storage ring commission-ing excellent performance has been achieved. The optics was corrected close to the design values. However, some minor adjustments are still needed. The commissioning of the Solaris 1.5 GeV storage ring required a big effort in machine parameters optimization. Performance of posi-tion monitoring devices has proven essential for the suc-cessful optimization of beam parameters such as: closed orbit, tune, chromaticity, and dispersion. Now, the effort is focused on fine-tuning the machine by implementing the linear optics from orbit correction (LOCO) and reduc-ing the disparity between model and measured results revealed by the phase advance analysis and dispersion measurement. Moreover, during daily operation the main task is to maintain long-term stability of the circulating electron beam allowing for beamlines commissioning. Within this presentation the current status of the Solaris facility and the commissioning results will be reported.

Slides WEOCA1 [13.180 MB]

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WEOCA3

Status of the Development of Superconducting Undulators at the Advanced Photon Source

undulator, vacuum, FEL, storage-ring

2499

Y. Ivanyushenkov, C.L. Doose, J.F. Fuerst, E. Gluskin, Q.B. Hasse, M. Kasa, Y. Shiroyanagi
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357
Superconducting planar undulator (SCU) technology has been developed and is currently in use at the Advanced Photon Source (APS). The experience of building and operating the first short-length, 16-mm period superconducting undulator, SCU0, paved the way for two 1-m long, 18-mm period devices, SCU18-1 and SCU18-2. The first of those undulators has been in operation since May 2015, while the second one replaced SCU0 in September 2016. The possibility of building planar SCUs with a high quality field has been demonstrated at the APS. The measured phase errors of SCU18-2 at the design operational current are only 2 degrees rms, for example. An FEL SCU prototype - a 1.5-m long, 21-mm period undulator - was also built and tested as part of an LCLS SCU R&D program. This undulator successfully achieved all LCLS-II undulator requirements including a phase error of 5 degrees rms. The superconducting undulator technology also allows the fabrication of circular polarizing devices. Currently, a new helical SCU is under construction at the APS. In addition, the concept of a novel Superconducting Arbitrarily Polarizing Emitter, or SCAPE, has been suggested and is now under development.

Slides WEOCA3 [2.826 MB]

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WEOBB1

Recirculated Electron Beam Photo-Converter for Rare Isotope Production

target, electron, TRIUMF, isotope-production

2526

A. Laxdal, R.A. Baartman, I.V. Bylinskii, S. Ganesh, A. Gottberg, F.W. Jones, P. Kunz, L.A. Lopera, T. Planche, A. Sen
TRIUMF, Vancouver, Canada

The TRIUMF 50 MeV electron linac has the potential to drive cw beams of up to 0.5 MW to the ARIEL photo-fission facility for rare isotope science. Due to the cooling requirements, the use of a thick Bremsstrahlung target for electron to photon conversion is a difficult technical challenge in this intensity regime. Here we present a different concept in which electrons are injected into a small storage ring to make multiple passes through a thin internal photo-conversion target, eventually depositing their remaining energy in a cooled central core absorber. We discuss the design requirements and propose a set of design parameters for the Fixed Field Alternating Gradient (FFAG) ring. Using particle simulation models, we estimate various beam properties, as well as the MPS for the electron loss.

Slides WEOBB1 [4.650 MB]

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WEPAB014

PETRA III Operation

operation, timing, experiment, optics

2589

M. Bieler, I.V. Agapov, H. Ehrlichmann, J. Keil, G.K. Sahoo, R. Wanzenberg
DESY, Hamburg, Germany

At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. This paper describes the challenges of daily operation, including different bunch patterns and their side effects, a procedure to clear spurious bunches, the operational statistics and the main contributions to down time.

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WEPAB016

Experience in Operating sFLASH With High-Gain Harmonic Generation

FEL, laser, electron, radiation

2596

J. Bödewadt, R.W. Aßmann, N. Ekanayake, B. Faatz, I. Hartl, T. Laarmann, C. Lechner, M.M. Mohammad Kazemi, A. Przystawik
DESY, Hamburg, Germany
Ph. Amstutz, A. Azima, M. Drescher, W. Hillert, L.L. Lazzarino, Th. Maltezopoulos, V. Miltchev, T. Plath, J. Roßbach
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
K.E. Hacker, S. Khan, N.M. Lockmann, R. Molo
DELTA, Dortmund, Germany

sFLASH, the experimental setup for external seeding of free-electron lasers (FEL) at FLASH, has been operated in the high-gain harmonic generation (HGHG) mode. A detailed characterization of the laser-induced energy modulation, as well as the temporal characterization of the seeded FEL pulses is possible by using a transverse deflecting structure and an electron spectrometer. FEL saturation was reached for the 7th harmonic of the 266 nm seed laser. In this contribution, we present the latest experimental results.

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WEPAB025

Status of the Soft X-Ray Free Electron Laser FLASH

laser, FEL, experiment, operation

2628

M. Vogt, B. Faatz, K. Honkavaara, M. Kuhlmann, J. Rönsch-Schulenburg, S. Schreiber, R. Treusch
DESY, Hamburg, Germany

The superconducting free-electron laser user facility FLASH at DESY in Hamburg, routinely produces several thousand photon pulses per second. The operational parameters cover a wavelength range from 90 nm down to 4 nm with pulse energies from several uJ up to 1 mJ and with pulse durations of several hundred fs down to a few fs. The FLASH injector and linac drives two undulator beam lines (FLASH1, FLASH2) and therefore FLASH is capable of serving 2 independent experiments with photon pulse (sub-) trains of several 100 bunches at the full train repetition frequency of 10 Hz. We summarize here the highlights of the user operation at FLASH1/2 and the study program (machine development and FEL optimization) of the FLASH facility.

