IBIC2012 - List of Keywords (feedback)

Paper	Title	Other Keywords	Page
MOCB01	Beam Instrumentation for the SuperKEKB Rings	detector, kicker, radiation, damping	6
	H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama KEK, Ibaraki, Japan G. Bonvicini, H. Farhat, R.S. Gillard Wayne State University, USA G.S. Varner University of Hawaii, Honolulu, HI, USA
	The electron-positron collider KEKB B-factory is currently being upgraded to SuperKEKB. The design luminosity of 8 x 10³⁵ /cm²/s will be achieved using beams with low emittance of several nm and doubling beam currents to 2.6 A in the electron ring (HER) and 3.6 A in the positron ring (LER). A beam position monitor (BPM) system of HER and LER will be equipped with super-heterodyne detectors, turn by turn log ratio detectors with fast gates to measure optics parameters during collision operation and detectors of BPMs near the collision point (IP) for orbit feedback to maintain stable collision. New X-ray beam profile monitors based on the coded aperture method will be installed aiming at bunch by bunch measurement of the beam profile. A large angle beamstrahlung monitor detecting polarization of the synchrotron radiation generated by beam-beam interaction will be installed near IP to obtain information about the beam-beam geometry. The bunch by bunch feedback system will be upgraded using low noise frontend electronics and new 12 bits iGp digital filters. An overview of beam instrumentation of SuperKEKB rings will be given in this paper.
	Slides MOCB01 [8.073 MB]

MOPA20	Development of 3D EO-Sampling System for the Ultimate Temporal Resolution	FEL, laser, electron, timing	98
	K. Ogawa, H. Tomizawa RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan S. Matsubara, Y. Okayasu JASRI/SPring-8, Hyogo, Japan
	We have been developing three dimensional bunch charge distribution (3D-BCD) monitor for FEL seeded with high-order harmonic (HH) pulse. 3D-BCD is based on EO-sampling technique with multiple EO crystal detectors in the manner of spectral decoding. Using this 3D-EO sampling technique, the positioning and timing of electron bunch is obtained in real-time with non-destructive measurement. For obtaining the high temporal resolution, an octave broadband probe laser with linear chirp rate of 1 fs/nm is required. We are developing an EO-probe laser pulse with ~10 μJ pulse energy and the bandwidth over 300 nm (FWHM). For meet these bandwidth and pulse energy, this EO-probe pulse is using a supercontinuum generated by photonic crystal fiber (PCF) and amplified with optical parametric amplification (OPA). Especially, for amplification with maintaining octave bandwidth, non-collinear OPA (NOPA) using BBO crystal and a pump source with a wavelength of 450 nm are adopted. The EO-probe pulse energy of 10 μJ provides for high S/N ratio to each detector and the bandwidth of 300 nm with 300 fs pulse duration allows the measurement for the 30 fs electron bunch duration (FWHM).

MOPA21	Improvement of the SIAM Photon Source Storage Ring BPM System	storage-ring, shielding, photon, operation	101
	S. Klinkhieo, S. Boonsuya, P. Klysubun, S. Krainara, P. Songsiriritthigul, P. Sudmuang, N. Suradet, S. Tesprasitte SLRI, Nakhon Ratchasima, Thailand J.-R. Chen, H.P. Hsueh, Y.-H. Liu NSRRC, Hsinchu, Taiwan
	This report describes the improvement of the Beam Position Monitoring (BPM) systems for the 1.2 GeV storage ring of the Siam Photon Source (SPS). The systematic studies and investigations for improving the machine performance, and storage ring BPM system has been carried out in the last few years. Some major technical problems have been found and solved. The inefficiency and unreliability of the original BPM system were also identified. They are mainly caused due to the use of low quality signal and improper installation of cables. Detailed descriptions of the replacement with the higher quality (lower loss and better interference shielding) BPM cables and implementation of a separated cable trays for the BPM cables, as well as the work on BPM electronic board calibration will be described. The measurement results before and after the improvement of the BPM system will also be presented.

MOPA34	Improvement of Hardware and Software Setup for the Acquisition and Processing of SIAM Photon Source BPM Signal	storage-ring, photon, PLC, software	130
	N. Suradet, S. Boonsuya, S. Klinkhieo, P. Klysubun, S. Krainara, C.P. Preecha, P. Sudmuang SLRI, Nakhon Ratchasima, Thailand
	Data acquisition and processing system has been developed for the Siam Photon Source storage ring BPM system in order to improve monitoring and logging performances. BPM readout, i.e. scanning of BPM electrode voltage outputs and subsequently converting to X-Y position values, is now performed by an upgraded Programmable Logic Controller (PLC) with higher bit resolution (16-bit) analog-to-digital converter (ADC). Moving averaging is then performed on the obtained BPM data utilizing a LabVIEW code to reduce background noise during on-line measurement. All data is then stored on a dedicated computer serving as a central data logging system, which can be remotely accessed via a network communication link. In this report, details of the new setup will be presented, and comparison will be made between the performance of the new and previous setups, together with suggestions on further improvements.

