NAPAC2016 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
MOPOB12	A High Bandwidth Bipolar Power Supply for the Fast Correctors in the APS Upgrade	ion, power-supply, ISOL, interface	96
	J. Wang, G.S. Sprau ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB12
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MOPOB17	Resonant Frequency Control for the PIP-II Injector Test RFQ: Control Framework and Initial Results	ion, rfq, framework, operation	109
	A.L. Edelen, S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA D.L. Bowring, B.E. Chase, J.P. Edelen, D.J. Nicklaus, J. Steimel Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359. For the PIP-II Injector Test (PI-Test) at Fermilab, a four-vane radio frequency quadrupole (RFQ) is designed to accelerate a 30-keV, 1-mA to 10-mA H' beam to 2.1 MeV under both pulsed and continuous wave (CW) RF operation. The available headroom of the RF amplifiers limit the maximum allowable detuning to 3 kHz, and the detuning is controlled entirely via thermal regulation. Fine control over the detuning, minimal manual intervention, and fast trip recovery is desired. In addition, having active control over both the walls and vanes provides a wider tuning range. For this, we intend to use model predictive control (MPC). To facilitate these objectives, we developed a dedicated control framework that handles higher-level system decisions as well as executes control calculations. It is written in Python in a modular fashion for easy adjustments, readability, and portability. Here we describe the framework and present the first control results for the PI-Test RFQ under pulsed and CW operation.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB17
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MOPOB27	Superconducting Coil Winding Machine Control System	ion, FPGA, operation, software	127
	J.M. Nogiec, S. Kotelnikov, A. Makulski, K. Trombly-Freytag, D.G.C. Walbridge Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy under contract no. DE-AC02-07CH11359. The Spirex magnet coil winder has been equipped with an automation system, which allows operation from both a computer and a remote control unit. This machine is about 6m long with a bridge that moves along a track and supports a rotating boom holding a spool of cable and providing cable tension. The machine control system is distributed between three layers: PC, RTOS, and FPGA providing respectively HMI, operational logic and controls. The PC stores the history of operation, shows the machine positions, status, and their history. Keeping cable tension constant is non-trivial in situations where the length of the cable changes with varying speeds. This has been addressed by a PID controller with feed forward augmentation and low-pass filters. Another challenging problem, synchronizing multiple servo motors, has been solved by designing an innovative decentralized algorithm. Extra attention was given to the safety aspects; a fail-safe, redundant safety system with interlocks has been developed, including protection for the operator and the superconducting cable against such situations as accidental over tension, or fast movement of the cable due to operational errors.
	Poster MOPOB27 [1.952 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB27
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MOPOB30	Development and Comparison of Mechanical Structures for FNAL 15 T Nb3Sn Dipole Demonstrator	ion, dipole, operation, collider	137
	A.V. Zlobin, I. Novitski Fermilab, Batavia, Illinois, USA
	Funding: *Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy Main design challenges for 15 T accelerator magnets are large Lorentz forces at this field level. The large Lorentz forces generate high stresses in the coil and mechanical structure and, thus, need stress control to maintain them at the acceptable level for brittle Nb3Sn coils and other elements of magnet mechanical structure. To provide these conditions and achieve the design field in the FNAL 15 T dipole demonstrator, several mechanical structures have been developed and analysed. The possibilities and limitations of these designs are discussed in this paper.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB30
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MOPOB68	A New Method for Grain Texture Manipulation in Post-Deposition Niobium Films	ion, laser, niobium, electron	221
	J. Musson, K. Macha, H.L. Phillips JLab, Newport News, Virginia, USA W. Cao, H. Elsayed-Ali ODU, Norfolk, Virginia, USA
	Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Old Dominion University Niobium films are frequently grown using forms of energetic condensation, with modest substrate temperatures to control grain structure. As an alternative, energetic deposition onto a cold substrate results in a dense amorphous film, with a much larger energy density than the re-crystallized state. Re-crystallization is then performed using a pulsed UV (HIPPO) laser, with minimal damage to the substrate. In addition, a graded interface between the substrate and Nb film is created during the early stages of energetic deposition. Experimental approach and apparatus are described.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB68
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MOPOB72	Update on CW 8 kW 1.5 GHz Klystron Replacement	ion, klystron, operation, ISOL	232
	A.V. Smirnov, S. Boucher RadiaBeam Systems, Santa Monica, California, USA R.B. Agustsson, D.I. Gavryushkin, J.J. Hartzell, K.J. Hoyt, A.Y. Murokh, T.J. Villabona RadiaBeam, Santa Monica, California, USA G.R. Branner, K.S. Yuk UC Davis, Davis, USA V. Khodos Sierra Nevada Corporation, Irvine, USA
	Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC0013136). JLAB upgrade program requires a ~8 kW, 1497 MHz amplifier operating at more than 55-60% efficiency, and 8 kW CW power to replace up to 340 klystrons. One of possibilities for the klystron replacement is usage of high electron mobility packaged GaN transistors applied in array of highly efficient amplifiers using precise in-phase, low-loss combiners-dividers. Design features and challenges related to amplifier modules and radial multi-way dividers/combiners are discussed including HFSS simulations and measurements.
	Poster MOPOB72 [1.199 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-MOPOB72
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TUA2CO03	A Novel Technique of Power Control in Magnetron Transmitters for Intense Accelerators	ion, cavity, operation, power-supply	271
	G.M. Kazakevich, R.P. Johnson, M.L. Neubauer Muons, Inc, Illinois, USA V.A. Lebedev, W. Schappert, V.P. Yakovlev Fermilab, Batavia, Illinois, USA
	A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The concept uses magnetrons driven by a sufficient resonant (injection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wideband phase and mid-frequency power controls is presented and discussed.
	Slides TUA2CO03 [0.714 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUA2CO03
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TUB2IO02	Advanced Concepts for Seeded FELs	ion, FEL, electron, laser	284
	E. Ferrari, E. Allaria Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy
	The use of an external laser to seed an electron beam at the beginning of the Free Electron Laser process has been proposed as a way to improve temporal coherence of modern short wavelength FELs. More recent studies and experiments have shown that electron beam manipulation through interaction with a seed laser can be exploited for tailoring FEL properties to specific users requests. Recently, experiment for phase control, multi-color emission and coherent control have been reported.
	Slides TUB2IO02 [15.975 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUB2IO02
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TUPOA07	IoT Application in the Control System of the BEPCII Power Supplies	ion, power-supply, status, operation	302
	C.H. Wang, L.F. Li, X.L. Wang IHEP, Beijing, People's Republic of China C.P. Chu MSU, East Lansing, Michigan, USA
	Funding: This prject is support by NSFC(1137522) In recent years in the development of Internet technology, the Internet of things (IoT) has begun to apply to each domain. The paper introduces the idea how to apply IoT to the accelerator control system and take the existing control system of the BEPCII power supplies as an example for IoT application. It not only introduce the status of the control system of the BEPCII power supplies, but also present a solution how to apply IoT to the existing control system. The purpose is to make the control system more intelligent and automatically identify what and where problem when the alarm of the control system of the power supplies. That means that IoT can help to automatically identify which crate and which PSC board inserted in the crates and which PSI sittiing in the power supply crates as well as the optic fiber cables between the PSCs and the PSIs. It is great convenient for the maintainer to use a mobile phone to diagnose faults and create the electronic maintenance record.
