IBIC2012 - List of Keywords (controls)

Paper	Title	Other Keywords	Page
MOPA04	An Electron Beam Profile Monitor for the Race-track Microtron	electron, microtron, experiment, operation	54
	S.D. Dhole, V.N. Bhoraskar, B.J. Patil, N.S. Shinde University of Pune, Pune, India
	In electron irradiation experiments on materials such as semiconductors, solar cells etc., an uniformity and the charge distribution in the electron beam is very important. Therefore, an electron beam current monitor and its electronic system have been designed and built to measure the distribution of a beam current either in the horizontal or vertical direction along with the beam dimensions. To obtain X-Y beam profile, a special type of Faraday Cup was designed which mainly consists of charge collecting electrodes made up of thin copper strips. Each strip having dimensions 0.5 mm wide, 4 mm thick and 20 mm long were fixed parallel to each other and separation between them was ~ 0.5 mm. This multi electrode Faraday was mounted at the extraction port of the Race Track Microtron, where 1 MeV electron beam allowed to fall on it. The beam characterization in the form of current and uniformity were measured. The current from each strip were measured using an electronic circuit developed based on the multiplexing principle. The uniformity of the beam can be measured with an accuracy of 10%. The minimum and maximum dimensions which can be measured are 3 mm and 15 mm respectively.

MOPA08	Various Usages of Wall Current Monitors for Commissioning of RF Systems in J-PARC Synchrotrons	cavity, impedance, synchrotron, bunching	63
	F. Tamura, M. Nomura, A. Schnase, T. Shimada, M. Yamamoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii KEK, Tokai, Ibaraki, Japan
	Wall current monitors (WCM) for rf system commissioning are installed in the J-PARC synchrotrons, the RCS and the MR. The WCM signals are used as the input of the beam loading compensation system, and also used diagnosis to adjust the rf system parameters. Since the rf and beam frequency is in the range of a few MHz, direct measurement of the WCM signals is possible. For the diagnosis, the WCM signals are taken by an oscilloscope with the revolution clock signal generated by the LLRF control system, and slices of the WCM waveform with lengths of the revolution periods are generated. By stacking the slices, one can get a mountain plot, which shows motions of bunches and variations of the bunch shapes. Also, time variations of the bunching factor, which are important for acceleration of high intensity proton beams, are obtained. The harmonic analysis is performed on the WCM signal and the cavity voltage monitor signal. By using complex amplitudes of them, one can calculate the impedance seen by the beam. In this presentation, we show examples of the analyses described above. The rf parameters for high intensity beams have been successfully adjusted by using these analyses.

MOPA28	Turn-by-turn BPM System using Coaxial Switches and ARM Microcontroller at UVSOR	electron, injection, betatron, storage-ring	112
	T. Toyoda IMS, Okazaki, Japan K. Hayashi, M. Katoh UVSOR, Okazaki, Japan
	A major upgrade of the electron storage ring at UVSOR (Institute for Molecular Science, Japan) started from April 2012. To assist the commissioning procedure, we have developed a turn-by-turn Beam Position Monitor (BPM) system which consists of a signal switching circuit, a digital oscilloscope and software. The storage ring has 24 BPMs, each of which consists of four electrodes. By using the signal switching circuit, we can select one BPM from eight BPM's. The four signals from the BPM are sent to a digital oscilloscope and are recorded. In the switching circuit, coaxial switches of SPDT (Single Pole Dual Throw) and SP4T type are used. To control coaxial switches, we adopted 'mbed', the ARM microcontroller development kit. The 'mbed' stores the control applications configured in the HTML file and JavaScript library which can handle multiple I/O ports. It responds as a HTTP server and the control application runs on a Web browser. By clicking buttons with a mouse, we can control the I/O ports of 'mbed' through JavaScript library and accordingly can control coaxial switches. In the presentation, we will report the detail of the developed BPM system and its performance.

MOPA31	Design and Fabrication of the Stripline BPM at ESS-Bilbao	pick-up, coupling, impedance, electronics	122
	S. Varnasseri, I. Arredondo, D. Belver, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira ESS Bilbao, LEIOA, Spain V. Etxebarria, J. Jugo, J. Portilla University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain
	A Stripline type BPM is designed and fabricated at ESSB. In order to compare, in the future, the functionality and response of the previous BPM capacitive pick-ups design with stripline, a design for stripline BPM is proposed. The design is based on travelling wave electrodes principles to detect the transverse position of the beam in the vacuum chamber. In the design of stripline setup, it has been considered to keep the comparison conditions with pick-ups as similar as possible. The length of strip electrodes is 200 mm and the coverage angle is 0.952 rad. The structure is rotationally pi/2 symmetric and the alignment of electrodes are pi/4, 3pi/, 5pi/4 and 7pi/4. The design is optimized for a frequency of 352 MHz, however it can function on a wide range of frequencies out coming from the measurement results. Striplines in general have well defined behavior even for low beta and low intensity beams as well as functionality at low and high frequencies. A report on the design and characteristics measurement of Stripline will be presented. The characteristics like frequency range, electrodes insulation, electrode response, sensitivities to beam power and position will be presented.

