IPAC2016 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOYAA01	Commissioning of the MAX IV Light Source	storage-ring, emittance, lattice, vacuum	11
	M. Eriksson, E. Al-Dmour, Å. Andersson, M.A.G. Johansson, S.C. Leemann, L. Malmgren, P.F. Tavares, S. Thorin MAX IV Laboratory, Lund University, Lund, Sweden
	This presentation reports on the beam commissioning status of MAX IV, experience gained and lessons learned, as well as future plans.
	Slides MOYAA01 [6.682 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOYAA01
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MOPMB025	The Development of 16-Electrode Monitor for Measurement of the Multipole-Moment	quadrupole, coupling, impedance, proton	140
	Y. Nakanishi, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya Kyoto University, Kyoto, Japan T. Koseki, H. Kuboki KEK, Tokai, Ibaraki, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled 'Unification and　Development of the Neutrino Science Frontier' In the J-PARC main ring, the beam intensity is greatly increased to 750 kW or more in near future. Even the beam intensity become higher, the beam loss must be kept at the same level as present. Aiming to make the cause of beam loss clear, we have been developing the beam monitor to measure the beam size. The quadrupole moment is related to the beam size. In principle, monitors with more than four electrodes can measure the quadrupole moment. In addition, two monitors located at the places with different beta functions can measure the emittances and beam sizes, providing the horizontal and vertical beta functions. To obtain more precise quadrupole moment and higher multipoles, we are developing the multi-electrode monitor, tentatively, with 16 electrodes. As a reference of 16-electrode monitor, two 4-electrode BPMs are investigated to measure quadrupole moments. We will present the measurement result of 4-electrode monitors and the status of the development of the 32-electrode monitor.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB025
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MOPMB045	Development of FPGA-based Bunch-by-Bunch Beam Current Monitor	FPGA, storage-ring, feedback, LabView	193
	Liu, C.S. Liu, Q. Luo, B.G. Sun, Z.R. Zhou USTC/NSRL, Hefei, Anhui, People's Republic of China
	Funding: Supported by the National Science Foundation of China 11575181, 11375178. And by the Fundamental Research Funds for the Central Universities WK2310000046, WK2310000056 Bunch-by-bunch (BxB) beam current measurement is an important method to study filling pattern of injection and beam instability threshold for multi-bunch operation storage ring, also, necessary equipment for top-up injection. A high-speed high-precision ADC and FPGA are used to construct the bunch-by-bunch beam current measurement system. FPGA reads data from ADC, and transfer the data to PC via USB. A LabVIEW program is running on PC to process the data, and communicates with other accelerator equipment with EPICS by CA Lab. Besides the bunch-by-bunch beam current measurement, the BxB longitudinal tune is measured by the system, and other potential bunch-by-bunch beam diagnostics study could be done in future, like bunch-by-bunch beam life etc., to improve the performance of the storage ring of Hefei light source.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB045
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MOPMB048	Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring	experiment, storage-ring, electron, synchrotron-radiation	199
	L.W. Duan, Y.B. Leng, R.X. Yuan SINAP, Shanghai, People's Republic of China N. Zhang SSRF, Shanghai, People's Republic of China
	Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB048
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MOPMB052	On-axis Injection using a Sin Wave RF Kicker	kicker, storage-ring, lattice, emittance	211
	B.C. Jiang, Y.B. Leng, S.Q. Tian, L.Y. Yu, M.Z. Zhang, Q.L. Zhang, Z.T. Zhao SINAP, Shanghai, People's Republic of China
	On-axis injection is one of the critical issues for an ul-tra-low emittance storage ring which holds a rather small dynamic aperture. In order to reduce the challenges of the fast pulsed kicker design, a sin wave RF kicker is studied which is suitable for longitudinal on-axis injection. Since the injected bunch is longitudinally apart from the stored bunches, the location of the stored bunches can be at the π knot of the sin wave, while the injected bunches are launched at a phase around π/2+n·π. At this situation the injected bunches will receive a transverse kick, however the store bunches are almost un-affected.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB052
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MOPMB060	Upgrade of the LHC Schottky Monitor, Operational Experience and First Results	pick-up, proton, ion, emittance	226
	M. Betz, O.R. Jones, T. Lefèvre, M. Wendt CERN, Geneva, Switzerland
	The LHC Schottky system allows the measurement of beam parameters such as tune and chromaticity in an entirely non-invasive way by extracting information from the statistical fluctuations in the incoherent motion of particles. The system was commissioned in 2011 and provided satisfactory beam-parameter measurements during LHC run 1 for lead-ions. However, for protons its usability was substantially limited due to strong interfering signals originating from the coherent motion of the particle bunch. The system has recently been upgraded with optimized travelling-wave pick-ups and an improved 4.8~GHz microwave signal path, with the front-end and the triple down-mixing chain optimized to reduce coherent signals. Design and operational aspects for the complete system are shown and the results from measurements with LHC beams in Run II are presented and discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMB060
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MOPMR002	Bunch by Bunch Position Measurement and Analysis at PLS-II	kicker, operation, betatron, pick-up	232
	J. Lee, M.-H. Chun, I. Hwang, D.T. Kim, G. Kim, T.-Y. Lee, D.C. Shin, S. Shin PAL, Pohang, Republic of Korea
	Beam dynamic phenomena described by bunch-by-bunch motion are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam position related to different dynamical mechanisms are a useful information to accelerator optimization. In PLS-II, 20 GHz sampling oscilloscope synchronized with injection event (or triggered by beam loss signal) is used to measure direct bunch by bunch motion. Based on the measured data, the principal component analysis had been performed to get the insight into beam dynamic phenomena such as couple bunch instability and beam oscillation due to kicker leakage. In this paper, we will describe the measurement method and the result of analysis for coupled bunch instability.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR002
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MOPMR014	Beam Diagnostics Overview for Collector Ring at FAIR	diagnostics, ion, antiproton, pick-up	255
	Yu. A. Rogovsky, E.A. Bekhtenev, M.I. Bryzgunov, O.I. Meshkov, D.B. Shwartz BINP SB RAS, Novosibirsk, Russia E.A. Bekhtenev, Yu. A. Rogovsky, D.B. Shwartz NSU, Novosibirsk, Russia O. Chorniy GSI, Darmstadt, Germany
	The Collector Ring (CR) is a dedicated storage ring in the FAIR project, where the main emphasis is laid on the effective stochastic precooling of intense secondary beams of stable ions, rare isotopes or antiprotons. A complex operation scheme with several types of operational cycles with beams in CR starting from injection, RF gymnastics, stochastic cooling then, and finishing to extraction is foreseen. Beam parameters changes significantly during the cycles. This demands an exceptional high dynamic range for the beam instrumentation. Non-destructive methods are mandatory for high currents as well as for the low current secondary beams due to the low repetition rate. Precise measurements of all beam parameters and automatic steering with short response time are required due to the necessary exploitation of the full ring acceptances. An overview of the challenges and solutions for various diagnostic installations will be given.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR014
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MOPMR029	Experience with DOROS BPMs for Coupling Measurement and Correction	coupling, dipole, electronics, controls	303
	T. Persson, J.M. Coello de Portugal, A. Garcia-Tabares, M. Gąsior, A. Langner, T. Lefèvre, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, R. Tomás CERN, Geneva, Switzerland J. Olexa STU, Bratislava, Slovak Republic
	The Diode ORbit and OScillation System (DOROS) system is designed to provide accurate measurements of the beam position in the LHC. The oscillation part of the system, which is able to provide turn-by-turn data, is used to measure the transverse coupling. Since the system provides high resolution measurements for many turns only small excitations are needed to accurately measure the transverse coupling. In this article we present the performance the system to measure coupling and compare it to the BPMs not equipped with this system.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR029
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MOPMR031	Investigation of Injection Losses at the Large Hadron Collider with Diamond Based Particle Detectors	kicker, proton, flattop, detector	310
	O. Stein, W. Bartmann, F. Burkart, B. Dehning, V. Kain, R. Schmidt, D. Wollmann CERN, Geneva, Switzerland E. Griesmayer CIVIDEC Instrumentation, Wien, Austria
	During the operation of the Large Hadron Collider (LHC) in 2015, increased injection losses were observed. To minimize stress on accelerator components in the injection regions of the LHC and to guarantee an efficient operation these losses needed to be understood and possible mitigation techniques should be studied. Measurements with diamond particle detectors revealed the loss structure with ns-resolution for the first time. Based on these measurements, recaptured beam from the Super Proton Synchrotron (SPS) surrounding the nominal bunch train was identified as the major contributor to the injection loss signals. Methods to reduce the recaptured beam in the SPS were successfully tested and verified with the diamond particle detectors. In this paper the detection and classification of LHC injection losses are described. The methods to reduce these losses and verification measurements are presented and discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR031
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MOPMR033	Characterization of Beam Properties Using Synchrotron Light at Taiwan Photon Source	synchrotron, booster, storage-ring, photon	316
	C.Y. Liao, Y.-S. Cheng, K.T. Hsu, K.H. Hu, C.-C. Kuo, H.-J. Tsai, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a third-generation 3-GeV synchrotron light facility, located in National Synchrotron Radiation Research Center (NSRRC) at Hsinchu Science Park. After overcoming many challenges, the storage beam current attained 520 mA in 2015 December. The synchrotron light monitors, including X-ray and visible light, are important diagnostic tools to characterize the various machine conditions. The booster beam dynamics during ramping and the beam properties of the storage ring were studied with synchrotron light. The results of measurements are presented in this report.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR033
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MOPMW011	The Second Harmonic RF System for J-PARC MR Upgrade	cavity, impedance, operation, proton	420
	C. Ohmori, K. Hara, K. Hasegawa, M. Toda, M. Yoshii KEK, Tokai, Ibaraki, Japan M. Nomura, T. Shimada, F. Tamura, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	Power upgrade scenario of J-PARC Main Ring includes replacement of RF cavities with higher field gradient using magnetic alloy cores, FT3L than the present ones. It also need to install the second harmonic RF cavity in the other section where dedicated water system for RF cavities is not available. Installation scenario of the second harmonic RF will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMW011
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MOPMY002	Simulation and Experimental Studies of a 2.45GHz Magnetron Source for an SRF Cavity with Field Amplitude and Phase Controls	controls, cavity, LLRF, SRF	514
	H. Wang, T. E. Plawski, R.A. Rimmer JLab, Newport News, Virginia, USA A. Dudas, M.L. Neubauer Muons, Inc, Illinois, USA
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and NP STTR Grant DE-SC0013203. Phase lock to an SRF cavity by using injection signal through output waveguide of a magnetron has been demonstrated [1, 3]. Amplitude control using magnetic field trimming and anode voltage modulation has been studied using MATLAB/Simulink simulations [2]. Based on these, we are planning to use an FPGA based digital LLRF system, which allows applying various types of control algorithms in order to achieve the required accelerating field stability. Since the 1497 MHz magnetron is still in the design stage, the proof of principle measurements of a commercial 2450 MHz magnetron are carried out to characterize the anode I-V curve, output power (the tube electronic efficiency), frequency dependence on the anode current (frequency pushing) and the Rieke diagram (frequency pulling by the reactive load). Based on early Simulink simulation, experimental data and extension of the Adler equation governing injection phase stability by Chen's model, the specification of the new LLRF control chassis for both 2450 and 1497MHz systems are presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMY002
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MOPOR003	Simulation Studies and Measurements of Beam Instabilities Caused by the Kicker Impedance at High Intensities in the 3-GeV RCS of J-PARC	simulation, impedance, kicker, betatron	589
	P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, M. Nomura, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, M. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	The transverse impedance of the extraction kickers is a significant beam instability source in the 3-GeV Rapid Cycling Synchrotron of J-PARC. ORBIT code was developed for space charge and beam instability simulations by successfully introducing realistic time dependent machine parameters. The beam instability at high intensities, especially at the designed 1 MW beam power was found be very critical. As there was no practical measure yet to reduce the kicker impedance, a detail simulation studies were done in order to determine realistic machine parameters to suppress the beam instability. The simulation results were found to be very consistent with measurements to successfully accomplish 1 MW beam power. The simulation and beam study results in detail are presented in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR003
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MOPOR004	Recent Progress of 1-MW Beam Tuning in the J-PARC 3-GeV RCS	resonance, emittance, scattering, power-supply	592
	H. Hotchi, H. Harada, S. Kato, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, K. Yamamoto, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	The J-PARC 3-GeV RCS started 1 MW beam test from October 2014, and successfully achieved a 1 MW beam acceleration in January 2015. Since then, a large fraction of our effort has been focused on reducing and managing beam losses. This paper presents the recent progress of 1 MW beam tuning, especially focusing on our approaches to beam loss issues, such as space-charge induced beam loss and foil scattering beam loss during charge-exchange injection, etc.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR004
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MOPOR008	Beam Induced RF Heating in LHC in 2015	impedance, operation, vacuum, monitoring	602
	B. Salvant, O. Aberle, M. Albert, R. Alemany-Fernandez, G. Arduini, J. Baechler, M.J. Barnes, P. Baudrenghien, O.E. Berrig, N. Biancacci, G. Bregliozzi, J.V. Campelo, F. Carra, F. Caspers, P. Chiggiato, A. Danisi, H.A. Day, M. Deile, D. Druzhkin, J. F. Esteban Müller, S. Jakobsen, J. Kuczerowski, A. Lechner, R. Losito, A. Masi, N. Minafra, E. Métral, A.A. Nosych, A. Perillo Marcone, D. Perini, S. Redaelli, F. Roncarolo, G. Rumolo, E.N. Shaposhnikova, J.A. Uythoven, C. Vollinger, A.J. Välimaa, N. Wang, M. Wendt, J. Wenninger, C. Zannini CERN, Geneva, Switzerland M. Bozzo INFN Genova, Genova, Italy J.F. Esteban Müller EPFL, Lausanne, Switzerland N. Wang IHEP, Beijing, People's Republic of China
	Following the recurrent beam induced RF issues that perturbed LHC operation during LHC Run 1, a series of actions were put in place to minimize the risk that similar issues would occur in LHC Run 2: longitudinal impedance reduction campaign and/or improvement of cooling for equipment that were problematic or at the limit during Run 1, stringent constraints enforced on new equipment that would be installed in the machine, tests to control the bunch length and longitudinal distribution, additional monitoring of temperature, new monitoring tools and warning chains. This contribution reports the outcome of these actions, both successes as well as shortcomings, and details the lessons learnt for the future runs.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR008
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MOPOR021	Space Charge Studies with High Intensity Single Bunch Beams in the CERN SPS	emittance, brightness, resonance, space-charge	644
	H. Bartosik, F. Schmidt CERN, Geneva, Switzerland A. Oeftiger EPFL, Lausanne, Switzerland M. Titze HZB, Berlin, Germany
	In order to reach the target beam parameters of the LHC injectors upgrade (LIU) project the beam degradation due to losses and emittance growth on the long injection plateau of the SPS needs to be minimized. A detailed study of the dependence of losses, transverse emittance blow-up and transverse beam tail creation as function of the working point is presented here for a high brightness single bunch beam with a vertical space charge tune spread of about 0.2 on the 26 GeV injection plateau. The beam behaviour close to important betatron resonances is characterised and a region in the tune diagram with minimal beam degradation is identified. Implications about the performance for LIU beams are discussed.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR021
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MOPOR022	Beam Dynamics Observations of the 2015 High Intensity Scrubbing Runs at the Cern Sps	electron, operation, octupole, emittance	648
	H. Bartosik, G. Iadarola, K.S.B. Li, L. Mether, A. Romano, G. Rumolo, M. Schenk CERN, Geneva, Switzerland
	Beam quality degradation caused by e-cloud effects has been identified as one of the main performance limitations for high intensity LHC beams with 25 ns bunch spacing in the SPS. In view of the beam parameters targeted with the LHC injectors upgrade (LIU) project, about two weeks of SPS machine time in 2015 were devoted to dedicated scrubbing runs with high intensity LHC 25 ns and dedicated 'doublet' beams in order to study the achievable reduction of e-cloud effects and quantify the consequent beam performance improvements. This paper describes the main observations concerning the coherent instabilities and beam dynamics limitations encountered as well as a detailed characterisation of the performance reach with the highest beam intensity presently available from the pre-injectors.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR022
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MOPOR023	Flat Bunches with a Hollow Distribution for Space Charge Mitigation	space-charge, synchrotron, emittance, resonance	652
	A. Oeftiger, H. Bartosik, A. Findlay, S. Hancock, G. Rumolo CERN, Geneva, Switzerland A. Oeftiger EPFL, Lausanne, Switzerland
	Funding: CERN, Doctoral Studentship EPFL, Doctorate Longitudinally hollow bunches provide one means to mitigate the impact of transverse space charge. The hollow distributions are created via dipolar parametric excitation during acceleration in CERN's Proton Synchrotron Booster. We present simulation work and beam measurements. Particular emphasis is given to the alleviation of space charge effects on the long injection plateau of the downstream Proton Synchrotron machine, which is the main goal of this study.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR023
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MOPOR024	Evolution of High Intensity Beams in the CERN PS Booster after H⁻ Injection and Phase Space Painting	emittance, space-charge, booster, lattice	656
	M. Cieslak-Kowalska, J.L. Abelleira, E. Benedetto, C. Bracco CERN, Geneva, Switzerland
	With the LHC Injector Upgrade (LIU) project, the injection energy of PS Booster (PSB) ' first circular accelerator in the LHC injector chain ' will be raised from 50 MeV to 160 MeV and the present multiturn injection will be upgraded to H⁻ injection with transverse and longitudinal painting. In the scope of this project, it is planned to double the beam intensities, profiting from the fact that the βγ2 factor will be two times larger (0.35 at 50 MeV and 0.71 at 160 MeV), so the resulting tune spread driven by a direct space charge should remain similar. This paper describes the feasibility to double the intensity of high intensity and large emittance beams, looking into the evolution under space charge and taking into account losses constrains in the ring and in the extraction lines.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR024
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MOPOR025	3D Emittances Tailoring Techniques and Optimization with Space Charge for the Future CERN PS Booster Operations with Linac4	emittance, coupling, simulation, linac	660
	V. Forte, J.L. Abelleira, E. Benedetto, C. Bracco, M. Cieslak-Kowalska, G.P. Di Giovanni CERN, Geneva, Switzerland
	In the frame of the LIU (LHC Injectors Upgrade) project, the CERN PS Booster is going to be renovated to host a new H⁻ charge-exchange injection from the Linac4. One important feature of the new injection scheme is the possibility to tailor a wide range of 3D emittances for CERN's different users in an intensity span in the order of 5·10⁹ to 1.6·10¹³ protons per PSB ring. This paper gives an overview of 3D multi-turn injection techniques, focusing on the future LHC beams, which aim at reaching high brightness, and on highest intensity beams (ISOLDE), where losses are the main concern. Complete RF capture simulations and transverse injection maps, including space charge effects, are presented and also intended to be used during the commissioning with Linac4.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR025
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MOPOR042	Beam Dynamics Modeling of Drift-tube Linacs with CST Particle Studio	DTL, simulation, rfq, linac	689
	S.S. Kurennoy LANL, Los Alamos, New Mexico, USA
	The CST Studio provides convenient tools for self-consistent 3D modeling of accelerators, even large ones. Here we demonstrate this approach for the LANSCE drift-tube linac (DTL) taken as an example. The RF fields in 3D models of full DTL tanks are calculated and tuned with MicroWave Studio (MWS). Beam dynamics in the DTL is modeled with Particle Studio for bunches and bunch trains with realistic initial beam distributions using the MWS-calculated RF fields and quadrupole magnetic fields. The output beam parameters and locations of particle losses are calculated and compared for different beam distributions. Our main emphasis is on the formation of low-energy tails (longitudinal halo) and their interaction with regular bunches. Such effects are usually not taken into account in standard multi-particle phase-space codes.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOR042
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MOPOW052	Status of the Preparation to the Commissioning of the ThomX Storage Ring	storage-ring, dipole, electron, controls	833
	I. Chaikovska, C. Bruni, S. Chancé, A.R. Gamelin, H. Monard LAL, Orsay, France A. Loulergue SOLEIL, Gif-sur-Yvette, France
	Funding: Work is supported by the French Agence Nationale de la Recherche as part of the program EQUIPEX under reference ANR-10-EQPX-51, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI ThomX is a compact Compton based X-ray source under construction at LAL in Orsay (France). The ThomX facility is composed by a 50-70 MeV linac, a transfer line and a 18 meters long Storage Ring (SR). The Compton scattering between the 50 MeV electron bunch of 1 nC and the 30 mJ laser pulses stacked in the Fabry-Perot cavity results in the production of photons with energies (up to 90 keV) with a maximum flux of 10¹³ photons/s. The ThomX construction will start shortly aiming to be completed in the middle of 2017. The preparation to the SR commissioning as far as a control system and beam physics applications are concerned is progressing gradually in order to prepare and test all the tools well ahead the start of the machine. The SR commissioning will face with many challenges providing the low energy, compactness, the nonlinear beam dynamics, the limited beam storage and need for the precision and stabilization in the Interaction Region. Several techniques used at the Synchrotron Light Sources should be modified/adapted to meet all the specificity of the ThomX. This is a report on preparation of the ThomX SR commissioning, its status, planning, main challenges and expectations.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW052
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MOPOW055	Injection Using a Non-linear Kicker Located in the Existing Injection Straight at Diamond Storage Ring	septum, kicker, storage-ring, optics	840
	B. Singh, M. Apollonio, R. Bartolini, I.P.S. Martin DLS, Oxfordshire, United Kingdom A. Alekou, R. Bartolini, T. Pulampong JAI, Oxford, United Kingdom
	Injection studies using a non-linear kicker for the Diamond storage ring have been carried out previously. These studies have been recently extended to investigate whether the non-linear kicker can be located in the injection straight downstream of the septum and outside the existing dipole kicker bump. If so, injection with a non-linear kicker becomes independent of the optics used, making it suitable for use in both standard and low alpha mode. With this configuration, the existing injection scheme could also be left in place, leaving open the possibility to study both schemes in situ before potentially removing the existing dipole kickers at a later date. In order to operate with the non-linear kicker, the injected beam needs to exit the transfer line at an angle of 3mrad; this has been successfully demonstrated during machine development time. The concept and feasibility studies of this scheme are presented in this paper. T. Pulampong, et al., Proc. IPAC 2013, Shanghai, WEPWA065, (2013)
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOW055
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MOPOY001	MedAustron Synchrotron RF Commissioning for Medical Proton Beams	acceleration, synchrotron, proton, cavity	844
	C. Schmitzer, F. Farinon, A. Garonna, M. Kronberger, T.K.D. Kulenkampff, C. Kurfürst, S. Myalski, S. Nowak, F. Osmić, L.C. Penescu, M.T.F. Pivi, P. Urschütz, A. Wastl EBG MedAustron, Wr. Neustadt, Austria
	MedAustron is a medical accelerator facility for hadron therapy cancer treatment using protons and carbon ions. The Synchrotron is driven by a 0.47-3.26 MHz Finemet® loaded wideband cavity powered by 12x 1kW solid state amplifiers connected to a digital Low Level RF system. It was developed in collaboration with CERN and put to operation at MedAustron in early 2014. The main Synchrotron RF (sRF )commissioning steps for proton beams involved the setup of the adiabatic capture process, the setup of the frequency and voltage ramps and feedback loops for fast acceleration and the RF jump for extraction. The adiabatic capture process was optimized in terms of energy and voltage mismatch by analyzing longitudinal empty bucket scans after beam injection into the synchrotron. The acceleration ramp optimization was based on calculations using a software tool developed in-house and adapted experimentally to minimize losses at injection and during acceleration. This paper provides an overview of the acceleration system and describes the commissioning process of the sRF system and the related beam commissioning efforts at MedAustron.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY001
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MOPOY007	High Energy Booster Options for a Future Circular Collider at CERN	booster, collider, extraction, hadron	856
	L.S. Stoel, M.J. Barnes, W. Bartmann, F. Burkart, B. Goddard, W. Herr, T. Kramer, A. Milanese, G. Rumolo, E.N. Shaposhnikova CERN, Geneva, Switzerland
	In case a Future Circular Collider for hadrons (FCC-hh) is constructed at CERN, the tunnels for SPS, LHC and the 100 km collider will be available to house a High Energy Booster (HEB). The different machine options cover a large technology range from an iron-dominated machine in the 100 km tunnel to a superconducting machine in the SPS tunnel. Using a modified LHC as reference, these options are compared with respect to their energy reach, magnet technology and filling time of the collider. Potential issues with beam transfer, reliability and beam stability are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY007
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MOPOY059	LHC Injectors Upgrade (LIU) Project at CERN	ion, proton, linac, brightness	992
	E.N. Shaposhnikova, J. Coupard, H. Damerau, A. Funken, S.S. Gilardoni, B. Goddard, K. Hanke, L. Kobzeva, A.M. Lombardi, D. Manglunki, S. Mataguez, M. Meddahi, B. Mikulec, G. Rumolo, R. Scrivens, M. Vretenar CERN, Geneva, Switzerland