MOPA35	Design Status of the European X-FEL Tranverse Intra Bunch Train Feedback	kicker, undulator, FPGA, cavity	133
	B. Keil, R. Baldinger, C.D. Beard, M.M. Dehler, W. Koprek, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer PSI, Villigen PSI, Switzerland V. Balandin, W. Decking, N. Golubeva DESY, Hamburg, Germany
	Funding: Work supported by Swiss State Secretariat for Education and Research SER The European X-Ray Free Electron Laser (E-XFEL) will have a fast transverse intra-bunch train feedback (IBFB) system to stabilize the beam position in the SASE undulators. E-XFEL bunch trains consist of up to 2700 bunches with a minimum bunch spacing of 222ns and typ. 10Hz train repetition rate. The IBFB will measure the positions of each bunch in the bunch train, and apply intra-train feedback corrections with fast kickers, in addition to a feed-forward correction for reproducible trajectory perturbations. By achieving a feedback loop latency in the order of one microsecond, the IBFB will allow the beam position to converge quickly to the nominal orbit as required for stable SASE operation. The latest conceptual design of the IBFB and the status of IBFB components will be presented.

MOPA37	Reliable Beam-Intensity Control Technique at the HIMAC Synchrotron	extraction, controls, synchrotron, ion	143
	K. Mizushima, T. Furukawa, Y. Hara, Y. Iwata, K. Katagiri, K. Noda, S. Sato, T. Shirai NIRS, Chiba-shi, Japan
	The carbon-ion beam is slowly extracted from the Heavy Ion Medical Accelerator in Chiba (HIMAC) synchrotron using the third-order resonance with the RF-knockout method for scanned carbon-ion therapy. However, an overshoot of the beam spill at the start of extraction is often induced by a slight variation of the beam emittance in operation cycles. It brings dose hot spot inside the target volume, because the tolerable beam-intensity in scanning irradiation is low. We have added short extraction, called preliminary extraction, before irradiation in order to remove the uncontrollable spilled particles. During preliminary extraction, it is necessary to prevent the beam delivering to the patient. Therefore, a fast beam shutter on which an ionization chamber is mounted was developed, and it was installed in the extraction line. The fast shutter enables us to switch from preliminary extraction to irradiation within 100 ms, and the reliability of the beam-intensity control system was drastically improved by the preliminary extraction technique.

MOPA39	Introduction of Photon BPMs in SOLEIL Global Orbit Feedback Systems	photon, dipole, operation, insertion	150
	N. Hubert, L. Cassinari, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	SOLEIL global orbit feedback systems (slow and fast), based on 122 electron Beam Position Monitor (e-BPM) readings, are in operation since 2008 and give very satisfying performances (0.1Hz-500Hz vertical noise below 300 nm RMS and long term (8h) drifts below 1μm RMS). Whereas each straight section is equipped with an upstream and downstream e-BPM, there is no e-BPM next to a dipole magnet. For that reason, photon BPMs (x-BPMs) in the dipole beamline frontends give additional information that can be used to better stabilize the source point in the dipoles. In fact x-BPMs provide also a better position angular measurement resolution, as they are located at 4 meters from the source point. Results presented in this paper show that vertical position stability on bending magnet beamlines can be improved by including their x-BPM measurements in the global orbit feedback systems. As a first step x-BPMs have been introduced in the Slow Orbit FeedBack system (SOFB) that corrects the orbit with a repetition rate of 0.1Hz. In a second step x-BPMs will be introduced in the Fast Orbit FeedBack system (FOFB) running at a repetition rate of 10 kHz.

MOPB70	The Synchrotron Radiation Diagnostic Line at SSRF	emittance, synchrotron, radiation, synchrotron-radiation	232
	J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, K.R. Ye, W.M. Zhou SINAP, Shanghai, People's Republic of China
	The synchrotron radiation photon beam line has been operated since 2009 at Shanghai Synchrotron Radiation Facility. There are two diagnostic beam lines of the storage ring behind bending magnet, which is employed conventional X-ray and visible imaging techniques. A synchrotron radiation (SR) interferometer using visible light region in order to measure the small transverse electron beam size (about 22μm); low emittance and a low coupling. A small off-axis mirror is set for the convenience of the observation. Wave front testing is used for interferometer to calibrate the deformation effect of optical components. An X-ray pin-hole camera is also employed in the diagnostics beamline of the ring to characterize beam. Typically the point spread function of the X-ray pinhole camera is calculated via analytical or numerical method. Those two methods check each other. As a result, the measurement with SR system has quite enough resolution of itself even though the absolute beam size acquired. The existed system suffers with dynamic problem for beam physics studies. It has been measured 2.8nm.rad in small emittance mode at SSRF.

