DIPAC2011 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
MOPD02	The CNAO Qualification Monitor	extraction, power-supply, proton, controls	32
	C. Viviani, G. Balbinot, J. Bosser, M. Caldara, H. Caracciolo, M.A. Garella, V. Lante, A. Parravicini, M. Pullia CNAO Foundation, Milan, Italy
	The CNAO (Centro Nazionale di Adroterapia Oncologica) Foundation is the first Italian center for deep hadrontherapy. It will treat patients using Protons and Carbon ions in the next coming months. Patient safety is the first priority and many diagnostics devices have been developed to guarantee it. This work presents the so-called Qualification Monitor (QM). It is mounted in the common part of the four extraction lines, in front of the Chopper Dump, and it aims to qualify the extracted beam profile and intensity, before sending it to the treatment rooms. It is made of two different detectors: the first one, called Qualification Profile Monitor (QPM), is made by two dimensional harp of scintillating fibers to measure horizontal and vertical profiles. The second one, named Qualification Intensity Monitor (QIM) is a scintillating plate for intensity measurement. At the beginning of each extracted spill the beam is dumped on the Chopper Dump and it hit the QM. Only a positive result from beam qualification allows to switch on Chopper magnets and to send the beam to the patient. The QM is working with beam from some months, first results and future upgrades are presented.

MOPD07	Newly Installed Beam Diagnostics at the Australian Synchrotron	injection, booster, diagnostics, linac	47
	E.D. van Garderen, M.J. Boland, G. LeBlanc, B. Mountford, A. Rhyder, A. C. Starritt, A. Walsh, K. Zingre ASCo, Clayton, Victoria, Australia
	The Australian Synchrotron (AS) is aiming at implementing Top-Up operations in 2012. To reduce costs only one of the two klystrons in the linac will be used. The electron beam in the linac will only be accelerated to 80 MeV, instead of 100 MeV achieved currently. The injection system will need to be recommissioned. The beam position monitors in the booster have been upgraded and YAG:Ce screens have been added to the booster-to-storage ring (BTS) transfer line. In addition the injection efficiency will be optimized and monitored. For this purpose another Fast Current Transformer has also been installed at the end of the BTS.

MOPD16	Advanced Digital Signal Processing for Effective Beam Position Monitoring	antiproton, monitoring, heavy-ion, proton	74
	D.A. Liakin ITEP, Moscow, Russia P. Forck, K. Lang, R. Singh GSI, Darmstadt, Germany
	A latest experience in digital signal processing of BPM data obtained in synchrotrons of ITEP and GSI is discussed. The data in ITEP was collected by BPM processor prototype while the SIS18 in GSI uses a renovated digital system. Due to different concept of BPM architectures on those facilities it is possible to compare algorithms oriented to certain hardware. Several algorithms of position detection are compared to each other. Performances of ‘collective’ and partly distributed algorithms are estimated. Data reduction methods and visualization solutions are considered. Finally low- and wideband data evaluation for longitudinal phase space is presented.
	Poster MOPD16 [13.416 MB]

MOPD22	Beam Based Gain Calibration of Beam Position Monitors at J-PARC MR	simulation, ion, pick-up	92
	M. Tejima, T. Toyama KEK, Ibaraki, Japan S. Hatakeyama JAEA/J-PARC, Tokai-mura, Japan
	The output data from a beam position monitor (BPM) system usually was calibrated on the test bench and so on. The gain of the output data may drift due to unpredictable imbalance among output signals from the pickup electrodes, because they must travel through separate paths,cables, connectors, attenuators, switches, and then are measured by detectors. The gain calibration has been tried to apply for the BPM system in J-PARC Main Ring. This paper reports the result of beam based gain callibration to estimate the imbalance, which was performed measuring the response from four output data of a BPM head.