	A massive improvement program of the LHC injector chain is presently being conducted under the LIU project. For the proton chain, this includes the replacement of Linac2 with Linac4 as well as all necessary upgrades to the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS) and Super Proton Synchrotron (SPS), aimed at producing beams with the challenging High Luminosity LHC (HL-LHC) parameters. Regarding the heavy ions, plans to improve the performance of Linac3 and the Low Energy Ion Ring (LEIR) are also pursued under the general LIU program. The full LHC injection chain returned to operation after Long Shutdown 1, with extended beam studies taking place in Run 2. A general project Cost and Schedule Review also took place in March 2015, and several dedicated LIU project reviews were held to address issues awaiting pending decisions. In view of these developments, 2014 and 2015 have been key years to define a number of important aspects of the final LIU path. This paper will describe the reviewed LIU roadmap and revised performance objectives of the main upgrades, including the work status and outlook in terms of the required installation and commissioning stages.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY059
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MOPOY060	Performance Analysis for the New g-2 Experiment at Fermilab	simulation, storage-ring, experiment, dipole	996
	D. Stratakis, M.E. Convery, C. Johnstone, J.A. Johnstone, J.P. Morgan, M.J. Syphers Fermilab, Batavia, Illinois, USA J.D. Crmkovic, W. Morse, V. Tishchenko BNL, Upton, Long Island, New York, USA N.S. Froemming University of Washington, CENPA, Seattle, USA M. Korostelev Cockcroft Institute, Warrington, Cheshire, United Kingdom M. Korostelev Lancaster University, Lancaster, United Kingdom
	The new g-2 experiment at Fermilab aims to measure the muon anomalous magnetic moment to a precision of ±0.14 ppm ─ a fourfold improvement over the 0.54 ppm precision obtained in the g-2 BNL E821experiment. Achieving this goal requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we describe a muon capture and transport scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we describe its basic features. Then, we detail its performance numerically by simulating the pion production in the (g-2) production target, the muon collection by the downstream beamline optics as well as the beam polarization and spin-momentum correlation up to the storage ring. The sensitivity in performance of our proposed channel against key parameters such as magnet apertures and magnet positioning errors is analyzed
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPOY060
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TUXA01	Status and Future Upgrade of J-PARC Accelerators	linac, operation, extraction, hadron	999
	M. Kinsho JAEA/J-PARC, Tokai-mura, Japan
	The linac energy reached to 400 MeV as a design value and also a beam current was upgraded to 50 mA by replacing a new ion source. At the 3 GeV synchrotron, a high power beam of 8.41x10¹³ protons per pulse was demonstrated, which was equivalent to 1 MW when the repetition would be 25 Hz. At the main ring, beam loss was reduced by suppression of transverse instabilities and so on. The beam power for both the neutrino experiment and hadron experimental facility is increasing to reduce beam loss. J-PARC accelerators each have their own upgrade plan to increase beam power. The progress and future plan of J-PARC accelerators are reported in this paper.
	Slides TUXA01 [11.427 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUXA01
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TUOAA03	Long Term Plans to Increase Fermilab's Proton Intensity to Meet the Needs of the Long Baseline Neutrino Program	proton, linac, booster, experiment	1010
	E. Prebys, P. Adamson, S.C. Childress, P. Derwent, S.D. Holmes, I. Kourbanis, V.A. Lebedev, W. Pellico, A. Romanenko, V.D. Shiltsev, E.G. Stern, A. Valishev, R.M. Zwaska Fermilab, Batavia, Illinois, USA
	Funding: This work is supported by the US Department of Energy under contract No. De-AC02-07CH11359. The flagship of Fermilab's long term research program is the Deep Underground Neutrino Experiment (DUNE), located Sanford Underground Research Facility (SURF) in Lead, South Dakota, which will study neutrino oscillations with a baseline of 1300 km. The neutrinos will be produced in the Long Baseline Neutrino Facility (LBNF), a proposed new beam line from Fermilab's Main Injector. The physics goals of the DUNE require a proton beam with a power of roughly 2.5 MW at 120 GeV, which is roughly five times the current maximum power. This poster outlines the staged plan to achieve the required power over the next 15 years.
	Slides TUOAA03 [4.129 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUOAA03
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TUPMB007	Research and Development of the Pulse Bump Magnet for the Injection System in CSNS/RCS	neutron, radiation, high-voltage, synchrotron	1118
	L. Huo, M.Y. Huang, W. Kang, Y.Q. Liu, J. Qiu, L. Wang, S. Wang IHEP, Beijing, People's Republic of China
	The H⁻ stripping painting injection is adopted in the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS). Painting injection is realized by eight pulse bump magnets. The pulse bump magnet is the key of the performance of painting, as well as the beam loss control. The manufacture and the field measurement of the eight pulse bump magnets have been completed. In the development of the magnets, some key technical problems on fabrication of coil were solved, and the field measurement results show that the magnets fulfil the design specification.
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TUPMB017	The Injection Septum Magnet for the Collector Ring (FAIR)	septum, vacuum, operation, lattice	1145
	P.Yu. Shatunov, D.E. Berkaev, I. Koop, E.P. Semenov, D.B. Shwartz BINP SB RAS, Novosibirsk, Russia A. Dolinskyy, S.A. Litvinov GSI, Darmstadt, Germany Yu. A. Rogovsky Budker INP & NSU, Novosibirsk, Russia
	Collector Ring is one of the key installations of the FAIR project (Darmstadt, Germany). It is dedicated for stochastic cooling of incoming beams of antiprotons and rare ions. Additionally there is a mode of operation for experiments in the ring. Beams for all modes of operation are injected through one transfer channel. Extremely high acceptance of the ring (240 mm*mrad) leads to large apertures of all magnetic elements including the septum magnet. Meanwhile planned parameters of the magnetic field and magnetic field quality are comparatively strict. The present state of the design of the pulsed injection septum for the CR is presented in this article together with the concept of the injection system.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB017
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TUPMB018	Magnetic Measurements of SESAME Storage Ring Dipoles at ALBA	dipole, alignment, multipole, storage-ring	1148
	J. Marcos, J. Campmany, V. Massana ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain A. Milanese, C. Petrone, L. Walckiers CERN, Geneva, Switzerland
	Funding: This work is partially supported by the EC under the CESSAMag project, FP7 contract 338602. In this work we present the results of the measurement campaign of the main bending magnets of the SESAME storage ring, that were fully characterized at ALBA-CELLS magnetic measurements facility. A total of 17 combined function dipoles ' 16 series magnets plus a pre-series one ' has been tested and characterized. This campaign has been performed using a dedicated Hall probe bench. The main measurements include the transfer function at the center of the magnet and field maps of the three components of the field in a plane around the nominal trajectory of the electron beam, at two different operating currents. In this paper we describe the experimental setup and procedures, before reporting the main results, including statistics of magnet-to-magnet reproducibility and integrated field quality. Finally, we show how the measured data can be exploited for an optimal 3D alignment of the dipoles in the machine.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB018
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TUPMB048	Compensation of Beam Induced Effects in LHC Cryogenic Systems	cryogenics, controls, electron, simulation	1205
	B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González CERN, Geneva, Switzerland
	This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.
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TUPMB052	High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers	experiment, simulation, proton, radiation	1218
	F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven CERN, Geneva, Switzerland
	In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMB052
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TUPMR012	Investigation of Central Region Design of 10MeV AVF Cyclotron	cyclotron, ion, ion-source, acceleration	1253
	M. Afkhami Karaei, H. Afarideh, S. Azizpourian, R. Solhju AUT, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	Recently, studies on the central region of 10 MeV AVF Cyclotron have been done at AmirKabir University of Technology. In this study, the aim of the cyclotron design is to accelerate the ions up to 10MeV energy. The cyclotron, consist of four sector magnets and 2 RF cavities which will be operated at 71 MHz. The internal PIG ion source is used in this cyclotron. The purpose of this work is to investigate the behavior of trajectories of ions in the magnetic and electric fields at the center of the cyclotron. The electric and magnetic field distribution was designed by OPERA-3DTOSCA. In order to solve the equation of motion, numerical code was written in C++ program that used the conventional Rung-Kutta method. The obtained results of simulation were the horizontal and vertical motion of an ion in the center of cyclotron, and motion of the center of the orbits.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR012
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TUPMR028	Spin Correlations Study for the New g-2 Experiment at Fermilab	experiment, storage-ring, simulation, quadrupole	1301
	D. Stratakis, J.D. Crnkovic, W. Morse, V. Tishchenko BNL, Upton, Long Island, New York, USA
	The muon g-2 experiment executed at Brookhaven concluded in 2001 and measured a discrepancy of more than three standard deviations compared to the Standard Model (SM) calculation. A new initiative at Fermilab is under construction to improve the experimental accuracy four-fold. Achieving this goal, however, requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we examine systematic errors that can arise from correlations between muon spin and transverse coordinates for the new g-2 experiment. To achieve this goal we perform end-to-end spin tracking simulations from the production target up to the ring injection point and compare our findings against the results from the Brookhaven experiment. We detail similarities and differences.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR028
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TUPMR039	The Development of a New High Field Injection Septum Magnet System for Main Ring of J-Parc	septum, operation, power-supply, flattop	1337
	T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto KEK, Ibaraki, Japan K. Fan HUST, Wuhan, People's Republic of China
	We are improving the Main Ring (MR) for beam power of 750 kw which is the first goal of J-PARC. The repetition period of the fast extraction must be short to 1.3 second from the current period of 2.48 second for the improvement of the beam power. It is necessary to exchange a high field injection septum magnet which will be installed at the injection line from RCS to MR and its power supply, because the current injection septum system can not be operated with 1.3 second repetition. Since confirmed the large leakage field around current circling beam line of the injection magnet, we must improve the shielding structure which make low leakage field. We started the development of the new injection septum magnet and its power supply in 2013. It can operate with 1 Hz repetition and the low leakage field which its order is 10^-4 of the gap field. The new Injection septum magnet and the new power supply were constructed in Winter of 2014. We had many improvement of the magnet and power supply. We will install the new injection septum magnet system in this summer. In this presentation, we will report the detail of the results of its performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR039
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TUPMR046	Sources of Emittance Growth at the CERN PS Booster to PS Transfer	emittance, kicker, optics, betatron	1352
	W. Bartmann, J.L. Abelleira, F. Burkart, B. Goddard, J. Jentzsch, R. Ostojić CERN, Geneva, Switzerland
	The CERN PS Booster (PSB) has four vertically stacked rings. After extraction from each ring, the bunches are recombined in two stages, comprising septum and kicker systems, such that the accumulated bunch train is injected through a single line into the PS. Bunches from the four rings go through a different number of vertical bends, which leads to differences in the betatron and dispersion functions due to edge focussing. The fast pulsed systems at PSB extraction, recombination and PS injection lead to systematic errors of delivery precision at the injection point. These error sources are quantified in terms of emittance growth and particle loss. Mitigations to reduce the overall emittance growth at the PSB to PS transfer within the LHC injectors upgrade are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR046
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TUPMR048	SPS Injection and Beam Quality for LHC Heavy Ions With 150 ns Kicker Rise Time	ion, kicker, damping, proton	1360
	B. Goddard, E. Carlier, L. Ducimetière, G. Kotzian, J.A. Uythoven CERN, Geneva, Switzerland F.M. Velotti EPFL, Lausanne, Switzerland
	As part of the LHC Injectors Upgrade project for LHC heavy ions, the SPS injection kicker system rise time needs reduction below its present 225 ns. One technically challenging option under consideration is the addition of fast Pulse Forming Lines in parallel to the existing Pulse Forming Networks for the 12 kicker magnets MKP-S, targeting a system field rise time of 100 ns. An alternative option is to optimise the system to approach the existing individual magnet field rise time (2-98%) of 150 ns. This would still significantly increase the number of colliding bunches in LHC while minimising the cost and effort of the system upgrade. The observed characteristics of the present system are described, compared to the expected system rise time, together with results of simulations and measurements with 175 and 150 ns injection batch spacing. The expected beam quality at injection into LHC is quantified, with the emittance growth and simulated tail population taking into account expected jitter and synchronisation errors, damper performance and SPS non-linear optics behavior. The outlook for deployment is discussed, with the implications for LHC operation and HL-LHC performance.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR048
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TUPMR049	Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode	simulation, kicker, flattop, operation	1363
	T. Kramer, W. Bartmann, J.C.C.M. Borburgh, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, B. Goddard, L. Sermeus CERN, Geneva, Switzerland
	Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying the performance of upgrade options have been taken during the last end of the year stop. The paper concludes with an upgrade plan and a brief overview of implementation risks.
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TUPMR053	Initial Experience with Carbon Stripping Foils at ISIS	operation, synchrotron, proton, vacuum	1378
	B. Jones, D.J. Adams, H. V. Smith STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	The ISIS Facility at the Rutherford Appleton Laboratory is a spallation neutron and muon source based upon a 50 Hz rapid cycling synchrotron accelerating ~3×10¹³ protons per pulse from 70 to 800 MeV to deliver a mean beam power of 0.2 MW to two target stations. Throughout its 30 years of operation ISIS has developed aluminium oxide foils in-house for H− charge exchange injection. The manufacturing and installation processes for these foils are time consuming, radiologically dose intensive and require a high degree of skill. Commercially available carbon based foils commonly used at other facilities, have the potential to greatly simplify foil preparation and installation in addition to improving beam quality. Similar foils would also be necessary for facility upgrades which increase injection energy to withstand the higher operating temperatures. This paper describes the initial experience of carbon foils in the ISIS synchrotron including issues relating to handling and mounting foils, their performance under beam operation and plans for further development.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMR053
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TUPMR058	An Upgrade for the 1.4 MeV/u Gas Stripper at the GSI UNILAC	target, ion, dipole, heavy-ion	1394
	P. Scharrer, W.A. Barth, Ch.E. Düllmann, J. Khuyagbaatar, A. Yakushev HIM, Mainz, Germany W.A. Barth, M. Bevcic, Ch.E. Düllmann, L. Groening, K.P. Horn, E. Jäger, J. Khuyagbaatar, J. Krier, P. Scharrer, A. Yakushev GSI, Darmstadt, Germany Ch.E. Düllmann Johannes Gutenberg University Mainz, Institut of Nuclear Chemistry, Mainz, Germany P. Scharrer Mainz University, Mainz, Germany
	The GSI UNILAC will serve as part of an injector system for the future FAIR facility, currently under construction in Darmstadt, Germany. For this, it has to deliver short-pulsed, high-current, heavy-ion beams with highest beam quality. An upgrade for the 1.4 MeV/u gas stripper is ongoing to increase the yield of uranium ions in the desired charge state. The new setup features a pulsed gas injection synchronized with the beam pulse transit to increase the effective density of the stripper target while keeping the gas load for the differential pumping system low. Systematic measurements of charge state distributions and energy-loss were conducted with 238U-ion beams and different stripper gases, including H2 and He. By using H2 as a stripper gas, the yield into the most populated charge state was increased by over 50%, compared to the current stripper. Furthermore, the high gas density, enabled by the pulsed injection, results in increased mean charge states.
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TUPMW014	Improved Aperture Measurements at the LHC and Results from their Application in 2015	alignment, operation, insertion, beam-losses	1446
	P.D. Hermes, R. Bruce, M. Fiascaris, H. Garcia, M. Giovannozzi, A. Mereghetti, D. Mirarchi, E. Quaranta, S. Redaelli, B. Salvachua, G. Valentino CERN, Geneva, Switzerland R. Kwee-Hinzmann Royal Holloway, University of London, Surrey, United Kingdom E. Quaranta Politecnico/Milano, Milano, Italy
	A good knowledge of the available aperture in the LHC is essential for a safe operation due to the risk of magnet quenches or even damage in case of uncontrolled beam losses. Experimental validations of the available aperture are therefore crucial and were in the past carried out by either a collimator scan combined with beam excitations or through the use of local orbit bumps. In this paper, we show a first comparison of these methods in the same machine configuration, as well as a new very fast method based on a beam-based collimator alignment and a new faster variant of the collimator scan method. The methods are applied to the LHC operational configuration for 2015 at injection and with squeezed beams and the measured apertures are presented.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW014
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TUPMW017	Electron Cloud Observations during LHC Operation with 25 ns Beams	electron, operation, simulation, cryogenics	1458
	K.S.B. Li, H. Bartosik, G. Iadarola, L. Mether, A. Romano, G. Rumolo, M. Schenk CERN, Geneva, Switzerland
	While during the Run 1 (2010-2012) of the Large Hadron Collider (LHC) most of the integrated luminosity was produced with 50 ns bunch spacing, for the Run 2 start-up (2015) it was decided to move to the nominal bunch spacing of 25 ns. As expected, with this beam configuration strong electron cloud effects were observed in the machine, which had to be mitigated with dedicated 'scrubbing' periods at injection energy. This enabled to start the operation with 25 ns beams at 6.5 TeV, but e-cloud effects continued to pose challenges while gradually increasing the number of circulating bunch trains. This contribution will review the encountered limitations and the mitigation measures that where put in place and will discuss possible strategies for further performance gain.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW017
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TUPMW019	First Evaluation of Dynamic Aperture at Injection for FCC-hh	dipole, dynamic-aperture, target, simulation	1466
	B. Dalena, D. Boutin, A. Chancé, J. Payet CEA/IRFU, Gif-sur-Yvette, France B.J. Holzer, R. Martin, D. Schulte CERN, Geneva, Switzerland
	Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Programme under grant agreement no. 654305. In the hadron machine option, proposed in the context of the Future Circular Colliders (FCC) study, the dipole field quality is expected to play an important role, as in the LHC. A preliminary evaluation of the field quality of dipoles, based on the Nb3Sn technology, has been provided by the magnet group. The effect of these field imperfections on the dynamic aperture, using the present lattice design, is presented and first tolerances on the main multipole components are evaluated.
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TUPMW026	Feed-Forward Corrections for Tune and Chromaticity Injection Decay During 2015 LHC Operation	operation, hadron, collider, octupole	1489
	M. Solfaroli Camillocci, M. Juchno, M. Lamont, M. Schaumann, E. Todesco, J. Wenninger CERN, Geneva, Switzerland
	After two years of shutdown, the Large Hadron Collider (LHC) has been operated in 2015 at 6.5 TeV, close to its designed energy. When the current is stable at low field, the harmonic components of the main circuits are subject to a dynamic variation induced by current redistribution on the superconducting cables. The Field Description of the LHC (FiDel) foresaw an increase of the decay at injection of tune (quadrupolar components) and chromaticity (sextupolar components) of about 50% with respect to LHC Run1 due to the higher operational current. This paper discusses the beam-based measurements of the decay during the injection plateau and the implementation and accuracy of the feed-forward corrections as present in 2015. Moreover, the observed tune shift proportional to the circulating beam intensity and it's foreseen feed-forward correction are covered.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPMW026
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TUPMW029	Tune and Chromaticity Control During Snapback and Ramp in 2015 LHC Operation	controls, sextupole, dipole, lattice	1501
	M. Schaumann, M. Juchno, M. Lamont, M. Solfaroli Camillocci, E. Todesco, J. Wenninger CERN, Geneva, Switzerland
	Because of current redistribution on the superconducting cables, the harmonic components of the magnetic fields of the superconducting magnets in the Large Hadron Collider (LHC) show decay during the low field injection plateau. This results in tune and chromaticity variations for the beams. In the first few seconds of the ramp the original hysteresis state of the magnetic field is restored - the field snaps back. These fast dynamic field changes lead to strong tune and chromaticity excursions that, if not properly controlled, induce beam losses and potentially trigger a beam dump. A feed-forward system applies predicted corrections during the injection plateau and to the first part of the ramp to avoid violent changes of beam conditions. This paper discusses the snapback of tune and chromaticity as observed in 2015, as well as the control of beam parameters during the ramp. It also evaluates the quality of the applied feed-forward corrections and their reproducibility.
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TUPMW034	A 200 MHz SC-RF System for the HL-LHC	cavity, emittance, luminosity, impedance	1513
	R. Calaga, R. Tomás CERN, Geneva, Switzerland
	Funding: Research supported by the High Luminosity LHC project A quarter wave β=1 superconducting cavity at 200 MHz is proposed for the LHC as an alternative to the present 400 MHz RF system. The primary motivation of such a system would be to accelerate higher intensity and longer bunches with improved capture efficiency. Advantages related to minimizing electron cloud effects, intra-beam scattering, heating and the possibility of luminosity levelling with bunch length are described. Some considerations related to cavity optimization, beam loading and technological challenges are addressed.
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TUPMW038	RHIC Operation with Asymmetric Collisions in 2015	proton, operation, emittance, cavity	1527
	C. Liu, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, J.S. Laster, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, G. Narayan, S.K. Nayak, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, G. Wang, K. Yip, A. Zaltsman, K. Zeno, S.Y. Zhang BNL, Upton, Long Island, New York, USA S.M. White ESRF, Grenoble, France
	Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy. Collisions with beams of highly asymmetric rigidities (proton-Gold and proton-Aluminum) were provided for the RHIC physics programs in 2015. Magnets were moved for the first time in RHIC prior to the run to accommodate the asymmetric beam trajectories during acceleration and at store. A special ramping scheme was designed to keep the revolution frequencies of the beams in the two rings equal. The unique operational experience of the asymmetric run will be reviewed.
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TUPMY005	A Muon Source Proton Driver at JPARC-based Parameters	proton, booster, linac, operation	1550
	D.V. Neuffer Fermilab, Batavia, Illinois, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the U. S. Department of Energy. An "ultimate" high intensity proton source for neutrino factories and/or muon colliders was projected to be a ~4 MW multi-GeV proton source providing short, intense proton pulses at ~15 Hz. The JPARC ~1 MW accelerators provide beam at parameters that in many respects overlap these goals. Proton pulses from the JPARC Main Ring can readily meet the pulsed intensity goals. We explore these parameters, describing the overlap and consider extensions that may take a JPARC-like facility toward this "ultimate" source. JPARC itself could serve as a stage 1 source for such a facility.
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TUPMY015	Ultrafast Electron Guns for the Efficient Acceleration using Single-Cycle THz Pulses	electron, gun, acceleration, laser	1578
	A. Fallahi, F.X. Kärtner, A. Yahaghi CFEL, Hamburg, Germany M. Fakhari DESY, Hamburg, Germany
	Funding: European Research Council (ERC) Over the past decades, advances in ultrafast technologies led to the production of intense ultrashort THz to optical pulses reaching single-cycle pulse duration. Using such pulses for electron acceleration offers advantages in terms of higher thresholds for materials breakdown, thus introducing a promising path towards increasing acceleration gradients. Conventional accelerator technology is based on either continuous wave or long pulse operation, where resonant or guiding structures are usually employed. We introduce novel structures for electron acceleration which operate with single-cycle pulses named as single-cycle ultrafast guns. The operating frequencies considered here are at THz wavelengths inspired by the recent progress in the optical generation of intense single-cycle THz pulses. We begin with designing guns for low energy pulses and proceed with structures designed for high energy pulses. More importantly, it is shown that the already achieved THz pulse energies of 20 uJ are enough to realize relativistic fields for electron acceleration. These structures will underpin future devices for fabricating miniaturized electron guns and linear accelerators.
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TUPMY026	Electron Beam Generation and Injection From a Pyroelectric Crystal Array	acceleration, electron, laser, radiation	1604
	R.B. Yoder, Z. Kabilova, B. Saeks Goucher College, Baltimore, Maryland, USA
	Novel acceleration structures (e.g. dielectric laser accelerators [DLAs]) powered by lasers have the potential to greatly reduce the footprint and cost of both industrial linacs and colliders. As these devices have dimensions comparable to optical wavelengths, they require injection of a sub-micron-scale electron bunch to generate high-quality output beams, which are well beyond the capability of conventional rf photocathodes. Photoexcitation and field emission from an array of nanotips, followed by further acceleration and focusing, is a promising approach to achieving the requisite small beam sizes for successful injection. Pyroelectric crystals can provide electrostatic fields of sufficient magnitude and uniformity to enable emission and acceleration. We present an initial design for a low-energy injection module using the accelerating electrostatic fields provided by pyroelectric crystals. The approach is modeled numerically and supported by direct benchtop measurements of pyroelectric fields from a 2-crystal array. R. J. England et al., Rev. Mod. Phys. 86, p. 1337 (2014).
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TUPOW008	Generation of Short Bunch Electron Beam from Compact Accelerator for Terahertz Radiation	laser, electron, radiation, detector	1757