TUCA01	Beam Instrumentation Global NETwork [BIGNet]: A Common Web Portal for Beam Instrumentalists	site, instrumentation, network, HOM	294
	J-J. Gras CERN, Geneva, Switzerland
	This document will present an initiative launched during the International Particle Accelerator Conference (IPAC11) to define and produce a common web portal for Beam Instrumentation, with the aim of allowing any beam instrumentalist to easily and efficiently: - find the laboratories with machines using beams of similar characteristics (particle type, total beam intensity, bunch intensity, frequency, energy) - find the person who is working there on the beam observable concerned (i.e. beam position, loss, intensity, transverse or longitudinal profile, tune) and how to contact him/her. - create discussion forums with the right audience on hot beam instrumentation topics or issues - advertise topical events and workshop - provide links towards documents describing system designs and performance assessments. - and possibly more This document will cover the status and prospects of the project with the aim to invite and welcome new laboratories to join the adventure.
	Slides TUCA01 [1.304 MB]

TUPA01	Diagnostics Update of the Taiwan Photon Source	diagnostics, storage-ring, booster, synchrotron	324
	C.H. Kuo, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, S.Y. Hsu, K.H. Hu, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a 3 GeV synchrotron light source which is being construction at campus of NSRRC. Various diagnostics are in implementation and will deploy in the future to satisfy stringent requirements of TPS for commissioning, top-up injection, and operation. These designs include beam intensity observation, trajectory and beam positions measurement, destructive profile measurement, synchrotron radiation monitors, beam loss monitors, orbit and bunch-by-bunch feedbacks, filling pattern and etc. are in final design phase. Progress of construction of the planned beam instrumentation system for the TPS will be summarized in this report.

TUPA26	Development of New BPM Electronics for the Swiss Light Source	FPGA, electronics, controls, hardware	399
	W. Koprek, R. Baldinger, R. Ditter, B. Keil, G. Marinkovic, M. Roggli, M. Stadler PSI, Villigen PSI, Switzerland
	PSI is currently developing new BPM electronics for the Swiss Light Source (SLS). Although the present "DBPM1" system that was designed 12 years ago still allows to achieve excellent beam stability and uptime, the development of a new system is motivated by long-term maintenance, improved performance in line with increasing user requirements, and new features and functionality provided by latest electronics technology. The new electronics is based on a generic modular BPM electronics platform developed by PSI that will also be used for linac based FELs like European XFEL and SwissFEL. The hardware and firmware architecture of the present prototypes as well as first test results will be presented.

TUPA27	Beam Test Results of Undulator Cavity BPM Electronics for the European XFEL	cavity, electronics, pick-up, undulator	404
	M. Stadler, R. Baldinger, R. Ditter, B. Keil, R. Kramert, G. Marinkovic, M. Roggli PSI, Villigen PSI, Switzerland D. Lipka, D. Nölle, M. Pelzer, S. Vilcins DESY, Hamburg, Germany
	Funding: Work supported by Swiss State Secretariat for Education and Research SER The European X-ray Free Electron Laser (E-XFEL) will use dual-resonator cavity BPMs (CBPMs) in the SASE undulators to measure and stabilize the beam trajectory. The BPM electronics is developed by PSI, while the pickup mechanics is developed by DESY. First beam tests with three adjacent pickups have been performed. The system architecture and algorithms, achieved performance and noise correlation measurements of the present electronics prototypes will be presented.

TUPA32	Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System	pick-up, controls, network, resonance	424
	K.M. Pollock, J.E. Dusatko, J.D. Fox, C.H. Rivetta, D. Van Winkle SLAC, Menlo Park, California, USA R. Secondo CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract #DE-AC02-76F00515 and the US LHC Accelerator Research Program. The 4GS/sec electron cloud and transverse mode coupled instability (TMCI) control system in development for the CERN Super Proton Synchrotron (SPS) requires 1.5GHz of processing bandwidth for the beam pickups and signal digitizer. An exponentially tapered stripline pickup has sufficient bandwidth, but has a phase response that distorts the beam signal in the time domain. We report on results from the design and implementation of an equalizer for the front end signal processing with correction for the pickup and cable responses. Using a model of the transfer functions for the pickups and the cabling, we determine a desired frequency response for the equalizer. Design for the circuitry, component value fitting is discussed as well as board construction and reduction of parasitic impedances. Finally, we show results from the measurement of an assembled equalizer, compare them with simulations and show beam signals from use at the SPS.

TUPA33	Fast Orbit Feedback Calculation Implementation for TPS	brilliance, controls, storage-ring, FPGA	428
	P. Leban, A. Bardorfer I-Tech, Solkan, Slovenia K.T. Hsu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	Fast orbit feedback (FOFB) application is planned for the Taiwan Photon Source (TPS) at storage ring commissioning. Part of the application is transferred to the beam position electronics which implements global orbit position data concentration, its processing and actuating the magnet power supply controllers via optical links. The beam position electronics (Libera Brilliance+) includes gigabit data exchange (GDX) modules with Virtex6 field programmable gate array. The feedback calculation algorithm is based on the SVD ' the PI controller will be applied in the modal space for individual eigenmodes. The calculation will be distributed to all GDX modules to reduce overall latency. Each GDX module will calculate either 4 vertical or 4 horizontal magnet corrections. This article presents details about the FOFB topology and implementation in the GDX module.