	Poster TUPOA07 [0.762 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA07
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TUPOA12	An Updated LLRF Control System for the TLS Linac	ion, linac, EPICS, LLRF	308
	C.Y. Wu, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, D. Lee, C.Y. Liao NSRRC, Hsinchu, Taiwan
	The amplitude and phase of the RF field at the linear accelerator (LINAC) decides the beam quality. To study and to improve the performance of the LINAC system for Taiwan Light Source (TLS), a new design of a low-level radio-frequency (LLRF) control system was developed and set up for the TLS LINAC. The main components of the LLRF control system are an I/Q modulator, an Ethernet-based arbitrary waveform generator, a digital oscilloscope and an I/Q demodulator; these are essential parts of the LLRF feed-forward control. This paper presents the efforts to improve the LLRF control system. The feasibility of the RF feed-forward control will be studied at the linear accelerator of TLS.
	Poster TUPOA12 [1.425 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA12
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TUPOA14	An Internet Rack Monitor-Controller for APS LINAC RF Electronics Upgrade	ion, linac, network, klystron	314
	H. Ma, A. Nassiri, T.L. Smith, Y. Sun ANL, Argonne, Illinois, USA L.R. Doolittle, A. Ratti LBNL, Berkeley, California, USA
	Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences To support the current research and development in APS LINAC area, the existing LINAC rf control performance needs to be much improved, and thus an upgrade of the legacy LINAC rf electronics becomes necessary. The proposed upgrade plan centers on the concept of using a modern, network-attached, rack-mount digital electronics platform 'Internet Rack Monitor-Controller (or IRMC) to replace the existing analog ones on the legacy crate/backplane-based hardware. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance processor in the mid- layer to handle the general digital signal processing (DSP). The custom FPGA IP's in the bottom layer handle the high-speed, real-time, low-latency DSP tasks, and provide the interface ports. A network communication gateway, in conjunction with an embedded event receiver (EVR), in the top layer merges the Internet Rack Monitor-Controller device into the networks of the accelerator controls infrastructure. Although the concept is very much in trend with today's Internet-of-Things (IoT), this implementation has actually been used in accelerators for over two decades.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA14
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TUPOA16	A VME and FPGA Based Data Acquisition System for Intensity Monitors	ion, software, data-acquisition, instrumentation	317
	J.S. Diamond, A. Ibrahim, N. Liu, E.S.M. McCrory, A. Semenov Fermilab, Batavia, Illinois, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy A universal data acquisition system supporting toroids, DCCTs, Faraday cups, srapers and other types of instru-mentation has been developed for reporting beam inten-sity measurements to the Fermilab Accelerator Controls System (ACNet). Instances of this front end, supporting dozens of intensity monitor devices have been deployed throughout the Fermilab accelerator complex in the Main Injector, Recycler, Fermilab Accelerator Science and Technology (FAST) facility and the PIP-II Injector Exper-iment (PXIE). Each front end consists of a VME chassis containing a single board computer (SBC), timing and clock module and one or more 8 to 12-channel digitizer modules. The digitizer modules are based on a Cyclone III FPGA with firmware developed in-house allowing a wide range of flexibility and digital signal processing capability. The front end data acquisition software adds a list of new features to the previous generation allowing users to: take beam intensity measurements at custom points in the acceleration cycle, access waveform data, control machine protection system (MPS) parameters and calculate beam energy loss.
	Poster TUPOA16 [1.532 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA16
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TUPOA18	Low Level RF Control for the PIP-II Injector Test RFQ	ion, rfq, LLRF, cavity	323
	J.P. Edelen, B.E. Chase, E. Cullerton, J. Einstein, P. Varghese Fermilab, Batavia, Illinois, USA
	The PIP-II injector test radio frequency quadrupole (RFQ) arrived at Fermilab in the fall of 2015. The RFQ is a 162.5MHz H⁻ accelerator with a nominal drive power of 100kW, which produces a bunched H⁻ beam at 2.1MeV. In this paper we discuss commissioning, operational performance, and improvements to the low level RF (LLRF) control system for the RFQ. We begin by describing the general system configuration and initial simulation results. We will then highlight temperature related issues in the high power RF system, which necessitate active control over the phase balance of the two amplifiers. Finally we demonstrate performance of the RF feedback and feed-forward compensation needed to meet specification during a 20-microsecond beam pulse.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA18
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TUPOA30	Fermilab Switchyard Resonant Beam Position Monitor Electronics Upgrade Results	ion, electron, electronics, power-supply	352
	T.B. Petersen, J.S. Diamond, N. Liu, P.S. Prieto, D. Slimmer, A.C. Watts Fermilab, Batavia, Illinois, USA
	The readout electronics for the resonant beam position monitors (BPMs) in the Fermilab Switchyard (SY) have been upgraded, utilizing a low noise amplifier transition board and Fermilab designed digitizer boards. The stripline BPMs are estimated to have an average signal output of between -110 dBm and -80 dBm, with an esti-mated peak output of -70 dBm. The external resonant circuit is tuned to the SY machine frequency of 53.10348 MHz. Both the digitizer and transition boards have vari-able gain in order to accommodate the large dynamic range and irregularity of the resonant extraction spill. These BPMs will aid in auto-tuning of the SY beamline as well as enabling operators to monitor beam position through the spill.
	Poster TUPOA30 [0.833 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA30
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TUPOA31	Fermilab Cryomodule Test Stand RF Interlock System	ion, monitoring, interlocks, cavity	355
	T.B. Petersen, J.S. Diamond, D. McDowell, D.J. Nicklaus, P.S. Prieto, A. Semenov Fermilab, Batavia, Illinois, USA
	An interlock system has been designed for the Fermilab Cryomodule Test Stand (CMTS), a test bed for the cryomodules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, consisting of a superconducting RF cavity, a coupler, and solid state amplifier (SSA). Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of a fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off SSA. Additionally, each input signal is available for remote viewing and recording via a Fermilab designed digitizer board.
	Poster TUPOA31 [0.762 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA31
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TUPOA41	FPGA Control of Coherent Pulse Stacking	ion, cavity, FPGA, feedback	367
	Y.L. Xu, J.M. Byrd, L.R. Doolittle, Q. Du, G. Huang, W. Leemans, R.B. Wilcox, Y. Yang LBNL, Berkeley, California, USA J. Dawson LLNL, Livermore, California, USA A. Galvanauskas, J.M. Ruppe University of Michigan, Ann Arbor, Michigan, USA
	Coherent pulse stacking (CPS) is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy from fiber lasers. Due to advantages of precise timing and fast processing, we use an FPGA to process digital signals and do feedback control so as to realize stacking-cavity stabilization. We develop a hardware and firmware design platform to support the coherent pulse stacking application. A firmware bias control module stabilizes the amplitude modulator at the minimum of its transfer function. A cavity control module ensures that each optical cavity is kept at a certain individually-prescribed and stable round-trip phase with 2.5 deg rms phase error.
	Poster TUPOA41 [5.546 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA41
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TUPOA42	Multicavity Coherent Pulse Stacking Using Herriott Cells	cavity, ion, laser, experiment	370
	Y. Yang, J.M. Byrd, L.R. Doolittle, G. Huang, W. Leemans, Q. Qiang, R.B. Wilcox LBNL, Berkeley, California, USA J. Dawson LLNL, Livermore, California, USA A. Galvanauskas, J.M. Ruppe University of Michigan, Ann Arbor, Michigan, USA Y.L. Xu TUB, Beijing, People's Republic of China