MOPA36	Development of Bunch Current and Oscillation Recorder for SuperKEKB Accelerator	FPGA, timing, EPICS, damping	138
	M. Tobiyama, J.W. Flanagan KEK, Ibaraki, Japan
	A High-speed digital signal memory has been developed for the bunch current and oscillation recorder for SuperKEKB. The memory consists of an 8-bit ADC and a FPGA daughter card with Spartan6 and DDR2 memories commercially available on a double width VME card. The block-RAM on the FPGA is used to transfer bunch current data with low latency for prompt bunch current measurements, and the large DDR2 memory is used for long-duration position recording, such as post-mortem bunch oscillation recording. The performance of the board, including data transfer rate, will be presented.

MOPA37	Reliable Beam-Intensity Control Technique at the HIMAC Synchrotron	extraction, synchrotron, ion, feedback	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.

MOPB51	Beam Monitors of NIRS Fast Scanning System for Particle Therapy	ion, cathode, monitoring, vacuum	182
	T. Furukawa, Y. Hara, T. Inaniwa, K. Katagiri, K. Mizushima, K. Noda, S. Sato, T. Shirai, E. Takeshita NIRS, Chiba-shi, Japan
	At National Institute of Radiological Sciences, more than 6500 patients have been successfully treated by carbon beams since 1994. The successful results of treatments have led us to construct a new treatment facility equipped with three-dimensional pencil beam scanning irradiation system. The commissioning of NIRS fast scanning system installed into the new facility was started in September 2010, and the treatment with scanned ion beam was started in May 2011. In the scanning delivery system, beam monitors are some of the most important components. In order to measure and control the dose of each spot, the main and the sub ionization chambers are placed separately as flux monitors. For monitoring of the scanned beam position, a beam position monitor, which is multi-wire proportional chamber, is installed just downstream from the flux monitors. This monitor can output not only the beam position but also the 2D fluence distribution using dynamic fast convolution algorithm. In this paper, the design and the commissioning of these monitors are described.

MOPB58	Beam Quality Ensuring Instruments at the Gunma University Heavy-ion Medical Center	ion, linac, heavy-ion, synchrotron	209
	E. Takeshita, T. Kanai, M. Kawashima, Y. Kubota, A. Matsumura, A. Saito, H. Shimada, M. Tashiro, K. Torikai, S. Yamada, K. Yusa Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan
	Since the carbon beam based cancer therapy started at the Gunma University Heavy-ion Medical Center in the year 2010, the total number of treated patients increased to 306 by the end of fiscal 2011. This year, already 82 patients have been treated. In order to control the medical beam qualities, i.e., position, size and intensity of the beam, monitoring devices were mounted on the high-energy beam transport line. The beam position and size can be measured and tuned with a screen monitor, which consists of a fluorescent screen and a CCD camera. Just before starting the treatment, the operators check for a proper beam position by strip-line monitor measurements placed close to the iso center. The irradiation dose is controlled using two secondary electron emission monitors placed before the wobbling magnets. This dose monitor is helpful for high fluence of the beam because it's less affected by the recombination effect. In the conference, we would like to report on details of each monitoring device.

MOPB63	Emittance Measurement using X-ray Beam Profile Monitor at KEK-ATF	emittance, software, damping, electron	215
	T. Naito, H. Hayano, K. Kubo, S. Kuroda, N. Nakamura, T. Okugi, H. Sakai, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	The X-ray profile monitor (XPM) is used for the beam size measurement in the KEK-ATF damping ring(ATF-DR) at all times. The XPM consists of a crystal monochromator, two Fresnel zone plates(FZPs) and X-ray CCD camera. Two FZPs make the imaging optics. The design resolution of the selected wavelength 3.8nm is less than 1μm, which is sufficiently small for the emittance measurement of the ATF-DR. However, the measured results at the early stage were affected by the mechanical vibration. This paper describes the improvement of the resolution and the measurement results.