TUPA34	Inverse Response Matrix Computation for the Storage Ring Slow Orbit Feedback Control: Synthesized Topological Inversion Computation	controls, simulation, closed-orbit, betatron	431
	J.M. Lee, J.Y. Huang, C. Kim PAL, Pohang, Kyungbuk, Republic of Korea
	Using the derivative response matrix between BPM-data and MPS-setting, we described the inverse computation methodology for the storage ring orbit feedback control. Practically useful for SOFB with assistance of FOFB, the inverse of SVD manipulation is less efficient because a type of consecutive instability noise irreversibly accumulates in the beam trajectory deviation. In contrast, a novel numerical recipe based on topological math can lead to a self-consistent solution, dramatically suppressing ill-posed instability problems. This approach, known as a singularity regularization method, makes it feasible to compute a system-matched de-noising filter. The response matrix in H/V dimensions reflects a global beam dynamics along the storage ring lattices. Matrix refinement manipulatcan can be made to filter out the uncertainty of measurement errors escaping from beam dynamics constraints. Then we believe that algorithm filter can be effective as a software part of FOFB control. Our math STIC (Synthesized Topological Inversion Computation) appears to be the most reliable inverse computation methodology. Our PLS-2 response matrix will be presented to explain our ORBIT-STIC test. Jay Min Lee et al, presented at the 15th International Conference on X-ray Absorption Fine Structure, Beijing, July 22-28, 2012.

TUPA35	Digital Longitudinal Bunch-by-bunch Feedback System for the HLS II	kicker, cavity, impedance, storage-ring	434
	W.B. Li, P. Lu, B.G. Sun, F.F. Wu, W. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou USTC/NSRL, Hefei, Anhui, People's Republic of China
	In order to suppress the longitudinal coupled bunch instabilities, a digital longitudinal bunch-by-bunch feedback system will be developed in the upgrade project of Hefei Light Source (HLS II). The longitudinal feedback system consists of a pickup BPM, a front-end signal processor unit to detect the phase errors of all electron bunches, an iGp signal processor to calculate correction signals of those bunches, two RF power amplifiers, and a longitudinal kicker to supply proper correction energy kicks to individual bunches. A new waveguide overloaded cavity longitudinal feedback kicker has been designed with broadband and high shunt impedance. In this paper, we describe an overview of the new longitudinal feedback system.

TUPA37	FPGA Based Fast Orbit Feedback System for the Australian Synchrotron	FPGA, vacuum, fibre-optics, sextupole	437
	Y.E. Tan, T.D. Cornall, S.A. Griffiths, S. Murphy, E. Vettoor ASCo, Clayton, Victoria, Australia
	An initial design for a Fast Global Orbit Feedback System based on FPGAs has been proposed for the Australian Synchrotron Light Source (ASLS). The design uses a central processor (Xilinx Virtex 6) for all the computations and fast optical connections to distribute the computed data to corrector magnet power supplies. The network topology consists of two fibre optic rings. The first ring is used by the Libera Electron's to aggregate the beam position data at 10 kHz using Instrumentation Technologies' Grouping algorithm. The second ring is used to transmit the computed data. The cycle frequency of the feedback is 10 kHz with a targeted total latency of under 350 us. We shall give an overview of the design goals and discuss the merits of the current implementation. We shall also present the measured bandwidth of the stainless steel vacuum chamber and test results from initial prototyping work.

TUPA44	Status of the LCLS Experiment Timing System	timing, laser, experiment, electron	453
	J.C. Frisch, C. Bostedt, R.N. Coffee, A.R. Fry, N. Hartmann, J. May, D.J. Nicholson, S. Schorb, S.R. Smith SLAC, Menlo Park, California, USA
	Funding: Work Supported by Department of Energy Contract DE AC03 76SF00515 X-ray / optical laser pump - probe experiments are used for a significant fraction of the scientific work performed at LCLS. The experimental laser systems are locked to the timing of the electron beam through a combination of RF and optical fiber based systems. The remaining ~100 femtosecond RMS jitter of the X-rays relative to the optical laser is measured shot-to-shot by both a RF timing detector, and by direct X-ray to optical cross-correlation, and the result is used to correct the experiment timing to 10s of femtoseconds. We present the present status of the system and plans for future upgrades.