MOPD28	Loss Factor Measurement using Time Correlated Single Photon Counting of Synchrotron Radiation	photon, cavity, storage-ring, vacuum	110
	G. Rehm, C. Bloomer, C.A. Thomas Diamond, Oxfordshire, United Kingdom
	A method to derive the total loss factor from the variation of SR photon arrival times with bunch charge has been developed. A time correlated single photon counting system is used operationally for fill pattern and bunch purity measurements. By fitting the individual peaks in the photon arrival time histogram, their relative timing can be retrieved with ps resolution and reproducibility. For a measurement of the loss factor, a fill pattern comprising a range of different bunch charges is stored and then their timing relative to the RF buckets is charted against charge. Examples of measurements illustrate the variation of loss factor with RF voltage and change in Insertion Device gap.

MOPD30	Bunch Length Measurement for PETRA III Light Source Storage Ring	ion, extraction, vacuum, radiation	113
	H.-C. Schröder, A. Affeldt, H.P. Gausepohl, G. Kube, G. Priebe DESY, Hamburg, Germany
	To fulfill the demand for a very high brilliance synchrotron light source, it is required, that the individual particle bunches, used to create the synchrotron light in special undulator sections, do not exceed certain limits in linear dimension and divergence during the storage time. The bunch length measurement in the visible region of the spectrum is the sole system to measure the longitudinal beam parameter needed for a complete description of the behavior of the PETRAIII positron beam. A detailed description of the dipole magnet visible synchrotron light extraction, the light transport and the analysis by means of a Streak Camera System (SCS) in the context of the PETRAIII storage ring is given. The influence of the custom designed apochromatic refractive optics transport line on the time resolution of the bunch length measurement is discussed and values are given. The final time resolution of the whole system transport optics and Streak camera is shown to be not bigger than 4 ps. Several measurements from PETRAIII runs are presented and results of the bunch length measurements are shown. The typical bunch length measured is about 40 ps.
	Poster MOPD30 [6.402 MB]

MOPD32	Bunch Length Measurement from Power Fluctuation at Diamond	radiation, cavity, synchrotron-radiation, lattice	119
	C.A. Thomas, I.P.S. Martin, G. Rehm Diamond, Oxfordshire, United Kingdom
	Bunch length can be measured using the visible light power fluctuation statistics of an individual bunch. This method developed at ALS has been implemented at Diamond with further improvement on the detection method and the speed of the measurement. In this paper, we firstly report on the development and implementation of the method. We will show the performance of several detector diodes used and the limits of the method. Validation of the method will be demonstrated against streak camera measurement with picosecond long bunches. Before concluding, we will discuss about the strengths and weaknesses of the method.

MOPD51	Progress with the Scintillation Profile Monitor at COSY	vacuum, proton, power-supply, target	164
	V. Kamerdzhiev, J. Dietrich, F. Klehr, K. Reimers FZJ, Jülich, Germany
	After successful demonstration measurements with the Scintillation Profile Monitor at COSY, a dedicated vacuum chamber with two vacuum windows and supporting vacuum ports was installed in the COSY synchrotron. The chamber is blackened inside to suppress light reflection. Since residual gas pressure is too low to support reliable profile measurements based on beam induced scintillation, a piezo-electric dosing valve was installed allowing fast injections of defined amount of nitrogen. A 32-channel photomultiplier is used to detect light. Beam profile measurements and first operational experience are reported.

MOPD61	Vertical Emittance Measurement at the ESRF	emittance, radiation, photon, dipole	188
	F. Ewald, P. Elleaume, L. Farvacque, A. Franchi, D. Robinson, K.B. Scheidt, A. Snigirev, I. Snigireva ESRF, Grenoble, France
	In the short term the ESRF aims to reach emittances of less than 2 pm. We review the existing emittance diagnostics – X-ray projection monitors and pinhole cameras – and evaluate their ability to resolve such ultra-small vertical emittances. Even though these devices are reliable and show good agreement between measurements and theoretical predictions down to vertical emittance values of less than 10 pm, they will reach their limit of resolution for emittances decreasing below a few picometers. In addition to the existing emittance diagnostics, a new device was installed that images bending magnet radiation using compound refractive lenses (CRLs).