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WEPAB032

A Novel Optical Beam Concept for Producing Coherent Synchrotron Radiation with Large Energy Spread Beams

undulator, radiation, laser, electron

2646

R. Rossmanith, A. Bernhard, V. Saile, P. Wesolowski
KIT, Karlsruhe, Germany
R.W. Aßmann, U. Dorda, B. Marchetti
DESY, Hamburg, Germany

Up to now two FEL concepts are known in conventional accelerators: 1.) In THz lasers an off-crest cavity adds a chirp to the bunch followed by a bunch compressor. Particles with different energies travel on different trajectories to the radiator. 2.) For EUV and X-ray FELs the beam enters an undulator which produces microbunches which then radiate. In this paper it is proposed to copy the THz laser scheme for EUV lasers. The incoming beam is chirped and a dogleg forces afterwards the particles with different energies to move on different parallel trajectories. Considering a detector plane perpendicular to the trajectories the particles with different energies arrive in general at different times. When in this plane for instance a TGU (Transverse Gradient Undulator) is positioned the emitted radiation in the TGU is monochromatic. If in addition chirp and dogleg are selected in such a way that the particles with different energies arrive at the same time at the entrance of the TGU the radiation is monochromatic and coherent similar to the THz laser concept.

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WEPAB035

Elettra Status Present Upgrades and Plans

undulator, operation, controls, storage-ring

2657

E. Karantzoulis, A. Carniel, M. Cautero, B. Diviacco, S. Krecic, R. Visintini
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The operational status of the Italian 2.4/2.0 GeV third generation light source Elettra is presented together with an account of some present upgrades and plans for the near future.

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WEPAB041

Status Report of Hiroshima Synchrotron Radiation Center Hiroshima University

undulator, synchrotron, synchrotron-radiation, radiation

2672

S. Matsuba, K. Goto, K. Kawase
HSRC, Higashi-Hiroshima, Japan

The Hiroshima Synchrotron Radiation Center (HSRC) at Hiroshima University was established in 1996 for the research of solid state physics. The HSRC equips a 700 MeV electron storage ring nicknamed HiSOR. Recently, we are considering upgrade of the instrumentation beamline for the optical monitoring. In this paper, we report the present status of HSRC.

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WEPAB085

Siam Photon Source: Present Machine Status and Future Upgrades

storage-ring, injection, electron, operation

2770

P. Klysubun, S. Boonsuya, N. Juntong, K. Kittimanapun, S. Kongtawong, S. Krainara, A. Kwankasem, T. Pulampong, P. Sudmuang, N. Suradet
SLRI, Nakhon Ratchasima, Thailand

Siam Photon Source, the Thailand synchrotron light source, has received several upgrades in recent years. Most important of which are the improvement of the positional stability of the stored electron beam, and the installation of 2 IDs, i.e. a 2.2 T hybrid multipole wiggler and a 6.5 T superconducting wavelength shifter, to extend the available SR spectrum into hard x-ray region. The beam stability improvement was achieved through several activities, including improving the BPM system, upgrading the existing corrector power supplies, and implementing global orbit feedback. The two new IDs provide higher-intensity and higher-energy (up to 25 keV) synchrotron light, which will be utilized for MX, high-energy SAXS, WAXS, XAS, and microtomography. Ongoing machine upgrades include increasing the energy of the booster and transport line to 1.2 GeV for full-energy injection and eventual top-up operation. Utilization of the electron beam is also being explored. A beam test facility, which extracts electron beam in the booster for characterizing high-energy particle sensors, as well as calibrating other beam diagnostic instruments, has been constructed and is now in operation.

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WEPAB098

Dielectrically-Loaded Waveguide as a Microwave Undulator for High Brillance X-Rays at 45 - 90 Kev

undulator, brightness, operation, coupling

2812

R. Kustom, A. Nassiri, G.J. Waldschmidt
ANL, Argonne, Illinois, USA

The HEM12 mode in a cylindrical, dielectrically-loaded waveguide provides E and H fields on the central axis that are significantly higher than the fields on the conducting walls. This structure, operating near the cutoff frequency of the HEM12 mode, spans a frequency range where the wavelength and phase velocity vary significantly. This property can be exploited to generate undulator action with short periods for the generation of high brightness x-rays. The frequency range of interest would be from 18 to 34.5-GHz. The goal would be to generate x-rays on the fundamental mode over a range of 45 to 90-kev. The tunability would be achieved by changing the source frequency while maintaining a constant on-axis equivalent undulator field strength of 0.5-T.

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WEPAB115

Normal Conducting CW Transverse Crab Cavity For Producing Short Pulses In SPEAR3

cavity, HOM, impedance, damping

2840

Z. Li, V.A. Dolgashev, M. Dunham, K.J. Gaffney, R.O. Hettel, X. Huang, N. Kurita, J.A. Safranek, J.J. Sebek, K. Tian
SLAC, Menlo Park, California, USA

Funding: This work was supported by DOE Contract No. DE-AC02-76SF00515.
The ability to produce short pulse X-rays on the scale of 1-10 ps fwhm in the SPEAR3 storage ring light source would enable enhanced timing mode studies of dynamic processes in materials as they occur. The crab cavity approach appears to be optimal for SPEAR3 to produce short pulse X-rays. Furthermore, by using a two-frequency crabbing scheme, SPEAR3 would be able to produce short-pulse bunches while supplying the high average flux needed for regular users. While supercon-ducting RF (SCRF) technology could be a natural choice for the CW crab cavity, the deflecting voltage for SPEAR3 crabbing appears to be within reach of more affordable normal conducting RF (NCRF). In this paper, we present a preliminary NCRF CW crab cavity design for SPEAR3.