	S. Suphakul, T. Kii, K. Masuda, K. Morita, H. Ohgaki, K. Torgasin, H. Zen Kyoto University, Kyoto, Japan
	We are developing a new compact accelerator system to generate a high power terahertz (THz) radiation at the Institute of Advanced Energy, Kyoto University. THz radiations are produced by injecting ultra-short and intense electron pulses to a short plannar undulator. The bunch compression characteristic by the newly installed chicane was investigated by observation of a coherent part of an optical transition radiation (OTR). As the result, the chicane can compress the electron bunch at the laser injection phase from 10 to 40 degree. The beam energy and relative rms energy spread were also measured and the results were 4.6 MeV and 1.3 %, respectively.
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TUPOW009	Generation of Coherent Undulator Radiation using Extremely Short Electron Bunch at t-ACTS, Tohoku University	radiation, undulator, electron, bunching	1760
	S. Kashiwagi, T. Abe, H. Hama, F. Hinode, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	An accelerator test facility, t-ACTS, was established at Research Center for Electron Photon Science, Tohoku University, in which an intense coherent terahertz (THz) radiation is generated from an extremely short electron bunch. Velocity bunching scheme in a traveling-wave accelerating structure is employed to produce the short electron bunch, and a production of sub-picosecond electron bunch was demonstrated. A long-period linear undulator, which has 25 periods with a period length of 10 cm and a peak magnetic field of 0.41 T, has been developed to produce intense coherent THz radiation. Properties of the radiation from the THz undulator such as radiation fields, spectrum and angular distribution were numerically investigated based on the parameters of short electron bunch and THz undulator. By optimization of bunch compression, it is possible to extract a coherent radiation of fundamental mode excluding higher-order mode. The detail of the numerical studies for the coherent undulator radiation will be reported in the conference.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-TUPOW009
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TUPOW010	Production of Ultra-short Electron Pulse and Observation of Coherent Transition Radiation at t-ACTS, Tohoku University	radiation, electron, bunching, detector	1763
	T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki, K. Takahashi, C. Tokoku Tohoku University, Research Center for Electron Photon Science, Sendai, Japan
	A test-Accelerator as Coherent Terahertz Source (t-ACTS) project has been under development at Research Center for Electron Photon Science, Tohoku University. In order to generate a coherent radiation in terahertz (THz) region, it is necessary to produce sub-picosecond electron pulses. Velocity bunching scheme is employed for the short electron pulse production in t-ACTS. We experimentally confirmed the production of short electron pulse under 500 fs by measuring the bunch length using a streak camera. Coherent transition radiation in THz region was produced by which the short electron pulses pass through a vacuum-metal interface. Several radiation properties including　spatial distribution, polarization and spectrum were measured and compared with theoretical calculations. The details of the beam experiment at t-ACTS are described.
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TUPOY022	A Fixed Field Alternating Gradient Accelerator for Helium Therapy	ion, proton, acceleration, emittance	1953
	J. Taylor IIAA, Huddersfield, United Kingdom T.R. Edgecock, R. Seviour University of Huddersfield, Huddersfield, United Kingdom S. Green University Birmingham, Birmingham, United Kingdom C. Johnstone PAC, Batavia, Illinois, USA
	A non-scaling fixed field alternating gradient (nsFFAG) accelerator is being designed for helium ion therapy. This facility will consist of 2 nested superconducting rings, treating with helium ions (He²⁺) and image with hydrogen ions (H²⁺). Compared to protons, ions deliver a more conformal dose with a significant reduction in range straggling and beam broadening. Carbon ions are currently used and there are no current facilities providing helium therapy. We are investigating the feasibility of an FFAG approach for helium therapy, which has never been previously considered. We investigate emittance and demonstrate that the machine meets isochronicity requirements for fixed frequency RF.
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TUPOY023	A Compact and High Current FFAG for the Production of Radioisotopes for Medical Applications	target, proton, simulation, space-charge	1957
	D. Bruton, R.J. Barlow, T.R. Edgecock, R. Seviour University of Huddersfield, Huddersfield, United Kingdom C. Johnstone PAC, Batavia, Illinois, USA
	A low energy Fixed Field Alternating Gradient (FFAG) accelerator has been designed for the production of radioisotopes. Tracking studies have been conducted using the OPAL code, including the effects of space charge. Radioisotopes have a wide range of uses in medicine, and recent disruption to the supply chain has seen a renewed effort to find alternative isotopes and production methods. The design features separate sector magnets with non-scaling, non-linear field gradients but without the counter bends commonly found in FFAG's. The machine is isochronous at the level of 0.3% up to at least 28 MeV and hence able to operate in Continuous Wave (CW) mode. Both protons and helium ions can be used with this design and it has been demonstrated that proton beams with currents of up to 20 mA can be accelerated. An interesting option for the production of radioisotopes is the use of a thin internal target. We have shown that this design has large acceptance, ideal for allowing the beam to be recirculated through the target many times, the lost energy being restored on each cycle. In this way, the production of Technetium-99m, for example, can take place at the optimum energy.
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WEOAA01	Transverse Emittance Exchange for Improved Injection Efficiency	emittance, resonance, coupling, synchrotron	2028
	P. Kuske, F. Kramer HZB, Berlin, Germany
	In most cases beam is injected into electron storage rings in the horizontal plane and off-axis. The larger the horizontal emittance of the injected beam the larger the acceptance of the ring has to be. The injected beam is usually delivered by a synchrotron. In case the vertical acceptance of the ring is sufficiently large one can take advantage of the small vertical emittance reached in well aligned and tuned synchrotrons since the transverse emit-tances can be exchanged with the help of skew quadru-pole magnets. A few possible processes will be discussed: emittance exchange with static magnets in the transfer line between synchrotron and ring or emittance exchange in the synchrotron shortly before extraction with time dependent magnets. This could be a suddenly switched-on normal or skew quadrupole magnet or skew quadru-pole fields oscillating at a frequency fulfilling the reso-nance condition. Estimates for these magnets and their design will be given.
	Slides WEOAA01 [0.852 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA01
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WEOAA02	On-axis Beam Accumulation Enabled by Phase Adjustment of a Double-frequency RF System for Diffraction-limited Storage Rings	lattice, kicker, synchrotron, storage-ring	2032
	G. Xu, J. Chen, Z. Duan, J. Qiu IHEP, Beijing, People's Republic of China
	Funding: Work supported by NSFC (Y4113G005C) Future synchrotron light sources aim to achieve ultra- low emittances on both transverse planes, approaching or even reaching the diffraction limit of X-ray photon energies. These diffraction-limited storage rings (DLSRs) feature very strong lattice nonlinearities and thus very small dynamic aperture, which exclude off-axis injection schemes. In this paper, we propose a longitudinal on-axis injection scheme, which is based on a double-frequency RF system and in- dependently adjustment of the RF phase of each cavity to enable RF gymnastics. Such a scheme looks feasible with the state-of-art technology of fast injection kicker. Compari- son with other on-axis injection schemes is also discussed.
	Slides WEOAA02 [1.712 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOAA02
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WEOBA03	High Brilliance Uranium Beams for FAIR	brilliance, emittance, ion, target	2052
	W.A. Barth, A. Adonin, Ch.E. Düllmann, M. Heilmann, R. Hollinger, E. Jäger, O.K. Kester, J. Khuyagbaatar, J. Krier, E. Plechov, P. Scharrer, W. Vinzenz, H. Vormann, A. Yakushev, S. Yaramyshev GSI, Darmstadt, Germany Ch.E. Düllmann, J. Khuyagbaatar, P. Scharrer, A. Yakushev HIM, Mainz, Germany Ch.E. Düllmann Johannes Gutenberg University Mainz, Institut of Nuclear Chemistry, Mainz, Germany P. Scharrer Mainz University, Mainz, Germany
	The 40 years old GSI-UNILAC (Universal Linear Accelerator) as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the new FAIR (Facility for Antiproton and Ion Research) synchrotron SIS100. Due to an advanced machine investigation program in combination with the ongoing UNILAC upgrade program, a new uranium beam intensity record (10 emA, U²⁹⁺) at very high beam brilliance was achieved recently in a machine experiment campaign. This is an important step paving the way to fulfill the FAIR heavy ion high intensity beam requirements. Results of high current uranium beam measurements applying a newly developed pulsed hydrogen gas stripper (at 1.4 MeV/u) will be presented in detail.
	Slides WEOBA03 [2.281 MB]
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEOBA03
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WEPMR046	Thermal Analysis of the Injection Beam Dump at J-PARC RCS	radiation, proton, shielding, synchrotron	2380
	J. Kamiya, M. Kinsho, P.K. Saha, K. Yamamoto JAEA/J-PARC, Tokai-mura, Japan
	In the J-PARC accelerator facility, 400 MeV H⁻ ions are injected from linac to rapid cycling synchrotron (RCS). A thin graphite foil with the thickness of about 300 ug/cm² is located at the injection point to strip two electrons from H⁻ ion and convert it to proton. The charge stripping efficiency is usually more than 99.7 %. In other words, less than 0.3 % H⁻ ions are not accurately exchanged to protons. Most of those remaining H⁻ ions or H⁰ atoms (stripped only one electron from H⁻ ion) are eventually converted to protons by second and third graphite foils and transported to the beam dump. This beam dump consists of an iron block with the size of 0.3×0.3×0.4 m3 for beam stop and the iron block with the size of 3×3×2.5 m3 and concrete with the size of 6×6×6 m3 around the iron block for the radiation shielding. The radiation shielding was designed to endure the 4 kW proton beam to the beam dump. In this presentation, we show the thermal analysis of the beam dump and compare it to the real operation.
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WEPMW007	Validation of Off-momentum Cleaning Performance of the LHC Collimation System	proton, collimation, beam-losses, alignment	2427
	B. Salvachua, P. Baudrenghien, R. Bruce, H. Garcia, P.D. Hermes, S. Jackson, M. Jaussi, A. Mereghetti, D. Mirarchi, S. Redaelli, H. Timko, G. Valentino, A. Valloni CERN, Geneva, Switzerland R. Kwee-Hinzmann Royal Holloway, University of London, Surrey, United Kingdom
	The LHC collimation system is designed to provide effective cleaning against losses coming from off-momentum particles, either due to un-captured beam or to an unexpected RF frequency change. For this reason the LHC is equipped with a hierarchy of collimators in IR3: primary, secondary and absorber collimators. After every collimator alignment or change of machine configuration the off-momentum cleaning efficiency is validated with loss maps at low intensity. We describe here the improved technique used in 2015 to generate such loss maps without completely dumping the beam into the collimators. The achieved performance of the collimation system for momentum cleaning is reviewed.
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WEPMW011	Stable Spin Direction Investigations in RHIC	kicker, extraction, emittance, septum	2442
	F. Méot, H. Huang, N. Tsoupas 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. Beam and spin dynamics investigations are part of the preparations and studies regarding RHIC collider runs, they are part as well of the efforts dedicated to improving stored beam polarization, and in view of the eRHIC EIC project. Some recent studies and their outcomes are discussed.
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WEPMW012	Injection Optics for the JLEIC Ion Collider Ring	quadrupole, optics, ion, collider	2445
	V.S. Morozov, Y.S. Derbenev, F. Lin, F.C. Pilat, G.H. Wei, Y. Zhang JLab, Newport News, Virginia, USA Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang SLAC, Menlo Park, California, USA
	Funding: * Work supported by the U.S. DOE Contract DE-AC02-76SF00515. ** Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. The Jefferson Lab Electron-Ion Collider (JLEIC) will accelerate protons and ions from 8 GeV to 100 GeV. A very low beta function at the Interaction Point (IP) is needed to achieve the required luminosity. One consequence of the low beta optics is that the beta function in the final focusing (FF) quadrupoles is extremely high. This leads to a large beam size in these magnets as well as strong sensitivity to errors which limits the dynamic aperture. These effects are stronger at injection energy where the beam size is maximum, and therefore very large aperture FF magnets are required to allow a large dynamic aperture. A standard solution is a relaxed injection optics with IP beta function large enough to provide a reasonable FF aperture. This also reduces the effects of FF errors resulting in a larger dynamic aperture at injection. We describe the ion ring injection optics design as well as a beta-squeeze transition from the injection to collision optics.
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WEPOR001	Beam Studies with a New Longitudinal Feedback System at the ANKA Storage Ring	feedback, synchrotron, storage-ring, kicker	2658
	E. Blomley, A.-S. Müller, M. Schedler KIT, Karlsruhe, Germany
	With the now fully commissioned longitudinal feedback system at the ANKA Storage Ring - in addition to the already operational transverse feedback system - the stability throughout the injection process was increased considerably. This opened up the possibility to investigate beam dynamics and limitations during injection more systematically. This paper presents the results of these studies, an overview of the limiting parameters and discusses possible approaches to increase the efficiency of the injection.
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WEPOW005	Updates on Lattice Modeling and Tuning for the ESRF-EBS Lattice.	lattice, dipole, quadrupole, radiation	2818
	S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, G. Le Bec, B. Nash, P. Raimondi, R. Versteegen, S.M. White ESRF, Grenoble, France
	The ESRF-EBS lattice model is updated to include the effect of magnetic lengths in dipoles, quadrupoles, sextupoles and combined function magnets. The effect of this modification and the updates to the injection cell are considered with particular focus on injection efficiency and Touschek lifetime. The solutions to introduce new sources of radiation suitable for the existing bending magnet radiation beamlines are also presented.
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WEPOW007	Status and Prospects of the BESSY II Injector System	booster, storage-ring, linac, synchrotron	2826
	T. Atkinson, W. Anders, P. Goslawski, A. Jankowiak, F. Kramer, P. Kuske, D. Malyutin, A.N. Matveenko, A. Neumann, M. Ries, M. Ruprecht, A. Schälicke, T. Schneegans, D. Schüler, P.I. Volz, G. Wüstefeld HZB, Berlin, Germany H.G. Glass BESSY GmbH, Berlin, Germany
	The BESSY II injector system consists of a 50 MeV Linac, installed in preparation for TopUp operation, and a 10 Hz fast-ramping booster synchrotron. The system provides injection efficiencies into the BESSY II storage ring well above 90 % . This contribution reports on the present status, measurements of energy acceptance and other essential beam parameters as well as studies on coupled-bunch-by-bunch instability. Requirements for BESSY-VSR and possible upgrade scenarios are discussed.
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WEPOW023	Present Status of Accelerators in Aichi Synchrotron Radiation Center	synchrotron, radiation, storage-ring, synchrotron-radiation	2877
	Y. Takashima, M. Hosaka, A. Mano Nagoya University, Nagoya, Japan Y. Hori, N. Yamamoto KEK, Ibaraki, Japan M. Katoh UVSOR, Okazaki, Japan S. Koda SAGA, Tosu, Japan S. Sasaki JASRI/SPring-8, Hyogo, Japan T. Takano Hitachi Ltd., Ibaraki-ken, Japan
	Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.
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WEPOW024	Commissioning of SESAME Booster	booster, septum, quadrupole, extraction	2880
	M. Attal, I.A. Abid, T.H. Abu-Hanieh, H. Al-Mohammad, M.A. Al-Najdawi, D.S. Foudeh, A. Hamad, E. Huttel, A. Ismail, S.Kh. Jafar, F. Makahleh, M. Mansouri Sharifabad, K. Manukyan, I. Saleh, N.Kh. Sawai, M.M. Shehab SESAME, Allan, Jordan
	Commissioning of the 800 MeV booster of SESAME light source started in December 2013. The 38.4 m circumference booster is a part of SESAME injector which includes also a 20 MeV classical microtron as a pre-injector that is in operation since 2012. The main results and experience obtained during the commissioning period are reported in this paper.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW024
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WEPOW026	Recent Physical Studies for the HEPS Project	lattice, booster, emittance, sextupole	2886
	G. Xu, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, X.Y. Li, Y.M. Peng, Q. Qin, J. Qiu, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, C.H. Yu IHEP, Beijing, People's Republic of China
	The High Energy Photon Source (HEPS), a kilometre- scale storage ring light source, with a beam energy of 5 to 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. In this paper we reported the progress and status of the physical studies for the HEPS project, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, longitudinal dynamics, etc.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW026
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WEPOW031	Performance of the Vacuum System for the Solaris 1.5 GeV Electron Storage Ring	storage-ring, vacuum, electron, synchrotron	2898
	A.M. Marendziak, C.J. Bocchetta, P.B. Borowiec, P. Bulira, L.J. Dudek, P.P. Goryl, K. Karaś, A. Kisiel, W.T. Kitka, M.P. Kopec, M. Madura, R. Nietubyć, M.P. Nowak, M.J. Stankiewicz, A.I. Wawrzyniak, K. Wawrzyniak, J.J. Wiechecki, J. Wikłacz, M. Zając, Z. Zbylut, L. Żytniak Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland
	Solaris is a third generation light source recently constructed at the Jagiellonian University in Kraków, Poland. The machine was designed by the team at the MAX IV Laboratory. A replica of the 1.5 GeV MAX IV storage ring with a 96 m circumference was successfully built at Solaris and now the facility is in its 3rd phase of commissioning. The average pressure in the storage ring was 1.2·10^-10 mbar before beam commissioning and increases to 1.2·10-8 mbar with 511 mA of stored beam current for electron energy of 524 MeV. With 10 A·h accumulated beam dose, beam cleaning has permitted an average pressure of 3·10-10 mbar/mA. In this paper the result of vacuum performance from beam cleaning and the beam lifetime will be presented. Moreover vacuum maintenance procedures will be reported.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOW031
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WEPOW039	Preliminary Beam Loss Study of TPS during Beam Commissioning	radiation, photon, scattering, EPICS	2926
	C.H. Huang, J. Chen, Y.-S. Cheng, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Taiwan photon source (TPS) is a 3rd generation and 3 GeV synchrotron light source in NSRRC. Several types of beam loss monitors (BLMs) such as RadFETs and PIN-diode BLMs are installed in the storage ring to understand the beam loss distribution and mechanism during the injection, decay mode, top-up operation and beam trip. Several RadFETs are also installed around the inserting devices to study the beam loss near the linear scalar. The preliminary beam loss study using RadFETs are PIN-diode BLMs in the storage will be summarized in this report.
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WEPOW049	Physics Design Progress towards a Diffraction Limited Upgrade of the ALS	emittance, lattice, brightness, dynamic-aperture	2956
	C. Steier, J.M. Byrd, S. De Santis, H. Nishimura, D. Robin, F. Sannibale, C. Sun, M. Venturini, W. Wan LBNL, Berkeley, California, USA
	Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of more than two orders of magnitude are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source. We will describe the progress in the physics design of this upgrade, including lattice evolution, error tolerance studies, simulations of collective effects, and intra beam scattering.
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WEPOW050	Optimization of the ALS-U Storage Ring Lattice	lattice, emittance, storage-ring, quadrupole	2959
	C. Sun, H. Nishimura, D. Robin, F. Sannibale, C. Steier, M. Venturini, W. Wan LBNL, Berkeley, California, USA
	Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231 The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is proposing the upgrade of its synchrotron light source to reach soft x-ray diffraction limits within the present ALS footprint. The storage ring lattice design and optimization of this light source is one of the challenging aspects for this proposed upgrade. The candidate upgrade lattice needs not only to fulfill the physics design requirements such as brightness, injection efficiency and beam lifetime, but also to meet engineering constraints such as space limitations, maximum magnet strength as well as beamline port locations. In this paper, we will present the approach that we applied to design and optimize a multi-bend achromat based storage ring lattice for the proposed ALS upgrade.
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WEPOW051	R+D Progress Towards a Diffraction Limited Upgrade of the ALS	vacuum, undulator, emittance, storage-ring	2962
	C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y. Yang LBNL, Berkeley, California, USA
	Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231. Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R&D program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.
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WEPOW053	CESR Lattice for Two Beam Operations with Narrow Gap Undulators at CHESS	undulator, lattice, operation, simulation	2968
	S. Wang, D. L. Rubin, J.P. Shanks Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA
	Funding: Work was supported by NSF DMR-0936384 and NSF DMR-1332208. CESR has operated as a dedicated light source since the conclusion of colliding beam program in 2008. Two undulators with a 6.5mm-vertical gap were installed in Fall 2014, replacing a wiggler in the sextant of CESR that is the home to all CHESS beam lines. In order to operate narrow gap undulators with two beams, CESR pretzel lattice was redesigned so that e^- and e⁺ orbits are coincident in one machine sextant but separated in return arcs. In particular both e^- and e⁺ orbits are on axis through undulators. This "arc-pretzel" lattice has been the basis for undulator operation. To better understand the beam dynamics and improve machine performance, we developed many simulation tools: undulator modeling, injection tracking, etc. With installation of an additional quadrupole near undulators, the CESR lattice will be further modified with a low beta waist in the insertion devices, allowing a more than two fold reduction of local beta functions. This reduction is anticipated to mitigate the effects of small aperture and undulator field errors and to enhance the xray brightness. The characterization of the lattice will be compared with measurements of injection efficiency, tune scans, etc.
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WEPOW058	Top-off Tests and Controls Optimization	operation, controls, booster, timing	2982
	G.M. Wang, M.A. Davidsaver, A.A. Derbenev, R.P. Fliller, Y. Hu, T.V. Shaftan BNL, Upton, Long Island, New York, USA
	Funding: DOE No.DE-AC02- 98CH10886 The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. As in many other light sources, top-off injection is considered as a standard operation mode resulting in more stable beam intensity to minimize heat load variation on the beamline optics. Top off injection specifications include maintaining the stored beam current within 0.5% and the bunch to bunch charge variation within 20% bands. To make the top off commissioning smooth and efficient, a virtual machine model based on the measured beam properties was developed. The model helped to study robustness of this application operating under different conditions and optimize the input parameters. Once tested the model was transitioned to beam commissioning. To make the beam tests more efficient, the beam lifetime was controlled by adjusting RF voltage and scrapers. In this paper, we'll share the experience from the test stage to machine implementation of the top-off controls.
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WEPOW059	The NSLS-II Top Off Safety System	operation, storage-ring, radiation, controls	2985
	R.P. Fliller, D. Bergman, A. Caracappa, L. Doom, G. Ganetis, Y. Hu, Y. Li, W. Louie, D. Padrazo, O. Singh, J. Tagger, G.M. Wang, Z. Xia BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Top Off operation is the desired mode of operation for 3rd generation light sources to ensure beam current stability for user experiments. However, top off operation introduces the hazard of injecting electrons into the front ends with the beamline shutters open. This hazard can be mitigated with the appropriate safety system. This past year, the NSLS-II has transitioned from decay mode to top off operation with the introduction of the Top Off Safety System (TOSS). Top Off was initially demonstrated September 22, 2015 and become standard mode of operating. In this paper we discuss the top off safety system, operation with the system, and future directions.
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WEPOW060	Top Off Algorithm Development and Commissioning at NSLS-II	operation, storage-ring, target, feedback	2988
	R.P. Fliller, A.A. Derbenev, T.V. Shaftan, G.M. Wang BNL, Upton, Long Island, New York, USA
	Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. Recently, NSLS-II introduced top off as the standard mode of beam delivery for the users. During top off, we are required to maintain the beam current within ±0.5% of nominal, and the bunch to bunch variation over the train less than 20% for all operating conditions. In this paper, we discuss the algorithm used for top off, simulations of various operating conditions and performance of the algorithm during operations.
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WEPOY030	First BTF Measurements at the Large Hadron Collider	octupole, betatron, damping, simulation	3051
	C. Tambasco, A. Boccardi, X. Buffat, K. Fuchsberger, M. Gąsior, R. Giachino, T. Lefèvre, T.E. Levens, T. Pieloni, M. Pojer, B. Salvachua, M. Solfaroli Camillocci CERN, Geneva, Switzerland J. Barranco, C. Tambasco EPFL, Lausanne, Switzerland
	During the Run I in 2012, several instabilities have been observed at the Large Hadron Collider (LHC) during the Betatron squeeze. The predictions of instability thresholds are based on the computation of the beam Landau damping by calculating the Stability Diagrams (SD). These instabilities could be explained by a deterioration of the SD due to beam-beam resonance excitation which could change the particle distributions. Beam Transfer Functions (BTF) provide a measurement of the Stability Diagram. The BTFs are sensitive to the particle detuning with amplitude as well as to the particle distributions therefore they represent a powerful tool to understand experimentally the stability of beams during the LHC operational cycle. First BTF measurements at the LHC are presented for different machine configurations and settings and compared to predictions.
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WEPOY036	Progress in Automatic Software-based Optimization of Accelerator Performance	linac, software, storage-ring, FEL	3064
	S.I. Tomin, G. Geloni XFEL. EU, Hamburg, Germany I.V. Agapov, I. Zagorodnov DESY, Hamburg, Germany W.S. Colocho, T.M. Cope, A.B. Egger, D.F. Ratner SLAC, Menlo Park, California, USA Y.A. Fomin, Y.V. Krylov, A.G. Valentinov NRC, Moscow, Russia
	Funding: partial support from Ioffe Roentgen Institute grant EDYN EMRAD For modern linac- and storage-ring-based light sources certain amount of empirical tuning is used to reach ultimate performance. The possibility to perform such empirical tuning by automatic methods has now been demonstrated by several authors (e.g. I.Agapov et al. in proc IPAC 2015). In this paper we present the progress in development of our automatic optimisation software based on OCELOT and its applications to SASE FEL optimization at FLASH and LCLS, and its potential for storage ring optimization.
DOI •	reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-WEPOY036
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WEPOY045	Benchmarking the Beam Longitudinal Dynamics Code BLonD	simulation, impedance, synchrotron, feedback	3094
	H. Timko, J. F. Esteban Müller, A. Lasheen, D. Quartullo CERN, Geneva, Switzerland