MOPB76	Evaluation of a Fluorescent Screen with a CCD System for Quality Assurance in Heavy-Ion Beam Scanning Irradiation System	ion, heavy-ion, radiation, background	249
	Y. Hara, T. Furukawa, T. Inaniwa, K. Mizushima, K. Noda, S. Sato, T. Shirai, E. Takeshita NIRS, Chiba-shi, Japan
	The precise heavy-ion therapy such as the scanning irradiation system necessitates the precise quality assurance (QA) procedures to verify the performance of therapeutic scanned ion beams. To evaluate the uniformity of the 2D field, radiographic film is used due to its high spatial resolution and suit for the measurements of the integral dose. However, this technique is time consuming. Thus, we developed the QA tool with high spatial resolution to verify accuracy of the lateral size, position and uniformity of scanned ion beams in clinical application at the HIMAC, which we called the QA-SCN. The QA-SCN consists of a fluorescent screen, a CCD camera, a mirror, camera controllers and a dark box to protect against surrounding light. In this paper, to evaluate the performance of the QA-SCN, we compared the results obtained by using it with the measurements by radiographic film performed in the same experimental conditions. Also, we verified several types of corrections about errors, e.g. background, vignetting, to distort the measurement results. As a result, we confirmed that the QA-SCN can be used as the system for QA procedures of therapeutic scanned ion beams.

TUPA06	Pulsed Electron Beam Current and Flux Monitor for the Race-track Microtron	electron, induction, microtron, experiment	337
	S.D. Dhole, S. Akhter, V.N. Bhoraskar, B.J. Patil, N.S. Shinde University of Pune, Pune, India
	In electron irradiation experiments on the materials, a true current of the electron beam is to be known to calculate the electron fluence received by the sample. Therefore, a pulsed electron beam current and flux monitor alongwith electronic system for an electron accelerator called Race-Track Microtron has been designed and developed. The sensing device used was a ferrite core having suitable number of turns of copper wire wound around it, through which the electron beam was passed without loss in the intensity. With an appropriate developed electronic circuit, the instantaneous value of the induced voltage was measured which in turn provides value of the electron beam pulsed current. The total charge passed through the ferrite core per unit time was therefore recorded and an integrated value of the total charge in a given period could be derived. This system can be used to measure the electron flux in the range from 10⁸ electron/cm² to 10¹⁶ electron/cm². Moreover, this system has been used successfully in a few electron irradiation experiments where the knowledge of the electron fluence received by the sample is required.

TUPA09	System Architecture for Measuring and Monitoring Beam Losses in the Injector Complex at CERN	FPGA, detector, monitoring, injection	347
	C. Zamantzas, M. Alsdorf, B. Dehning, S. Jackson, M. Kwiatkowski, W. Viganò CERN, Geneva, Switzerland
	The strategy for beam setup and machine protection of the accelerators at the European Organisation for Nuclear Research (CERN) is mainly based on its Beam Loss Monitoring (BLM) systems. For their upgrade to higher beam energies and intensities, a new BLM system is under development with the aim of providing faster measurement updates with higher dynamic range and the ability to accept more types of detectors as input compared to its predecessors. In this paper, the architecture of the complete system is explored giving an insight to the design choices made to provide a highly reconfigurable system that is able to fulfil the different requirements of each accelerator using reprogrammable devices.

TUPA12	A DBPM Calibration Method Implemented on FPGA	FPGA, experiment, operation, linac	358
	X.D. Sun, Y.B. Leng SINAP, Shanghai, People's Republic of China
	An calibration method on the four channels of DBPM is discussed . Using interpolation, the method is implemented on FPGA , which can handle the data on-line. The calibration algorithm is mono-channel dependent and is intended to solve the beam current dependence problem and increase resolution. Orientations of the method is presented. Basic design diagrams of the pipelined FPGA modules are listed and comparisons are made before and after the calibration

TUPA17	TPS BPM Electronics Performance Measurement and Statistics	electronics, FPGA, EPICS, booster	369
	P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo NSRRC, Hsinchu, Taiwan
	The new BPM electronics Libera Brilliance Plus are developed for Taiwan Photon Source (TPS) which is a 3 GeV synchrotron light source constructed at NSRRC. This new BPM electronics can accommodate four BPM modules with integrated FPGA-based hardware. The preliminary test for the first arrival unit had been performed in the TLS (Taiwan Light Source) and had shown nearly equal performance compared with Libera Brilliance. The extra 75 sets had been delivered in 2011 and 2012. Performance of each unit are individually tested and measured.

TUPA26	Development of New BPM Electronics for the Swiss Light Source	FPGA, electronics, feedback, 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.

TUPA32	Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System	pick-up, feedback, 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, feedback, 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	feedback, 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.