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WEPAB118

High Power Sub-Femtosecond X-Ray Pulse Study for the LCLS

undulator, electron, simulation, space-charge

2848

J.P. MacArthur
Stanford University, Stanford, California, USA
J.P. Duris, Z. Huang, A. Marinelli
SLAC, Menlo Park, California, USA

The desire to resolve sub-femtosecond electron dynamics has pushed FEL facilities to shorter pulse lengths. However, current short-pulse schemes provide low pulse energy and a gain-length limited lower bound on the pulse duration. The X-ray Laser-Enhanced Attosecond Pulses (XLEAP) project at SLAC is designed implement an Enhanced Self Amplified Spontaneous Emission (ESASE) scheme, which produces sub-fs current spikes by modulating and compressing the electron beam. We show through a series of Genesis simulations that the current spike is capable of producing sub-fs pulses with a peak power well above 100 GW. Space-charge induced beam chirp can decrease pulse lengths below 400 as, and multi-stage schemes can increase peak x-ray powers to around 1 TW.

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WEPAB124

Study of Hadron-Photon Colliders for Secondary Beam Generation

proton, collider, hadron, secondary-beams

2865

L. Serafini, C. Curatolo
Istituto Nazionale di Fisica Nucleare, Milano, Italy
F. Broggi
INFN/LASA, Segrate (MI), Italy

We summarize the potentialities of combining two well developed technologies, which are advancing the frontiers of hadron colliders and of light sources, namely the hadron colliders for high energy physics, and the FELs for applied and fundamental science with light, towards the generation of secondary beams with unprecedented characteristics. The collision between their typical pulses of high energy protons and X-ray photons opens a collider scenario with potentials for luminosities in excess of 10³⁸ s^-1*cm^-2, adequate to generate TeV-class pion, muon, neutrino and photon beams with very high phase space densities. We report results based on Monte Carlo simulations of such a hadron-photon collider*, aiming at qualifying the features of these secondary beams in view of experiments to be performed directly, or towards the design of a new kind of muon collider.
C. Curatolo, et al., Nuclear Instruments & Methods in Physics Research A (2016), http://dx.doi.org/10.1016/j. nima.2016.09.002i

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WEPIK002

Experimental Activities on High Intensity Positron Sources Using Channeling

positron, target, electron, experiment

2910

I. Chaikovska, R. Chehab, H. Guler, V. Kubytskyi
LAL, Orsay, France
X. Artru
IN2P3 IPNL, Villeurbanne, France
K. Furukawa, T. Kamitani, F. Miyahara, M. Satoh, Y. Seimiya, T. Suwada
KEK, Ibaraki, Japan
V. Rodin
National Taras Shevchenko University of Kyiv, The Faculty of Physics, Kyiv, Ukraine
P. Sievers
CERN, Geneva, Switzerland

The positron source under investigation is using channeling radiation of multi-GeV electrons in a tungsten crystal. The radiated photons are impinging on the amorphous targets creating e⁺e⁻ pairs. A dipole magnet between the crystal-radiator and the amorphous-converter allows the charged particles to be swept off and only emitted photons to generate e⁺e⁻ pairs in the converter. Granular targets of different thicknesses, made of small tungsten spheres, have been recently investigated as a target-converter. This paper is describing the experimental studies conducted at the KEKB linac with such device. After the description of the experimental set-up and beam parameters, the measurement methods and preliminary results are presented.

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WEPIK004

Luminosity- and Beam- Induced Backgrounds for the FCC-ee Interaction Region Design

detector, background, luminosity, interaction-region

2914

G.G. Voutsinas, P. Janot, A.M. Kolano, E. Perez, N.A. Tehrani
CERN, Geneva, Switzerland
N. Bacchetta
INFN- Sez. di Padova, Padova, Italy
M. Boscolo
INFN/LNF, Frascati (Roma), Italy
M.K. Sullivan
SLAC, Menlo Park, California, USA

A preliminary study on machine induced backgrounds has been performed for the proposed FCC-ee interaction region (IR) and proto-detector. Synchrotron radiation has the strongest impact on the present design of the IR and both radiation from dipoles and quadrupoles have been taken into account. The effect of luminosity backgrounds like gamma gamma to hadrons and pair production have also been studied. The impact of background particles on the detector occupancy has also been studied in full simulation.

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WEPIK008

Problems in SuperKEKB Vacuum System During the Phase-1 Commissioning and Their Mitigation Measures

wiggler, vacuum, electron, positron

2925

Y. Suetsugu, H. Hisamatsu, T. Ishibashi, K. Kanazawa, K. Shibata, M. Shirai, S. Terui
KEK, Ibaraki, Japan

The first (Phase-1) commissioning of the SuperKEKB, an energy-asymmetric electron-positron collider in KEK, Japan, started in February and ended in June, 2016. The vacuum system of the main ring worked well through the commissioning period as a whole, but experienced several problems, such as the electron cloud effect (ECE) in the positron ring, the pressure bursts accompanying beam losses due to dust particles in the beam pipe, an air leak at a connection flange due to the direct hitting of synchrotron radiation (SR), and so on. Towards the next (Phase-2) commissioning, countermeasures to these problems are taken during the shutdown period. For example, permanent magnets generating axial magnetic fields are attached to beam pipes at drift spaces for the suppression of the ECE. Knockers, which can artificially drop dust particles attached to the top surface in beam pipes by continuous impacts, are prepared to the beam pipes at which the pressure bursts had been frequently observed. Bellows chambers with masks are installed to protect the leaked flange from SR. The problems and their mitigation measures will be summarized in the presentation.