Paper

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MOYAA01

Commissioning of the MAX IV Light Source

storage-ring, emittance, lattice, vacuum

11

M. Eriksson, E. Al-Dmour, Å. Andersson, M.A.G. Johansson, S.C. Leemann, L. Malmgren, P.F. Tavares, S. Thorin
MAX IV Laboratory, Lund University, Lund, Sweden

This presentation reports on the beam commissioning status of MAX IV, experience gained and lessons learned, as well as future plans.

Slides MOYAA01 [6.682 MB]

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MOPMB025

The Development of 16-Electrode Monitor for Measurement of the Multipole-Moment

quadrupole, coupling, impedance, proton

140

Y. Nakanishi, A. Ichikawa, A. Minamino, K.G. Nakamura, T. Nakaya
Kyoto University, Kyoto, Japan
T. Koseki, H. Kuboki
KEK, Tokai, Ibaraki, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

Funding: This work was supported by MEXT KAKENHI Grant Number 25105002, Grant-in-Aid for Scientific Research on Innovative Areas titled 'Unification and　Development of the Neutrino Science Frontier'
In the J-PARC main ring, the beam intensity is greatly increased to 750 kW or more in near future. Even the beam intensity become higher, the beam loss must be kept at the same level as present. Aiming to make the cause of beam loss clear, we have been developing the beam monitor to measure the beam size. The quadrupole moment is related to the beam size. In principle, monitors with more than four electrodes can measure the quadrupole moment. In addition, two monitors located at the places with different beta functions can measure the emittances and beam sizes, providing the horizontal and vertical beta functions. To obtain more precise quadrupole moment and higher multipoles, we are developing the multi-electrode monitor, tentatively, with 16 electrodes. As a reference of 16-electrode monitor, two 4-electrode BPMs are investigated to measure quadrupole moments. We will present the measurement result of 4-electrode monitors and the status of the development of the 32-electrode monitor.

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MOPMB045

Development of FPGA-based Bunch-by-Bunch Beam Current Monitor

FPGA, storage-ring, feedback, LabView

193

Liu, C.S. Liu, Q. Luo, B.G. Sun, Z.R. Zhou
USTC/NSRL, Hefei, Anhui, People's Republic of China

Funding: Supported by the National Science Foundation of China 11575181, 11375178. And by the Fundamental Research Funds for the Central Universities WK2310000046, WK2310000056
Bunch-by-bunch (BxB) beam current measurement is an important method to study filling pattern of injection and beam instability threshold for multi-bunch operation storage ring, also, necessary equipment for top-up injection. A high-speed high-precision ADC and FPGA are used to construct the bunch-by-bunch beam current measurement system. FPGA reads data from ADC, and transfer the data to PC via USB. A LabVIEW program is running on PC to process the data, and communicates with other accelerator equipment with EPICS by CA Lab. Besides the bunch-by-bunch beam current measurement, the BxB longitudinal tune is measured by the system, and other potential bunch-by-bunch beam diagnostics study could be done in future, like bunch-by-bunch beam life etc., to improve the performance of the storage ring of Hefei light source.

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MOPMB048

Bunch Length Measurement at Bunch by Bunch in Harmonics Method at Shanghai SSRF Storage Ring

experiment, storage-ring, electron, synchrotron-radiation

199

L.W. Duan, Y.B. Leng, R.X. Yuan
SINAP, Shanghai, People's Republic of China
N. Zhang
SSRF, Shanghai, People's Republic of China

Harmonics method in frequency domain is an effective and inexpensive bunch length measurement method. With advances in technology, it is possible to do bunch length measurement at bunch by bunch using electronic method. We design and make an electronic system to realize metering at bunch by bunch, and believe it has reasonable bunch length resolution. All selected harmonic signals will be mixed down to 500 MHz and digitized at bunch-by-bunch rate by a multi-channel DBPM processor. The primary beam experiment results will be presented and discussed in this paper.

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MOPMB052

On-axis Injection using a Sin Wave RF Kicker

kicker, storage-ring, lattice, emittance

211

B.C. Jiang, Y.B. Leng, S.Q. Tian, L.Y. Yu, M.Z. Zhang, Q.L. Zhang, Z.T. Zhao
SINAP, Shanghai, People's Republic of China

On-axis injection is one of the critical issues for an ul-tra-low emittance storage ring which holds a rather small dynamic aperture. In order to reduce the challenges of the fast pulsed kicker design, a sin wave RF kicker is studied which is suitable for longitudinal on-axis injection. Since the injected bunch is longitudinally apart from the stored bunches, the location of the stored bunches can be at the π knot of the sin wave, while the injected bunches are launched at a phase around π/2+n·π. At this situation the injected bunches will receive a transverse kick, however the store bunches are almost un-affected.

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MOPMB060

Upgrade of the LHC Schottky Monitor, Operational Experience and First Results

pick-up, proton, ion, emittance

226

M. Betz, O.R. Jones, T. Lefèvre, M. Wendt
CERN, Geneva, Switzerland

The LHC Schottky system allows the measurement of beam parameters such as tune and chromaticity in an entirely non-invasive way by extracting information from the statistical fluctuations in the incoherent motion of particles. The system was commissioned in 2011 and provided satisfactory beam-parameter measurements during LHC run 1 for lead-ions. However, for protons its usability was substantially limited due to strong interfering signals originating from the coherent motion of the particle bunch. The system has recently been upgraded with optimized travelling-wave pick-ups and an improved 4.8~GHz microwave signal path, with the front-end and the triple down-mixing chain optimized to reduce coherent signals. Design and operational aspects for the complete system are shown and the results from measurements with LHC beams in Run II are presented and discussed.

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MOPMR002

Bunch by Bunch Position Measurement and Analysis at PLS-II

kicker, operation, betatron, pick-up

232

J. Lee, M.-H. Chun, I. Hwang, D.T. Kim, G. Kim, T.-Y. Lee, D.C. Shin, S. Shin
PAL, Pohang, Republic of Korea

Beam dynamic phenomena described by bunch-by-bunch motion are important issues for a storage ring and are described by various theoretical formalisms. Direct measurements of the beam position related to different dynamical mechanisms are a useful information to accelerator optimization. In PLS-II, 20 GHz sampling oscilloscope synchronized with injection event (or triggered by beam loss signal) is used to measure direct bunch by bunch motion. Based on the measured data, the principal component analysis had been performed to get the insight into beam dynamic phenomena such as couple bunch instability and beam oscillation due to kicker leakage. In this paper, we will describe the measurement method and the result of analysis for coupled bunch instability.

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MOPMR014

Beam Diagnostics Overview for Collector Ring at FAIR

diagnostics, ion, antiproton, pick-up

255

Yu. A. Rogovsky, E.A. Bekhtenev, M.I. Bryzgunov, O.I. Meshkov, D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia
E.A. Bekhtenev, Yu. A. Rogovsky, D.B. Shwartz
NSU, Novosibirsk, Russia
O. Chorniy
GSI, Darmstadt, Germany

The Collector Ring (CR) is a dedicated storage ring in the FAIR project, where the main emphasis is laid on the effective stochastic precooling of intense secondary beams of stable ions, rare isotopes or antiprotons. A complex operation scheme with several types of operational cycles with beams in CR starting from injection, RF gymnastics, stochastic cooling then, and finishing to extraction is foreseen. Beam parameters changes significantly during the cycles. This demands an exceptional high dynamic range for the beam instrumentation. Non-destructive methods are mandatory for high currents as well as for the low current secondary beams due to the low repetition rate. Precise measurements of all beam parameters and automatic steering with short response time are required due to the necessary exploitation of the full ring acceptances. An overview of the challenges and solutions for various diagnostic installations will be given.

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MOPMR029

Experience with DOROS BPMs for Coupling Measurement and Correction

coupling, dipole, electronics, controls

303

T. Persson, J.M. Coello de Portugal, A. Garcia-Tabares, M. Gąsior, A. Langner, T. Lefèvre, E.H. Maclean, L. Malina, J. Olexa, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland
J. Olexa
STU, Bratislava, Slovak Republic

The Diode ORbit and OScillation System (DOROS) system is designed to provide accurate measurements of the beam position in the LHC. The oscillation part of the system, which is able to provide turn-by-turn data, is used to measure the transverse coupling. Since the system provides high resolution measurements for many turns only small excitations are needed to accurately measure the transverse coupling. In this article we present the performance the system to measure coupling and compare it to the BPMs not equipped with this system.

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MOPMR031

Investigation of Injection Losses at the Large Hadron Collider with Diamond Based Particle Detectors

kicker, proton, flattop, detector

310

O. Stein, W. Bartmann, F. Burkart, B. Dehning, V. Kain, R. Schmidt, D. Wollmann
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria

During the operation of the Large Hadron Collider (LHC) in 2015, increased injection losses were observed. To minimize stress on accelerator components in the injection regions of the LHC and to guarantee an efficient operation these losses needed to be understood and possible mitigation techniques should be studied. Measurements with diamond particle detectors revealed the loss structure with ns-resolution for the first time. Based on these measurements, recaptured beam from the Super Proton Synchrotron (SPS) surrounding the nominal bunch train was identified as the major contributor to the injection loss signals. Methods to reduce the recaptured beam in the SPS were successfully tested and verified with the diamond particle detectors. In this paper the detection and classification of LHC injection losses are described. The methods to reduce these losses and verification measurements are presented and discussed.

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MOPMR033

Characterization of Beam Properties Using Synchrotron Light at Taiwan Photon Source

synchrotron, booster, storage-ring, photon

316

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

Taiwan Photon Source (TPS) is a third-generation 3-GeV synchrotron light facility, located in National Synchrotron Radiation Research Center (NSRRC) at Hsinchu Science Park. After overcoming many challenges, the storage beam current attained 520 mA in 2015 December. The synchrotron light monitors, including X-ray and visible light, are important diagnostic tools to characterize the various machine conditions. The booster beam dynamics during ramping and the beam properties of the storage ring were studied with synchrotron light. The results of measurements are presented in this report.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-MOPMR033

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MOPMW011

The Second Harmonic RF System for J-PARC MR Upgrade

cavity, impedance, operation, proton

420

C. Ohmori, K. Hara, K. Hasegawa, M. Toda, M. Yoshii
KEK, Tokai, Ibaraki, Japan
M. Nomura, T. Shimada, F. Tamura, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

Power upgrade scenario of J-PARC Main Ring includes replacement of RF cavities with higher field gradient using magnetic alloy cores, FT3L than the present ones. It also need to install the second harmonic RF cavity in the other section where dedicated water system for RF cavities is not available. Installation scenario of the second harmonic RF will be presented.

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MOPMY002

Simulation and Experimental Studies of a 2.45GHz Magnetron Source for an SRF Cavity with Field Amplitude and Phase Controls

controls, cavity, LLRF, SRF

514

H. Wang, T. E. Plawski, R.A. Rimmer
JLab, Newport News, Virginia, USA
A. Dudas, M.L. Neubauer
Muons, Inc, Illinois, USA

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177 and NP STTR Grant DE-SC0013203.
Phase lock to an SRF cavity by using injection signal through output waveguide of a magnetron has been demonstrated [1, 3]. Amplitude control using magnetic field trimming and anode voltage modulation has been studied using MATLAB/Simulink simulations [2]. Based on these, we are planning to use an FPGA based digital LLRF system, which allows applying various types of control algorithms in order to achieve the required accelerating field stability. Since the 1497 MHz magnetron is still in the design stage, the proof of principle measurements of a commercial 2450 MHz magnetron are carried out to characterize the anode I-V curve, output power (the tube electronic efficiency), frequency dependence on the anode current (frequency pushing) and the Rieke diagram (frequency pulling by the reactive load). Based on early Simulink simulation, experimental data and extension of the Adler equation governing injection phase stability by Chen's model, the specification of the new LLRF control chassis for both 2450 and 1497MHz systems are presented in this paper.

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MOPOR003

Simulation Studies and Measurements of Beam Instabilities Caused by the Kicker Impedance at High Intensities in the 3-GeV RCS of J-PARC

simulation, impedance, kicker, betatron

589

P.K. Saha, H. Harada, N. Hayashi, H. Hotchi, M. Kinsho, M. Nomura, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, M. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

The transverse impedance of the extraction kickers is a significant beam instability source in the 3-GeV Rapid Cycling Synchrotron of J-PARC. ORBIT code was developed for space charge and beam instability simulations by successfully introducing realistic time dependent machine parameters. The beam instability at high intensities, especially at the designed 1 MW beam power was found be very critical. As there was no practical measure yet to reduce the kicker impedance, a detail simulation studies were done in order to determine realistic machine parameters to suppress the beam instability. The simulation results were found to be very consistent with measurements to successfully accomplish 1 MW beam power. The simulation and beam study results in detail are presented in this paper.

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MOPOR004

Recent Progress of 1-MW Beam Tuning in the J-PARC 3-GeV RCS

resonance, emittance, scattering, power-supply

592

H. Hotchi, H. Harada, S. Kato, M. Kinsho, K. Okabe, P.K. Saha, Y. Shobuda, F. Tamura, N. Tani, Y. Watanabe, K. Yamamoto, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

The J-PARC 3-GeV RCS started 1 MW beam test from October 2014, and successfully achieved a 1 MW beam acceleration in January 2015. Since then, a large fraction of our effort has been focused on reducing and managing beam losses. This paper presents the recent progress of 1 MW beam tuning, especially focusing on our approaches to beam loss issues, such as space-charge induced beam loss and foil scattering beam loss during charge-exchange injection, etc.

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MOPOR008

Beam Induced RF Heating in LHC in 2015

impedance, operation, vacuum, monitoring

602

B. Salvant, O. Aberle, M. Albert, R. Alemany-Fernandez, G. Arduini, J. Baechler, M.J. Barnes, P. Baudrenghien, O.E. Berrig, N. Biancacci, G. Bregliozzi, J.V. Campelo, F. Carra, F. Caspers, P. Chiggiato, A. Danisi, H.A. Day, M. Deile, D. Druzhkin, J. F. Esteban Müller, S. Jakobsen, J. Kuczerowski, A. Lechner, R. Losito, A. Masi, N. Minafra, E. Métral, A.A. Nosych, A. Perillo Marcone, D. Perini, S. Redaelli, F. Roncarolo, G. Rumolo, E.N. Shaposhnikova, J.A. Uythoven, C. Vollinger, A.J. Välimaa, N. Wang, M. Wendt, J. Wenninger, C. Zannini
CERN, Geneva, Switzerland
M. Bozzo
INFN Genova, Genova, Italy
J.F. Esteban Müller
EPFL, Lausanne, Switzerland
N. Wang
IHEP, Beijing, People's Republic of China

Following the recurrent beam induced RF issues that perturbed LHC operation during LHC Run 1, a series of actions were put in place to minimize the risk that similar issues would occur in LHC Run 2: longitudinal impedance reduction campaign and/or improvement of cooling for equipment that were problematic or at the limit during Run 1, stringent constraints enforced on new equipment that would be installed in the machine, tests to control the bunch length and longitudinal distribution, additional monitoring of temperature, new monitoring tools and warning chains. This contribution reports the outcome of these actions, both successes as well as shortcomings, and details the lessons learnt for the future runs.

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MOPOR021

Space Charge Studies with High Intensity Single Bunch Beams in the CERN SPS

emittance, brightness, resonance, space-charge

644

H. Bartosik, F. Schmidt
CERN, Geneva, Switzerland
A. Oeftiger
EPFL, Lausanne, Switzerland
M. Titze
HZB, Berlin, Germany

In order to reach the target beam parameters of the LHC injectors upgrade (LIU) project the beam degradation due to losses and emittance growth on the long injection plateau of the SPS needs to be minimized. A detailed study of the dependence of losses, transverse emittance blow-up and transverse beam tail creation as function of the working point is presented here for a high brightness single bunch beam with a vertical space charge tune spread of about 0.2 on the 26 GeV injection plateau. The beam behaviour close to important betatron resonances is characterised and a region in the tune diagram with minimal beam degradation is identified. Implications about the performance for LIU beams are discussed.

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MOPOR022

Beam Dynamics Observations of the 2015 High Intensity Scrubbing Runs at the Cern Sps

electron, operation, octupole, emittance

648

H. Bartosik, G. Iadarola, K.S.B. Li, L. Mether, A. Romano, G. Rumolo, M. Schenk
CERN, Geneva, Switzerland

Beam quality degradation caused by e-cloud effects has been identified as one of the main performance limitations for high intensity LHC beams with 25 ns bunch spacing in the SPS. In view of the beam parameters targeted with the LHC injectors upgrade (LIU) project, about two weeks of SPS machine time in 2015 were devoted to dedicated scrubbing runs with high intensity LHC 25 ns and dedicated 'doublet' beams in order to study the achievable reduction of e-cloud effects and quantify the consequent beam performance improvements. This paper describes the main observations concerning the coherent instabilities and beam dynamics limitations encountered as well as a detailed characterisation of the performance reach with the highest beam intensity presently available from the pre-injectors.

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MOPOR023

Flat Bunches with a Hollow Distribution for Space Charge Mitigation

space-charge, synchrotron, emittance, resonance

652

A. Oeftiger, H. Bartosik, A. Findlay, S. Hancock, G. Rumolo
CERN, Geneva, Switzerland
A. Oeftiger
EPFL, Lausanne, Switzerland

Funding: CERN, Doctoral Studentship EPFL, Doctorate
Longitudinally hollow bunches provide one means to mitigate the impact of transverse space charge. The hollow distributions are created via dipolar parametric excitation during acceleration in CERN's Proton Synchrotron Booster. We present simulation work and beam measurements. Particular emphasis is given to the alleviation of space charge effects on the long injection plateau of the downstream Proton Synchrotron machine, which is the main goal of this study.

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MOPOR024

Evolution of High Intensity Beams in the CERN PS Booster after H⁻ Injection and Phase Space Painting

emittance, space-charge, booster, lattice

656

M. Cieslak-Kowalska, J.L. Abelleira, E. Benedetto, C. Bracco
CERN, Geneva, Switzerland

With the LHC Injector Upgrade (LIU) project, the injection energy of PS Booster (PSB) ' first circular accelerator in the LHC injector chain ' will be raised from 50 MeV to 160 MeV and the present multiturn injection will be upgraded to H⁻ injection with transverse and longitudinal painting. In the scope of this project, it is planned to double the beam intensities, profiting from the fact that the βγ2 factor will be two times larger (0.35 at 50 MeV and 0.71 at 160 MeV), so the resulting tune spread driven by a direct space charge should remain similar. This paper describes the feasibility to double the intensity of high intensity and large emittance beams, looking into the evolution under space charge and taking into account losses constrains in the ring and in the extraction lines.

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MOPOR025

3D Emittances Tailoring Techniques and Optimization with Space Charge for the Future CERN PS Booster Operations with Linac4

emittance, coupling, simulation, linac

660

V. Forte, J.L. Abelleira, E. Benedetto, C. Bracco, M. Cieslak-Kowalska, G.P. Di Giovanni
CERN, Geneva, Switzerland

In the frame of the LIU (LHC Injectors Upgrade) project, the CERN PS Booster is going to be renovated to host a new H⁻ charge-exchange injection from the Linac4. One important feature of the new injection scheme is the possibility to tailor a wide range of 3D emittances for CERN's different users in an intensity span in the order of 5·10⁹ to 1.6·10¹³ protons per PSB ring. This paper gives an overview of 3D multi-turn injection techniques, focusing on the future LHC beams, which aim at reaching high brightness, and on highest intensity beams (ISOLDE), where losses are the main concern. Complete RF capture simulations and transverse injection maps, including space charge effects, are presented and also intended to be used during the commissioning with Linac4.

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MOPOR042

Beam Dynamics Modeling of Drift-tube Linacs with CST Particle Studio

DTL, simulation, rfq, linac

689

S.S. Kurennoy
LANL, Los Alamos, New Mexico, USA

The CST Studio provides convenient tools for self-consistent 3D modeling of accelerators, even large ones. Here we demonstrate this approach for the LANSCE drift-tube linac (DTL) taken as an example. The RF fields in 3D models of full DTL tanks are calculated and tuned with MicroWave Studio (MWS). Beam dynamics in the DTL is modeled with Particle Studio for bunches and bunch trains with realistic initial beam distributions using the MWS-calculated RF fields and quadrupole magnetic fields. The output beam parameters and locations of particle losses are calculated and compared for different beam distributions. Our main emphasis is on the formation of low-energy tails (longitudinal halo) and their interaction with regular bunches. Such effects are usually not taken into account in standard multi-particle phase-space codes.

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MOPOW052

Status of the Preparation to the Commissioning of the ThomX Storage Ring

storage-ring, dipole, electron, controls

833

I. Chaikovska, C. Bruni, S. Chancé, A.R. Gamelin, H. Monard
LAL, Orsay, France
A. Loulergue
SOLEIL, Gif-sur-Yvette, France

Funding: Work is supported by the French Agence Nationale de la Recherche as part of the program EQUIPEX under reference ANR-10-EQPX-51, the Ile de France region, CNRS-IN2P3 and Université Paris Sud XI
ThomX is a compact Compton based X-ray source under construction at LAL in Orsay (France). The ThomX facility is composed by a 50-70 MeV linac, a transfer line and a 18 meters long Storage Ring (SR). The Compton scattering between the 50 MeV electron bunch of 1 nC and the 30 mJ laser pulses stacked in the Fabry-Perot cavity results in the production of photons with energies (up to 90 keV) with a maximum flux of 10¹³ photons/s. The ThomX construction will start shortly aiming to be completed in the middle of 2017. The preparation to the SR commissioning as far as a control system and beam physics applications are concerned is progressing gradually in order to prepare and test all the tools well ahead the start of the machine. The SR commissioning will face with many challenges providing the low energy, compactness, the nonlinear beam dynamics, the limited beam storage and need for the precision and stabilization in the Interaction Region. Several techniques used at the Synchrotron Light Sources should be modified/adapted to meet all the specificity of the ThomX. This is a report on preparation of the ThomX SR commissioning, its status, planning, main challenges and expectations.

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MOPOW055

Injection Using a Non-linear Kicker Located in the Existing Injection Straight at Diamond Storage Ring

septum, kicker, storage-ring, optics

840

B. Singh, M. Apollonio, R. Bartolini, I.P.S. Martin
DLS, Oxfordshire, United Kingdom
A. Alekou, R. Bartolini, T. Pulampong
JAI, Oxford, United Kingdom

Injection studies using a non-linear kicker for the Diamond storage ring have been carried out previously*. These studies have been recently extended to investigate whether the non-linear kicker can be located in the injection straight downstream of the septum and outside the existing dipole kicker bump. If so, injection with a non-linear kicker becomes independent of the optics used, making it suitable for use in both standard and low alpha mode. With this configuration, the existing injection scheme could also be left in place, leaving open the possibility to study both schemes in situ before potentially removing the existing dipole kickers at a later date. In order to operate with the non-linear kicker, the injected beam needs to exit the transfer line at an angle of 3mrad; this has been successfully demonstrated during machine development time. The concept and feasibility studies of this scheme are presented in this paper.
* T. Pulampong, et al., Proc. IPAC 2013, Shanghai, WEPWA065, (2013)

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MOPOY001

MedAustron Synchrotron RF Commissioning for Medical Proton Beams

acceleration, synchrotron, proton, cavity

844

C. Schmitzer, F. Farinon, A. Garonna, M. Kronberger, T.K.D. Kulenkampff, C. Kurfürst, S. Myalski, S. Nowak, F. Osmić, L.C. Penescu, M.T.F. Pivi, P. Urschütz, A. Wastl
EBG MedAustron, Wr. Neustadt, Austria

MedAustron is a medical accelerator facility for hadron therapy cancer treatment using protons and carbon ions. The Synchrotron is driven by a 0.47-3.26 MHz Finemet® loaded wideband cavity powered by 12x 1kW solid state amplifiers connected to a digital Low Level RF system. It was developed in collaboration with CERN and put to operation at MedAustron in early 2014. The main Synchrotron RF (sRF )commissioning steps for proton beams involved the setup of the adiabatic capture process, the setup of the frequency and voltage ramps and feedback loops for fast acceleration and the RF jump for extraction. The adiabatic capture process was optimized in terms of energy and voltage mismatch by analyzing longitudinal empty bucket scans after beam injection into the synchrotron. The acceleration ramp optimization was based on calculations using a software tool developed in-house and adapted experimentally to minimize losses at injection and during acceleration. This paper provides an overview of the acceleration system and describes the commissioning process of the sRF system and the related beam commissioning efforts at MedAustron.