	Coherent Pulse Stacking provides a promising way to generate a single high-intensity laser pulse by stacking a sequence of phase and amplitude modulated laser pulses using multiple optical cavities. Optical misalignment and phase stability are two critical issues that need to be addressed. Herriott cells are implemented for their relaxed alignment tolerance and a phase stabilization method based on cavity output pattern matching has been developed. A single pulse with intensity enhancement factor over 7.4 has been generated by stacking 13 modulated pules through a four-cavity stacking system. This can be a possible path for generating TW KHz laser pulses for a future laser-driven plasma accelerator.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA42
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TUPOA48	A High-Level Python Interface to the Fermilab ACNET Control System	ion, quadrupole, emittance, interface	383
	P. Piot Fermilab, Batavia, Illinois, USA A. Halavanau Northern Illinois University, DeKalb, Illinois, USA
	This paper discusses the implementation of a PYTHON-based high-level interface to the Fermilab ACNET control system. We will especially present examples of applications which include the interfacing of an ELEGANT beam-dynamics model to assist lattice matching and an automated emittance measurement via the quadrupole-scan method.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA48
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TUPOA51	First Steps Toward Incorporating Image Based Diagnostics into Particle Accelerator Control Systems Using Convolutional Neural Networks	ion, gun, network, solenoid	390
	A.L. Edelen, S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA J.P. Edelen Fermilab, Batavia, Illinois, USA
	At present, a variety of image-based diagnostics are used in particle accelerator systems. Often times, these are viewed by a human operator who then makes appropriate adjustments to the machine. Given recent advances in using convolutional neural networks (CNNs) for image processing, it should be possible to use image diagnostics directly in control routines (NN-based or otherwise). This is especially appealing for non-intercepting diagnostics that could run continuously during beam operation. Here, we show results of a first step toward implementing such a controller: our trained CNN can predict multiple simulated downstream beam parameters at the Fermilab Accelerator Science and Technology (FAST) facility's low energy beamline using simulated virtual cathode laser images, gun phases, and solenoid strengths.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA51
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TUPOA52	Updates to the Low-Level RF Architecture for Fermilab	ion, LLRF, simulation, hardware	394
	J. Einstein, B.E. Chase, E. Cullerton, P. Varghese Fermilab, Batavia, Illinois, USA S. Biedron, S.V. Milton CSU, Fort Collins, Colorado, USA D. Sharma RRCAT, Indore (M.P.), India
	Fermilab has teamed with Colorado State University on several projects in LLRF controls and architecture. These projects include new LLRF hardware, updated controls techniques, and new system architectures. Here we present a summary of our work to date.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA52
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TUPOA61	Integrated Control System for an X-Band-Based Laser-Compton X-Ray Source	ion, laser, FPGA, LabView	408
	D.J. Gibson, G.G. Anderson, C.P.J. Barty, R.A. Marsh LLNL, Livermore, California, USA
	Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344. LLNL's compact, tunable, laser-Compton x-ray source has been built around an advanced X-band photogun and accelerator sections and two independent laser systems. In support of this source, the control system has evolved from a minimal, isolated control points to an integrated architecture that continues to grow to simplify operation of the system and to meet new needs of this research capability. In addition to a PLC-based machine protection component, a custom, LabView-based suite of control software monitors systems including low level and high power RF, vacuum, magnets, and beam imaging cameras. This system includes a comprehensive operator interface, automated arc detection and rf processing to optimize rf conditioning of the high-gradient structures, and automated quad-scan-based emittance measurements to explore the beam tuning parameter space. The latest upgrade to the system includes a switch from real-time OS to FPGA-based low-level RF generation and arc detection. This offloads processing effort from the main processor allowing for arbitrary expansion of the monitored points. It also allows the possibility of responding to arcs before the pulse is complete.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA61
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TUPOA63	Preliminary Study of Advanced LLRF Controls at LANSCE for Beam Loading Compensation in the MaRIE X-FEL	ion, beam-loading, LLRF, FPGA	411
	A. Scheinker, S.A. Baily, J.T. Bradley III, L.J. Castellano, J.O. Hill, D.J. Knapp, S. Kwon, J.T.M. Lyles, M.S. Prokop, D. Rees, P.A. Torrez LANL, Los Alamos, New Mexico, USA
	The analog low level RF (LLRF) control system of the Los Alamos Neutron Science Center is being upgraded to a Field Programmable Gate Array (FPGA)-based digital system (DLLRF). In this paper we give an overview of the FPGA design and the overall DLLRF system. We also present preliminary performance measurements including results utilizing model-independent iterative feedforward for beam-loading transient minimization, which is being studied for utilization in the future MaRIE X-FEL, which will face difficult beam loading conditions.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA63
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TUPOA74	The Design and Construction of a Resonance Control System for the IOTA RF Cavity	ion, cavity, bunching, proton	432
	G.M. Bruhaug ISU, Pocatello, Idaho, USA K. Carlson Fermilab, Batavia, Illinois, USA
	The IOTA ring will be an advanced storage ring used for non-linear beam dynamics experiments to assist in the construction of future accelerators. This ring is being built in conjunction with the FAST electron LINAC and the HINS RFQ proton source, at Fermilab, for injection into the ring. These accelerators will generate +150 MeV electron beams and 2.5 MeV proton beams respectively. As the beams are injected into the IOTA storage ring their longitudinal profile will begin to smear out and become more uniform. This will prevent detection of beam position with a Beam Position Monitoring system (BPM). To combat this a ferrite loaded bunching cavity is being constructed. This paper details the design and construction of an automatic resonance control system for this bunching cavity.
	Poster TUPOA74 [2.604 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOA74
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TUPOB15	Implementing the Fast Multipole Boundary Element Method With High-Order Elements	ion, multipole, simulation, lattice	518
	A.J. Gee, B. Erdelyi Northern Illinois University, DeKalb, Illinois, USA
	The next generation of beam applications will require high-intensity beams with unprecedented control. For the new system designs, simulations that model collective effects must achieve greater accuracies and scales than conventional methods allow. The fast multipole method is a strong candidate for modeling collective effects due to its linear scaling. It is well known the boundary effects become important for such intense beams. We implemented a constant element fast boundary element method (FMBEM) * as our first step in studying the boundary effects. To reduce the number of elements and discretization error, our next step is to allow for curvilinear elements. In this paper we will present our study on a quadratic and a cubic parametric method to model the surface. * A.Gee and B.Erdelyi, "A Differential Algebraic Framework for the Fast Indirect Boundary Element Method," in Proc. IPAC'16. Busan, South Korea.
	Poster TUPOB15 [1.727 MB]
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB15
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TUPOB18	Beam Test of Masked-Chicane Micro-Buncher	ion, simulation, electron, bunching	528
	Y.-M. Shin Northern Illinois University, DeKalb, Illinois, USA D.R. Broemmelsiek, D.J. Crawford, D.R. Edstrom, A.H. Lumpkin, J. Ruan, J.K. Santucci, J.C.T. Thangaraj, R.M. Thurman-Keup Fermilab, Batavia, Illinois, USA A.T. Green Northern Illinois Univerity, DeKalb, Illinois, USA