TUPA42	Diagnostics Beamline Optimisation and Image Processing for Sub-ps Streak Camera Bunch Length Measurement	synchrotron, optics, synchrotron-radiation, radiation	445
	C.A. Thomas, I.P.S. Martin, G. Rehm Diamond, Oxfordshire, United Kingdom
	Low alpha beam lattice at Diamond can generate bunch length as small as 0.6ps. In order to be able to measure reliably such a short bunch, we have been optimising the optical design of the visible Diagnostics beamline, and we have implemented image processing, taking into account the point spread function of the streak camera. The beamline optical design has removed a large chirp of 15ps/150nm bandwidth to 2ps /200nmbandwidth. It has also permit the transport of almost all the available power, increasing the power by a factor 20, yet maintaining the possibility to focus the beam down to less than 20um into the streak camera for the best static streak camera point spread function. The deconvolution technique implemented extends the performance of the streak camera to bunch length measurement much smaller than the 1ps PSF of the streak camera. In this paper we present these two essential features required to measure sub-ps bunched with a streak camera.

TUPB48	Beam Instrumentation for the COSY Electron Cooler	electron, gun, detector, laser	468
	V. Kamerdzhiev, L.J. Mao, K. Reimers FZJ, Jülich, Germany E.A. Bekhtenev, V.N. Bocharov, M.I. Bryzgunov, A.V. Bubley, A.P. Denisov, G.V. Karpov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva BINP SB RAS, Novosibirsk, Russia J. Dietrich HIM, Mainz, Germany
	The report deals with beam instrumentation of the electron cooler for COSY storage ring. The electron cooler is an electrostatic accelerator designed for beam energy up to 2 MeV and electron current up to 3 A with recuperation. The electron beam is immersed in longitudinal magnetic field so the electron motion is strongly magnetized. The control electrode in the electron gun is composed of four electrically isolated sectors. Applying AC voltage to one sector allows tracing of motion of that particular part of the beam. The electron beam shape is registered with the combination of 4-sector electron gun and the BPMs. This method allows observing both dipole and quadruple (galloping) modes of electron beam oscillation. Compass probe for measuring and tuning the direction of magnetic field in the cooling section is described. A profile monitor based on a few small Faraday cups for measuring distribution of the electron beam is presented.

TUPB61	The First Experience with the LHC Beam Gas Ionisation Monitor	electron, injection, emittance, proton	489
	M. Sapinski, W. Andreazza, B. Dehning, A. Guerrero, M. Patecki, R. Versteegen CERN, Geneva, Switzerland
	The Beam Gas Ionisation Monitors (BGI) are used to continuously measure the beam size at the LHC. This paper describes the detectors and their operation and discusses the issues encountered during the commissioning. It also discusses the various calibration procedures used to correct for non-uniformity of Multi-Channel plates and to correct the beam size for effects affecting the electron trajectory after ionisation.

TUPB81	Design of the Beam Profile Monitors for the SXFEL Facility	detector, electron, linac, FEL	534
	L.Y. Yu, J. Chen, Y.B. Leng, K.R. Ye, W.M. Zhou SINAP, Shanghai, People's Republic of China
	The Shanghai X-ray Free Electron Laser Facility will begin construction at next year. The linac electron beam energy is 0.84 GeV. Over 50 beam profile monitors with OTR and YaG screen will be installed along the linac and undulators. The profile monitor system design is a challenging task, since the system has to measure transverse electron beam sizes from millimeter down to 40μm scale with a 20μm resolution and 50μm repeat positioning accuracy. This paper describes the design of the mechanical detector , the integrated step-servo motor controlling system, the beam imaging system, as well as the software system.

WEIB02	Review of Reliability Concepts Applied to Beam Loss Monitoring Systems	survey, detector, operation, monitoring	550
	B. Dehning CERN, Geneva, Switzerland
	Beam loss measurement systems are often used for the protection of equipment against the damage caused by impacting particles creating secondary showers and their energy dissipation in the matter. Depending on the acceptable consequences and the frequency of particle impact events on equipment reliability requirements are scaling accordingly. Increasing reliability often leads to more complex systems. The downside of complexity is a reduction of availability, therefore an optimum has to be found for these conflicting requirements. A detailed review of selected concepts and solutions from real-life examples will be given to show approaches used in various parts of the system from the sensors, signal processing, and software implementations up to the requirements for operation and documentation.
	Slides WEIB02 [4.609 MB]

THCB02	Twisting Wire Scanner	vacuum, feedback, software, 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