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MOPOY007

High Energy Booster Options for a Future Circular Collider at CERN

booster, collider, extraction, hadron

856

L.S. Stoel, M.J. Barnes, W. Bartmann, F. Burkart, B. Goddard, W. Herr, T. Kramer, A. Milanese, G. Rumolo, E.N. Shaposhnikova
CERN, Geneva, Switzerland

In case a Future Circular Collider for hadrons (FCC-hh) is constructed at CERN, the tunnels for SPS, LHC and the 100 km collider will be available to house a High Energy Booster (HEB). The different machine options cover a large technology range from an iron-dominated machine in the 100 km tunnel to a superconducting machine in the SPS tunnel. Using a modified LHC as reference, these options are compared with respect to their energy reach, magnet technology and filling time of the collider. Potential issues with beam transfer, reliability and beam stability are presented.

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MOPOY059

LHC Injectors Upgrade (LIU) Project at CERN

ion, proton, linac, brightness

992

E.N. Shaposhnikova, J. Coupard, H. Damerau, A. Funken, S.S. Gilardoni, B. Goddard, K. Hanke, L. Kobzeva, A.M. Lombardi, D. Manglunki, S. Mataguez, M. Meddahi, B. Mikulec, G. Rumolo, R. Scrivens, M. Vretenar
CERN, Geneva, Switzerland

A massive improvement program of the LHC injector chain is presently being conducted under the LIU project. For the proton chain, this includes the replacement of Linac2 with Linac4 as well as all necessary upgrades to the Proton Synchrotron Booster (PSB), the Proton Synchrotron (PS) and Super Proton Synchrotron (SPS), aimed at producing beams with the challenging High Luminosity LHC (HL-LHC) parameters. Regarding the heavy ions, plans to improve the performance of Linac3 and the Low Energy Ion Ring (LEIR) are also pursued under the general LIU program. The full LHC injection chain returned to operation after Long Shutdown 1, with extended beam studies taking place in Run 2. A general project Cost and Schedule Review also took place in March 2015, and several dedicated LIU project reviews were held to address issues awaiting pending decisions. In view of these developments, 2014 and 2015 have been key years to define a number of important aspects of the final LIU path. This paper will describe the reviewed LIU roadmap and revised performance objectives of the main upgrades, including the work status and outlook in terms of the required installation and commissioning stages.

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MOPOY060

Performance Analysis for the New g-2 Experiment at Fermilab

simulation, storage-ring, experiment, dipole

996

D. Stratakis, M.E. Convery, C. Johnstone, J.A. Johnstone, J.P. Morgan, M.J. Syphers
Fermilab, Batavia, Illinois, USA
J.D. Crmkovic, W. Morse, V. Tishchenko
BNL, Upton, Long Island, New York, USA
N.S. Froemming
University of Washington, CENPA, Seattle, USA
M. Korostelev
Cockcroft Institute, Warrington, Cheshire, United Kingdom
M. Korostelev
Lancaster University, Lancaster, United Kingdom

The new g-2 experiment at Fermilab aims to measure the muon anomalous magnetic moment to a precision of ±0.14 ppm ─ a fourfold improvement over the 0.54 ppm precision obtained in the g-2 BNL E821experiment. Achieving this goal requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we describe a muon capture and transport scheme that should meet this requirement. First, we present the conceptual design of our proposed scheme wherein we describe its basic features. Then, we detail its performance numerically by simulating the pion production in the (g-2) production target, the muon collection by the downstream beamline optics as well as the beam polarization and spin-momentum correlation up to the storage ring. The sensitivity in performance of our proposed channel against key parameters such as magnet apertures and magnet positioning errors is analyzed

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TUXA01

Status and Future Upgrade of J-PARC Accelerators

linac, operation, extraction, hadron

999

M. Kinsho
JAEA/J-PARC, Tokai-mura, Japan

The linac energy reached to 400 MeV as a design value and also a beam current was upgraded to 50 mA by replacing a new ion source. At the 3 GeV synchrotron, a high power beam of 8.41x10¹³ protons per pulse was demonstrated, which was equivalent to 1 MW when the repetition would be 25 Hz. At the main ring, beam loss was reduced by suppression of transverse instabilities and so on. The beam power for both the neutrino experiment and hadron experimental facility is increasing to reduce beam loss. J-PARC accelerators each have their own upgrade plan to increase beam power. The progress and future plan of J-PARC accelerators are reported in this paper.

Slides TUXA01 [11.427 MB]

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TUOAA03

Long Term Plans to Increase Fermilab's Proton Intensity to Meet the Needs of the Long Baseline Neutrino Program

proton, linac, booster, experiment

1010

E. Prebys, P. Adamson, S.C. Childress, P. Derwent, S.D. Holmes, I. Kourbanis, V.A. Lebedev, W. Pellico, A. Romanenko, V.D. Shiltsev, E.G. Stern, A. Valishev, R.M. Zwaska
Fermilab, Batavia, Illinois, USA

Funding: This work is supported by the US Department of Energy under contract No. De-AC02-07CH11359.
The flagship of Fermilab's long term research program is the Deep Underground Neutrino Experiment (DUNE), located Sanford Underground Research Facility (SURF) in Lead, South Dakota, which will study neutrino oscillations with a baseline of 1300 km. The neutrinos will be produced in the Long Baseline Neutrino Facility (LBNF), a proposed new beam line from Fermilab's Main Injector. The physics goals of the DUNE require a proton beam with a power of roughly 2.5 MW at 120 GeV, which is roughly five times the current maximum power. This poster outlines the staged plan to achieve the required power over the next 15 years.

Slides TUOAA03 [4.129 MB]

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TUPMB007

Research and Development of the Pulse Bump Magnet for the Injection System in CSNS/RCS

neutron, radiation, high-voltage, synchrotron

1118

L. Huo, M.Y. Huang, W. Kang, Y.Q. Liu, J. Qiu, L. Wang, S. Wang
IHEP, Beijing, People's Republic of China

The H⁻ stripping painting injection is adopted in the Rapid Cycling Synchrotron (RCS) of China Spallation Neutron Source (CSNS). Painting injection is realized by eight pulse bump magnets. The pulse bump magnet is the key of the performance of painting, as well as the beam loss control. The manufacture and the field measurement of the eight pulse bump magnets have been completed. In the development of the magnets, some key technical problems on fabrication of coil were solved, and the field measurement results show that the magnets fulfil the design specification.

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TUPMB017

The Injection Septum Magnet for the Collector Ring (FAIR)

septum, vacuum, operation, lattice

1145

P.Yu. Shatunov, D.E. Berkaev, I. Koop, E.P. Semenov, D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia
A. Dolinskyy, S.A. Litvinov
GSI, Darmstadt, Germany
Yu. A. Rogovsky
Budker INP & NSU, Novosibirsk, Russia

Collector Ring is one of the key installations of the FAIR project (Darmstadt, Germany). It is dedicated for stochastic cooling of incoming beams of antiprotons and rare ions. Additionally there is a mode of operation for experiments in the ring. Beams for all modes of operation are injected through one transfer channel. Extremely high acceptance of the ring (240 mm*mrad) leads to large apertures of all magnetic elements including the septum magnet. Meanwhile planned parameters of the magnetic field and magnetic field quality are comparatively strict. The present state of the design of the pulsed injection septum for the CR is presented in this article together with the concept of the injection system.

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TUPMB018

Magnetic Measurements of SESAME Storage Ring Dipoles at ALBA

dipole, alignment, multipole, storage-ring

1148

J. Marcos, J. Campmany, V. Massana
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
A. Milanese, C. Petrone, L. Walckiers
CERN, Geneva, Switzerland

Funding: This work is partially supported by the EC under the CESSAMag project, FP7 contract 338602.
In this work we present the results of the measurement campaign of the main bending magnets of the SESAME storage ring, that were fully characterized at ALBA-CELLS magnetic measurements facility. A total of 17 combined function dipoles ' 16 series magnets plus a pre-series one ' has been tested and characterized. This campaign has been performed using a dedicated Hall probe bench. The main measurements include the transfer function at the center of the magnet and field maps of the three components of the field in a plane around the nominal trajectory of the electron beam, at two different operating currents. In this paper we describe the experimental setup and procedures, before reporting the main results, including statistics of magnet-to-magnet reproducibility and integrated field quality. Finally, we show how the measured data can be exploited for an optimal 3D alignment of the dipoles in the machine.

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TUPMB048

Compensation of Beam Induced Effects in LHC Cryogenic Systems

cryogenics, controls, electron, simulation

1205

B. Bradu, E. Blanco Viñuela, G. Ferlin, B. Fernández Adiego, G. Iadarola, P. Plutecki, E. Rogez, A. Tovar González
CERN, Geneva, Switzerland

This paper presents the different control strategies deployed in the LHC cryogenic system in order to compensate the beam induced effects in real-time. LHC beam is inducing important heat loads along the 27 km of beam screens due to synchrotron radiations, image current and electron clouds. These dynamic heat loads disturb significantly the cryogenic plants and automatic compensations are mandatory to operate the LHC at full energy. The LHC beam screens must be maintained in an acceptable temperature range around 20 K to ensure a good beam vacuum, especially during beam injections and energy ramping where the dynamic responses of cryogenic systems cannot be managed with conventional feedback control techniques. Consequently, several control strategies such as feed-forward compensation have been developed and deployed successfully on the machine during 2015 where the beam induced heat loads are forecast in real-time to anticipate their future effects on cryogenic systems. All these developments have been first entirely modeled and simulated dynamically to be validated, allowing then a smooth deployment during the LHC operation.

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TUPMB052

High Intensity Beam Test of Low Z Materials for the Upgrade of SPS-to-LHC Transfer Line Collimators and LHC Injection Absorbers

experiment, simulation, proton, radiation

1218

F.L. Maciariello, O. Aberle, M.E.J. Butcher, M. Calviani, R. Folch, V. Kain, K. Karagiannis, I. Lamas Garcia, A. Lechner, F.-X. Nuiry, G.E. Steele, J.A. Uythoven
CERN, Geneva, Switzerland

In the framework of the LHC Injector Upgrade (LIU) and High-Luminosity LHC (HL-LHC) project, the collimators in the SPS-to LHC transfer lines will undergo important modifications. The changes to these collimators will allow them to cope with beam brightness and intensity levels much increased with respect to their original design parameters: nominal and ultimate LHC. The necessity for replacement of the current materials will need to be confirmed by a test in the High Radiation to Materials (HRM) facility at CERN. This test will involve low Z materials (such as Graphite and 3-D Carbon/Carbon composite), and will recreate the worst case scenario those materials could see when directly impacted by High luminosity LHC (HL-LHC) or Batch Compression Merging and Splitting (BCMS) beams. Thermo-structural simulations used for the material studies and research, the experiment preparation phase, the experiment itself, pre irradiation analysis (including ultrasound and metrology tests on the target materials), the results and their correlation with numerical simulations will be presented.

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TUPMR012

Investigation of Central Region Design of 10MeV AVF Cyclotron

cyclotron, ion, ion-source, acceleration

1253

M. Afkhami Karaei, H. Afarideh, S. Azizpourian, R. Solhju
AUT, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

Recently, studies on the central region of 10 MeV AVF Cyclotron have been done at AmirKabir University of Technology. In this study, the aim of the cyclotron design is to accelerate the ions up to 10MeV energy. The cyclotron, consist of four sector magnets and 2 RF cavities which will be operated at 71 MHz. The internal PIG ion source is used in this cyclotron. The purpose of this work is to investigate the behavior of trajectories of ions in the magnetic and electric fields at the center of the cyclotron. The electric and magnetic field distribution was designed by OPERA-3DTOSCA. In order to solve the equation of motion, numerical code was written in C++ program that used the conventional Rung-Kutta method. The obtained results of simulation were the horizontal and vertical motion of an ion in the center of cyclotron, and motion of the center of the orbits.

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TUPMR028

Spin Correlations Study for the New g-2 Experiment at Fermilab

experiment, storage-ring, simulation, quadrupole

1301

D. Stratakis, J.D. Crnkovic, W. Morse, V. Tishchenko
BNL, Upton, Long Island, New York, USA

The muon g-2 experiment executed at Brookhaven concluded in 2001 and measured a discrepancy of more than three standard deviations compared to the Standard Model (SM) calculation. A new initiative at Fermilab is under construction to improve the experimental accuracy four-fold. Achieving this goal, however, requires the delivery of highly polarized 3.094 GeV/c muons with a narrow ±0.5% Δp/p acceptance to the g-2 storage ring. In this study, we examine systematic errors that can arise from correlations between muon spin and transverse coordinates for the new g-2 experiment. To achieve this goal we perform end-to-end spin tracking simulations from the production target up to the ring injection point and compare our findings against the results from the Brookhaven experiment. We detail similarities and differences.

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TUPMR039

The Development of a New High Field Injection Septum Magnet System for Main Ring of J-Parc

septum, operation, power-supply, flattop

1337

T. Shibata, K. Ishii, H. Matsumoto, N. Matsumoto, T. Sugimoto
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People's Republic of China

We are improving the Main Ring (MR) for beam power of 750 kw which is the first goal of J-PARC. The repetition period of the fast extraction must be short to 1.3 second from the current period of 2.48 second for the improvement of the beam power. It is necessary to exchange a high field injection septum magnet which will be installed at the injection line from RCS to MR and its power supply, because the current injection septum system can not be operated with 1.3 second repetition. Since confirmed the large leakage field around current circling beam line of the injection magnet, we must improve the shielding structure which make low leakage field. We started the development of the new injection septum magnet and its power supply in 2013. It can operate with 1 Hz repetition and the low leakage field which its order is 10^-4 of the gap field. The new Injection septum magnet and the new power supply were constructed in Winter of 2014. We had many improvement of the magnet and power supply. We will install the new injection septum magnet system in this summer. In this presentation, we will report the detail of the results of its performance.

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TUPMR046

Sources of Emittance Growth at the CERN PS Booster to PS Transfer

emittance, kicker, optics, betatron

1352

W. Bartmann, J.L. Abelleira, F. Burkart, B. Goddard, J. Jentzsch, R. Ostojić
CERN, Geneva, Switzerland

The CERN PS Booster (PSB) has four vertically stacked rings. After extraction from each ring, the bunches are recombined in two stages, comprising septum and kicker systems, such that the accumulated bunch train is injected through a single line into the PS. Bunches from the four rings go through a different number of vertical bends, which leads to differences in the betatron and dispersion functions due to edge focussing. The fast pulsed systems at PSB extraction, recombination and PS injection lead to systematic errors of delivery precision at the injection point. These error sources are quantified in terms of emittance growth and particle loss. Mitigations to reduce the overall emittance growth at the PSB to PS transfer within the LHC injectors upgrade are presented.

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TUPMR048

SPS Injection and Beam Quality for LHC Heavy Ions With 150 ns Kicker Rise Time

ion, kicker, damping, proton

1360

B. Goddard, E. Carlier, L. Ducimetière, G. Kotzian, J.A. Uythoven
CERN, Geneva, Switzerland
F.M. Velotti
EPFL, Lausanne, Switzerland

As part of the LHC Injectors Upgrade project for LHC heavy ions, the SPS injection kicker system rise time needs reduction below its present 225 ns. One technically challenging option under consideration is the addition of fast Pulse Forming Lines in parallel to the existing Pulse Forming Networks for the 12 kicker magnets MKP-S, targeting a system field rise time of 100 ns. An alternative option is to optimise the system to approach the existing individual magnet field rise time (2-98%) of 150 ns. This would still significantly increase the number of colliding bunches in LHC while minimising the cost and effort of the system upgrade. The observed characteristics of the present system are described, compared to the expected system rise time, together with results of simulations and measurements with 175 and 150 ns injection batch spacing. The expected beam quality at injection into LHC is quantified, with the emittance growth and simulated tail population taking into account expected jitter and synchronisation errors, damper performance and SPS non-linear optics behavior. The outlook for deployment is discussed, with the implications for LHC operation and HL-LHC performance.

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TUPMR049

Feasibility Study of the PS Injection for 2 GeV LIU Beams with an Upgraded KFA-45 Injection Kicker System Operating in Short Circuit Mode

simulation, kicker, flattop, operation

1363

T. Kramer, W. Bartmann, J.C.C.M. Borburgh, L. Ducimetière, L.M.C. Feliciano, A. Ferrero Colomo, B. Goddard, L. Sermeus
CERN, Geneva, Switzerland

Under the scope of the LIU project the CERN PS Booster to PS beam transfer will be modified to match the requirements for the future 2 GeV beams. This paper describes the evaluation of the proposed upgrade of the PS injection kicker. Different schemes of an injection for LIU beams into the PS have been outlined in the past already under the aspect of individual transfer kicker rise and fall time performances. Homogeneous rise and fall time requirements in the whole PSB to PS transfer chain have been established which allowed to consider an upgrade option of the present injection kicker system operated in short circuit mode. The challenging pulse quality constraints require an improvement of the flat top and post pulse ripples. Both operation modes, terminated and short circuit mode are analysed and analogue circuit simulations for the present and upgraded system are outlined. Recent measurements on the installed kickers are presented and analysed together with the simulation data. First measurements verifying the performance of upgrade options have been taken during the last end of the year stop. The paper concludes with an upgrade plan and a brief overview of implementation risks.

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TUPMR053

Initial Experience with Carbon Stripping Foils at ISIS

operation, synchrotron, proton, vacuum

1378

B. Jones, D.J. Adams, H. V. Smith
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

The ISIS Facility at the Rutherford Appleton Laboratory is a spallation neutron and muon source based upon a 50 Hz rapid cycling synchrotron accelerating ~3×10¹³ protons per pulse from 70 to 800 MeV to deliver a mean beam power of 0.2 MW to two target stations. Throughout its 30 years of operation ISIS has developed aluminium oxide foils in-house for H− charge exchange injection. The manufacturing and installation processes for these foils are time consuming, radiologically dose intensive and require a high degree of skill. Commercially available carbon based foils commonly used at other facilities, have the potential to greatly simplify foil preparation and installation in addition to improving beam quality. Similar foils would also be necessary for facility upgrades which increase injection energy to withstand the higher operating temperatures. This paper describes the initial experience of carbon foils in the ISIS synchrotron including issues relating to handling and mounting foils, their performance under beam operation and plans for further development.

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TUPMR058

An Upgrade for the 1.4 MeV/u Gas Stripper at the GSI UNILAC

target, ion, dipole, heavy-ion

1394

P. Scharrer, W.A. Barth, Ch.E. Düllmann, J. Khuyagbaatar, A. Yakushev
HIM, Mainz, Germany
W.A. Barth, M. Bevcic, Ch.E. Düllmann, L. Groening, K.P. Horn, E. Jäger, J. Khuyagbaatar, J. Krier, P. Scharrer, A. Yakushev
GSI, Darmstadt, Germany
Ch.E. Düllmann
Johannes Gutenberg University Mainz, Institut of Nuclear Chemistry, Mainz, Germany
P. Scharrer
Mainz University, Mainz, Germany

The GSI UNILAC will serve as part of an injector system for the future FAIR facility, currently under construction in Darmstadt, Germany. For this, it has to deliver short-pulsed, high-current, heavy-ion beams with highest beam quality. An upgrade for the 1.4 MeV/u gas stripper is ongoing to increase the yield of uranium ions in the desired charge state. The new setup features a pulsed gas injection synchronized with the beam pulse transit to increase the effective density of the stripper target while keeping the gas load for the differential pumping system low. Systematic measurements of charge state distributions and energy-loss were conducted with 238U-ion beams and different stripper gases, including H2 and He. By using H2 as a stripper gas, the yield into the most populated charge state was increased by over 50%, compared to the current stripper. Furthermore, the high gas density, enabled by the pulsed injection, results in increased mean charge states.

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TUPMW014

Improved Aperture Measurements at the LHC and Results from their Application in 2015

alignment, operation, insertion, beam-losses

1446

P.D. Hermes, R. Bruce, M. Fiascaris, H. Garcia, M. Giovannozzi, A. Mereghetti, D. Mirarchi, E. Quaranta, S. Redaelli, B. Salvachua, G. Valentino
CERN, Geneva, Switzerland
R. Kwee-Hinzmann
Royal Holloway, University of London, Surrey, United Kingdom
E. Quaranta
Politecnico/Milano, Milano, Italy

A good knowledge of the available aperture in the LHC is essential for a safe operation due to the risk of magnet quenches or even damage in case of uncontrolled beam losses. Experimental validations of the available aperture are therefore crucial and were in the past carried out by either a collimator scan combined with beam excitations or through the use of local orbit bumps. In this paper, we show a first comparison of these methods in the same machine configuration, as well as a new very fast method based on a beam-based collimator alignment and a new faster variant of the collimator scan method. The methods are applied to the LHC operational configuration for 2015 at injection and with squeezed beams and the measured apertures are presented.

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TUPMW017

Electron Cloud Observations during LHC Operation with 25 ns Beams

electron, operation, simulation, cryogenics

1458

K.S.B. Li, H. Bartosik, G. Iadarola, L. Mether, A. Romano, G. Rumolo, M. Schenk
CERN, Geneva, Switzerland

While during the Run 1 (2010-2012) of the Large Hadron Collider (LHC) most of the integrated luminosity was produced with 50 ns bunch spacing, for the Run 2 start-up (2015) it was decided to move to the nominal bunch spacing of 25 ns. As expected, with this beam configuration strong electron cloud effects were observed in the machine, which had to be mitigated with dedicated 'scrubbing' periods at injection energy. This enabled to start the operation with 25 ns beams at 6.5 TeV, but e-cloud effects continued to pose challenges while gradually increasing the number of circulating bunch trains. This contribution will review the encountered limitations and the mitigation measures that where put in place and will discuss possible strategies for further performance gain.

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TUPMW019

First Evaluation of Dynamic Aperture at Injection for FCC-hh

dipole, dynamic-aperture, target, simulation

1466

B. Dalena, D. Boutin, A. Chancé, J. Payet
CEA/IRFU, Gif-sur-Yvette, France
B.J. Holzer, R. Martin, D. Schulte
CERN, Geneva, Switzerland

Funding: This Research and Innovation Action project submitted to call H2020-INFRADEV-1-2014-1 receives funding from the European Union's H2020 Framework Programme under grant agreement no. 654305.
In the hadron machine option, proposed in the context of the Future Circular Colliders (FCC) study, the dipole field quality is expected to play an important role, as in the LHC. A preliminary evaluation of the field quality of dipoles, based on the Nb3Sn technology, has been provided by the magnet group. The effect of these field imperfections on the dynamic aperture, using the present lattice design, is presented and first tolerances on the main multipole components are evaluated.

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TUPMW026

Feed-Forward Corrections for Tune and Chromaticity Injection Decay During 2015 LHC Operation

operation, hadron, collider, octupole

1489

M. Solfaroli Camillocci, M. Juchno, M. Lamont, M. Schaumann, E. Todesco, J. Wenninger
CERN, Geneva, Switzerland

After two years of shutdown, the Large Hadron Collider (LHC) has been operated in 2015 at 6.5 TeV, close to its designed energy. When the current is stable at low field, the harmonic components of the main circuits are subject to a dynamic variation induced by current redistribution on the superconducting cables. The Field Description of the LHC (FiDel) foresaw an increase of the decay at injection of tune (quadrupolar components) and chromaticity (sextupolar components) of about 50% with respect to LHC Run1 due to the higher operational current. This paper discusses the beam-based measurements of the decay during the injection plateau and the implementation and accuracy of the feed-forward corrections as present in 2015. Moreover, the observed tune shift proportional to the circulating beam intensity and it's foreseen feed-forward correction are covered.