	Funding: This work was supported by the DOE contract No.DEAC02-07CH11359 to the Fermi Research Alliance LLC. We also thank the FAST Department team for the helpful discussion and technical supports. Masking a dispersive beamline such as a dogleg or a chicane [1, 2] is a simple way to shape a beam in the longitudinal and transverse space. This technique is often employed to generate arbitrary bunch profiles for beam/laser-driven accelerators and FEL undulators or even to reduce a background noise from dark currents in electron linacs. We have been investigating a beam-modulation of a slit-masked chicane, which was deployed for crystal-channeling experiments at the injector beamline of the Fermilab Accelerator Science and Technology (FAST) facility. With a nominal beam of 3 ps bunch length, Elegant simulations showed that a slit-mask with slit period 900 um and aperture width 300 um induces a modulation with bunch-to-bunch space of about 187 um (0.25 nC), 270 um (1 nC) and 325 um (3.2 nC) with 3 ~ 6% correlated energy spread: An initial energy modulation pattern has been observed in the electron spectrometer downstream of the masked chicane using a micropulse charge of 260 pC and 40 micropulses. Investigations of the beam longitudinal modulation are planned with a Martin-Puplett interferometer and a synchro-scan streak camera at a station between the chicane and spectrometer. [1] D.C.Nguyen, B.E.Carlsten, NIMA 375, 597 (1996) [2] P.Muggli, V.Yakimeno, M.Babzien, et al., PRL 101, 054801 (2008)
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB18
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TUPOB30	Spin Flipping System in the JLEIC Collider Ring	ion, collider, polarization, solenoid	558
	V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang JLab, Newport News, Virginia, USA Y. Filatov MIPT, Dolgoprudniy, Moscow Region, Russia A.M. Kondratenko, M.A. Kondratenko Science and Technique Laboratory Zaryad, Novosibirsk, Russia
	Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357. The figure-8 JLEIC collider ring opens wide possibilities for manipulating proton and deuteron spin directions during an experiment. Using 3D spin rotators, one can, at the same time, efficiently control the polarization direction as well as the spin tune value. The 3D spin rotators allow one to arrange a system for reversals of the spin direction in all beam bunches during an experiment, i.e. a spin-flipping system. To preserve the polarization, one has to satisfy the condition of adiabatic change of the spin direction. When adjusting the polarization direction, one can stabilize the spin tune value, which completely eliminates resonant beam depolarization during the spin manipulation process. We provide the results of numerical modeling of a spin-flipping system in the JLEIC ion collider ring. The presented results demonstrate the feasibility of organizing a spin-flipping system using a 3D rota-tor. The figure-8 JLEIC collider provides a unique capability of doing high-precision experiments with polarized ion beams.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-TUPOB30
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WEPOA15	Installation Progress at the PIP-II Injector Test at Fermilab	ion, rfq, MMI, linac	722
	C.M. Baffes, M.L. Alvarez, R. Andrews, A.Z. Chen, J. Czajkowski, P. Derwent, J.P. Edelen, B.M. Hanna, B.D. Hartsell, K.R. Kendziora, D.V. Mitchell, L.R. Prost, V.E. Scarpine, A.V. Shemyakin, J. Steimel, T.J. Zuchnik Fermilab, Batavia, Illinois, USA A.L. Edelen CSU, Fort Collins, Colorado, USA
	Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy A CW-compatible, pulsed H⁻ superconducting linac 'PIP-II' is being planned to upgrade Fermilab's injection complex. To validate the concept of the front-end of such a machine, a test accelerator (The PIP-II Injector Test, formerly known as "PXIE") is under construction. The warm part of this accelerator comprises a 10 mA DC 30 keV H⁻ ion source, a 2m-long LEBT, a 2.1 MeV CW RFQ, and a 10-m long MEBT that is capable of creating a large variety of bunch structures. The paper will report on the installation of the RFQ and the first sections of the MEBT and related mechanical design considerations.
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WEA3IO02	Start-to-End Beam Dynamics Optimization of X-Ray FEL Light Source Accelerators	ion, linac, electron, FEL	838
	J. Qiang LBNL, Berkeley, California, USA
	State-of-the-art tools have been developed that allow start-to-end modeling of the beam formation at the cathode, to its transport, acceleration, and delivery to the undulator. Algorithms are based on first principles, enabling the capture of detailed physics such as shot-noise driven micro-bunching instabilities. The most recent generation of the IMPACT code, using multi-level parallelization on massively parallel supercomputers, now enables multi-objective parametric optimization. This is facilitated by recent advances such as the unified differential evolution algorithm. The most recent developments will be described, together with applications to the modeling of LCLS-II. J. Qiang, et al, http://www.optimization-online.org/DB_FILE/2015/03/4796.pdf, submitted **J. Qiang, et al, in preparation
	Slides WEA3IO02 [10.928 MB]
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WEB4CO04	100 kW Very Compact Pulsed Solid-State RF Amplifier. Development and Tests	ion, rf-amplifier, vacuum, power-supply	873
	G.B. Sharkov, A.A. Krasnov, S.A. Polikhov NIITFA, Moscow, Russia R. Cisneros, R.J. Patrick TMD Technologies, Middlesex, United Kingdom
	A high power solid-state RF amplifier system has been developed and tested. The modular scalable architecture of the system allows to build megawatt-range compact, robust, cost effective RF amplifiers/generators with high plug efficiency. Using a special designed technology of RF power on-board combination for several LDMOS transistors and very compact high power RF combiners, the amplifier with output power of 100 kW and duty cycle of 5% has been fit into a single 19" cabinet. The system has been tested at the output power up to 104 kW with 3.5 ms pulses. The overview of the technologies, the design of the machine, and its main subsystems is given in this talk. The test results and the market perspectives are also presented.
	Slides WEB4CO04 [19.504 MB]
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WEPOB04	Beamline-Controlled Steering of Source-Point Angle at the Advanced Photon Source	ion, EPICS, feedback, operation	887
	L. Emery, G.I. Fystro, H. Shang, M.L. Smith ANL, Argonne, Illinois, USA
	Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357 An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering by the value of "angle request" EPICS records that beamlines have set. The new system effectively bypasses floor coordinators and MCR operators, and makes the steering process much faster than before, although these older protocols can still be used. As with the original steering there are EPICS alarm limits that prevent large steering from occurring and avoid other problems. Error messages and statuses, OPI windows and alarm configurations are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way. In principle and in practice, many simultaneous steering commands from many beamlines are possible. We report on a complete 3-month run of experience.
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THPOA17	Computing Eigen-Emittances from Tracking Data	ion, emittance, optics, simulation	1132
	Y.I. Alexahin Fermilab, Batavia, Illinois, USA
	Funding: Work supported by Fermi Research Alliance, LLC under Contract DE-AC02-07CH11359 with the U.S. DOE In a strongly nonlinear system the particle distribution in the phase space may develop long tails which contribution to the covariance (σ) matrix should be suppressed for a correct estimate of the beam emittance. A method is offered based on Gaussian approximation of the original particle distribution in the phase space (Klimontovich distribution) which leads to an equation for the σ matrix which provides efficient suppression of the tails and cannot be obtained by introducing weights. This equation is easily solved by iterations in the multi-dimensional case. It is also shown how the eigen-emittances and coupled optics functions can be retrieved from the σ matrix in a strongly coupled system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-NAPAC2016-THPOA17
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FRA2IO02	High Precision RF Control for the LCLS-II	ion, cavity, LLRF, feedback	1292
	G. Huang, K. Campbell, L.R. Doolittle, J.A. Jones, C. Serrano, V.K. Vytla LBNL, Berkeley, California, USA S. Babel, M. Boyes, G.W. Brown, D. Cha, B. Hong, A. Ratti, C.H. Rivetta SLAC, Menlo Park, California, USA R. Bachimanchi, C. Hovater, D.J. Seidman JLab, Newport News, Virginia, USA B.E. Chase, E. Cullerton, Q. Du, J. Einstein, D.W. Klepec Fermilab, Batavia, Illinois, USA
	Funding: Work supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515 The LCLS-II is a CW superconducting linac under construction to drive an X-ray FEL. The energy and timing stability requirements of the FEL drive the need for very high precision RF control. This paper summarize the design considerations and early demonstration of the performance of the components and system we developed.
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Paper