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WEPIK048

Evaluation and Mitigation of Synchrotron Radiation Background in the eRHIC Ring-Ring Interaction Region

detector, electron, radiation, quadrupole

3032

C. Montag
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Synchrotron radiation is a potential source of background in the detector of any future electron-ion collider. In the case of the eRHIC ring-ring design, a 22mrad crossing angle eliminates the need for a separator dipole, which would otherwise be a major source of synchrotron radiation. However, electrons in the transverse tails experience strong magnetic fields in the low-beta quadrupoles near the interaction point. Despite the low electron density in the tails the resulting hard radiation generated in these strong fields is a major concern, and a set of masks needs to be in place to shield the detector from these photons. We present simulation studies and a first design of a synchrotron radiation masking scheme.

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WEPIK065

Research Activities Towards a Conversion of PETRA III Into a Diffraction Limited Synchrotron Light Source

lattice, emittance, sextupole, synchrotron

3077

R. Wanzenberg, I.V. Agapov, K. Balewski, M. Bieler, W. Brefeld, R. Brinkmann, M. Dohlus, H. Ehrlichmann, X.N. Gavaldà, J. Keil, M. Körfer, G.K. Sahoo, C.G. Schroer, E. Weckert
DESY, Hamburg, Germany
M. Eriksson
MAX IV Laboratory, Lund University, Lund, Sweden

At DESY the Synchrotron Light Source PETRA III offers scientists outstanding opportunities for experiments with hard X-rays of exceptionally high brilliance since 2009. Research activities have been started towards a future upgrade scenario of PETRA III which envisions the conversion of the PETRA ring into a ultra-low emittance hard X-ray radiation source: PETRA IV. The lattice design is aiming for a horizontal emittance in the range between 10 pm rad and 30 pm rad at a beam energy of 6 GeV. Two different approaches have been considered for the lattice design: a design based on a hybrid multibend achromat with an interleaved sextupole configuration based on the ESRF design, and a lattice with a non-interleaved sextupole configuration with a special phase space exchange configuration. We are reporting the current status of the design activities including studies related to the injector.

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WEPVA058

Development of HOM Absorber for SuperKEKB

electron, HOM, vacuum, plasma

3394

S. Terui, T. Ishibashi, Y. Suetsugu, Y. Takeuchi, K. Watanabe
KEK, Ibaraki, Japan
H. Ishizaki, A. Kimura, T. Sawhata
Metal Technology Co. Ltd., Ibaraki, Japan

Higher-order modes (HOM) absorbers are necessary components for recent high-power accelerators in order to prevent beam instabilities (e.g. HOM- Beam Break Up instabilities) or the overheating of vacuum components. Several kinds of absorber materials, such as SiC, ferrite and Kanthal, have been investigated and applied in accelerators. Among these materials, ferrite has been found to be superior to others because of its higher HOM absorbing efficiency. However, because of its low tensile strength and small thermal expansion rate, it cannot be easily bonded to other metals thus limiting its use as a HOM absorber. We reported the success of the fabrication of ferrite-copper-blocks using the spark plasma sintering (SPS)-technique last year. This year we report testing with a high-power RF source and measuring gas desorption rate after baking and secondary electron yield.

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WEPVA127

Design of a 3.5 T Superconducting Multipole Wiggler

vacuum, radiation, wiggler, simulation

3564

J.C. Jan, C.-H. Chang, H.-H. Chen, S.D. Chen, T.Y. Chung, C.-S. Hwang, F.-Y. Lin, G.-H. Luo
NSRRC, Hsinchu, Taiwan

A 3.5 T superconducting multipole wiggler (SMPW) has been designed through the collaboration of National Synchrotron Radiation Research Center (NSRRC) and Synchrotron Light Research Institute (SLRI). The SMPW will support the hard X-ray source for the X-ray absorption spectroscopy (XAS) beamline in SLRI. The design concept of the SMPW follows from, and improves on, the operating experience of the superconducting magnet in NSRRC. An improvement of the operation and compatible with the cooling capacity of the cryogenic system, is the design goal. A quick and easy recovery of the magnet from a quench event is also required. The design of the magnet circuit and the mechanical of the SMPW are also discussed herein.

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WEPVA129

Arc-Flash Hazard and Protection for Electric Switchboard at NSRRC

detector, site, power-supply, impedance

3571

T.-S. Ueng, Y.F. Chiu, C.K. Kuan, K.C. Kuo, Y.-C. Lin
NSRRC, Hsinchu, Taiwan

During the operation of electrical equipment the arc-flash accident could damage the equipment and endanger the working personnel. In order to prevent this type of accidents from happening and to minimize the damages, a delicate setup is being installed inside the electric switchboard for suppressing the accidents at the initial stage of arcing at NSRRC's power system. The installed device includes the arc sensor, the smoke detector, the high rupturing capacity fuse, the circuit breaker and the protection relay. Further improvement on preventing the arc-flash accidents is also under study.