MOPA04

An Electron Beam Profile Monitor for the Race-track Microtron

electron, microtron, experiment, operation

54

S.D. Dhole, V.N. Bhoraskar, B.J. Patil, N.S. Shinde
University of Pune, Pune, India

In electron irradiation experiments on materials such as semiconductors, solar cells etc., an uniformity and the charge distribution in the electron beam is very important. Therefore, an electron beam current monitor and its electronic system have been designed and built to measure the distribution of a beam current either in the horizontal or vertical direction along with the beam dimensions. To obtain X-Y beam profile, a special type of Faraday Cup was designed which mainly consists of charge collecting electrodes made up of thin copper strips. Each strip having dimensions 0.5 mm wide, 4 mm thick and 20 mm long were fixed parallel to each other and separation between them was ~ 0.5 mm. This multi electrode Faraday was mounted at the extraction port of the Race Track Microtron, where 1 MeV electron beam allowed to fall on it. The beam characterization in the form of current and uniformity were measured. The current from each strip were measured using an electronic circuit developed based on the multiplexing principle. The uniformity of the beam can be measured with an accuracy of 10%. The minimum and maximum dimensions which can be measured are 3 mm and 15 mm respectively.

MOPA08

Various Usages of Wall Current Monitors for Commissioning of RF Systems in J-PARC Synchrotrons

cavity, impedance, synchrotron, bunching

63

F. Tamura, M. Nomura, A. Schnase, T. Shimada, M. Yamamoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
K. Hara, K. Hasegawa, C. Ohmori, M. Toda, M. Yoshii
KEK, Tokai, Ibaraki, Japan

Wall current monitors (WCM) for rf system commissioning are installed in the J-PARC synchrotrons, the RCS and the MR. The WCM signals are used as the input of the beam loading compensation system, and also used diagnosis to adjust the rf system parameters. Since the rf and beam frequency is in the range of a few MHz, direct measurement of the WCM signals is possible. For the diagnosis, the WCM signals are taken by an oscilloscope with the revolution clock signal generated by the LLRF control system, and slices of the WCM waveform with lengths of the revolution periods are generated. By stacking the slices, one can get a mountain plot, which shows motions of bunches and variations of the bunch shapes. Also, time variations of the bunching factor, which are important for acceleration of high intensity proton beams, are obtained. The harmonic analysis is performed on the WCM signal and the cavity voltage monitor signal. By using complex amplitudes of them, one can calculate the impedance seen by the beam. In this presentation, we show examples of the analyses described above. The rf parameters for high intensity beams have been successfully adjusted by using these analyses.

MOPA28

Turn-by-turn BPM System using Coaxial Switches and ARM Microcontroller at UVSOR

electron, injection, betatron, storage-ring

112

T. Toyoda
IMS, Okazaki, Japan
K. Hayashi, M. Katoh
UVSOR, Okazaki, Japan

A major upgrade of the electron storage ring at UVSOR (Institute for Molecular Science, Japan) started from April 2012. To assist the commissioning procedure, we have developed a turn-by-turn Beam Position Monitor (BPM) system which consists of a signal switching circuit, a digital oscilloscope and software. The storage ring has 24 BPMs, each of which consists of four electrodes. By using the signal switching circuit, we can select one BPM from eight BPM's. The four signals from the BPM are sent to a digital oscilloscope and are recorded. In the switching circuit, coaxial switches of SPDT (Single Pole Dual Throw) and SP4T type are used. To control coaxial switches, we adopted 'mbed', the ARM microcontroller development kit. The 'mbed' stores the control applications configured in the HTML file and JavaScript library which can handle multiple I/O ports. It responds as a HTTP server and the control application runs on a Web browser. By clicking buttons with a mouse, we can control the I/O ports of 'mbed' through JavaScript library and accordingly can control coaxial switches. In the presentation, we will report the detail of the developed BPM system and its performance.

MOPA31

Design and Fabrication of the Stripline BPM at ESS-Bilbao

pick-up, coupling, impedance, electronics

122

S. Varnasseri, I. Arredondo, D. Belver, F.J. Bermejo, J. Feuchtwanger, N. Garmendia, P.J. González, L. Muguira
ESS Bilbao, LEIOA, Spain
V. Etxebarria, J. Jugo, J. Portilla
University of the Basque Country, Faculty of Science and Technology, Bilbao, Spain

A Stripline type BPM is designed and fabricated at ESSB. In order to compare, in the future, the functionality and response of the previous BPM capacitive pick-ups design with stripline, a design for stripline BPM is proposed. The design is based on travelling wave electrodes principles to detect the transverse position of the beam in the vacuum chamber. In the design of stripline setup, it has been considered to keep the comparison conditions with pick-ups as similar as possible. The length of strip electrodes is 200 mm and the coverage angle is 0.952 rad. The structure is rotationally pi/2 symmetric and the alignment of electrodes are pi/4, 3pi/, 5pi/4 and 7pi/4. The design is optimized for a frequency of 352 MHz, however it can function on a wide range of frequencies out coming from the measurement results. Striplines in general have well defined behavior even for low beta and low intensity beams as well as functionality at low and high frequencies. A report on the design and characteristics measurement of Stripline will be presented. The characteristics like frequency range, electrodes insulation, electrode response, sensitivities to beam power and position will be presented.