THCB02	Twisting Wire Scanner	vacuum, software, controls, monitoring	607
	V. Gharibyan, A. Delfs, I. Krouptchenkov, D. Nölle, H. Tiessen, M. Werner, K. Wittenburg DESY, Hamburg, Germany
	A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors will be presented.
	Slides THCB02 [5.591 MB]

Paper

Title

Other Keywords

Page

MOCB01

Beam Instrumentation for the SuperKEKB Rings

detector, kicker, radiation, damping

6

H. Fukuma, A. Arinaga, J.W. Flanagan, H. Ikeda, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
KEK, Ibaraki, Japan
G. Bonvicini, H. Farhat, R.S. Gillard
Wayne State University, USA
G.S. Varner
University of Hawaii, Honolulu, HI, USA

The electron-positron collider KEKB B-factory is currently being upgraded to SuperKEKB. The design luminosity of 8 x 10³⁵ /cm²/s will be achieved using beams with low emittance of several nm and doubling beam currents to 2.6 A in the electron ring (HER) and 3.6 A in the positron ring (LER). A beam position monitor (BPM) system of HER and LER will be equipped with super-heterodyne detectors, turn by turn log ratio detectors with fast gates to measure optics parameters during collision operation and detectors of BPMs near the collision point (IP) for orbit feedback to maintain stable collision. New X-ray beam profile monitors based on the coded aperture method will be installed aiming at bunch by bunch measurement of the beam profile. A large angle beamstrahlung monitor detecting polarization of the synchrotron radiation generated by beam-beam interaction will be installed near IP to obtain information about the beam-beam geometry. The bunch by bunch feedback system will be upgraded using low noise frontend electronics and new 12 bits iGp digital filters. An overview of beam instrumentation of SuperKEKB rings will be given in this paper.

Slides MOCB01 [8.073 MB]

MOPA20

Development of 3D EO-Sampling System for the Ultimate Temporal Resolution

FEL, laser, electron, timing

98

K. Ogawa, H. Tomizawa
RIKEN SPring-8 Center, Sayo-cho, Sayo-gun, Hyogo, Japan
S. Matsubara, Y. Okayasu
JASRI/SPring-8, Hyogo, Japan

We have been developing three dimensional bunch charge distribution (3D-BCD) monitor for FEL seeded with high-order harmonic (HH) pulse. 3D-BCD is based on EO-sampling technique with multiple EO crystal detectors in the manner of spectral decoding. Using this 3D-EO sampling technique, the positioning and timing of electron bunch is obtained in real-time with non-destructive measurement. For obtaining the high temporal resolution, an octave broadband probe laser with linear chirp rate of 1 fs/nm is required. We are developing an EO-probe laser pulse with ~10 μJ pulse energy and the bandwidth over 300 nm (FWHM). For meet these bandwidth and pulse energy, this EO-probe pulse is using a supercontinuum generated by photonic crystal fiber (PCF) and amplified with optical parametric amplification (OPA). Especially, for amplification with maintaining octave bandwidth, non-collinear OPA (NOPA) using BBO crystal and a pump source with a wavelength of 450 nm are adopted. The EO-probe pulse energy of 10 μJ provides for high S/N ratio to each detector and the bandwidth of 300 nm with 300 fs pulse duration allows the measurement for the 30 fs electron bunch duration (FWHM).

MOPA21

Improvement of the SIAM Photon Source Storage Ring BPM System

storage-ring, shielding, photon, operation

101

S. Klinkhieo, S. Boonsuya, P. Klysubun, S. Krainara, P. Songsiriritthigul, P. Sudmuang, N. Suradet, S. Tesprasitte
SLRI, Nakhon Ratchasima, Thailand
J.-R. Chen, H.P. Hsueh, Y.-H. Liu
NSRRC, Hsinchu, Taiwan

This report describes the improvement of the Beam Position Monitoring (BPM) systems for the 1.2 GeV storage ring of the Siam Photon Source (SPS). The systematic studies and investigations for improving the machine performance, and storage ring BPM system has been carried out in the last few years. Some major technical problems have been found and solved. The inefficiency and unreliability of the original BPM system were also identified. They are mainly caused due to the use of low quality signal and improper installation of cables. Detailed descriptions of the replacement with the higher quality (lower loss and better interference shielding) BPM cables and implementation of a separated cable trays for the BPM cables, as well as the work on BPM electronic board calibration will be described. The measurement results before and after the improvement of the BPM system will also be presented.

MOPA34

Improvement of Hardware and Software Setup for the Acquisition and Processing of SIAM Photon Source BPM Signal

storage-ring, photon, PLC, software

130

N. Suradet, S. Boonsuya, S. Klinkhieo, P. Klysubun, S. Krainara, C.P. Preecha, P. Sudmuang
SLRI, Nakhon Ratchasima, Thailand

Data acquisition and processing system has been developed for the Siam Photon Source storage ring BPM system in order to improve monitoring and logging performances. BPM readout, i.e. scanning of BPM electrode voltage outputs and subsequently converting to X-Y position values, is now performed by an upgraded Programmable Logic Controller (PLC) with higher bit resolution (16-bit) analog-to-digital converter (ADC). Moving averaging is then performed on the obtained BPM data utilizing a LabVIEW code to reduce background noise during on-line measurement. All data is then stored on a dedicated computer serving as a central data logging system, which can be remotely accessed via a network communication link. In this report, details of the new setup will be presented, and comparison will be made between the performance of the new and previous setups, together with suggestions on further improvements.