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WEPVA132

Switching Power Supply Automatic Test System in Taiwan Photon Source

radiation, power-supply, synchrotron, simulation

3580

Y.S. Wong, C.Y. Liu, K.-B. Liu, B.S. Wang
NSRRC, Hsinchu, Taiwan

This paper studies the use of a novel switching power supply automatic test system used in Taiwan photon source, Model 8000 is the ultimate solution for power electronic testing, the system includes a wide range of hardware choice such as AC/DC source, electronic loads, DMM, oscillate scope, noise analyzer and short/OVP tester. The ATS 8000 system uses a unique test command optimazation technology to prevent repetitive control commands from being sent to system hardware devices. This improve test speed dramatically and makes ideal choice for both high speed production applications as well as design verification.

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WEPVA134

Impedance Measurement of Vacuum Chamber Components for the Advance Photon Source (APS) Upgrade

impedance, simulation, cavity, vacuum

3583

M.P. Sangroula
IIT, Chicago, Illinois, USA
R.M. Lill, R.R. Lindberg, X. Sun
ANL, Argonne, Illinois, USA

Funding: U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC0206CH11357.
The proposed Advance Photon Source Upgrade (APS-U) employs a multi-bend achromat (MBA) lattice to increase the photon brightness by two to three orders of magnitude. One of the main design challenges of the upgrade is to minimize rf heating and collective instabilities associated with the impedance of small-aperture vacuum components. As part of this effort, my research focuses on impedance measurement and simulation of various MBA vacuum components. Here, we present the summary of the impedance contributions for the APS-U and describe our planned impedance measurement technique, including some measurement results for the non-evaporative getter (NEG)-coated copper chamber and simulation results for other critical components using a novel Goubau line (G-line) set up.

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WEPVA136

Vacuum System for the Diamond Light Source DDBA Upgrade

vacuum, dipole, simulation, electron

3587

M.P. Cox, M.J. Duignan, R. Howard, S.C. Lay, A.G. Miller, H.S. Shiers, A. Wolfenden
DLS, Oxfordshire, United Kingdom

One cell of the Diamond Light Source (Diamond) storage ring was upgraded in late 2016 to a Double Double Bend Achromat (DDBA) configuration to provide an additional mid-achromat insertion device straight. For practical reasons it was decided to use discrete non-evaporable getter (NEG) pumps rather than NEG coatings. This paper outlines the vacuum design of the up-grade, the reasons for the choices made and the vacuum simulation tools used as well as describing the vacuum system engineering, assembly, installation and commissioning. The measured vacuum performance is found to be in close agreement with the simulations and a simple expression is derived for the beam gas lifetime.

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WEPVA137

Progress on the Design of the Storage Ring Vacuum System for the Advanced Photon Source Upgrade Project

vacuum, storage-ring, lattice, radiation

3590

B.K. Stillwell, B. Billett, B. Brajuskovic, J.A. Carter, E.S. Kirkus, M.A. Lale, J.E. Lerch, J. R. Noonan, M.M. O'Neill, B.G. Rocke, K.J. Suthar, D.R. Walters, G.E. Wiemerslage, J. Zientek
ANL, Argonne, Illinois, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
Recent work on the design of the storage ring vacuum system for the Advanced Photon Source Upgrade project (APS-U) includes: revising the vacuum system design to accommodate a new lattice with reverse bend magnets, modifying the designs of vacuum chambers in the FODO sections for more intense incident synchrotron radiation power, modifying the design of rf-shielding bellows liners for better performance and reliability, modifying photon absorber designs to make better use of available space, and integrated planning of components needed in the injection, extraction, and rf cavity straight sections. An overview of progress in these areas is presented.

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WEPVA148

Dynamics of Target Motion Under Exposure of Hard Gamma Undulator Radiation

target, positron, electron, undulator

3618

A.A. Mikhailichenko
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

We describe time dependent dynamics of the target motion under exposure by undulator radiation in a system for positron production. We took into account inertia of material of target. Calculations carried with help of FlexPDE code.

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THOBA1

Studies of the Micro-Bunching Instability in Multi-Bunch Operation at the ANKA Storage Ring

synchrotron, bunching, radiation, storage-ring

3645

M. Brosi, E. Blomley, E. Bründermann, M. Caselle, B. Kehrer, A. Kopmann, A.-S. Müller, L. Rota, M. Schedler, M. Schuh, M. Schwarz, P. Schönfeldt, J.L. Steinmann, M. Weber
KIT, Eggenstein-Leopoldshafen, Germany

Funding: Supported by the German Federal Ministry of Education and Research (05K13VKA & 05K16VKA), the Helmholtz Association (VH-NG-320) and the Helmholtz International Research School for Teratronics (HIRST)
The test facility and synchrotron light source ANKA at the Karlsruhe Institute of Technology (KIT) operates in the energy range from 0.5 to 2.5 GeV and can generate brilliant coherent synchrotron radiation (CSR) in the THz range employing a dedicated bunch length-reducing optic at 1.3 GeV beam energy. The high degree of spatial compression leads to complex longitudinal dynamics and to time evolving sub-structures in the longitudinal phase space of the electron bunches. The results of the micro-bunching instability are time-dependent fluctuations and strong bursts in the radiated THz power. To study these fluctuations in the emitted THz radiation simultaneously for each individual bunch in a multi-bunch environment, fast THz detectors are combined with KAPTURE, the dedicated KArlsruhe Pulse Taking and Ultrafast Readout Electronics system, developed at KIT. In this contribution we present measurements conducted to study possible multi-bunch effects on the characteristic bursting behavior of the micro-bunch instability.