MOPA36

Development of Bunch Current and Oscillation Recorder for SuperKEKB Accelerator

FPGA, timing, EPICS, damping

138

M. Tobiyama, J.W. Flanagan
KEK, Ibaraki, Japan

A High-speed digital signal memory has been developed for the bunch current and oscillation recorder for SuperKEKB. The memory consists of an 8-bit ADC and a FPGA daughter card with Spartan6 and DDR2 memories commercially available on a double width VME card. The block-RAM on the FPGA is used to transfer bunch current data with low latency for prompt bunch current measurements, and the large DDR2 memory is used for long-duration position recording, such as post-mortem bunch oscillation recording. The performance of the board, including data transfer rate, will be presented.

MOPA37

Reliable Beam-Intensity Control Technique at the HIMAC Synchrotron

extraction, synchrotron, ion, feedback

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.

MOPB51

Beam Monitors of NIRS Fast Scanning System for Particle Therapy

ion, cathode, monitoring, vacuum

182

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

At National Institute of Radiological Sciences, more than 6500 patients have been successfully treated by carbon beams since 1994. The successful results of treatments have led us to construct a new treatment facility equipped with three-dimensional pencil beam scanning irradiation system. The commissioning of NIRS fast scanning system installed into the new facility was started in September 2010, and the treatment with scanned ion beam was started in May 2011. In the scanning delivery system, beam monitors are some of the most important components. In order to measure and control the dose of each spot, the main and the sub ionization chambers are placed separately as flux monitors. For monitoring of the scanned beam position, a beam position monitor, which is multi-wire proportional chamber, is installed just downstream from the flux monitors. This monitor can output not only the beam position but also the 2D fluence distribution using dynamic fast convolution algorithm. In this paper, the design and the commissioning of these monitors are described.

MOPB58

Beam Quality Ensuring Instruments at the Gunma University Heavy-ion Medical Center

ion, linac, heavy-ion, synchrotron

209

E. Takeshita, T. Kanai, M. Kawashima, Y. Kubota, A. Matsumura, A. Saito, H. Shimada, M. Tashiro, K. Torikai, S. Yamada, K. Yusa
Gunma University, Heavy-Ion Medical Research Center, Maebashi-Gunma, Japan

Since the carbon beam based cancer therapy started at the Gunma University Heavy-ion Medical Center in the year 2010, the total number of treated patients increased to 306 by the end of fiscal 2011. This year, already 82 patients have been treated. In order to control the medical beam qualities, i.e., position, size and intensity of the beam, monitoring devices were mounted on the high-energy beam transport line. The beam position and size can be measured and tuned with a screen monitor, which consists of a fluorescent screen and a CCD camera. Just before starting the treatment, the operators check for a proper beam position by strip-line monitor measurements placed close to the iso center. The irradiation dose is controlled using two secondary electron emission monitors placed before the wobbling magnets. This dose monitor is helpful for high fluence of the beam because it's less affected by the recombination effect. In the conference, we would like to report on details of each monitoring device.

MOPB63

Emittance Measurement using X-ray Beam Profile Monitor at KEK-ATF

emittance, software, damping, electron

215

T. Naito, H. Hayano, K. Kubo, S. Kuroda, N. Nakamura, T. Okugi, H. Sakai, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

The X-ray profile monitor (XPM) is used for the beam size measurement in the KEK-ATF damping ring(ATF-DR) at all times. The XPM consists of a crystal monochromator, two Fresnel zone plates(FZPs) and X-ray CCD camera. Two FZPs make the imaging optics. The design resolution of the selected wavelength 3.8nm is less than 1μm, which is sufficiently small for the emittance measurement of the ATF-DR. However, the measured results at the early stage were affected by the mechanical vibration. This paper describes the improvement of the resolution and the measurement results.