MOPA35

Design Status of the European X-FEL Tranverse Intra Bunch Train Feedback

kicker, undulator, FPGA, cavity

133

B. Keil, R. Baldinger, C.D. Beard, M.M. Dehler, W. Koprek, G. Marinkovic, M. Roggli, M. Rohrer, M. Stadler, D.M. Treyer
PSI, Villigen PSI, Switzerland
V. Balandin, W. Decking, N. Golubeva
DESY, Hamburg, Germany

Funding: Work supported by Swiss State Secretariat for Education and Research SER
The European X-Ray Free Electron Laser (E-XFEL) will have a fast transverse intra-bunch train feedback (IBFB) system to stabilize the beam position in the SASE undulators. E-XFEL bunch trains consist of up to 2700 bunches with a minimum bunch spacing of 222ns and typ. 10Hz train repetition rate. The IBFB will measure the positions of each bunch in the bunch train, and apply intra-train feedback corrections with fast kickers, in addition to a feed-forward correction for reproducible trajectory perturbations. By achieving a feedback loop latency in the order of one microsecond, the IBFB will allow the beam position to converge quickly to the nominal orbit as required for stable SASE operation. The latest conceptual design of the IBFB and the status of IBFB components will be presented.

MOPA37

Reliable Beam-Intensity Control Technique at the HIMAC Synchrotron

extraction, controls, synchrotron, ion

143

K. Mizushima, T. Furukawa, Y. Hara, Y. Iwata, K. Katagiri, K. Noda, S. Sato, T. Shirai
NIRS, Chiba-shi, Japan

The carbon-ion beam is slowly extracted from the Heavy Ion Medical Accelerator in Chiba (HIMAC) synchrotron using the third-order resonance with the RF-knockout method for scanned carbon-ion therapy. However, an overshoot of the beam spill at the start of extraction is often induced by a slight variation of the beam emittance in operation cycles. It brings dose hot spot inside the target volume, because the tolerable beam-intensity in scanning irradiation is low. We have added short extraction, called preliminary extraction, before irradiation in order to remove the uncontrollable spilled particles. During preliminary extraction, it is necessary to prevent the beam delivering to the patient. Therefore, a fast beam shutter on which an ionization chamber is mounted was developed, and it was installed in the extraction line. The fast shutter enables us to switch from preliminary extraction to irradiation within 100 ms, and the reliability of the beam-intensity control system was drastically improved by the preliminary extraction technique.

MOPA39

Introduction of Photon BPMs in SOLEIL Global Orbit Feedback Systems

photon, dipole, operation, insertion

150

N. Hubert, L. Cassinari, L.S. Nadolski
SOLEIL, Gif-sur-Yvette, France

SOLEIL global orbit feedback systems (slow and fast), based on 122 electron Beam Position Monitor (e-BPM) readings, are in operation since 2008 and give very satisfying performances (0.1Hz-500Hz vertical noise below 300 nm RMS and long term (8h) drifts below 1μm RMS). Whereas each straight section is equipped with an upstream and downstream e-BPM, there is no e-BPM next to a dipole magnet. For that reason, photon BPMs (x-BPMs) in the dipole beamline frontends give additional information that can be used to better stabilize the source point in the dipoles. In fact x-BPMs provide also a better position angular measurement resolution, as they are located at 4 meters from the source point. Results presented in this paper show that vertical position stability on bending magnet beamlines can be improved by including their x-BPM measurements in the global orbit feedback systems. As a first step x-BPMs have been introduced in the Slow Orbit FeedBack system (SOFB) that corrects the orbit with a repetition rate of 0.1Hz. In a second step x-BPMs will be introduced in the Fast Orbit FeedBack system (FOFB) running at a repetition rate of 10 kHz.

MOPB70

The Synchrotron Radiation Diagnostic Line at SSRF

emittance, synchrotron, radiation, synchrotron-radiation

232

J. Chen, Z.C. Chen, G.Q. Huang, Y.B. Leng, K.R. Ye, W.M. Zhou
SINAP, Shanghai, People's Republic of China

The synchrotron radiation photon beam line has been operated since 2009 at Shanghai Synchrotron Radiation Facility. There are two diagnostic beam lines of the storage ring behind bending magnet, which is employed conventional X-ray and visible imaging techniques. A synchrotron radiation (SR) interferometer using visible light region in order to measure the small transverse electron beam size (about 22μm); low emittance and a low coupling. A small off-axis mirror is set for the convenience of the observation. Wave front testing is used for interferometer to calibrate the deformation effect of optical components. An X-ray pin-hole camera is also employed in the diagnostics beamline of the ring to characterize beam. Typically the point spread function of the X-ray pinhole camera is calculated via analytical or numerical method. Those two methods check each other. As a result, the measurement with SR system has quite enough resolution of itself even though the absolute beam size acquired. The existed system suffers with dynamic problem for beam physics studies. It has been measured 2.8nm.rad in small emittance mode at SSRF.