Title

Other Keywords

Page

MOPOB12

A High Bandwidth Bipolar Power Supply for the Fast Correctors in the APS Upgrade

ion, power-supply, ISOL, interface

96

J. Wang, G.S. Sprau
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.
The APS Upgrade of a multi-bend achromat (MBA) storage ring requires a fast bipolar power supply for the fast correction magnets. The key performance requirement of the power supply includes a small-signal bandwidth of 10 kHz for the output current. This requirement presents a challenge to the design because of the high inductance of the magnet load and a limited input DC voltage. A prototype DC/DC power supply utilizing a MOSFET H-bridge circuit with a 500 kHz PWM has been developed and tested successfully. The prototype achieved a 10-kHz bandwidth with less than 3-dB attenuation for a signal 0.5% of the maximum operating current of 15 amperes. This paper presents the design of the power circuit, the PWM method, the control loop, and the test results.

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MOPOB17

Resonant Frequency Control for the PIP-II Injector Test RFQ: Control Framework and Initial Results

ion, rfq, framework, operation

109

A.L. Edelen, S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
D.L. Bowring, B.E. Chase, J.P. Edelen, D.J. Nicklaus, J. Steimel
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermilab Research Alliance, LLC under Contract No. DE-AC02-07CH11359.
For the PIP-II Injector Test (PI-Test) at Fermilab, a four-vane radio frequency quadrupole (RFQ) is designed to accelerate a 30-keV, 1-mA to 10-mA H' beam to 2.1 MeV under both pulsed and continuous wave (CW) RF operation. The available headroom of the RF amplifiers limit the maximum allowable detuning to 3 kHz, and the detuning is controlled entirely via thermal regulation. Fine control over the detuning, minimal manual intervention, and fast trip recovery is desired. In addition, having active control over both the walls and vanes provides a wider tuning range. For this, we intend to use model predictive control (MPC). To facilitate these objectives, we developed a dedicated control framework that handles higher-level system decisions as well as executes control calculations. It is written in Python in a modular fashion for easy adjustments, readability, and portability. Here we describe the framework and present the first control results for the PI-Test RFQ under pulsed and CW operation.

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MOPOB27

Superconducting Coil Winding Machine Control System

ion, FPGA, operation, software

127

J.M. Nogiec, S. Kotelnikov, A. Makulski, K. Trombly-Freytag, D.G.C. Walbridge
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the U.S. Department of Energy under contract no. DE-AC02-07CH11359.
The Spirex magnet coil winder has been equipped with an automation system, which allows operation from both a computer and a remote control unit. This machine is about 6m long with a bridge that moves along a track and supports a rotating boom holding a spool of cable and providing cable tension. The machine control system is distributed between three layers: PC, RTOS, and FPGA providing respectively HMI, operational logic and controls. The PC stores the history of operation, shows the machine positions, status, and their history. Keeping cable tension constant is non-trivial in situations where the length of the cable changes with varying speeds. This has been addressed by a PID controller with feed forward augmentation and low-pass filters. Another challenging problem, synchronizing multiple servo motors, has been solved by designing an innovative decentralized algorithm. Extra attention was given to the safety aspects; a fail-safe, redundant safety system with interlocks has been developed, including protection for the operator and the superconducting cable against such situations as accidental over tension, or fast movement of the cable due to operational errors.

Poster MOPOB27 [1.952 MB]

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MOPOB30

Development and Comparison of Mechanical Structures for FNAL 15 T Nb3Sn Dipole Demonstrator

ion, dipole, operation, collider

137

A.V. Zlobin, I. Novitski
Fermilab, Batavia, Illinois, USA

Funding: *Work is supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy
Main design challenges for 15 T accelerator magnets are large Lorentz forces at this field level. The large Lorentz forces generate high stresses in the coil and mechanical structure and, thus, need stress control to maintain them at the acceptable level for brittle Nb3Sn coils and other elements of magnet mechanical structure. To provide these conditions and achieve the design field in the FNAL 15 T dipole demonstrator, several mechanical structures have been developed and analysed. The possibilities and limitations of these designs are discussed in this paper.

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MOPOB68

A New Method for Grain Texture Manipulation in Post-Deposition Niobium Films

ion, laser, niobium, electron

221

J. Musson, K. Macha, H.L. Phillips
JLab, Newport News, Virginia, USA
W. Cao, H. Elsayed-Ali
ODU, Norfolk, Virginia, USA

Funding: Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. Old Dominion University
Niobium films are frequently grown using forms of energetic condensation, with modest substrate temperatures to control grain structure. As an alternative, energetic deposition onto a cold substrate results in a dense amorphous film, with a much larger energy density than the re-crystallized state. Re-crystallization is then performed using a pulsed UV (HIPPO) laser, with minimal damage to the substrate. In addition, a graded interface between the substrate and Nb film is created during the early stages of energetic deposition. Experimental approach and apparatus are described.

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MOPOB72

Update on CW 8 kW 1.5 GHz Klystron Replacement

ion, klystron, operation, ISOL

232

A.V. Smirnov, S. Boucher
RadiaBeam Systems, Santa Monica, California, USA
R.B. Agustsson, D.I. Gavryushkin, J.J. Hartzell, K.J. Hoyt, A.Y. Murokh, T.J. Villabona
RadiaBeam, Santa Monica, California, USA
G.R. Branner, K.S. Yuk
UC Davis, Davis, USA
V. Khodos
Sierra Nevada Corporation, Irvine, USA

Funding: This work was supported by the U.S. Department of Energy (award No. DE-SC0013136).
JLAB upgrade program requires a ~8 kW, 1497 MHz amplifier operating at more than 55-60% efficiency, and 8 kW CW power to replace up to 340 klystrons. One of possibilities for the klystron replacement is usage of high electron mobility packaged GaN transistors applied in array of highly efficient amplifiers using precise in-phase, low-loss combiners-dividers. Design features and challenges related to amplifier modules and radial multi-way dividers/combiners are discussed including HFSS simulations and measurements.

Poster MOPOB72 [1.199 MB]

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TUA2CO03

A Novel Technique of Power Control in Magnetron Transmitters for Intense Accelerators

ion, cavity, operation, power-supply

271

G.M. Kazakevich, R.P. Johnson, M.L. Neubauer
Muons, Inc, Illinois, USA
V.A. Lebedev, W. Schappert, V.P. Yakovlev
Fermilab, Batavia, Illinois, USA

A novel concept of a high-power magnetron transmitter allowing dynamic phase and power control at the frequency of locking signal is proposed. The transmitter compensating parasitic phase and amplitude modulations inherent in Superconducting RF (SRF) cavities within closed feedback loops is intended for powering of the intensity-frontier superconducting accelerators. The concept uses magnetrons driven by a sufficient resonant (injection-locking) signal and fed by the voltage which can be below the threshold of self-excitation. This provides an extended range of power control in a single magnetron at highest efficiency minimizing the cost of RF power unit and the operation cost. Proof-of-principle of the proposed concept demonstrated in pulsed and CW regimes with 2.45 GHz, 1kW magnetrons is discussed here. A conceptual scheme of the high-power transmitter allowing the dynamic wideband phase and mid-frequency power controls is presented and discussed.

Slides TUA2CO03 [0.714 MB]

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TUB2IO02

Advanced Concepts for Seeded FELs

ion, FEL, electron, laser

284

E. Ferrari, E. Allaria
Elettra-Sincrotrone Trieste S.C.p.A., Basovizza, Italy

The use of an external laser to seed an electron beam at the beginning of the Free Electron Laser process has been proposed as a way to improve temporal coherence of modern short wavelength FELs. More recent studies and experiments have shown that electron beam manipulation through interaction with a seed laser can be exploited for tailoring FEL properties to specific users requests. Recently, experiment for phase control, multi-color emission and coherent control have been reported.

Slides TUB2IO02 [15.975 MB]

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TUPOA07

IoT Application in the Control System of the BEPCII Power Supplies

ion, power-supply, status, operation

302

C.H. Wang, L.F. Li, X.L. Wang
IHEP, Beijing, People's Republic of China
C.P. Chu
MSU, East Lansing, Michigan, USA

Funding: This prject is support by NSFC(1137522)
In recent years in the development of Internet technology, the Internet of things (IoT) has begun to apply to each domain. The paper introduces the idea how to apply IoT to the accelerator control system and take the existing control system of the BEPCII power supplies as an example for IoT application. It not only introduce the status of the control system of the BEPCII power supplies, but also present a solution how to apply IoT to the existing control system. The purpose is to make the control system more intelligent and automatically identify what and where problem when the alarm of the control system of the power supplies. That means that IoT can help to automatically identify which crate and which PSC board inserted in the crates and which PSI sittiing in the power supply crates as well as the optic fiber cables between the PSCs and the PSIs. It is great convenient for the maintainer to use a mobile phone to diagnose faults and create the electronic maintenance record.

Poster TUPOA07 [0.762 MB]

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TUPOA12

An Updated LLRF Control System for the TLS Linac

ion, linac, EPICS, LLRF

308

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

The amplitude and phase of the RF field at the linear accelerator (LINAC) decides the beam quality. To study and to improve the performance of the LINAC system for Taiwan Light Source (TLS), a new design of a low-level radio-frequency (LLRF) control system was developed and set up for the TLS LINAC. The main components of the LLRF control system are an I/Q modulator, an Ethernet-based arbitrary waveform generator, a digital oscilloscope and an I/Q demodulator; these are essential parts of the LLRF feed-forward control. This paper presents the efforts to improve the LLRF control system. The feasibility of the RF feed-forward control will be studied at the linear accelerator of TLS.