MOPB76

Evaluation of a Fluorescent Screen with a CCD System for Quality Assurance in Heavy-Ion Beam Scanning Irradiation System

ion, heavy-ion, radiation, background

249

Y. Hara, T. Furukawa, T. Inaniwa, K. Mizushima, K. Noda, S. Sato, T. Shirai, E. Takeshita
NIRS, Chiba-shi, Japan

The precise heavy-ion therapy such as the scanning irradiation system necessitates the precise quality assurance (QA) procedures to verify the performance of therapeutic scanned ion beams. To evaluate the uniformity of the 2D field, radiographic film is used due to its high spatial resolution and suit for the measurements of the integral dose. However, this technique is time consuming. Thus, we developed the QA tool with high spatial resolution to verify accuracy of the lateral size, position and uniformity of scanned ion beams in clinical application at the HIMAC, which we called the QA-SCN. The QA-SCN consists of a fluorescent screen, a CCD camera, a mirror, camera controllers and a dark box to protect against surrounding light. In this paper, to evaluate the performance of the QA-SCN, we compared the results obtained by using it with the measurements by radiographic film performed in the same experimental conditions. Also, we verified several types of corrections about errors, e.g. background, vignetting, to distort the measurement results. As a result, we confirmed that the QA-SCN can be used as the system for QA procedures of therapeutic scanned ion beams.

TUPA06

Pulsed Electron Beam Current and Flux Monitor for the Race-track Microtron

electron, induction, microtron, experiment

337

S.D. Dhole, S. Akhter, V.N. Bhoraskar, B.J. Patil, N.S. Shinde
University of Pune, Pune, India

In electron irradiation experiments on the materials, a true current of the electron beam is to be known to calculate the electron fluence received by the sample. Therefore, a pulsed electron beam current and flux monitor alongwith electronic system for an electron accelerator called Race-Track Microtron has been designed and developed. The sensing device used was a ferrite core having suitable number of turns of copper wire wound around it, through which the electron beam was passed without loss in the intensity. With an appropriate developed electronic circuit, the instantaneous value of the induced voltage was measured which in turn provides value of the electron beam pulsed current. The total charge passed through the ferrite core per unit time was therefore recorded and an integrated value of the total charge in a given period could be derived. This system can be used to measure the electron flux in the range from 10⁸ electron/cm² to 10¹⁶ electron/cm². Moreover, this system has been used successfully in a few electron irradiation experiments where the knowledge of the electron fluence received by the sample is required.

TUPA09

System Architecture for Measuring and Monitoring Beam Losses in the Injector Complex at CERN

FPGA, detector, monitoring, injection

347

C. Zamantzas, M. Alsdorf, B. Dehning, S. Jackson, M. Kwiatkowski, W. Viganò
CERN, Geneva, Switzerland

The strategy for beam setup and machine protection of the accelerators at the European Organisation for Nuclear Research (CERN) is mainly based on its Beam Loss Monitoring (BLM) systems. For their upgrade to higher beam energies and intensities, a new BLM system is under development with the aim of providing faster measurement updates with higher dynamic range and the ability to accept more types of detectors as input compared to its predecessors. In this paper, the architecture of the complete system is explored giving an insight to the design choices made to provide a highly reconfigurable system that is able to fulfil the different requirements of each accelerator using reprogrammable devices.

TUPA12

A DBPM Calibration Method Implemented on FPGA

FPGA, experiment, operation, linac

358

X.D. Sun, Y.B. Leng
SINAP, Shanghai, People's Republic of China

An calibration method on the four channels of DBPM is discussed . Using interpolation, the method is implemented on FPGA , which can handle the data on-line. The calibration algorithm is mono-channel dependent and is intended to solve the beam current dependence problem and increase resolution. Orientations of the method is presented. Basic design diagrams of the pipelined FPGA modules are listed and comparisons are made before and after the calibration

TUPA17

TPS BPM Electronics Performance Measurement and Statistics

electronics, FPGA, EPICS, booster

369

P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo
NSRRC, Hsinchu, Taiwan

The new BPM electronics Libera Brilliance Plus are developed for Taiwan Photon Source (TPS) which is a 3 GeV synchrotron light source constructed at NSRRC. This new BPM electronics can accommodate four BPM modules with integrated FPGA-based hardware. The preliminary test for the first arrival unit had been performed in the TLS (Taiwan Light Source) and had shown nearly equal performance compared with Libera Brilliance. The extra 75 sets had been delivered in 2011 and 2012. Performance of each unit are individually tested and measured.

TUPA26

Development of New BPM Electronics for the Swiss Light Source

FPGA, electronics, feedback, 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.

TUPA32

Signal Equalizer for SPS Ecloud/TMCI Instability Feedback Control System

pick-up, feedback, 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, feedback, 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

feedback, 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.