TUCA01

Beam Instrumentation Global NETwork [BIGNet]: A Common Web Portal for Beam Instrumentalists

site, instrumentation, network, HOM

294

J-J. Gras
CERN, Geneva, Switzerland

This document will present an initiative launched during the International Particle Accelerator Conference (IPAC11) to define and produce a common web portal for Beam Instrumentation, with the aim of allowing any beam instrumentalist to easily and efficiently: - find the laboratories with machines using beams of similar characteristics (particle type, total beam intensity, bunch intensity, frequency, energy) - find the person who is working there on the beam observable concerned (i.e. beam position, loss, intensity, transverse or longitudinal profile, tune) and how to contact him/her. - create discussion forums with the right audience on hot beam instrumentation topics or issues - advertise topical events and workshop - provide links towards documents describing system designs and performance assessments. - and possibly more This document will cover the status and prospects of the project with the aim to invite and welcome new laboratories to join the adventure.

Slides TUCA01 [1.304 MB]

TUPA01

Diagnostics Update of the Taiwan Photon Source

diagnostics, storage-ring, booster, synchrotron

324

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

Taiwan Photon Source (TPS) is a 3 GeV synchrotron light source which is being construction at campus of NSRRC. Various diagnostics are in implementation and will deploy in the future to satisfy stringent requirements of TPS for commissioning, top-up injection, and operation. These designs include beam intensity observation, trajectory and beam positions measurement, destructive profile measurement, synchrotron radiation monitors, beam loss monitors, orbit and bunch-by-bunch feedbacks, filling pattern and etc. are in final design phase. Progress of construction of the planned beam instrumentation system for the TPS will be summarized in this report.

TUPA26

Development of New BPM Electronics for the Swiss Light Source

FPGA, electronics, controls, hardware

399

W. Koprek, R. Baldinger, R. Ditter, B. Keil, G. Marinkovic, M. Roggli, M. Stadler
PSI, Villigen PSI, Switzerland

PSI is currently developing new BPM electronics for the Swiss Light Source (SLS). Although the present "DBPM1" system that was designed 12 years ago still allows to achieve excellent beam stability and uptime, the development of a new system is motivated by long-term maintenance, improved performance in line with increasing user requirements, and new features and functionality provided by latest electronics technology. The new electronics is based on a generic modular BPM electronics platform developed by PSI that will also be used for linac based FELs like European XFEL and SwissFEL. The hardware and firmware architecture of the present prototypes as well as first test results will be presented.

TUPA27

Beam Test Results of Undulator Cavity BPM Electronics for the European XFEL

cavity, electronics, pick-up, undulator

404

M. Stadler, R. Baldinger, R. Ditter, B. Keil, R. Kramert, G. Marinkovic, M. Roggli
PSI, Villigen PSI, Switzerland
D. Lipka, D. Nölle, M. Pelzer, S. Vilcins
DESY, Hamburg, Germany

Funding: Work supported by Swiss State Secretariat for Education and Research SER
The European X-ray Free Electron Laser (E-XFEL) will use dual-resonator cavity BPMs (CBPMs) in the SASE undulators to measure and stabilize the beam trajectory. The BPM electronics is developed by PSI, while the pickup mechanics is developed by DESY. First beam tests with three adjacent pickups have been performed. The system architecture and algorithms, achieved performance and noise correlation measurements of the present electronics prototypes will be presented.

TUPA32

Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System

pick-up, controls, network, resonance

424

K.M. Pollock, J.E. Dusatko, J.D. Fox, C.H. Rivetta, D. Van Winkle
SLAC, Menlo Park, California, USA
R. Secondo
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract #DE-AC02-76F00515 and the US LHC Accelerator Research Program.
The 4GS/sec electron cloud and transverse mode coupled instability (TMCI) control system in development for the CERN Super Proton Synchrotron (SPS) requires 1.5GHz of processing bandwidth for the beam pickups and signal digitizer. An exponentially tapered stripline pickup has sufficient bandwidth, but has a phase response that distorts the beam signal in the time domain. We report on results from the design and implementation of an equalizer for the front end signal processing with correction for the pickup and cable responses. Using a model of the transfer functions for the pickups and the cabling, we determine a desired frequency response for the equalizer. Design for the circuitry, component value fitting is discussed as well as board construction and reduction of parasitic impedances. Finally, we show results from the measurement of an assembled equalizer, compare them with simulations and show beam signals from use at the SPS.

TUPA33

Fast Orbit Feedback Calculation Implementation for TPS

brilliance, controls, storage-ring, FPGA

428

P. Leban, A. Bardorfer
I-Tech, Solkan, Slovenia
K.T. Hsu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

Fast orbit feedback (FOFB) application is planned for the Taiwan Photon Source (TPS) at storage ring commissioning. Part of the application is transferred to the beam position electronics which implements global orbit position data concentration, its processing and actuating the magnet power supply controllers via optical links. The beam position electronics (Libera Brilliance+) includes gigabit data exchange (GDX) modules with Virtex6 field programmable gate array. The feedback calculation algorithm is based on the SVD ' the PI controller will be applied in the modal space for individual eigenmodes. The calculation will be distributed to all GDX modules to reduce overall latency. Each GDX module will calculate either 4 vertical or 4 horizontal magnet corrections. This article presents details about the FOFB topology and implementation in the GDX module.