Poster TUPOA12 [1.425 MB]

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TUPOA14

An Internet Rack Monitor-Controller for APS LINAC RF Electronics Upgrade

ion, linac, network, klystron

314

H. Ma, A. Nassiri, T.L. Smith, Y. Sun
ANL, Argonne, Illinois, USA
L.R. Doolittle, A. Ratti
LBNL, Berkeley, California, USA

Funding: Work supported by U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences
To support the current research and development in APS LINAC area, the existing LINAC rf control performance needs to be much improved, and thus an upgrade of the legacy LINAC rf electronics becomes necessary. The proposed upgrade plan centers on the concept of using a modern, network-attached, rack-mount digital electronics platform 'Internet Rack Monitor-Controller (or IRMC) to replace the existing analog ones on the legacy crate/backplane-based hardware. The system model of the envisioned IRMC is basically a 3-tier stack with a high-performance processor in the mid- layer to handle the general digital signal processing (DSP). The custom FPGA IP's in the bottom layer handle the high-speed, real-time, low-latency DSP tasks, and provide the interface ports. A network communication gateway, in conjunction with an embedded event receiver (EVR), in the top layer merges the Internet Rack Monitor-Controller device into the networks of the accelerator controls infrastructure. Although the concept is very much in trend with today's Internet-of-Things (IoT), this implementation has actually been used in accelerators for over two decades.

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TUPOA16

A VME and FPGA Based Data Acquisition System for Intensity Monitors

ion, software, data-acquisition, instrumentation

317

J.S. Diamond, A. Ibrahim, N. Liu, E.S.M. McCrory, A. Semenov
Fermilab, Batavia, Illinois, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy
A universal data acquisition system supporting toroids, DCCTs, Faraday cups, srapers and other types of instru-mentation has been developed for reporting beam inten-sity measurements to the Fermilab Accelerator Controls System (ACNet). Instances of this front end, supporting dozens of intensity monitor devices have been deployed throughout the Fermilab accelerator complex in the Main Injector, Recycler, Fermilab Accelerator Science and Technology (FAST) facility and the PIP-II Injector Exper-iment (PXIE). Each front end consists of a VME chassis containing a single board computer (SBC), timing and clock module and one or more 8 to 12-channel digitizer modules. The digitizer modules are based on a Cyclone III FPGA with firmware developed in-house allowing a wide range of flexibility and digital signal processing capability. The front end data acquisition software adds a list of new features to the previous generation allowing users to: take beam intensity measurements at custom points in the acceleration cycle, access waveform data, control machine protection system (MPS) parameters and calculate beam energy loss.

Poster TUPOA16 [1.532 MB]

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TUPOA18

Low Level RF Control for the PIP-II Injector Test RFQ

ion, rfq, LLRF, cavity

323

J.P. Edelen, B.E. Chase, E. Cullerton, J. Einstein, P. Varghese
Fermilab, Batavia, Illinois, USA

The PIP-II injector test radio frequency quadrupole (RFQ) arrived at Fermilab in the fall of 2015. The RFQ is a 162.5MHz H⁻ accelerator with a nominal drive power of 100kW, which produces a bunched H⁻ beam at 2.1MeV. In this paper we discuss commissioning, operational performance, and improvements to the low level RF (LLRF) control system for the RFQ. We begin by describing the general system configuration and initial simulation results. We will then highlight temperature related issues in the high power RF system, which necessitate active control over the phase balance of the two amplifiers. Finally we demonstrate performance of the RF feedback and feed-forward compensation needed to meet specification during a 20-microsecond beam pulse.

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TUPOA30

Fermilab Switchyard Resonant Beam Position Monitor Electronics Upgrade Results

ion, electron, electronics, power-supply

352

T.B. Petersen, J.S. Diamond, N. Liu, P.S. Prieto, D. Slimmer, A.C. Watts
Fermilab, Batavia, Illinois, USA

The readout electronics for the resonant beam position monitors (BPMs) in the Fermilab Switchyard (SY) have been upgraded, utilizing a low noise amplifier transition board and Fermilab designed digitizer boards. The stripline BPMs are estimated to have an average signal output of between -110 dBm and -80 dBm, with an esti-mated peak output of -70 dBm. The external resonant circuit is tuned to the SY machine frequency of 53.10348 MHz. Both the digitizer and transition boards have vari-able gain in order to accommodate the large dynamic range and irregularity of the resonant extraction spill. These BPMs will aid in auto-tuning of the SY beamline as well as enabling operators to monitor beam position through the spill.

Poster TUPOA30 [0.833 MB]

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TUPOA31

Fermilab Cryomodule Test Stand RF Interlock System

ion, monitoring, interlocks, cavity

355

T.B. Petersen, J.S. Diamond, D. McDowell, D.J. Nicklaus, P.S. Prieto, A. Semenov
Fermilab, Batavia, Illinois, USA

An interlock system has been designed for the Fermilab Cryomodule Test Stand (CMTS), a test bed for the cryomodules to be used in the upcoming Linac Coherent Light Source 2 (LCLS-II) project at SLAC. The interlock system features 8 independent subsystems, consisting of a superconducting RF cavity, a coupler, and solid state amplifier (SSA). Each system monitors several devices to detect fault conditions such as arcing in the waveguides or quenching of the SRF system. Additionally each system can detect fault conditions by monitoring the RF power seen at the cavity coupler through a directional coupler. In the event of a fault condition, each system is capable of removing RF signal to the amplifier (via a fast RF switch) as well as turning off SSA. Additionally, each input signal is available for remote viewing and recording via a Fermilab designed digitizer board.

Poster TUPOA31 [0.762 MB]

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TUPOA41

FPGA Control of Coherent Pulse Stacking

ion, cavity, FPGA, feedback

367

Y.L. Xu, J.M. Byrd, L.R. Doolittle, Q. Du, G. Huang, W. Leemans, R.B. Wilcox, Y. Yang
LBNL, Berkeley, California, USA
J. Dawson
LLNL, Livermore, California, USA
A. Galvanauskas, J.M. Ruppe
University of Michigan, Ann Arbor, Michigan, USA

Coherent pulse stacking (CPS) is a new time-domain coherent addition technique that stacks several optical pulses into a single output pulse, enabling high pulse energy from fiber lasers. Due to advantages of precise timing and fast processing, we use an FPGA to process digital signals and do feedback control so as to realize stacking-cavity stabilization. We develop a hardware and firmware design platform to support the coherent pulse stacking application. A firmware bias control module stabilizes the amplitude modulator at the minimum of its transfer function. A cavity control module ensures that each optical cavity is kept at a certain individually-prescribed and stable round-trip phase with 2.5 deg rms phase error.

Poster TUPOA41 [5.546 MB]

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TUPOA42

Multicavity Coherent Pulse Stacking Using Herriott Cells

cavity, ion, laser, experiment

370

Y. Yang, J.M. Byrd, L.R. Doolittle, G. Huang, W. Leemans, Q. Qiang, R.B. Wilcox
LBNL, Berkeley, California, USA
J. Dawson
LLNL, Livermore, California, USA
A. Galvanauskas, J.M. Ruppe
University of Michigan, Ann Arbor, Michigan, USA
Y.L. Xu
TUB, Beijing, People's Republic of China

Coherent Pulse Stacking provides a promising way to generate a single high-intensity laser pulse by stacking a sequence of phase and amplitude modulated laser pulses using multiple optical cavities. Optical misalignment and phase stability are two critical issues that need to be addressed. Herriott cells are implemented for their relaxed alignment tolerance and a phase stabilization method based on cavity output pattern matching has been developed. A single pulse with intensity enhancement factor over 7.4 has been generated by stacking 13 modulated pules through a four-cavity stacking system. This can be a possible path for generating TW KHz laser pulses for a future laser-driven plasma accelerator.