Slides THOBA1 [12.910 MB]

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THPAB029

Simulation of the Single Bunch Instabilities for the High Energy Photon Source

impedance, injection, simulation, operation

3760

Z. Duan, N. Wang, H.S. Xu
IHEP, Beijing, People's Republic of China

Funding: Work supported by Natural Science Foundation of China (No.11605212).
Timing modes pursing a large single bunch charge will be important operation modes for the green-field High Energy Photon Source (HEPS). The single bunch instabilities are simulated with the elegant tracking code, based on the current impedance budget. In particular, a novel on-axis accumulation scheme* based on the RF gymnastics of an active double-RF system was proposed as a candidate injection scheme for HEPS, while the zero-current rms bunch length dramatically decreases during the injection, from 32 mm to 3 mm, over a time duration of about 200 ms. The single bunch instabilities are evaluated for both the operation mode with optimal bunch lengthening as well as the injection mode with the very short bunch length, as a first step in understanding the possible beam instability for this injection scheme.
* G. Xu, et al., in Proc. IPAC'16, pp. 2886-2888. Z. Duan, et al., in Proc. eeFACT 2016.

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THPAB066

Modeling Cathode Roughness, Work Function, and Field Enhancement Effects on Electron Emission

electron, emittance, simulation, scattering

3869

D.A. Dimitrov, G.I. Bell, D.N. Smithe, S.A. Veitzer
Tech-X, Boulder, Colorado, USA
I. Ben-Zvi, J. Smedley
BNL, Upton, Long Island, New York, USA
J. Feng, S.S. Karkare, H.A. Padmore
LBNL, Berkeley, California, USA

Funding: This work is supported by the US DOE Office of Science, department of Basic Energy Sciences under grant DE-SC0013190.
Recent developments in material design and growth have resulted in photocathodes that can deliver high quantum efficiency and are sufficiently robust to use in high electric field gradient photoinjectors and free electron lasers. The growth process usually produces photoemissive material layers with rough surface profiles that lead to transverse accelerating fields and possible work function variation resulting in emittance growth. To better understand the effects of surface roughness on emitted electron beams, we have developed realistic three-dimensional models for photocathode materials with grated surface structures. They include general modeling of electron excitation due to photon absorption, charge transport and emission from rough surfaces taking into account image charge and field enhancement effects. We implemented these models in the VSim particle-in-cell code. We report results from simulations using different photocathode materials with grated and flat surfaces to investigate how controlled roughness, work function variation, and field enhancement affect emission properties.

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THPAB132

MCP Based Detectors Installation in European XFEL

detector, ion, radiation, laser

4031

E. Syresin, O.I. Brovko, A.Yu. Grebentsov
JINR, Dubna, Moscow Region, Russia
W. Freund
XFEL. EU, Hamburg, Germany
J. Grünert
European XFEL, Schenefeld, Germany
M.V. Yurkov
DESY, Hamburg, Germany

An important task of the photon beam diagnostics at the European XFEL is providing reliable tools for measurements aiming at the search for and fine tuning of the amplification process in the SASE FEL. Radiation detectors based onμchannel plates (MCP) were prepared for such measurements. These detectors operate in a wide dynamic range from the level of spontaneous emission to the saturation level (between a few nJ to 25 mJ), and in a wide wavelength range from 0.05 nm to 0.4 nm for SASE1 and SASE2, and from 0.4 nm to 5.1 nm for SASE3. Photon pulse energies are measured at the MCP anode and with a photodiode. The transverse photon beam profile is measured by an MCP imager with phosphor screen anode. Three MCP devices are being installed, one in each of the three FEL beamlines (SASE1, SASE2, and SASE3). The units for SASE1 and SASE3 were already installed in the XFEL tunnel, and the technical commissioning of the MCP detectors and their electronics is progressing. Calibration and acceptance test experiments with beam are scheduled for early 2017.

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THPAB154

Mechanical Design of Compact Vertical and Horizontal Linear Nanopositioning Flexure Stages With Centimeter-Level Travel Range for X-Ray Beamline Instrumentation

controls, laser, instrumentation, synchrotron

4096

D. Shu, J.W.J. Anton, S.P. Kearney, B. Lai, W. Liu, J. Maser, C. Roehrig, J.Z. Tischler
ANL, Argonne, Illinois, USA
J.W.J. Anton
University of Illinois at Chicago, Chicago, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, under Contract No. DE-AC02-06CH11357.
Nanopositioning techniques present an important capability to support the state-of-the-art x-ray instrumentation research for the APS operations and upgrade project. To overcome the performance limitations of precision ball-bearing-based or roller-bearing-based linear stage systems, compact vertical and horizontal linear nanopositioning flexure stages have been designed and developed at the APS with centimeter-level travel range and nanometer-level resolution for x-ray beamline instrumentation. Using improved deformation compensated linear guiding mechanisms [*,**], the APS T8-55 vertical linear flexure stage and T8-56 horizontal linear flexure stage are initially designed as a pair of sample scanning stages for a hard x-ray scanning microscope at the APS sector 2. Due to their unique repeatable nanopositioning performance over the centimeter-level travel range, these stages are also suitable for many photon beam lines optics with repeatable and stable nanopositioning requirements. The mechanical design and finite element analyses of the APS T8-55 and T8-56 flexural stages, as well as its initial mechanical test results with laser interferometer are described in this paper.
* D. Shu, W. Liu, S. Kearney, J. Anton, B. Lai, J. Maser, C. Roehrig, and J. Z. Tischler, Proceedings of MEDSI-2016, Sept. 11-16, 2016, Barcelona, Spain.
** U.S. Patent granted No. 8,957, 567, D. Shu, S. Kearney, and C. Preissner, 2015.