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TUPMW029

Tune and Chromaticity Control During Snapback and Ramp in 2015 LHC Operation

controls, sextupole, dipole, lattice

1501

M. Schaumann, M. Juchno, M. Lamont, M. Solfaroli Camillocci, E. Todesco, J. Wenninger
CERN, Geneva, Switzerland

Because of current redistribution on the superconducting cables, the harmonic components of the magnetic fields of the superconducting magnets in the Large Hadron Collider (LHC) show decay during the low field injection plateau. This results in tune and chromaticity variations for the beams. In the first few seconds of the ramp the original hysteresis state of the magnetic field is restored - the field snaps back. These fast dynamic field changes lead to strong tune and chromaticity excursions that, if not properly controlled, induce beam losses and potentially trigger a beam dump. A feed-forward system applies predicted corrections during the injection plateau and to the first part of the ramp to avoid violent changes of beam conditions. This paper discusses the snapback of tune and chromaticity as observed in 2015, as well as the control of beam parameters during the ramp. It also evaluates the quality of the applied feed-forward corrections and their reproducibility.

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TUPMW034

A 200 MHz SC-RF System for the HL-LHC

cavity, emittance, luminosity, impedance

1513

R. Calaga, R. Tomás
CERN, Geneva, Switzerland

Funding: Research supported by the High Luminosity LHC project
A quarter wave β=1 superconducting cavity at 200 MHz is proposed for the LHC as an alternative to the present 400 MHz RF system. The primary motivation of such a system would be to accelerate higher intensity and longer bunches with improved capture efficiency. Advantages related to minimizing electron cloud effects, intra-beam scattering, heating and the possibility of luminosity levelling with bunch length are described. Some considerations related to cavity optimization, beam loading and technological challenges are addressed.

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TUPMW038

RHIC Operation with Asymmetric Collisions in 2015

proton, operation, emittance, cavity

1527

C. Liu, E.C. Aschenauer, G. Atoian, M. Blaskiewicz, K.A. Brown, D. Bruno, R. Connolly, T. D'Ottavio, K.A. Drees, W. Fischer, C.J. Gardner, X. Gu, T. Hayes, H. Huang, R.L. Hulsart, J.S. Laster, Y. Luo, Y. Makdisi, G.J. Marr, A. Marusic, F. Méot, K. Mernick, R.J. Michnoff, M.G. Minty, C. Montag, J. Morris, G. Narayan, S.K. Nayak, S. Nemesure, P.H. Pile, A. Poblaguev, V.H. Ranjbar, G. Robert-Demolaize, T. Roser, W.B. Schmidke, V. Schoefer, F. Severino, T.C. Shrey, K.S. Smith, D. Steski, S. Tepikian, D. Trbojevic, N. Tsoupas, G. Wang, K. Yip, A. Zaltsman, K. Zeno, S.Y. Zhang
BNL, Upton, Long Island, New York, USA
S.M. White
ESRF, Grenoble, France

Funding: Work supported by Brookhaven Science Associates, LLC under Contract No. DE-AC02-98CH10886 with the U.S. Department of Energy.
Collisions with beams of highly asymmetric rigidities (proton-Gold and proton-Aluminum) were provided for the RHIC physics programs in 2015. Magnets were moved for the first time in RHIC prior to the run to accommodate the asymmetric beam trajectories during acceleration and at store. A special ramping scheme was designed to keep the revolution frequencies of the beams in the two rings equal. The unique operational experience of the asymmetric run will be reviewed.

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TUPMY005

A Muon Source Proton Driver at JPARC-based Parameters

proton, booster, linac, operation

1550

D.V. Neuffer
Fermilab, Batavia, Illinois, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the U. S. Department of Energy.
An "ultimate" high intensity proton source for neutrino factories and/or muon colliders was projected to be a ~4 MW multi-GeV proton source providing short, intense proton pulses at ~15 Hz. The JPARC ~1 MW accelerators provide beam at parameters that in many respects overlap these goals. Proton pulses from the JPARC Main Ring can readily meet the pulsed intensity goals. We explore these parameters, describing the overlap and consider extensions that may take a JPARC-like facility toward this "ultimate" source. JPARC itself could serve as a stage 1 source for such a facility.

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TUPMY015

Ultrafast Electron Guns for the Efficient Acceleration using Single-Cycle THz Pulses

electron, gun, acceleration, laser

1578

A. Fallahi, F.X. Kärtner, A. Yahaghi
CFEL, Hamburg, Germany
M. Fakhari
DESY, Hamburg, Germany

Funding: European Research Council (ERC)
Over the past decades, advances in ultrafast technologies led to the production of intense ultrashort THz to optical pulses reaching single-cycle pulse duration. Using such pulses for electron acceleration offers advantages in terms of higher thresholds for materials breakdown, thus introducing a promising path towards increasing acceleration gradients. Conventional accelerator technology is based on either continuous wave or long pulse operation, where resonant or guiding structures are usually employed. We introduce novel structures for electron acceleration which operate with single-cycle pulses named as single-cycle ultrafast guns. The operating frequencies considered here are at THz wavelengths inspired by the recent progress in the optical generation of intense single-cycle THz pulses. We begin with designing guns for low energy pulses and proceed with structures designed for high energy pulses. More importantly, it is shown that the already achieved THz pulse energies of 20 uJ are enough to realize relativistic fields for electron acceleration. These structures will underpin future devices for fabricating miniaturized electron guns and linear accelerators.

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TUPMY026

Electron Beam Generation and Injection From a Pyroelectric Crystal Array

acceleration, electron, laser, radiation

1604

R.B. Yoder, Z. Kabilova, B. Saeks
Goucher College, Baltimore, Maryland, USA

Novel acceleration structures (e.g. dielectric laser accelerators [DLAs]*) powered by lasers have the potential to greatly reduce the footprint and cost of both industrial linacs and colliders. As these devices have dimensions comparable to optical wavelengths, they require injection of a sub-micron-scale electron bunch to generate high-quality output beams, which are well beyond the capability of conventional rf photocathodes. Photoexcitation and field emission from an array of nanotips, followed by further acceleration and focusing, is a promising approach to achieving the requisite small beam sizes for successful injection. Pyroelectric crystals can provide electrostatic fields of sufficient magnitude and uniformity to enable emission and acceleration. We present an initial design for a low-energy injection module using the accelerating electrostatic fields provided by pyroelectric crystals. The approach is modeled numerically and supported by direct benchtop measurements of pyroelectric fields from a 2-crystal array.
*R. J. England et al., Rev. Mod. Phys. 86, p. 1337 (2014).

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TUPOW008

Generation of Short Bunch Electron Beam from Compact Accelerator for Terahertz Radiation

laser, electron, radiation, detector

1757

S. Suphakul, T. Kii, K. Masuda, K. Morita, H. Ohgaki, K. Torgasin, H. Zen
Kyoto University, Kyoto, Japan

We are developing a new compact accelerator system to generate a high power terahertz (THz) radiation at the Institute of Advanced Energy, Kyoto University. THz radiations are produced by injecting ultra-short and intense electron pulses to a short plannar undulator. The bunch compression characteristic by the newly installed chicane was investigated by observation of a coherent part of an optical transition radiation (OTR). As the result, the chicane can compress the electron bunch at the laser injection phase from 10 to 40 degree. The beam energy and relative rms energy spread were also measured and the results were 4.6 MeV and 1.3 %, respectively.

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TUPOW009

Generation of Coherent Undulator Radiation using Extremely Short Electron Bunch at t-ACTS, Tohoku University

radiation, undulator, electron, bunching

1760

S. Kashiwagi, T. Abe, H. Hama, F. Hinode, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki, K. Takahashi, C. Tokoku
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

An accelerator test facility, t-ACTS, was established at Research Center for Electron Photon Science, Tohoku University, in which an intense coherent terahertz (THz) radiation is generated from an extremely short electron bunch. Velocity bunching scheme in a traveling-wave accelerating structure is employed to produce the short electron bunch, and a production of sub-picosecond electron bunch was demonstrated. A long-period linear undulator, which has 25 periods with a period length of 10 cm and a peak magnetic field of 0.41 T, has been developed to produce intense coherent THz radiation. Properties of the radiation from the THz undulator such as radiation fields, spectrum and angular distribution were numerically investigated based on the parameters of short electron bunch and THz undulator. By optimization of bunch compression, it is possible to extract a coherent radiation of fundamental mode excluding higher-order mode. The detail of the numerical studies for the coherent undulator radiation will be reported in the conference.

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TUPOW010

Production of Ultra-short Electron Pulse and Observation of Coherent Transition Radiation at t-ACTS, Tohoku University

radiation, electron, bunching, detector

1763

T. Abe, H. Hama, F. Hinode, S. Kashiwagi, T. Muto, I. Nagasawa, K. Nanbu, H. Saito, Y. Shibasaki, K. Takahashi, C. Tokoku
Tohoku University, Research Center for Electron Photon Science, Sendai, Japan

A test-Accelerator as Coherent Terahertz Source (t-ACTS) project has been under development at Research Center for Electron Photon Science, Tohoku University. In order to generate a coherent radiation in terahertz (THz) region, it is necessary to produce sub-picosecond electron pulses. Velocity bunching scheme is employed for the short electron pulse production in t-ACTS. We experimentally confirmed the production of short electron pulse under 500 fs by measuring the bunch length using a streak camera. Coherent transition radiation in THz region was produced by which the short electron pulses pass through a vacuum-metal interface. Several radiation properties including　spatial distribution, polarization and spectrum were measured and compared with theoretical calculations. The details of the beam experiment at t-ACTS are described.

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TUPOY022

A Fixed Field Alternating Gradient Accelerator for Helium Therapy

ion, proton, acceleration, emittance

1953

J. Taylor
IIAA, Huddersfield, United Kingdom
T.R. Edgecock, R. Seviour
University of Huddersfield, Huddersfield, United Kingdom
S. Green
University Birmingham, Birmingham, United Kingdom
C. Johnstone
PAC, Batavia, Illinois, USA

A non-scaling fixed field alternating gradient (nsFFAG) accelerator is being designed for helium ion therapy. This facility will consist of 2 nested superconducting rings, treating with helium ions (He²⁺) and image with hydrogen ions (H²⁺). Compared to protons, ions deliver a more conformal dose with a significant reduction in range straggling and beam broadening. Carbon ions are currently used and there are no current facilities providing helium therapy. We are investigating the feasibility of an FFAG approach for helium therapy, which has never been previously considered. We investigate emittance and demonstrate that the machine meets isochronicity requirements for fixed frequency RF.

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TUPOY023

A Compact and High Current FFAG for the Production of Radioisotopes for Medical Applications

target, proton, simulation, space-charge

1957

D. Bruton, R.J. Barlow, T.R. Edgecock, R. Seviour
University of Huddersfield, Huddersfield, United Kingdom
C. Johnstone
PAC, Batavia, Illinois, USA

A low energy Fixed Field Alternating Gradient (FFAG) accelerator has been designed for the production of radioisotopes. Tracking studies have been conducted using the OPAL code, including the effects of space charge. Radioisotopes have a wide range of uses in medicine, and recent disruption to the supply chain has seen a renewed effort to find alternative isotopes and production methods. The design features separate sector magnets with non-scaling, non-linear field gradients but without the counter bends commonly found in FFAG's. The machine is isochronous at the level of 0.3% up to at least 28 MeV and hence able to operate in Continuous Wave (CW) mode. Both protons and helium ions can be used with this design and it has been demonstrated that proton beams with currents of up to 20 mA can be accelerated. An interesting option for the production of radioisotopes is the use of a thin internal target. We have shown that this design has large acceptance, ideal for allowing the beam to be recirculated through the target many times, the lost energy being restored on each cycle. In this way, the production of Technetium-99m, for example, can take place at the optimum energy.

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WEOAA01

Transverse Emittance Exchange for Improved Injection Efficiency

emittance, resonance, coupling, synchrotron

2028

P. Kuske, F. Kramer
HZB, Berlin, Germany

In most cases beam is injected into electron storage rings in the horizontal plane and off-axis. The larger the horizontal emittance of the injected beam the larger the acceptance of the ring has to be. The injected beam is usually delivered by a synchrotron. In case the vertical acceptance of the ring is sufficiently large one can take advantage of the small vertical emittance reached in well aligned and tuned synchrotrons since the transverse emit-tances can be exchanged with the help of skew quadru-pole magnets. A few possible processes will be discussed: emittance exchange with static magnets in the transfer line between synchrotron and ring or emittance exchange in the synchrotron shortly before extraction with time dependent magnets. This could be a suddenly switched-on normal or skew quadrupole magnet or skew quadru-pole fields oscillating at a frequency fulfilling the reso-nance condition. Estimates for these magnets and their design will be given.

Slides WEOAA01 [0.852 MB]

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WEOAA02

On-axis Beam Accumulation Enabled by Phase Adjustment of a Double-frequency RF System for Diffraction-limited Storage Rings

lattice, kicker, synchrotron, storage-ring

2032

G. Xu, J. Chen, Z. Duan, J. Qiu
IHEP, Beijing, People's Republic of China

Funding: Work supported by NSFC (Y4113G005C)
Future synchrotron light sources aim to achieve ultra- low emittances on both transverse planes, approaching or even reaching the diffraction limit of X-ray photon energies. These diffraction-limited storage rings (DLSRs) feature very strong lattice nonlinearities and thus very small dynamic aperture, which exclude off-axis injection schemes. In this paper, we propose a longitudinal on-axis injection scheme, which is based on a double-frequency RF system and in- dependently adjustment of the RF phase of each cavity to enable RF gymnastics. Such a scheme looks feasible with the state-of-art technology of fast injection kicker. Compari- son with other on-axis injection schemes is also discussed.

Slides WEOAA02 [1.712 MB]

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WEOBA03

High Brilliance Uranium Beams for FAIR

brilliance, emittance, ion, target

2052

W.A. Barth, A. Adonin, Ch.E. Düllmann, M. Heilmann, R. Hollinger, E. Jäger, O.K. Kester, J. Khuyagbaatar, J. Krier, E. Plechov, P. Scharrer, W. Vinzenz, H. Vormann, A. Yakushev, S. Yaramyshev
GSI, Darmstadt, Germany
Ch.E. Düllmann, J. Khuyagbaatar, P. Scharrer, A. Yakushev
HIM, Mainz, Germany
Ch.E. Düllmann
Johannes Gutenberg University Mainz, Institut of Nuclear Chemistry, Mainz, Germany
P. Scharrer
Mainz University, Mainz, Germany

The 40 years old GSI-UNILAC (Universal Linear Accelerator) as well as the heavy ion synchrotron SIS18 will serve as a high current heavy ion injector for the new FAIR (Facility for Antiproton and Ion Research) synchrotron SIS100. Due to an advanced machine investigation program in combination with the ongoing UNILAC upgrade program, a new uranium beam intensity record (10 emA, U²⁹⁺) at very high beam brilliance was achieved recently in a machine experiment campaign. This is an important step paving the way to fulfill the FAIR heavy ion high intensity beam requirements. Results of high current uranium beam measurements applying a newly developed pulsed hydrogen gas stripper (at 1.4 MeV/u) will be presented in detail.

Slides WEOBA03 [2.281 MB]

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WEPMR046

Thermal Analysis of the Injection Beam Dump at J-PARC RCS

radiation, proton, shielding, synchrotron

2380

J. Kamiya, M. Kinsho, P.K. Saha, K. Yamamoto
JAEA/J-PARC, Tokai-mura, Japan

In the J-PARC accelerator facility, 400 MeV H⁻ ions are injected from linac to rapid cycling synchrotron (RCS). A thin graphite foil with the thickness of about 300 ug/cm² is located at the injection point to strip two electrons from H⁻ ion and convert it to proton. The charge stripping efficiency is usually more than 99.7 %. In other words, less than 0.3 % H⁻ ions are not accurately exchanged to protons. Most of those remaining H⁻ ions or H⁰ atoms (stripped only one electron from H⁻ ion) are eventually converted to protons by second and third graphite foils and transported to the beam dump. This beam dump consists of an iron block with the size of 0.3×0.3×0.4 m3 for beam stop and the iron block with the size of 3×3×2.5 m3 and concrete with the size of 6×6×6 m3 around the iron block for the radiation shielding. The radiation shielding was designed to endure the 4 kW proton beam to the beam dump. In this presentation, we show the thermal analysis of the beam dump and compare it to the real operation.

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WEPMW007

Validation of Off-momentum Cleaning Performance of the LHC Collimation System

proton, collimation, beam-losses, alignment

2427

B. Salvachua, P. Baudrenghien, R. Bruce, H. Garcia, P.D. Hermes, S. Jackson, M. Jaussi, A. Mereghetti, D. Mirarchi, S. Redaelli, H. Timko, G. Valentino, A. Valloni
CERN, Geneva, Switzerland
R. Kwee-Hinzmann
Royal Holloway, University of London, Surrey, United Kingdom

The LHC collimation system is designed to provide effective cleaning against losses coming from off-momentum particles, either due to un-captured beam or to an unexpected RF frequency change. For this reason the LHC is equipped with a hierarchy of collimators in IR3: primary, secondary and absorber collimators. After every collimator alignment or change of machine configuration the off-momentum cleaning efficiency is validated with loss maps at low intensity. We describe here the improved technique used in 2015 to generate such loss maps without completely dumping the beam into the collimators. The achieved performance of the collimation system for momentum cleaning is reviewed.

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WEPMW011

Stable Spin Direction Investigations in RHIC

kicker, extraction, emittance, septum

2442

F. Méot, H. Huang, N. Tsoupas
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.
Beam and spin dynamics investigations are part of the preparations and studies regarding RHIC collider runs, they are part as well of the efforts dedicated to improving stored beam polarization, and in view of the eRHIC EIC project. Some recent studies and their outcomes are discussed.

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WEPMW012

Injection Optics for the JLEIC Ion Collider Ring

quadrupole, optics, ion, collider

2445

V.S. Morozov, Y.S. Derbenev, F. Lin, F.C. Pilat, G.H. Wei, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Cai, Y. Nosochkov, M.K. Sullivan, M.-H. Wang
SLAC, Menlo Park, California, USA

Funding: * Work supported by the U.S. DOE Contract DE-AC02-76SF00515. ** Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The Jefferson Lab Electron-Ion Collider (JLEIC) will accelerate protons and ions from 8 GeV to 100 GeV. A very low beta function at the Interaction Point (IP) is needed to achieve the required luminosity. One consequence of the low beta optics is that the beta function in the final focusing (FF) quadrupoles is extremely high. This leads to a large beam size in these magnets as well as strong sensitivity to errors which limits the dynamic aperture. These effects are stronger at injection energy where the beam size is maximum, and therefore very large aperture FF magnets are required to allow a large dynamic aperture. A standard solution is a relaxed injection optics with IP beta function large enough to provide a reasonable FF aperture. This also reduces the effects of FF errors resulting in a larger dynamic aperture at injection. We describe the ion ring injection optics design as well as a beta-squeeze transition from the injection to collision optics.

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WEPOR001

Beam Studies with a New Longitudinal Feedback System at the ANKA Storage Ring

feedback, synchrotron, storage-ring, kicker

2658

E. Blomley, A.-S. Müller, M. Schedler
KIT, Karlsruhe, Germany

With the now fully commissioned longitudinal feedback system at the ANKA Storage Ring - in addition to the already operational transverse feedback system - the stability throughout the injection process was increased considerably. This opened up the possibility to investigate beam dynamics and limitations during injection more systematically. This paper presents the results of these studies, an overview of the limiting parameters and discusses possible approaches to increase the efficiency of the injection.

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WEPOW005

Updates on Lattice Modeling and Tuning for the ESRF-EBS Lattice.

lattice, dipole, quadrupole, radiation

2818

S.M. Liuzzo, N. Carmignani, J. Chavanne, L. Farvacque, G. Le Bec, B. Nash, P. Raimondi, R. Versteegen, S.M. White
ESRF, Grenoble, France

The ESRF-EBS lattice model is updated to include the effect of magnetic lengths in dipoles, quadrupoles, sextupoles and combined function magnets. The effect of this modification and the updates to the injection cell are considered with particular focus on injection efficiency and Touschek lifetime. The solutions to introduce new sources of radiation suitable for the existing bending magnet radiation beamlines are also presented.

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WEPOW007

Status and Prospects of the BESSY II Injector System

booster, storage-ring, linac, synchrotron

2826

T. Atkinson, W. Anders, P. Goslawski, A. Jankowiak, F. Kramer, P. Kuske, D. Malyutin, A.N. Matveenko, A. Neumann, M. Ries, M. Ruprecht, A. Schälicke, T. Schneegans, D. Schüler, P.I. Volz, G. Wüstefeld
HZB, Berlin, Germany
H.G. Glass
BESSY GmbH, Berlin, Germany

The BESSY II injector system consists of a 50 MeV Linac, installed in preparation for TopUp operation, and a 10 Hz fast-ramping booster synchrotron. The system provides injection efficiencies into the BESSY II storage ring well above 90 % . This contribution reports on the present status, measurements of energy acceptance and other essential beam parameters as well as studies on coupled-bunch-by-bunch instability. Requirements for BESSY-VSR and possible upgrade scenarios are discussed.

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WEPOW023

Present Status of Accelerators in Aichi Synchrotron Radiation Center

synchrotron, radiation, storage-ring, synchrotron-radiation

2877

Y. Takashima, M. Hosaka, A. Mano
Nagoya University, Nagoya, Japan
Y. Hori, N. Yamamoto
KEK, Ibaraki, Japan
M. Katoh
UVSOR, Okazaki, Japan
S. Koda
SAGA, Tosu, Japan
S. Sasaki
JASRI/SPring-8, Hyogo, Japan
T. Takano
Hitachi Ltd., Ibaraki-ken, Japan

Aichi Synchrotron Radiation Center is the newest synchrotron radiation facility in Japan. The construction was started in 2010 and the facility was opened for public use on March 26, 2013. The circumference of the storage ring is 72 m with the electron energy of 1.2 GeV, the beam current of 300 mA and the natural emittance of about 53 nmrad. The beam is injected from a booster synchrotron with the energy of 1.2 GeV as full energy injection and the top-up operation has been carried out routinely with stored current of 300 mA since opened for public use. We have tested a pulsed multi-pole magnet for improving the deviation of the orbit of stored beam during the top-up beam injection. The storage ring consists of four triple bend cells. Eight of the twelve bending magnets are normal conducting ones. Four of them are 5 T superconducting magnets(superbend) of which bending angle is 12 degrees. The superbends are running without any trouble with refrigerator maintenance once per year. The accelerators have been operated about 1400 hours stable in a year. Eight of the synchrotron radiation beamlines have been operational for public use and other two beamlines are under construction.

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WEPOW024

Commissioning of SESAME Booster

booster, septum, quadrupole, extraction

2880

M. Attal, I.A. Abid, T.H. Abu-Hanieh, H. Al-Mohammad, M.A. Al-Najdawi, D.S. Foudeh, A. Hamad, E. Huttel, A. Ismail, S.Kh. Jafar, F. Makahleh, M. Mansouri Sharifabad, K. Manukyan, I. Saleh, N.Kh. Sawai, M.M. Shehab
SESAME, Allan, Jordan

Commissioning of the 800 MeV booster of SESAME light source started in December 2013. The 38.4 m circumference booster is a part of SESAME injector which includes also a 20 MeV classical microtron as a pre-injector that is in operation since 2012. The main results and experience obtained during the commissioning period are reported in this paper.

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WEPOW026

Recent Physical Studies for the HEPS Project

lattice, booster, emittance, sextupole

2886

G. Xu, Z. Duan, Y.Y. Guo, D. Ji, Y. Jiao, X.Y. Li, Y.M. Peng, Q. Qin, J. Qiu, S.K. Tian, J.Q. Wang, N. Wang, Y. Wei, C.H. Yu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS), a kilometre- scale storage ring light source, with a beam energy of 5 to 6 GeV and transverse emittances of a few tens of pm.rad, is to be built in Beijing and now is under design. In this paper we reported the progress and status of the physical studies for the HEPS project, covering issues of storage lattice design and optimization, booster design, injection design, collective effects, error study, insertion device effects, longitudinal dynamics, etc.

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WEPOW031

Performance of the Vacuum System for the Solaris 1.5 GeV Electron Storage Ring

storage-ring, vacuum, electron, synchrotron

2898

A.M. Marendziak, C.J. Bocchetta, P.B. Borowiec, P. Bulira, L.J. Dudek, P.P. Goryl, K. Karaś, A. Kisiel, W.T. Kitka, M.P. Kopec, M. Madura, R. Nietubyć, M.P. Nowak, M.J. Stankiewicz, A.I. Wawrzyniak, K. Wawrzyniak, J.J. Wiechecki, J. Wikłacz, M. Zając, Z. Zbylut, L. Żytniak
Solaris National Synchrotron Radiation Centre, Jagiellonian University, Kraków, Poland

Solaris is a third generation light source recently constructed at the Jagiellonian University in Kraków, Poland. The machine was designed by the team at the MAX IV Laboratory. A replica of the 1.5 GeV MAX IV storage ring with a 96 m circumference was successfully built at Solaris and now the facility is in its 3rd phase of commissioning. The average pressure in the storage ring was 1.2·10^-10 mbar before beam commissioning and increases to 1.2·10-8 mbar with 511 mA of stored beam current for electron energy of 524 MeV. With 10 A·h accumulated beam dose, beam cleaning has permitted an average pressure of 3·10-10 mbar/mA. In this paper the result of vacuum performance from beam cleaning and the beam lifetime will be presented. Moreover vacuum maintenance procedures will be reported.