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TUPOA48

A High-Level Python Interface to the Fermilab ACNET Control System

ion, quadrupole, emittance, interface

383

P. Piot
Fermilab, Batavia, Illinois, USA
A. Halavanau
Northern Illinois University, DeKalb, Illinois, USA

This paper discusses the implementation of a PYTHON-based high-level interface to the Fermilab ACNET control system. We will especially present examples of applications which include the interfacing of an ELEGANT beam-dynamics model to assist lattice matching and an automated emittance measurement via the quadrupole-scan method.

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TUPOA51

First Steps Toward Incorporating Image Based Diagnostics into Particle Accelerator Control Systems Using Convolutional Neural Networks

ion, gun, network, solenoid

390

A.L. Edelen, S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
J.P. Edelen
Fermilab, Batavia, Illinois, USA

At present, a variety of image-based diagnostics are used in particle accelerator systems. Often times, these are viewed by a human operator who then makes appropriate adjustments to the machine. Given recent advances in using convolutional neural networks (CNNs) for image processing, it should be possible to use image diagnostics directly in control routines (NN-based or otherwise). This is especially appealing for non-intercepting diagnostics that could run continuously during beam operation. Here, we show results of a first step toward implementing such a controller: our trained CNN can predict multiple simulated downstream beam parameters at the Fermilab Accelerator Science and Technology (FAST) facility's low energy beamline using simulated virtual cathode laser images, gun phases, and solenoid strengths.

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TUPOA52

Updates to the Low-Level RF Architecture for Fermilab

ion, LLRF, simulation, hardware

394

J. Einstein, B.E. Chase, E. Cullerton, P. Varghese
Fermilab, Batavia, Illinois, USA
S. Biedron, S.V. Milton
CSU, Fort Collins, Colorado, USA
D. Sharma
RRCAT, Indore (M.P.), India

Fermilab has teamed with Colorado State University on several projects in LLRF controls and architecture. These projects include new LLRF hardware, updated controls techniques, and new system architectures. Here we present a summary of our work to date.

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TUPOA61

Integrated Control System for an X-Band-Based Laser-Compton X-Ray Source

ion, laser, FPGA, LabView

408

D.J. Gibson, G.G. Anderson, C.P.J. Barty, R.A. Marsh
LLNL, Livermore, California, USA

Funding: This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
LLNL's compact, tunable, laser-Compton x-ray source has been built around an advanced X-band photogun and accelerator sections and two independent laser systems. In support of this source, the control system has evolved from a minimal, isolated control points to an integrated architecture that continues to grow to simplify operation of the system and to meet new needs of this research capability. In addition to a PLC-based machine protection component, a custom, LabView-based suite of control software monitors systems including low level and high power RF, vacuum, magnets, and beam imaging cameras. This system includes a comprehensive operator interface, automated arc detection and rf processing to optimize rf conditioning of the high-gradient structures, and automated quad-scan-based emittance measurements to explore the beam tuning parameter space. The latest upgrade to the system includes a switch from real-time OS to FPGA-based low-level RF generation and arc detection. This offloads processing effort from the main processor allowing for arbitrary expansion of the monitored points. It also allows the possibility of responding to arcs before the pulse is complete.

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TUPOA63

Preliminary Study of Advanced LLRF Controls at LANSCE for Beam Loading Compensation in the MaRIE X-FEL

ion, beam-loading, LLRF, FPGA

411

A. Scheinker, S.A. Baily, J.T. Bradley III, L.J. Castellano, J.O. Hill, D.J. Knapp, S. Kwon, J.T.M. Lyles, M.S. Prokop, D. Rees, P.A. Torrez
LANL, Los Alamos, New Mexico, USA

The analog low level RF (LLRF) control system of the Los Alamos Neutron Science Center is being upgraded to a Field Programmable Gate Array (FPGA)-based digital system (DLLRF). In this paper we give an overview of the FPGA design and the overall DLLRF system. We also present preliminary performance measurements including results utilizing model-independent iterative feedforward for beam-loading transient minimization, which is being studied for utilization in the future MaRIE X-FEL, which will face difficult beam loading conditions.

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TUPOA74

The Design and Construction of a Resonance Control System for the IOTA RF Cavity

ion, cavity, bunching, proton

432

G.M. Bruhaug
ISU, Pocatello, Idaho, USA
K. Carlson
Fermilab, Batavia, Illinois, USA

The IOTA ring will be an advanced storage ring used for non-linear beam dynamics experiments to assist in the construction of future accelerators. This ring is being built in conjunction with the FAST electron LINAC and the HINS RFQ proton source, at Fermilab, for injection into the ring. These accelerators will generate +150 MeV electron beams and 2.5 MeV proton beams respectively. As the beams are injected into the IOTA storage ring their longitudinal profile will begin to smear out and become more uniform. This will prevent detection of beam position with a Beam Position Monitoring system (BPM). To combat this a ferrite loaded bunching cavity is being constructed. This paper details the design and construction of an automatic resonance control system for this bunching cavity.

Poster TUPOA74 [2.604 MB]

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TUPOB15

Implementing the Fast Multipole Boundary Element Method With High-Order Elements

ion, multipole, simulation, lattice

518

A.J. Gee, B. Erdelyi
Northern Illinois University, DeKalb, Illinois, USA

The next generation of beam applications will require high-intensity beams with unprecedented control. For the new system designs, simulations that model collective effects must achieve greater accuracies and scales than conventional methods allow. The fast multipole method is a strong candidate for modeling collective effects due to its linear scaling. It is well known the boundary effects become important for such intense beams. We implemented a constant element fast boundary element method (FMBEM) * as our first step in studying the boundary effects. To reduce the number of elements and discretization error, our next step is to allow for curvilinear elements. In this paper we will present our study on a quadratic and a cubic parametric method to model the surface.
* A.Gee and B.Erdelyi, "A Differential Algebraic Framework for the Fast Indirect Boundary Element Method," in Proc. IPAC'16. Busan, South Korea.

Poster TUPOB15 [1.727 MB]

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TUPOB18

Beam Test of Masked-Chicane Micro-Buncher

ion, simulation, electron, bunching

528

Y.-M. Shin
Northern Illinois University, DeKalb, Illinois, USA
D.R. Broemmelsiek, D.J. Crawford, D.R. Edstrom, A.H. Lumpkin, J. Ruan, J.K. Santucci, J.C.T. Thangaraj, R.M. Thurman-Keup
Fermilab, Batavia, Illinois, USA
A.T. Green
Northern Illinois Univerity, DeKalb, Illinois, USA

Funding: This work was supported by the DOE contract No.DEAC02-07CH11359 to the Fermi Research Alliance LLC. We also thank the FAST Department team for the helpful discussion and technical supports.
Masking a dispersive beamline such as a dogleg or a chicane [1, 2] is a simple way to shape a beam in the longitudinal and transverse space. This technique is often employed to generate arbitrary bunch profiles for beam/laser-driven accelerators and FEL undulators or even to reduce a background noise from dark currents in electron linacs. We have been investigating a beam-modulation of a slit-masked chicane, which was deployed for crystal-channeling experiments at the injector beamline of the Fermilab Accelerator Science and Technology (FAST) facility. With a nominal beam of 3 ps bunch length, Elegant simulations showed that a slit-mask with slit period 900 um and aperture width 300 um induces a modulation with bunch-to-bunch space of about 187 um (0.25 nC), 270 um (1 nC) and 325 um (3.2 nC) with 3 ~ 6% correlated energy spread: An initial energy modulation pattern has been observed in the electron spectrometer downstream of the masked chicane using a micropulse charge of 260 pC and 40 micropulses. Investigations of the beam longitudinal modulation are planned with a Martin-Puplett interferometer and a synchro-scan streak camera at a station between the chicane and spectrometer.
[1] D.C.Nguyen, B.E.Carlsten, NIMA 375, 597 (1996)
[2] P.Muggli, V.Yakimeno, M.Babzien, et al., PRL 101, 054801 (2008)