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THPVA040

Magnetic Field Computation for PMTs Shielding Optimization

shielding, simulation, experiment, quadrupole

4522

E. Bouquerel, O. Dorvaux, S. Kihel, M. Krauth, P. Peaupardin
IPHC, Strasbourg Cedex 2, France
C. Ciemala
IFJ-PAN, Kraków, Poland

The Photon Array for the studies of Radioactive and Ion Stable beams (PARIS) is a multidetector of clusters. Each cluster is composed of 9 units of two-shells phoswiches of LaBr3/NaI scintillators optically coupled to one photomultiplier tube. PARIS will be used in combination with the VAMOS spectrometer at GANIL. During the experiment, PMTs will be exposed to the constant magnetic fringe fields produced by a quadrupole. Magnetic shielding is essential to efficiently lower the magnetic field inside the PMTs. The design and the optimization of this shield is presented. A comparison is done between the simulated and the experimental values.

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THPVA045

Telecommunication Concepts for Compact, Electro-Optical and Frequency Tunable Sensors for Accelerator Diagnostics

laser, electron, diagnostics, synchrotron

4534

E. Bründermann, A.-S. Müller
KIT, Karlsruhe, Germany
I. Hosako, I. Morohashi, S. Nakajima, S. Saito, N. Sekine
NICT, Tokyo, Japan

Funding: Supported by Invitation Fellowship for Research ID No. S16704 of Japan Society for the Promotion of Science (JSPS) awarded to E.B. hosted by I.H.
Terahertz diagnostics* for investigating the properties of electron and photon beams**, especially the investigation of electron bunch instabilities, accompanied by terahertz photon bursts is increasingly employed to monitor and investigate electron bunch dynamics***. Recent advances in information and communications technology promise compact sensors based on telecom and thus industry standards. We present potential applications of such technology concepts for accelerators, including a miniature probe for electro-optical sampling, which could be employed for electron bunch electrical near-field studies, and laser sources with widely tunable pulse repetition rates adaptable for pulsed diagnostics***.
* E. Bründermann, H.-W. Hübers, M.F. Kimmitt, Terahertz Techniques, Springer-Verlag (2012).
** J.L. Steinmann et al., Phys. Rev. Lett. 117, 174802, 2016.
*** M. Brosi et al., Phys. Rev. Accel. Beams 19, 110701, 2016.
**** I. Morohashi et al., Nano Commun Netw 10, 79, 2016.

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THPVA050

Latest Progress of Magnet Girder Prototypes for HEPS-TF

controls, alignment, target, interface

4551

H. Wang, C. H. Li, S.J. Li, H. Qu, Z. Wang, L. Wu
IHEP, Beijing, People's Republic of China

The magnet girder technology is one of the key tech-nologies which should be overcome in the stage of HEPS-TF (Test Facility of High Energy Photon Source). The girder should be beam-based aligned, and must has high adjusting precision and high stability as well. For these issues, two girder systems are designed and developed. This paper will describe the latest progress of the girder prototypes, including structure design updates, control system progress, and processing and assembling of Girder I prototype.

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THPVA051

Vibration Study of Magnet Girder of the HEPS-TF

experiment, factory, quadrupole, emittance

4554

Z. Wang, C. H. Li, H. Qu, H. Wang
IHEP, Beijing, People's Republic of China

Abstract: There are stringent requirements on beam stability in the High Energy Photon Source (HEPS). The stability of the magnet girder is an extremely important factor for the beam stability. This paper will discuss the influence of ground vibration to the beam stability. This influence will determine the scope of the vibration magnification of the magnet girder. By improving the stiffness of the magnet girder, the influence will be reduced and the beam stability shall be improved. Besides, the progress of the HEPS-TF girder prototype and the vibration test will be described.

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THPVA053

Design of the Girder Control System for HEPS-TF

controls, hardware, interface, status

4560

S.J. Li, C. H. Li, J. Liu, H. Wang, Z. Wang
IHEP, Beijing, People's Republic of China

To make the alignment become easier, the HEPS-TF (High Energy Photon Source-Test Facility) magnet girder, which is different from the conventional one, is designed to achieve the goal of adjusting the girder's position and orientation online. The control system is one of the key sub-part. This Paper will describe the control system design, especially on the hardware configuration, software programming as well as user interface design.

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THPVA068

General Design of ID Front Ends in the TPS

radiation, vacuum, synchrotron, storage-ring

4601

C.K. Kuan, C.K. Chan, Y.T. Cheng, J. -Y. Chuang, Y.M. Hsiao, I.C. Sheng, C. Shueh, H.Y. Yan
NSRRC, Hsinchu, Taiwan

The Taiwan Photon Source is a 3 GeV, 3rd generation synchrotron radiation source at the NSRRC. Phase-I commissioning includes seven Insertion Device (ID) Front Ends which are built to transmit intense synchro-tron radiation generated by In-vacuum Undulators and Elliptically Polarizing Undulators in the storage ring to the Photon Beamline. The total power and power distri-bution on Front End components is calculated and ana-lysed and Finite Element Analysis is used to verify the thermal performance under high heat loads while Monte-Carlo methods are utilized to simulate the vacuum pres-sure distribution. All apertures of the components are the same to simplify and standardize the design of the Front Ends. This paper describes main design considerations, especially the high heat load and vacuum pressure distri-bution.