TUPA42

Diagnostics Beamline Optimisation and Image Processing for Sub-ps Streak Camera Bunch Length Measurement

synchrotron, optics, synchrotron-radiation, radiation

445

C.A. Thomas, I.P.S. Martin, G. Rehm
Diamond, Oxfordshire, United Kingdom

Low alpha beam lattice at Diamond can generate bunch length as small as 0.6ps. In order to be able to measure reliably such a short bunch, we have been optimising the optical design of the visible Diagnostics beamline, and we have implemented image processing, taking into account the point spread function of the streak camera. The beamline optical design has removed a large chirp of 15ps/150nm bandwidth to 2ps /200nmbandwidth. It has also permit the transport of almost all the available power, increasing the power by a factor 20, yet maintaining the possibility to focus the beam down to less than 20um into the streak camera for the best static streak camera point spread function. The deconvolution technique implemented extends the performance of the streak camera to bunch length measurement much smaller than the 1ps PSF of the streak camera. In this paper we present these two essential features required to measure sub-ps bunched with a streak camera.

TUPB48

Beam Instrumentation for the COSY Electron Cooler

electron, gun, detector, laser

468

V. Kamerdzhiev, L.J. Mao, K. Reimers
FZJ, Jülich, Germany
E.A. Bekhtenev, V.N. Bocharov, M.I. Bryzgunov, A.V. Bubley, A.P. Denisov, G.V. Karpov, V.M. Panasyuk, V.V. Parkhomchuk, V.B. Reva
BINP SB RAS, Novosibirsk, Russia
J. Dietrich
HIM, Mainz, Germany

The report deals with beam instrumentation of the electron cooler for COSY storage ring. The electron cooler is an electrostatic accelerator designed for beam energy up to 2 MeV and electron current up to 3 A with recuperation. The electron beam is immersed in longitudinal magnetic field so the electron motion is strongly magnetized. The control electrode in the electron gun is composed of four electrically isolated sectors. Applying AC voltage to one sector allows tracing of motion of that particular part of the beam. The electron beam shape is registered with the combination of 4-sector electron gun and the BPMs. This method allows observing both dipole and quadruple (galloping) modes of electron beam oscillation. Compass probe for measuring and tuning the direction of magnetic field in the cooling section is described. A profile monitor based on a few small Faraday cups for measuring distribution of the electron beam is presented.

TUPB61

The First Experience with the LHC Beam Gas Ionisation Monitor

electron, injection, emittance, proton

489

M. Sapinski, W. Andreazza, B. Dehning, A. Guerrero, M. Patecki, R. Versteegen
CERN, Geneva, Switzerland

The Beam Gas Ionisation Monitors (BGI) are used to continuously measure the beam size at the LHC. This paper describes the detectors and their operation and discusses the issues encountered during the commissioning. It also discusses the various calibration procedures used to correct for non-uniformity of Multi-Channel plates and to correct the beam size for effects affecting the electron trajectory after ionisation.

TUPB81

Design of the Beam Profile Monitors for the SXFEL Facility

detector, electron, linac, FEL

534

L.Y. Yu, J. Chen, Y.B. Leng, K.R. Ye, W.M. Zhou
SINAP, Shanghai, People's Republic of China

The Shanghai X-ray Free Electron Laser Facility will begin construction at next year. The linac electron beam energy is 0.84 GeV. Over 50 beam profile monitors with OTR and YaG screen will be installed along the linac and undulators. The profile monitor system design is a challenging task, since the system has to measure transverse electron beam sizes from millimeter down to 40μm scale with a 20μm resolution and 50μm repeat positioning accuracy. This paper describes the design of the mechanical detector , the integrated step-servo motor controlling system, the beam imaging system, as well as the software system.

WEIB02

Review of Reliability Concepts Applied to Beam Loss Monitoring Systems

survey, detector, operation, monitoring

550

B. Dehning
CERN, Geneva, Switzerland

Beam loss measurement systems are often used for the protection of equipment against the damage caused by impacting particles creating secondary showers and their energy dissipation in the matter. Depending on the acceptable consequences and the frequency of particle impact events on equipment reliability requirements are scaling accordingly. Increasing reliability often leads to more complex systems. The downside of complexity is a reduction of availability, therefore an optimum has to be found for these conflicting requirements. A detailed review of selected concepts and solutions from real-life examples will be given to show approaches used in various parts of the system from the sensors, signal processing, and software implementations up to the requirements for operation and documentation.

Slides WEIB02 [4.609 MB]

THCB02

Twisting Wire Scanner

vacuum, feedback, software, 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]