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WEPOW039

Preliminary Beam Loss Study of TPS during Beam Commissioning

radiation, photon, scattering, EPICS

2926

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

Taiwan photon source (TPS) is a 3rd generation and 3 GeV synchrotron light source in NSRRC. Several types of beam loss monitors (BLMs) such as RadFETs and PIN-diode BLMs are installed in the storage ring to understand the beam loss distribution and mechanism during the injection, decay mode, top-up operation and beam trip. Several RadFETs are also installed around the inserting devices to study the beam loss near the linear scalar. The preliminary beam loss study using RadFETs are PIN-diode BLMs in the storage will be summarized in this report.

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WEPOW049

Physics Design Progress towards a Diffraction Limited Upgrade of the ALS

emittance, lattice, brightness, dynamic-aperture

2956

C. Steier, J.M. Byrd, S. De Santis, H. Nishimura, D. Robin, F. Sannibale, C. Sun, M. Venturini, W. Wan
LBNL, Berkeley, California, USA

Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.
Improvements in brightness and coherent flux of more than two orders of magnitude are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source. We will describe the progress in the physics design of this upgrade, including lattice evolution, error tolerance studies, simulations of collective effects, and intra beam scattering.

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WEPOW050

Optimization of the ALS-U Storage Ring Lattice

lattice, emittance, storage-ring, quadrupole

2959

C. Sun, H. Nishimura, D. Robin, F. Sannibale, C. Steier, M. Venturini, W. Wan
LBNL, Berkeley, California, USA

Funding: Work supported by the Director Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231
The Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory is proposing the upgrade of its synchrotron light source to reach soft x-ray diffraction limits within the present ALS footprint. The storage ring lattice design and optimization of this light source is one of the challenging aspects for this proposed upgrade. The candidate upgrade lattice needs not only to fulfill the physics design requirements such as brightness, injection efficiency and beam lifetime, but also to meet engineering constraints such as space limitations, maximum magnet strength as well as beamline port locations. In this paper, we will present the approach that we applied to design and optimize a multi-bend achromat based storage ring lattice for the proposed ALS upgrade.

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WEPOW051

R+D Progress Towards a Diffraction Limited Upgrade of the ALS

vacuum, undulator, emittance, storage-ring

2962

C. Steier, A. Anders, J.M. Byrd, K. Chow, S. De Santis, R.M. Duarte, J.-Y. Jung, T.H. Luo, H. Nishimura, T. Oliver, J.R. Osborn, H.A. Padmore, G.C. Pappas, D. Robin, F. Sannibale, D. Schlueter, C. Sun, C.A. Swenson, M. Venturini, W.L. Waldron, E.J. Wallén, W. Wan, Y. Yang
LBNL, Berkeley, California, USA

Funding: This work was supported by the Laboratory Directed Research and Development Program of Lawrence Berkeley National Laboratory under U.S. Department of Energy Contract No. DE-AC02-05CH11231.
Improvements in brightness and coherent flux of about two orders of magnitude over operational storage ring based light sources are possible using multi bend achromat lattice designs. These improvements can be implemented as upgrades of existing facilities, like the proposed upgrade of the Advanced Light Source, making use of the existing infrastructure, thereby reducing cost and time needed to reach full scientific productivity on a large number of beamlines. An R&D program was started at LBNL to further develop the technologies necessary for diffraction-limited storage rings. It involves many areas, and focuses on the specific needs of soft x-ray facilities: NEG coating of small chambers, swap-out injection, bunch lengthening, magnets/radiation production, x-ray optics, and beam physics design optimization. Hardware prototypes have been built and concepts and equipment was tested in beam tests on the existing ALS.

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WEPOW053

CESR Lattice for Two Beam Operations with Narrow Gap Undulators at CHESS

undulator, lattice, operation, simulation

2968

S. Wang, D. L. Rubin, J.P. Shanks
Cornell University (CLASSE), Cornell Laboratory for Accelerator-Based Sciences and Education, Ithaca, New York, USA

Funding: Work was supported by NSF DMR-0936384 and NSF DMR-1332208.
CESR has operated as a dedicated light source since the conclusion of colliding beam program in 2008. Two undulators with a 6.5mm-vertical gap were installed in Fall 2014, replacing a wiggler in the sextant of CESR that is the home to all CHESS beam lines. In order to operate narrow gap undulators with two beams, CESR pretzel lattice was redesigned so that e^- and e⁺ orbits are coincident in one machine sextant but separated in return arcs. In particular both e^- and e⁺ orbits are on axis through undulators. This "arc-pretzel" lattice has been the basis for undulator operation. To better understand the beam dynamics and improve machine performance, we developed many simulation tools: undulator modeling, injection tracking, etc. With installation of an additional quadrupole near undulators, the CESR lattice will be further modified with a low beta waist in the insertion devices, allowing a more than two fold reduction of local beta functions. This reduction is anticipated to mitigate the effects of small aperture and undulator field errors and to enhance the xray brightness. The characterization of the lattice will be compared with measurements of injection efficiency, tune scans, etc.

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WEPOW058

Top-off Tests and Controls Optimization

operation, controls, booster, timing

2982

G.M. Wang, M.A. Davidsaver, A.A. Derbenev, R.P. Fliller, Y. Hu, T.V. Shaftan
BNL, Upton, Long Island, New York, USA

Funding: DOE No.DE-AC02- 98CH10886
The National Synchrotron Light Source II (NSLS-II) is a state of the art 3 GeV third generation light source at Brookhaven National Laboratory. As in many other light sources, top-off injection is considered as a standard operation mode resulting in more stable beam intensity to minimize heat load variation on the beamline optics. Top off injection specifications include maintaining the stored beam current within 0.5% and the bunch to bunch charge variation within 20% bands. To make the top off commissioning smooth and efficient, a virtual machine model based on the measured beam properties was developed. The model helped to study robustness of this application operating under different conditions and optimize the input parameters. Once tested the model was transitioned to beam commissioning. To make the beam tests more efficient, the beam lifetime was controlled by adjusting RF voltage and scrapers. In this paper, we'll share the experience from the test stage to machine implementation of the top-off controls.

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WEPOW059

The NSLS-II Top Off Safety System

operation, storage-ring, radiation, controls

2985

R.P. Fliller, D. Bergman, A. Caracappa, L. Doom, G. Ganetis, Y. Hu, Y. Li, W. Louie, D. Padrazo, O. Singh, J. Tagger, G.M. Wang, Z. Xia
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Top Off operation is the desired mode of operation for 3rd generation light sources to ensure beam current stability for user experiments. However, top off operation introduces the hazard of injecting electrons into the front ends with the beamline shutters open. This hazard can be mitigated with the appropriate safety system. This past year, the NSLS-II has transitioned from decay mode to top off operation with the introduction of the Top Off Safety System (TOSS). Top Off was initially demonstrated September 22, 2015 and become standard mode of operating. In this paper we discuss the top off safety system, operation with the system, and future directions.

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WEPOW060

Top Off Algorithm Development and Commissioning at NSLS-II

operation, storage-ring, target, feedback

2988

R.P. Fliller, A.A. Derbenev, T.V. Shaftan, G.M. Wang
BNL, Upton, Long Island, New York, USA

Funding: This manuscript has been authored by Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy.
Recently, NSLS-II introduced top off as the standard mode of beam delivery for the users. During top off, we are required to maintain the beam current within ±0.5% of nominal, and the bunch to bunch variation over the train less than 20% for all operating conditions. In this paper, we discuss the algorithm used for top off, simulations of various operating conditions and performance of the algorithm during operations.

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WEPOY030

First BTF Measurements at the Large Hadron Collider

octupole, betatron, damping, simulation

3051

C. Tambasco, A. Boccardi, X. Buffat, K. Fuchsberger, M. Gąsior, R. Giachino, T. Lefèvre, T.E. Levens, T. Pieloni, M. Pojer, B. Salvachua, M. Solfaroli Camillocci
CERN, Geneva, Switzerland
J. Barranco, C. Tambasco
EPFL, Lausanne, Switzerland

During the Run I in 2012, several instabilities have been observed at the Large Hadron Collider (LHC) during the Betatron squeeze. The predictions of instability thresholds are based on the computation of the beam Landau damping by calculating the Stability Diagrams (SD). These instabilities could be explained by a deterioration of the SD due to beam-beam resonance excitation which could change the particle distributions. Beam Transfer Functions (BTF) provide a measurement of the Stability Diagram. The BTFs are sensitive to the particle detuning with amplitude as well as to the particle distributions therefore they represent a powerful tool to understand experimentally the stability of beams during the LHC operational cycle. First BTF measurements at the LHC are presented for different machine configurations and settings and compared to predictions.

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WEPOY036

Progress in Automatic Software-based Optimization of Accelerator Performance

linac, software, storage-ring, FEL

3064

S.I. Tomin, G. Geloni
XFEL. EU, Hamburg, Germany
I.V. Agapov, I. Zagorodnov
DESY, Hamburg, Germany
W.S. Colocho, T.M. Cope, A.B. Egger, D.F. Ratner
SLAC, Menlo Park, California, USA
Y.A. Fomin, Y.V. Krylov, A.G. Valentinov
NRC, Moscow, Russia

Funding: partial support from Ioffe Roentgen Institute grant EDYN EMRAD
For modern linac- and storage-ring-based light sources certain amount of empirical tuning is used to reach ultimate performance. The possibility to perform such empirical tuning by automatic methods has now been demonstrated by several authors (e.g. I.Agapov et al. in proc IPAC 2015). In this paper we present the progress in development of our automatic optimisation software based on OCELOT and its applications to SASE FEL optimization at FLASH and LCLS, and its potential for storage ring optimization.

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WEPOY045

Benchmarking the Beam Longitudinal Dynamics Code BLonD

simulation, impedance, synchrotron, feedback

3094

H. Timko, J. F. Esteban Müller, A. Lasheen, D. Quartullo
CERN, Geneva, Switzerland

The relatively recent Beam Longitudinal Dynamics code BLonD has already been applied to a wide range of studies for all present CERN synchrotrons. Its application area ranges from studies of RF manipulations, over single and multi-bunch interactions with impedance, to the action of feedback loops and RF noise. In this paper, we present benchmarks and comparisons with measurements, theory, or other codes, which have increased greatly the trust in the code. Tests related to bunch-to-bucket transfer, feedback loops, diffusion due to noise injection, as well as collective effects, are presented.

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WEPOY055

NSLS-II Accelerator Commissioning and Transition to Operations

operation, lattice, storage-ring, vacuum

3120

T.V. Shaftan
BNL, Upton, Long Island, New York, USA

Over past year NSLS-II has completed accelerator commissioning and enabled operations of first project beam lines. Recently we further optimized the NSLS-II accelerators, increased the beam current to 400 mA without- and to 250 mA with Insertion Devices (IDs), commissioned top-off mode of operations and stabilized beam orbit to below 10% of the beam size in the source points. In this paper we report progress on the NSLS-II accelerator commissioning and operations and plans for future facility developments.

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THPMB012

The HMBA Lattice Optimization for the New 3 GeV Light Source

lattice, brightness, emittance, storage-ring

3251

K. Harada, M. Adachi, N. Funamori, T. Honda, Y. Kobayashi, N. Nakamura, K. Oide, H. Sakai, S. Sakanaka, K. Tsuchiya
KEK, Ibaraki, Japan

For the design study of the HMBA (hybrid multi bend achromat) type most advanced light source, the new storage ring was designed from the lattice of the phase II upgrade project of the ESRF (ESRF II). Although the original 3 GeV test lattice from Dr. Pantaleo Raimondi of ESRF has no problem about the optical and magnetic parameters including the dynamic aperture, we reduce the cell numbers and inserted the short straight sections for the in-vacuum short-gap undulators. After the optimization of the linear and non-linear optics as the original design principle of ESRF II, the altered lattice has the circumference of about 440 m with 16 HMBA cells, the emittance about 440 pm rad with the intra-beam scattering effect at the beam current of 500 mA, and the large dynamic aperture of about 2 cm at the injection point even with the usual magnetic errors.

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THPMB018

Candidate Booster Design for the HEPS Project

emittance, booster, sextupole, lattice

3263

Y.M. Peng, Y.Y. Guo, Y. Jiao, Y. Wei, G. Xu
IHEP, Beijing, People's Republic of China

The High Energy Photon Source (HEPS), with trans-verse emittances of a few tens of pm.rad, is to be built in the suburbs of Beijing, China. The HEPS booster is a 2 Hz electron synchrotron. It accelerates electron bunches from a 300 MeV linac to a final energy of 6 GeV, and then extracts and injects them into the stor-age ring. We have made a candidate booster design, with a circumference of about 432 m and a natural emittance of about 4 nm.rad at 6GeV, which will be located in a separate tunnel. This lattice has a four-fold symmetry. Each super-period is composed of 13 iden-tical cells and two matching cells. The lattice design and optimization and other considerations are present-ed in a detail.

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THPMB030

Operation Improvement by Tuning of Storage Ring at PLS-II

kicker, operation, storage-ring, linac

3297

I. Hwang, M. Kim, T.-Y. Lee, C.D. Park
PAL, Pohang, Kyungbuk, Republic of Korea

After upgrade of the pohang light source (PLS-II), several problems reduced the quality of the top-up operation. Unbalance of the injection kicker system and it's lack of control had limited the efficiency of the injection from the linac to the storage ring. We tuned the storage ring to improve the injection efficiency and to stabilize the orbit during the injection.

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THPMB041

Optics-measurement-based BPM Calibration

optics, dipole, factory, focusing

3328

A. Garcia-Tabares, F.S. Carlier, J.M. Coello de Portugal, A. Langner, E.H. Maclean, L. Malina, T. Persson, P.K. Skowroński, M. Solfaroli Camillocci, R. Tomás
CERN, Geneva, Switzerland

The LHC beta functions (β) can be measured using the phase or the amplitude of betatron oscillations obtained with beam position monitors (BPMs). Using the amplitude information results in a β measurement affected by BPM calibration. This work aims at calibrating BPMs using optics measurements. For this, βs from amplitude and phase and normalized dispersion obtained from many different measurements in 2015 with different optics and corrections are analyzed. Simulations are also performed to support the analyses.

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THPMB044

Limitations on Optics Measurements in the LHC

optics, dipole, hadron, luminosity

3339

P.K. Skowroński, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, A. Langner, E.H. Maclean, L. Malina, M. McAteer, T. Persson, R. Tomás
CERN, Geneva, Switzerland
A. Langner
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany
L. Malina
University of Oslo, Oslo, Norway

In preparation of the optics commissioning at an energy of 6.5 TeV, many improvements have been done to cope with the expected reduced signal to noise ratio due to lowered bunch intensities imposed by machine protection considerations. This included, among others, an increase of the flat top duration of the AC dipole excitations, which allowed to use more turn-by-turn data for the analysis. The longer data acquisition revealed slow drifts of the optics, which limited the increased measurement precision. Furthermore, we will present how orbit drifts influenced dispersion measurements and, as a consequence, posed another limitation for the optics correction. In this paper we will discuss the implications of these observations for the measurement and correction of the optics.

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THPMR001

Online Suppression of the Sextupole Resonance Driving Terms in the Diamond Storage Ring

sextupole, resonance, storage-ring, optics

3381

I.P.S. Martin, M. Apollonio, R. Bartolini
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Suppression of the sextupole resonance driving terms (RDTs) is a widely used technique for optimising the theoretical on and off-momentum dynamic aperture for electron storage rings. Recently, this technique was applied online to the Diamond storage ring, with suppression of individual RDTs achieved via a sextupole family to RDT response matrix*. In this paper we present recent studies of the method, in which the ability to improve the lifetime and injection efficiency are investigated. An extension of the technique is investigated by combining it with the Robust Conjugate Direction Search (RCDS) optimisation algorithm**.
*J. Bengtsson, et al., Phys. Rev. ST Accel. Beams 18, 074002, (2015).
**X. Huang, et al., Nucl. Instrum. Methods Phys. Res. Sect. A 726, 77, (2013).

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THPMR011

Injection Dynamics for Sirius Using a Nonlinear Kicker

kicker, storage-ring, booster, accumulation

3406

L. Liu, X.R. Resende, A.R.D. Rodrigues, F. H. de Sá
LNLS, Campinas, Brazil

The concept of injection using a single nonlinear kicker has been proposed and tested in several existing storage rings with reduction in the stored beam oscillations during the accumulation process. Despite the good results, this scheme has not yet been adopted for routine operation in these machines due to the reduced injection efficiency. The main cause for reduction in efficiency is precisely the nonlinearity of the kick at the injected beam position and the generally large injected beam size. In this paper we study the injection dynamics in the Sirius storage ring where beam accumulation is based only on the use of a nonlinear kicker. The whole injection system has been optimized from the start for high injection efficiency.

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THPMR015

RCDS Optimizations for the ESRF Storage Ring

sextupole, optics, emittance, resonance

3420

S.M. Liuzzo, N. Carmignani, L. Farvacque, B. Nash, T.P. Perron, P. Raimondi, R. Versteegen, S.M. White
ESRF, Grenoble, France

The Robust Conjugate Direction Search (RCDS)* optimizer is applied for online optimizations of the ESRF accelerators. This paper presents the successful application of the algorithm in reducing vertical emittance, improving injection efficiency and increasing lifetime. A new set of sextupole settings to increase chromaticity has been obtained with lifetimes comparable to the existing one. This allows to run with double current in a single bunch, and unifies the optics for few bunch (except 4x10 bunches) and multi-bunch modes.
* X. Huang, J. Corbett, J. Safranek, J. Wu, "An algorithm for online optimization of accelerators", Nucl. Instr. Methods, A 726 (2013) 77-83.

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THPMR016

Horizontal Phase Space Shaping for Optimized Off-axis Injection Efficiency

sextupole, optics, lattice, septum

3424

S.M. White, S. Lagarde, S.M. Liuzzo, B. Ogier, T.P. Perron, P. Raimondi
ESRF, Grenoble, France

With the introduction of top-up operation at the ESRF it becomes important to reduce as much as possible any kind of perturbation seen by the users during injection. For this purpose, a novel technique to improve injection efficiency by shaping the horizontal beam phase space to better match the storage ring acceptance and hence reduce the duration of injections was developed. Theoretical concept, simulations and first experimental results are presented.

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THPMR022

Non-linear Optimization of Storage Ring Lattice for the SPring-8 Upgrade

sextupole, lattice, betatron, optics

3440

K. Soutome, K.K. Kaneki, Y. Shimosaki, M. Takao
JASRI/SPring-8, Hyogo-ken, Japan
H. Tanaka
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan

A project of upgrading the SPring-8 facility is ongoing to convert the present storage ring to a high-coherence hard X-ray source (SPring-8-II). To achieve the emittance value of less than 0.2 nmrad at 6 GeV, we adopted a 5-bend achromat lattice with dipoles having longitudinal field gradient. In this lattice the betatron phase between the two dispersion arcs was set to (2n+1)PI to suppress dominant harmful effects of chromaticity-correcting sextupoles. By detuning this phase, optimizing sextupole strengths in a cell and introducing octupoles, we obtained a sufficient dynamic aperture (DA) for beam injection even for the symmetry-broken ring having four long straight sections and a high-beta injection section. However, the off-momentum behavior such as the non-linear chromaticity still needs to be optimized to achieve the momentum acceptance (MA) of 3% or larger. We have thus been investigating the possibility to increase both the DA and MA by introducing several phase-matched sextupole pairs. The presentation will report the obtained results by this approach.

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THPMR037

Observations of Resonance Driving Terms in the LHC during Runs I and II

resonance, dipole, betatron, dynamic-aperture

3468

F.S. Carlier, J.M. Coello de Portugal, E.H. Maclean, T. Persson, R. Tomás
CERN, Geneva, Switzerland

Future operations of the LHC will require a good understanding of the nonlinear beam dynamics. In 2012, turn-by-turn measurements of large diagonal betatron excitations in LHC Beam 2 were taken at injection energy. Spectral analysis of these measurements shows an anomalous octupolar spectral line at frequency -Qx-2Qy in the horizontal motion. The presence of this spectral line, as well as other lines, was confirmed by measurements taken for LHC Beam 1 and Beam 2 during the commissioning in 2015. We take a close look at the various spectral lines appearing in the LHC transverse motion in order to improve the LHC nonlinear model.

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THPMR039

Commissioning of Non-linear Optics in the LHC at Injection Energy

dipole, octupole, optics, operation

3476

E.H. Maclean, F.S. Carlier, J.M. Coello de Portugal, A. Garcia-Tabares, A. Langner, L. Malina, T. Persson, P.K. Skowroński, R. Tomás
CERN, Geneva, Switzerland

Commissioning of the nonlinear optics at injection in the LHC was carried out for the first time in 2015 via beam-based methods. Building upon studies performed during Run I, corrections to the nonlinear chromaticity and detuning with amplitude were obtained. These corrections were observed to reduce beam-loss during measurement of linear optics.

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THPMR042

Design Guidelines for the Injector Complex of the FCC-ee

collider, linac, booster, optics

3488

Y. Papaphilippou, F. Zimmermann
CERN, Geneva, Switzerland
M. Aiba
PSI, Villigen PSI, Switzerland
K. Oide
KEK, Ibaraki, Japan
L. Rinolfi
JUAS, Archamps, France
D.B. Shwartz
BINP SB RAS, Novosibirsk, Russia

The design of the injector of the FCC-ee, a high-luminosity e⁺/e⁻ circular collider of 100 km in the Geneva area, is driven by the required particle flux for ring filling or top-up and for a variety of energies, from 45.5 to 175 GeV. In this paper, a set of parameters of the injector complex is presented, fulfilling the collider needs for all running scenarios. In particular, the challenges of the booster ring design are detailed, focusing on issues of optics, layout, low bending fields, injection schemes to the collider for maximizing transfer efficiency and synchrotron radiation handling.

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THPMR048

Analysis of Nonlinear Effects for IDs at the SPS Storage Ring

electron, coupling, storage-ring, quadrupole

3512

S. Krainara, P. Klysubun, S. Kongtawong, T. Pulampong, P. Sudmuang, P. Sunwong
SLRI, Nakhon Ratchasima, Thailand

Funding: Synchrotron Light Research Institute (Public Organization)
To generate intense and high energy synchrotron radiation at the Siam Photon Source (SPS) 1.2 GeV storage ring, two insertion devices (IDs), namely, a 2.2 T hybrid multipole wiggler (MPW) and a 6.5 T superconducting wavelength shifter (SWLS), have been installed and operated since 2013. The angular kicks due to the nonlinear effects generated by the IDs represented by kick maps were used in our analysis. The optics distortion was compared to the ones obtained from calculation using hard-edge model and measurement results. In order to investigate the effects of IDs on the beam dynamics, Frequency Map Analysis (FMA) was employed. The effects of the IDs and their compensation are presented herewith.

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THPMR050

Studies to Install a Multipole Wiggler by Removing a Chromatic Sextupole in the Diamond Storage Ring

sextupole, optics, lattice, emittance

3518

B. Singh, M. Apollonio, R. Bartolini, E. Koukovini-Platia, I.P.S. Martin, T. Pulampong, R.P. Walker
DLS, Oxfordshire, United Kingdom
R. Bartolini
JAI, Oxford, United Kingdom

Investigations are underway for the possible use of an achromat to install a short multipole wiggler by removing a chromatic sextupole in cell-11 of the storage ring. The effect on emittance and energy spread are found to be small, however the impact on lifetime and injection are very significant if the chromaticity is corrected normally (globally). The MOGA genetic algorithm is used to optimize the lifetime and injection efficiency in this case. We used local mirror chromatic sextupole and other chromatic sextupole family for chromaticity correction in which case the genetic algorithm found solution that restores lifetime and injection efficiency. In this paper the results of MOGA simulations using various schemes for chromaticity correction and test results in presently operational optics will be discussed.

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THPMR052

Compact, Microtron-Based Gamma Source

microtron, cathode, electron, cavity

3522

R.J. Abrams, M.A.C. Cummings, R.P. Johnson, S.A. Kahn, G.M. Kazakevich
Muons, Inc, Illinois, USA

Funding: This work was supported U.S. DOE SBIR Grant DE-SC0013795.
The conceptual design of a prototype S-band pulsed, 9.5 MeV compact microtron with type-II injection is described. Estimates of parameters such as beam current and cathode lifetime, and comparisons with X-band and C-band parameters are presented. The electron beam can be extracted at various energies up to 9.5 MeV. Estimated yields of gammas produced at 6.5 MeV operation and estimated yields of gammas and neutrons produced at 9.5 MeV are presented.