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TUPOB30

Spin Flipping System in the JLEIC Collider Ring

ion, collider, polarization, solenoid

558

V.S. Morozov, Y.S. Derbenev, F. Lin, Y. Zhang
JLab, Newport News, Virginia, USA
Y. Filatov
MIPT, Dolgoprudniy, Moscow Region, Russia
A.M. Kondratenko, M.A. Kondratenko
Science and Technique Laboratory Zaryad, Novosibirsk, Russia

Funding: Authored by Jefferson Science Associates, LLC under U.S. DOE Contracts No. DE-AC05-06OR23177 and DE-AC02-06CH11357.
The figure-8 JLEIC collider ring opens wide possibilities for manipulating proton and deuteron spin directions during an experiment. Using 3D spin rotators, one can, at the same time, efficiently control the polarization direction as well as the spin tune value. The 3D spin rotators allow one to arrange a system for reversals of the spin direction in all beam bunches during an experiment, i.e. a spin-flipping system. To preserve the polarization, one has to satisfy the condition of adiabatic change of the spin direction. When adjusting the polarization direction, one can stabilize the spin tune value, which completely eliminates resonant beam depolarization during the spin manipulation process. We provide the results of numerical modeling of a spin-flipping system in the JLEIC ion collider ring. The presented results demonstrate the feasibility of organizing a spin-flipping system using a 3D rota-tor. The figure-8 JLEIC collider provides a unique capability of doing high-precision experiments with polarized ion beams.

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WEPOA15

Installation Progress at the PIP-II Injector Test at Fermilab

ion, rfq, MMI, linac

722

C.M. Baffes, M.L. Alvarez, R. Andrews, A.Z. Chen, J. Czajkowski, P. Derwent, J.P. Edelen, B.M. Hanna, B.D. Hartsell, K.R. Kendziora, D.V. Mitchell, L.R. Prost, V.E. Scarpine, A.V. Shemyakin, J. Steimel, T.J. Zuchnik
Fermilab, Batavia, Illinois, USA
A.L. Edelen
CSU, Fort Collins, Colorado, USA

Funding: Fermilab is operated by Fermi Research Alliance, LLC under Contract No. De-AC02-07CH11359 with the United States Department of Energy
A CW-compatible, pulsed H⁻ superconducting linac 'PIP-II' is being planned to upgrade Fermilab's injection complex. To validate the concept of the front-end of such a machine, a test accelerator (The PIP-II Injector Test, formerly known as "PXIE") is under construction. The warm part of this accelerator comprises a 10 mA DC 30 keV H⁻ ion source, a 2m-long LEBT, a 2.1 MeV CW RFQ, and a 10-m long MEBT that is capable of creating a large variety of bunch structures. The paper will report on the installation of the RFQ and the first sections of the MEBT and related mechanical design considerations.

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WEA3IO02

Start-to-End Beam Dynamics Optimization of X-Ray FEL Light Source Accelerators

ion, linac, electron, FEL

838

J. Qiang
LBNL, Berkeley, California, USA

State-of-the-art tools have been developed that allow start-to-end modeling of the beam formation at the cathode, to its transport, acceleration, and delivery to the undulator. Algorithms are based on first principles, enabling the capture of detailed physics such as shot-noise driven micro-bunching instabilities. The most recent generation of the IMPACT code, using multi-level parallelization on massively parallel supercomputers, now enables multi-objective parametric optimization. This is facilitated by recent advances such as the unified differential evolution algorithm*. The most recent developments will be described, together with applications to the modeling of LCLS-II**.
*J. Qiang, et al, http://www.optimization-online.org/DB_FILE/2015/03/4796.pdf, submitted
**J. Qiang, et al, in preparation

Slides WEA3IO02 [10.928 MB]

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WEB4CO04

100 kW Very Compact Pulsed Solid-State RF Amplifier. Development and Tests

ion, rf-amplifier, vacuum, power-supply

873

G.B. Sharkov, A.A. Krasnov, S.A. Polikhov
NIITFA, Moscow, Russia
R. Cisneros, R.J. Patrick
TMD Technologies, Middlesex, United Kingdom

A high power solid-state RF amplifier system has been developed and tested. The modular scalable architecture of the system allows to build megawatt-range compact, robust, cost effective RF amplifiers/generators with high plug efficiency. Using a special designed technology of RF power on-board combination for several LDMOS transistors and very compact high power RF combiners, the amplifier with output power of 100 kW and duty cycle of 5% has been fit into a single 19" cabinet. The system has been tested at the output power up to 104 kW with 3.5 ms pulses. The overview of the technologies, the design of the machine, and its main subsystems is given in this talk. The test results and the market perspectives are also presented.

Slides WEB4CO04 [19.504 MB]

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WEPOB04

Beamline-Controlled Steering of Source-Point Angle at the Advanced Photon Source

ion, EPICS, feedback, operation

887

L. Emery, G.I. Fystro, H. Shang, M.L. Smith
ANL, Argonne, Illinois, USA

Funding: Work supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357
An EPICS-based steering software system has been implemented for beamline personnel to directly steer the angle of the synchrotron radiation sources at the Advanced Photon Source. A script running on a workstation monitors "start steering" beamline EPICS records, and effects a steering by the value of "angle request" EPICS records that beamlines have set. The new system effectively bypasses floor coordinators and MCR operators, and makes the steering process much faster than before, although these older protocols can still be used. As with the original steering there are EPICS alarm limits that prevent large steering from occurring and avoid other problems. Error messages and statuses, OPI windows and alarm configurations are provided to the beamlines and the accelerator operators. Underpinning this new steering protocol is the recent refinement of the global orbit feedback process whereby feedforward of dipole corrector set points and orbit set points are used to create a local steering bump in a rapid and seamless way. In principle and in practice, many simultaneous steering commands from many beamlines are possible. We report on a complete 3-month run of experience.

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THPOA17

Computing Eigen-Emittances from Tracking Data

ion, emittance, optics, simulation

1132

Y.I. Alexahin
Fermilab, Batavia, Illinois, USA

Funding: Work supported by Fermi Research Alliance, LLC under Contract DE-AC02-07CH11359 with the U.S. DOE
In a strongly nonlinear system the particle distribution in the phase space may develop long tails which contribution to the covariance (σ) matrix should be suppressed for a correct estimate of the beam emittance. A method is offered based on Gaussian approximation of the original particle distribution in the phase space (Klimontovich distribution) which leads to an equation for the σ matrix which provides efficient suppression of the tails and cannot be obtained by introducing weights. This equation is easily solved by iterations in the multi-dimensional case. It is also shown how the eigen-emittances and coupled optics functions can be retrieved from the σ matrix in a strongly coupled system.

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FRA2IO02

High Precision RF Control for the LCLS-II

ion, cavity, LLRF, feedback

1292

G. Huang, K. Campbell, L.R. Doolittle, J.A. Jones, C. Serrano, V.K. Vytla
LBNL, Berkeley, California, USA
S. Babel, M. Boyes, G.W. Brown, D. Cha, B. Hong, A. Ratti, C.H. Rivetta
SLAC, Menlo Park, California, USA
R. Bachimanchi, C. Hovater, D.J. Seidman
JLab, Newport News, Virginia, USA
B.E. Chase, E. Cullerton, Q. Du, J. Einstein, D.W. Klepec
Fermilab, Batavia, Illinois, USA

Funding: Work supported by the LCLS-II Project and the U.S. Department of Energy, Contract DE-AC02-76SF00515
The LCLS-II is a CW superconducting linac under construction to drive an X-ray FEL. The energy and timing stability requirements of the FEL drive the need for very high precision RF control. This paper summarize the design considerations and early demonstration of the performance of the components and system we developed.

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