TUPA34

Inverse Response Matrix Computation for the Storage Ring Slow Orbit Feedback Control: Synthesized Topological Inversion Computation

controls, simulation, closed-orbit, betatron

431

J.M. Lee, J.Y. Huang, C. Kim
PAL, Pohang, Kyungbuk, Republic of Korea

Using the derivative response matrix between BPM-data and MPS-setting, we described the inverse computation methodology for the storage ring orbit feedback control. Practically useful for SOFB with assistance of FOFB, the inverse of SVD manipulation is less efficient because a type of consecutive instability noise irreversibly accumulates in the beam trajectory deviation. In contrast, a novel numerical recipe based on topological math can lead to a self-consistent solution, dramatically suppressing ill-posed instability problems. This approach, known as a singularity regularization method, makes it feasible to compute a system-matched de-noising filter. The response matrix in H/V dimensions reflects a global beam dynamics along the storage ring lattices. Matrix refinement manipulatcan can be made to filter out the uncertainty of measurement errors escaping from beam dynamics constraints. Then we believe that algorithm filter can be effective as a software part of FOFB control. Our math STIC (Synthesized Topological Inversion Computation*) appears to be the most reliable inverse computation methodology. Our PLS-2 response matrix will be presented to explain our ORBIT-STIC test.
* Jay Min Lee et al, presented at the 15th International Conference on X-ray Absorption Fine Structure, Beijing, July 22-28, 2012.

TUPA35

Digital Longitudinal Bunch-by-bunch Feedback System for the HLS II

kicker, cavity, impedance, storage-ring

434

W.B. Li, P. Lu, B.G. Sun, F.F. Wu, W. Xu, Y.L. Yang, Z.R. Zhou, J.Y. Zou
USTC/NSRL, Hefei, Anhui, People's Republic of China

In order to suppress the longitudinal coupled bunch instabilities, a digital longitudinal bunch-by-bunch feedback system will be developed in the upgrade project of Hefei Light Source (HLS II). The longitudinal feedback system consists of a pickup BPM, a front-end signal processor unit to detect the phase errors of all electron bunches, an iGp signal processor to calculate correction signals of those bunches, two RF power amplifiers, and a longitudinal kicker to supply proper correction energy kicks to individual bunches. A new waveguide overloaded cavity longitudinal feedback kicker has been designed with broadband and high shunt impedance. In this paper, we describe an overview of the new longitudinal feedback system.

TUPA37

FPGA Based Fast Orbit Feedback System for the Australian Synchrotron

FPGA, vacuum, fibre-optics, sextupole

437

Y.E. Tan, T.D. Cornall, S.A. Griffiths, S. Murphy, E. Vettoor
ASCo, Clayton, Victoria, Australia

An initial design for a Fast Global Orbit Feedback System based on FPGAs has been proposed for the Australian Synchrotron Light Source (ASLS). The design uses a central processor (Xilinx Virtex 6) for all the computations and fast optical connections to distribute the computed data to corrector magnet power supplies. The network topology consists of two fibre optic rings. The first ring is used by the Libera Electron's to aggregate the beam position data at 10 kHz using Instrumentation Technologies' Grouping algorithm. The second ring is used to transmit the computed data. The cycle frequency of the feedback is 10 kHz with a targeted total latency of under 350 us. We shall give an overview of the design goals and discuss the merits of the current implementation. We shall also present the measured bandwidth of the stainless steel vacuum chamber and test results from initial prototyping work.

TUPA44

Status of the LCLS Experiment Timing System

timing, laser, experiment, electron

453

J.C. Frisch, C. Bostedt, R.N. Coffee, A.R. Fry, N. Hartmann, J. May, D.J. Nicholson, S. Schorb, S.R. Smith
SLAC, Menlo Park, California, USA

Funding: Work Supported by Department of Energy Contract DE AC03 76SF00515
X-ray / optical laser pump - probe experiments are used for a significant fraction of the scientific work performed at LCLS. The experimental laser systems are locked to the timing of the electron beam through a combination of RF and optical fiber based systems. The remaining ~100 femtosecond RMS jitter of the X-rays relative to the optical laser is measured shot-to-shot by both a RF timing detector, and by direct X-ray to optical cross-correlation, and the result is used to correct the experiment timing to 10s of femtoseconds. We present the present status of the system and plans for future upgrades.

THCB02

Twisting Wire Scanner

vacuum, software, controls, monitoring

607

V. Gharibyan, A. Delfs, I. Krouptchenkov, D. Nölle, H. Tiessen, M. Werner, K. Wittenburg
DESY, Hamburg, Germany

A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors will be presented.

Slides THCB02 [5.591 MB]