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THPMW021

Performance of a Compensation Kicker Magnet for J-PARC Main Ring

timing, kicker, pick-up, proton

3588

T. Sugimoto, K. Ishii, H. Matsumoto, T. Shibata
KEK, Ibaraki, Japan
K. Fan
HUST, Wuhan, People's Republic of China

Four lumped-type kicker magnets have been equipped in the J-PARC MR (Main Ring) to inject 8 proton bunches. To increase beam power, the bunch length will be increased up to 350 ns that will restricts the rise time of the injection kicker to be less than 250 ns. We have already developed a method to improve the rising time to 200 ns*. However, two reflection pulses are appeared at the waveform tail, which will kick the circulating bunches and induce coherent oscillation leading to beam loss. To compensate reflection pulses, we decide to install two new lumped-type kicker magnets, which are excited independently making operation flexible. A ceramic vacuum duct with TiN coating is inserted in the compensation kickers. Magnetic field measurement and coupling impedance measurement have been carried. In this paper, the results of both these measurements and performance study using proton beam will be discussed.
* T.Sugimot et.al, "Upgrade of the Injection Kicker System for J-PARC Main Ring", MOPME069, IPAC14, Dresden, Germany, 2014.

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THPMW028

High Voltage Performance of Surface Coatings on Alumina Insulators

kicker, high-voltage, vacuum, impedance

3603

A. Adraktas, M.J. Barnes, H.A. Day, L. Ducimetière
CERN, Geneva, Switzerland

Alumina insulators and dielectrics are required for a variety of applications in particle accelerators. Their use in high voltage devices, both pulsed and DC, is well established as both insulation and mechanical support. In accelerator equipment the alumina is usually used in ultra-high vacuum and hence charge accumulation can be an issue, especially when the alumina is near to the beam. To address challenges regarding surface flashover and high secondary electron yield in high intensity accelerators, surface treatments and coatings are being considered. This paper presents predictions of the influence of surface coatings, on alumina insulators, upon electric field.

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reference for this paper ※ DOI:10.18429/JACoW-IPAC2016-THPMW028

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THPMW029

Feasibility Study of the Fast SPS Ion Injection Kicker System

simulation, ion, kicker, flattop

3607

A. Ferrero Colomo, P. Burkel, D. Comte, L. Ducimetière, T. Kramer, V. Senaj, L. Sermeus, F.M. Velotti
CERN, Geneva, Switzerland

As part of the upgrade project for ions the rise time of the injection kicker system into the SPS needs to be improved. The changes being studied include the addition of a fast Pulse Forming Line parallel to the existing Pulse Forming Network for the fast kicker magnets MKP-S. With the PFL an improved magnetic field rise time of 100 ns is targeted. Two different configuration utilizing a 2nd thyratron or two fast diode stacks have been outlined in the past. This paper presents the recent progress on the analogue circuit simulations for both options as well as measurements carried out on a test system. Modelling, optimization and simulation of the entire system with diodes and a second configuration with two thyratron switches are outlined. Measurement results are given and the feasibility of the upgrade is discussed.

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THPMW031

Current and Future Beam Thermal Behaviour of the LHC Injection Kicker Magnet

impedance, kicker, simulation, coupling

3615

H.A. Day, M.J. Barnes, L. Ducimetière, L. Vega Cid, W.J.M. Weterings
CERN, Geneva, Switzerland

During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. Significant upgrades were carried out to the injection kicker magnets during long shutdown 1, including a new design of beam screen to reduce the beam induced heating. Nevertheless these kicker magnets may limit the performance of HL-LHC unless additional, mitigating, measures are taken. Hence extensive simulations have been carried out to predict the distribution of the beam induced power deposition within the magnet and detailed thermal analyses carried out to predict the temperature profiles. To benchmark the simulations the predicted temperatures are compared with observables in the LHC. This paper reports on observations of the thermal behaviour of the magnet during run 2 of the LHC, with 25ns beam. In addition the measurement data is used to extrapolate temperature rise for the beam parameters expected for high-luminosity LHC.

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THPMW033

Operational Experience of the Upgraded LHC Injection Kicker Magnets

kicker, vacuum, operation, impedance

3623

M.J. Barnes, A. Adraktas, G. Bregliozzi, S. Calatroni, H.A. Day, L. Ducimetière, B. Goddard, V. Gomes Namora, V. Mertens, B. Salvant, J.A. Uythoven, L. Vega Cid, W.J.M. Weterings, C. Yin Vallgren
CERN, Geneva, Switzerland

During Run 1 of the LHC the injection kicker magnets caused occasional operational delays due to beam induced heating with high bunch intensity and short bunch lengths. In addition, sometimes there were also sporadic issues with microscopic unidentified falling objects, vacuum activity and electrical flashover of the injection kickers. An extensive program of studies was launched and significant upgrades were carried out during long shutdown 1. These upgrades include a new design of a beam screen to both reduce the beam coupling impedance of the kicker magnet, and to significantly reduce the electric field associated with the screen conductors, hence decreasing the probability of electrical breakdown in this region. In addition new cleaning procedures were implemented and equipment adjacent to the injection kickers and various vacuum components were modified. This paper presents operational experience of the injection kicker magnets during Run 2 of the LHC and assesses the effectiveness of the various upgrades.

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THPMW038

Prototyping of the ALS-U Fast Kickers

kicker, impedance, coupling, vacuum

3637

G.C. Pappas, S. De Santis, J.-Y. Jung, T.H. Luo, C. Steier, C.A. Swenson, W.L. Waldron
LBNL, Berkeley, California, USA

Prototyping of major components for the ALS-U kickers is in progress. A tapered stripline kicker has been built for installation and testing in the ALS, and multiple modulator options to meet the fast rise time required for swap out injection have been considered. High voltage feedthroughs that are matched into the multi GHz range are also being studied.
* Pappas et al., "Fast Kicker Systems for ALS-U", Proc. of IPAC'14, Dresden, Germany, MOPME083.

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THPMW042

Overview of Driver Technologies for Nanosecond TEM Kickers

impedance, operation, controls, kicker

3645

A.K. Krasnykh
SLAC, Menlo Park, California, USA

Funding: Work supported in part by US Department of Energy under contract DE-AC02-76SF00515 and in part by US Department of Energy under contract DE-AC02-06CH11357
Overview of modern methods, circuits, and practical realizations for multi MW peak power pulsers will be presented. All used pulser components are manufactured by the US national industry and they are available for design and pulser fabrication. Two concepts will be discussed: (1) an approach is based on assistance of a nonlinear transmission line with ferromagnetic media and (2) an approach is based on assistance of special diodes which are working in a specific mode of operation. In both approaches the nonlinear characteristic of switching media (ferromagnetic and solid state plasma) are employed in final stage of the pulser to form the multi MW level nanosecond pulses.

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THPMY019

LHC Injection Protection Devices, Thermo-mechanical Studies through the Design Phase

operation, kicker, proton, impedance

3698

I. Lamas Garcia, N. Biancacci, G. Bregliozzi, M. Calviani, M.I. Frankl, L. Gentini, S.S. Gilardoni, A. Lechner, A. Perillo-Marcone, B. Salvant, N.V. Shetty, J.A. Uythoven
CERN, Geneva, Switzerland

The TDI is a beam intercepting device installed on the two injection lines of the LHC. Its function is to protect the superconducting machine elements during injection in the case of a malfunction of the injection kickers. The TDIS, which will replace the TDI, is foreseen to be installed for high luminosity operation. Due to the higher bunch intensities and smaller beam emittances expected, and following the operational experiences of the TDI, a complete revision of the design of the jaws must be performed, with a main focus on the material selection. Furthermore, the new TDIS will also improve the TDI reliability by means of a robust design of the jaw positioning mechanism, the efficiency of the cooling circuit and by reducing its impedance. A simplified installation procedure and maintenance will also be an important requirement for the new design. This paper introduces the main characteristics of the TDI as LHC injection protection device, showing the needs and requirements for its upgrade. It also discusses the thermo-mechanical simulations that are supporting and guiding the design phase and the material selection, and describes the modifications to be implemented, so far, for this new device.

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THPOR018

Comissioning of Upgraded VEPP-2000 Injection Chain

positron, electron, booster, linac

3811

D.E. Berkaev, A.V. Andrianov, K.V. Astrelina, V.V. Balakin, A.M. Barnyakov, O.V. Belikov, M.F. Blinov, D.V. Bochek, D. Bolkhovityanov, F.A. Emanov, A.R. Frolov, K. Gorchakov, Ye.A. Gusev, A.S. Kasaev, E. Kenzhbulatov, I. Koop, I.E. Korenev, G.Y. Kurkin, N.N. Lebedev, A.E. Levichev, P.V. Logatchov, A.P. Lysenko, D.A. Nikiforov, V.P. Prosvetov, Yu. A. Rogovsky, S.L. Samoylov, A.I. Senchenko, P.Yu. Shatunov, Y.M. Shatunov, D.B. Shwartz, A.A. Starostenko, I.M. Zemlyansky, Yu.M. Zharinov
BINP SB RAS, Novosibirsk, Russia
F.A. Emanov, Yu. A. Rogovsky, A.I. Senchenko, A.A. Starostenko
NSU, Novosibirsk, Russia

The upgrade of VEPP-2000 e⁺e⁻ collider injection chain includes the connection to BINP Injection Complex (IC) via newly constructed transfer line K-500 as well as upgrade of the booster synchrotron BEP to the energy of 1 GeV. Modernization has started in the middle of 2013 and now the electron and positron beams with highly increased production rate together with top-up injection from BEP are ready to feed VEPP-2000 ring and provide design luminosity at the whole energy range limited only by beam-beam effects. The design and operation experience of IC damping ring, 250 m transfer channel and booster BEP dealing with 2.6 T magnets at top energy will be presented.

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THPOR020

Status of VEPP-4M Collider

photon, experiment, storage-ring, detector

3818

E.B. Levichev, O.I. Meshkov, P.A. Piminov, A.N. Zhuravlev
BINP SB RAS, Novosibirsk, Russia

At present the VEPP-4 storage ring facility provides varied experimental programs including HEP, nuclear physics, synchrotron radiation, polarized electron/positron beam research, etc. Until now, the studies were mainly performed at the beam energy below 2 GeV but a strong interest of experimentalists encourages us to increase the beam energy up to 5 GeV. Reliable and high-performance operation at high energy is a challenge for the machine. Here we discuss the recent experimental results at the low energy, and prospects and constraints of the energy ramp.

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THPOR048

Beam Losses at CERNs PS and SPS Measured with Diamond Particle Detectors

extraction, detector, septum, kicker

3898

F. Burkart, W. Bartmann, B. Dehning, E. Effinger, M.A. Fraser, B. Goddard, V. Kain, O. Stein
CERN, Geneva, Switzerland
E. Griesmayer
CIVIDEC Instrumentation, Wien, Austria
O. Stein
University of Hamburg, Institut für Experimentalphysik, Hamburg, Germany

Diamond particle detectors have been used in the LHC to measure fast particle losses with a nanosecond time resolution. In addition, these detectors were installed in the PS and the SPS. The detectors are mounted close to the extraction septum of the PS (transfer line to SPS) and the SPS (transfer lines TI2 and TI8 to LHC). Mainly, they monitor the losses occurring during the extraction process but the detectors are also able to measure turn-by-turn losses in the accelerators. In addition, detailed studies concerning losses due to ghost bunches were performed. This paper will describe the installed diamond detector setup, discuss the measurement results and possible loss mitigations.

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THPOR049

Considerations for the Injection and Extraction Kicker Systems of a 100 TeV Centre-of-Mass FCC-hh Collider

kicker, extraction, impedance, collider

3901

T. Kramer, M.J. Barnes, W. Bartmann, F. Burkart, L. Ducimetière, B. Goddard, V. Senaj, T. Stadlbauer, D.G. Woog
CERN, Geneva, Switzerland
D. Barna
Wigner Research Centre for Physics, Institute for Particle and Nuclear Physics, Budapest, Hungary

A 100 TeV center-of-mass energy frontier proton collider in a new tunnel of ~100 km circumference is a central part of CERN's Future Circular Colliders (FCC) design study. One of the major challenges for such a machine will be the beam injection and extraction. This paper outlines the recent developments on the injection and extraction kicker system concepts. For injection the system requirements and progress on a new inductive adder design will be presented together with first considerations on the injection kicker magnets. The extraction kicker system comprises the extraction kickers itself as well as the beam dilution kickers, both of which will be part of the FCC beam dump system and will have to reliably abort proton beams with stored energies in the range of 8 Gigajoule. First concepts for the beam dump kicker magnet and generator as well as for the dilution kicker system are described and its feasibility for an abort gap in the 1 μs range is discussed. The potential implications on the overall machine and other key subsystems are outlined, including requirements on (and from) dilution patterns, interlocking, beam intercepting devices and insertion design.

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THPOR050

New Working Point for CERN Proton Synchrotron

multipole, resonance, proton, focusing

3905

F. Sperati, A. Beaumont, S.S. Gilardoni, D. Schoerling, M. Serluca, G. Sterbini
CERN, Geneva, Switzerland

The LHC High-luminosity project requests high brightness and intensity beams from the CERN Proton Synchrotron (PS). The generation of such beams is limited due to resonance effects at injection. The impact of resonances can be minimized by performing appropriate correction with dedicated magnets and by optimizing the tune working point. Currently the tune working point at injection is naturally set by the quadrupolar component generated by the one hundred combined function normal conducting magnets installed in the PS, and slightly corrected by low energy quadrupole magnets. In this paper, a study is presented exploiting the use of the available five auxiliary individually powered circuits to adjust the quadrupolar and higher-order multipole components for changing the tune integer at injection. Due to the non-linear contribution of each circuit to the magnetic field distribution a finite-element magnetic model was prepared to predict the required currents in the auxiliary coils. The magnetic model was benchmarked with magnetic measurements and then tested in the PS machine during dedicated machine development times.

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THPOR054

Analysis of the SPS Long Term Orbit Drifts

extraction, closed-orbit, operation, dipole

3914

F.M. Velotti, C. Bracco, K. Cornelis, L.N. Drøsdal, M.A. Fraser, B. Goddard, V. Kain, M. Meddahi
CERN, Geneva, Switzerland
E. Gianfelice-Wendt
Fermilab, Batavia, Illinois, USA

The Super Proton Synchrotron (SPS) is the last accelerator in the Large Hadron Collider (LHC) injector chain, and has to deliver the two high-intensity 450 GeV proton beams to the LHC. The transport from SPS to LHC is done through the two Transfer Lines (TL), TI2 and TI8, for Beam 1 (B1) and Beam 2 (B2) respectively. During the first LHC operation period Run 1, a long term drift of the SPS orbit was observed, causing changes in the LHC injection due to the resulting changes in the TL trajectories. This translated into longer LHC turnaround because of the necessity to periodically correct the TL trajectories in order to preserve the beam quality at injection into the LHC. Different sources for the SPS orbit drifts have been investigated: each of them can account only partially for the total orbit drift observed. In this paper, the possible sources of such drift are described, together with the simulated and measured effect they cause. Possible solutions and countermeasures are also discussed.

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THPOW029

Single Electron Extraction at the ELSA Detector Test Beamline

electron, extraction, synchrotron, detector

4002

F. Frommberger, N. Heurich, W. Hillert, T. Schiffer, M.T. Switka
ELSA, Bonn, Germany

The Electron pulse Stretcher Facility ELSA delivers polarized and non-polarized electrons with an adjustable beam energy of 0.5 - 3.2 GeV to external experimental stations. Extraction currents available range down from 1 nanoampere to several atto-amperes provided by single electron extraction. Especially the high energy physics community requires detector test stations with electron tagging rates between 100 Hz to 100 kHz, imposing particular requirements for stable minimum-current extraction from the storage ring. These requirements are met with the implementation of a low-injection mode for the booster synchrotron and photomultiplier-based stored current monitoring, providing feedback for a selectable limit of the injected current. A homogeneous extraction current with duty factor > 80% is routinely granted by the excitation of a 3rd integer optical resonance. The setup of the low-current injection system and measurements of the extraction properties at the preliminary detector test beamline are presented.

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THPOW032

Experimental Test on the TPS Booster Injection Scheme Exploration and the Associated Bunch Train Analysis

booster, kicker, septum, operation

4008

H.-P. Chang, C.L. Chen, C.-S. Fann, K.T. Hsu, S.Y. Hsu, K.-K. Lin, K.L. Tsai
NSRRC, Hsinchu, Taiwan

In order to explore the tuning range of injection septum and kicker for TPS booster operation, an experimental test on the designed injection scheme has been performed. Tuning of these injection units is based on the top-up operation process for storage ring vacuum cleaning purpose. It is set for a fast beam accumulation in the storage ring where the stored beam variation range is selected for efficient operation consideration. The measurement results of booster beam current variation while tuning of injection septum and kicker are presented. A preliminary analysis concerning the observation of deteriorated phase space acceptance in the TPS booster is given in this report. This study also includes an effort to extend the present available operation bunch train for TPS booster. It shows that the increase of the booster beam current by bunch train tuning indicates an upper bound of about 400 ns.

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THPOW033

Transient Orbit of Injection in Taiwan Light Source Storage Ring

kicker, storage-ring, factory, network

4012

H.C. Chen, H.H. Chen, K.T. Hsu, C.H. Huang, S.J. Huang, C.H. Kuo, A.P. Lee, J.A. Li, Y.K. Lin
NSRRC, Hsinchu, Taiwan

Top-up operation has been started since many years ago at Taiwan Light Source Storage Ring (SR). For this operation it is important to reduce the beam injections should not excite the oscillation of stored beams. For further reduction of these oscillations, corrections with kicker-magnets are used. The details of the study will be reported in this paper.

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THPOW034

TLS Booster Injection Scheme Exploration

booster, septum, kicker, electron

4016

H.H. Chen, H.-P. Chang, H.C. Chen, S.J. Huang, C.H. Kuo, A.P. Lee, J.A. Li, K.-K. Lin, Y.K. Lin
NSRRC, Hsinchu, Taiwan

In this paper, the booster injection efficiency and the parameter working range related to key components in-cluding septum magnet and kicker magnet for Taiwan Light Source (TLS) injector operation are introduced. Booster injection scheme for different lattice is explored by machine study plan using injector property. The study result may be used by the operator as booster injection parameter fine tuning reference. It is also helpful for the advanced injection scheme exploration.

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THPOW036

Evaluation of Immutability against Radiation-induced Demagnetization for a Hybrid Wiggler with NdFeB Magnets at the Canadian Light Source

radiation, wiggler, electron, operation

4022

C.K. Baribeau, D. Bertwistle, L.O. Dallin, J.M. Vogt, W.A. Wurtz
CLS, Saskatoon, Saskatchewan, Canada

The BioXAS beamline at Canadian Light Source installed a hybrid wiggler in 2013. Quantitative studies building on the experience of other facilities suggest the wiggler's NdFeB magnets are at risk of demagnetization due to radiation induced by the synchrotron's 2.9 GeV electrons. We use a phenomenological model to convert simulated peak demagnetizing fields into a radiation dose corresponding to a chosen %-demagnetization, and compare against an estimated dose per year due to injected beam. We find that injecting with the wiggler closed will cause 1% demagnetization in sections of its magnet blocks within 2 years of operation, assuming a worst case scenario. The wiggler has thus far been forced open for injections, but this will cease to be an option when CLS moves to top-up operation. In a related test, qualitative measurements of radiation during injections with the wiggler closed were taken by covering its magnets in Polaroid film. We find that radiation drops significantly when the injection efficiency is well-tuned. Our results suggest the wiggler will not receive damaging levels of radiation at closed gap so long as the injection system remains optimized.

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THPOW050

Upgrade of Septum Magnets of the Transfer Line in TPS

septum, power-supply, simulation, booster

4057

C.S. Yang, C.-H. Chang, Y.L. Chu, J.C. Huang, C.-S. Hwang, J.C. Jan, F.-Y. Lin
NSRRC, Hsinchu, Taiwan

Taiwan Photon Source (TPS) is a 3-GeV light source. The full current of the storage beam and commissioning of insertion devices are still in progress. An improved injection between the booster ring (BR) and the storage ring (SR) was implemented to increase the efficiency of injection and the reliability of the electrical parts. A DC septum (length 0.8 m) was replaced with an AC septum (length 1 m, type C) to decrease the leakage field and to relax the loading of the power supply. Mapping the field with mu-metal shielding was also implemented to diminish the leakage field from the AC septum. The lattice of the transfer line between the booster ring and the storage ring, BTS, was also rearranged to meet the new injection requirements. The performance of the AC septum with mu-metal shielding and the upgrade of the BTS lattice are discussed in this paper.

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THPOY001

Implementation of a New Ramp Computation Scheme for the Magnet Power Supplies at ELSA

controls, power-supply, electron, extraction

4085

D. Proft, W. Hillert
ELSA, Bonn, Germany

At the ELSA electron stretcher facility new power supply control units have been commissioned. These require a new software interface for set-point calculation based on the accelerator and timing model. Goal of the new scheme is a strict separation of the bidirectional ramp computation into an accelerator model dependent, a magnet dependent and a power supply dependent part. This introduces possible calibration/correction factors on each layer, thus allowing easy component replacement of the power supplies, the control units or even the magnets without the need for recalibration of the whole chain. In this contribution we will provide insights into the implementation of the new modeling scheme.

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THPOY019

Design and Implementation of Control Interface and Timing Support of TPS Phase-I Beamlines

EPICS, controls, timing, status

4128

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

Taiwan Photon Source (TPS) with low emittance provides extremely bright X-rays. Seven advanced phase-I beamlines of TPS are being constructed and commissioned. The control interfaces for a beamline or experimental station and support from the accelerator control system are designed and are being implemented. The beamline control interface and supports include a beamline interlock status monitor, accelerator timing transmission, broadcast of accelerator operating status, transmission of the beam-current reading and control of insertion devices. This report summarizes the efforts in implementing the beamline EPICS IOC and support from the accelerator control system during beamline commissioning in TPS phase-I.

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THPOY027

Commissioning Status of SuperKEKB Injector Linac

electron, gun, emittance, linac

4152

M. Satoh, M. Akemoto, D.A. Arakawa, Y. Arakida, A. Enomoto, Y. Enomoto, S. Fukuda, Y. Funakoshi, K. Furukawa, T. Higo, H. Honma, N. Iida, M. Ikeda, H. Iwase, H. Kaji, K. Kakihara, T. Kamitani, H. Katagiri, S. Kazama, M. Kikuchi, H. Koiso, S. Matsumoto, T. Matsumoto, H. Matsushita, S. Michizono, K. Mikawa, T. Mimashi, T. Miura, F. Miyahara, T. Mori, A. Morita, H. Nakajima, K. Nakao, T. Natsui, Y. Ogawa, Y. Ohnishi, S. Ohsawa, F. Qiu, I. Satake, D. Satoh, Y. Seimiya, T. Shidara, A. Shirakawa, M. Suetake, H. Sugimoto, T. Suwada, M. Tanaka, M. Tawada, Y. Yano, K. Yokoyama, M. Yoshida, R. Zhang, X. Zhou
KEK, Ibaraki, Japan

The SuperKEKB main ring is currently being constructed for aiming at the peak luminosity of 8 x 10³⁵ cm^-2s⁻¹. The electron/positron injector linac upgrade is also going on for increasing the intensity of bunch charge with keeping the small emittance. The key upgrade issues are the construction of positron damping ring, a new positron capture system, and a low emittance photo-cathode rf electron source. The injector linac beam commissioning started in the October of 2013. In this paper, we report the present status and future plan of SuperKEKB injector commissioning.

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THPOY045

Commissioning of the Machine Protection Systems of the Large Hadron Collider Following its First Long Shutdown

operation, dipole, hadron, beam-losses

4203

D. Wollmann, R. Schmidt, J.A. Uythoven, J. Wenninger, M. Zerlauth
CERN, Geneva, Switzerland

During the first long shutdown of the Large Hadron Collider (LHC) extending for more than 18 months, most Machine Protection Systems (MPS) have undergone significant changes, and upgrades. A full re-commissioning of the MPS was performed at the end of the shutdown and during the LHC beam commissioning in 2015. To verify the correct functioning of all protection-relevant systems with beam, a step-wise intensity ramp-up was performed, reaching at the end of 2015 a record stored beam energy of ~280 MJ per beam, nearly 80% of the value in the design report. This contribution summarizes the results of the MPS commissioning, the intensity ramp-up and the continuous follow-up during operation, focusing mainly on near misses and false triggers and their proposed mitigations. A strategy to minimize risks during machine development periods for future operation of the LHC, when the protection parameters are modified for several tests, is discussed. The machine protection strategy for the LHC run in 2016 is presented.

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