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THPVA072

Travelling Laser Focus System for the Particles Acceleration

laser, acceleration, radiation, emittance

4613

A.A. Mikhailichenko
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

We describe the result of the wake-fields calculation in a device for acceleration of particles in the micro-structures illuminated by the swept laser bust. Calculations carried with help of FlexPDE code.

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THPVA089

Optimization Study on Production of Mo-99 Using High Power Electron Accelerator Linac

target, electron, linac, neutron

4667

A. Taghibi Khotbeh-Sara, F. Rahmani
KNTU, Tehran, Iran
S. Ahmadiannamin
ILSF, Tehran, Iran
F. Ghasemi
NSTRI, Tehran, Iran

Molybdenum-99 is used for preparing 99mTc, which is the most widely used isotope in nuclear medicine. As a recent and now shortages in reactor-based supplies of 99Mo/99mTc and also some problems due to the time limitation in a direct production approach such as 100Mo(p, 2n)99mTc reaction by cyclotrons, many of developed countries have started the plan to produce this type of radioisotopes based on the production of non-reactor methods, especially by linac. In this study, the investigation on 99Mo production based on high power electron linac as an alternative approach has been performed, in which the use of 100Mo(gamma, n)99Mo (photoneutron production) has been proposed.

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THPVA097

Estimation and Measurements of Radiation Dose Distibution for the Radiation Test Area in J-PARC Main Ring

radiation, neutron, proton, operation

4689

M.J. Shirakata
KEK, Ibaraki, Japan

The J-PARC main ring has a beam collimator system in the first straight section for the beam halo rejection. Though it makes a high radiation area in the ring which requires a serious maintenance scheme, a high radiation dose can be applied to the tests of radiation resistible devices. The radiation dose distribution was estimated by using PHITS code, and it was confirmed by dose meas-urements using RadMon, nanoDot OSL dosimeters with continuous monitoring of beam losses. The availability of the radiation test area in the accelerator ring is reported in this paper.

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THPVA137

A Monte Carlo Approach to Imaging and Dose Simulations in Realistic Phantoms Using Compact X-Ray Source

simulation, electron, detector, radiation

4783

E. Skordis, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
E. Skordis, V. Vlachoudis
CERN, Geneva, Switzerland
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

X-ray emitters are amongst the most widely used tools in medicine. Based on compact electron beams, they are utilised for a range of applications, including medical imaging and cancer treatment. The optimisation of a specific X-ray source relies on detailed simulation studies into the achievable resolution and intensity distribution. Monte Carlo (MC) codes are widely used in the medical community for dose estimation to patients and the environment. They are also ideally suited for simulating 3D intensity distributions in realistic environments. This demands accurate and reliable physical models capable of handling all components of the expected radiation field. In this paper the capabilities of the FLUKA MC code to simulate complex X-ray sources are presented. Advanced phantoms, based on imported DICOM format, are used to evaluate the dose to relevant areas, including the patient, individual organs and the treatment room. It is also shown how they can provide a good basis to reproduce radiography images by scoring photon fluencies.

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THPVA139

Relative Insensitivity to Inhomogeneities on Very High Energy Electron Dose Distributions

electron, simulation, experiment, radiation

4791

A. Lagzda, R.M. Jones
UMAN, Manchester, United Kingdom
D. Angal-Kalinin, J.K. Jones
STFC/DL/ASTeC, Daresbury, Warrington, Cheshire, United Kingdom
K. Kirkby
The Christie NHS Foundation Trust, Manchester, United Kingdom

Funding: Science and Technology Facilities Council, United Kingdom Cockroft Institute, United Kingdom Christie Hospital, Manchester, United Kingdom
We investigated the effects of heterogeneous regions on dose deposition of very high-energy electrons (VHEE) using both Geant4 simulations and experiments performed at the CALIFES facility at CERN. Small air and acetal plastic (bone equivalent) cavities were embedded in a water phantom and irradiated with a 197 MeV electron beam. Experimentally determined transverse dose profiles were acquired using radiation sensitive EBT3 Gafchromic films embedded in the water phantom at various depths. EBT3 Gafchromic films were found to be a suitable dosimeter for relative dose dosimetry of VHEE beams. Simulated and measured results were found to be consistent with each other and the largest discrepancy was found to be no more than 5%. Dose profiles of VHEE beams were found to be relatively insensitive to embedded high and low density geometries.

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FRXAB1

Accelerator Vacuum Technology Challenges for Next-Generation Synchrotron-Light Sources

vacuum, impedance, storage-ring, lattice

4830

P. He
IHEP, Beijing, People's Republic of China

The development trend of future next-generation synchrotron light source storage rings is a compact lattice combined with small magnet apertures. This leads to important engineering challenges for the design and performance of a vacuum system because of lack of space, conductance limitation and high precision and stability positioning requirements. The speaker will review some possible solutions including the use of distributed pumping (NEG coating), distributed absorber (good thermal conducting material vacuum chamber wall), and distributed cooling (different water cooling channel design at the location where the synchrotron radiation hits the wall). In situ baking for NEG activation and precise installation will also be covered.

Slides FRXAB1 [3.627 MB]

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