MOPD66	Upgrade of the CERN PSB/CPS Fast Intensity Measurements	linac, proton, booster, status	200
	A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby CERN, Geneva, Switzerland G. Kasprowicz CREOTECH Ltd., Warsaw, Poland
	The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

MOPD71	Using the Transverse Digital Damper as a Real-time Tune Monitor for the Booster Synchrotron at Fermilab	booster, damping, kicker, controls	209
	N. Eddy, O. Lysenko Fermilab, Batavia, USA
	The Fermilab Booster is a fast ramping (15Hz) synchrotron which accelerates protons from 400MeV to 8GeV. During commissioning of a transverse digital damper system, it was shown that the damper could provide a measurement of the the machine tune throughout the cycle by exciting just 1 of the 84 bunches with minimal impact on the machine operation. The algorithms used to make the measurement have been incorporated into the damper FPGA firmware allowing for real-time tune monitoring of all Booster cycles. Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.

MOPD79	An FPGA-based Turn-by-Turn Beam Position Monitoring System for Studying Multiple Bunch Beams in the ATF Damping Ring	injection, extraction, damping, feedback	230
	G.B. Christian, D.R. Bett, B. Constance, M.R. Davis JAI, Oxford, United Kingdom R. Apsimon, P. Burrows, A. Gerbershagen, C. Perry Oxford University, Physics Department, Oxford, Oxon, United Kingdom J. Resta-López IFIC, Valencia, Spain
	Instabilities associated with beam-size blow-up have previously been observed with multi-bunch beam in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). A system has been developed to monitor such instabilities, utilising an ATF stripline beam position monitor (BPM) in the DR, and BPM processor hardware designed for the FONT upstream feedback system in the ATF extraction line. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. The maximum memory configuration on the FPGA allows 131071 bunch-turn-channels of data to be recorded from a particular machine pulse, and the system has the capability to select only certain turns at a regular interval in which to record data, in order to zoom out and cover the entire period of the damping cycle at the ATF. An overview of the system and initial results will be presented.

MOPD86	Development of FESA-based Data Acquisition and Control for FAIR	controls, diagnostics, high-voltage, power-supply	248
	R. Haseitl, H. Bräuning, T. Hoffmann, K. Lang, R. Singh GSI, Darmstadt, Germany
	GSI has selected the CERN Front End Software Architecture (FESA) to operate future beam diagnostic devices for the upcoming FAIR facility. The FESA framework is installed and operational at the GSI site, giving equipment specialists the possibility to develop FESA classes for device control and data acquisition. This contribution outlines first developments of FESA-based systems for various applications. Prototype DAQ systems based on FESA are the BPM system of the synchrotron SIS18 with data rates up to 7 GBit/s and a large scaler setup for particle counters called LASSIE. FESA classes that address gigabit Ethernet cameras are used for video imaging tasks like scintillator screen observation. Control oriented FESA classes access industrial Programmable Logic Controllers (PLCs) for the slow control of beam diagnostic devices. To monitor temperatures and set fan speeds of VME crates, a class communicating over the CAN bus has been developed.
	Poster MOPD86 [3.137 MB]

MOPD96	The Mirror Mounting of a Fast Switching Mirror Unit at FLASH	laser, site, target, simulation	269
	F. Perlick, A. Donat, R. Heller, J. Nagler, M. Sachwitz, L.V. Vu DESY Zeuthen, Zeuthen, Germany
	To provide different beam lines with laser light from one source, a fast switching mirror unit that allows permanent switching with a frequency of up to 2.5 Hz was developed. One part of the study deals with the mirror and the design of its mounting in the chamber. The challenge lies in achieving a firm mounting of the mirror without significant mirror deformation, since the users demand only very few divergence of the laser beam at the test sites. The newest design of the mounting brought considerable improvement with regard to the pitching and the torsion of the mirror, which have an important impact on the beam divergence.

TUOA02	Diagnostics during the ALBA Storage Ring Commissioning	diagnostics, injection, kicker, storage-ring	280
	U. Iriso, M. Alvarez, F.F.B. Fernandez, A. Olmos, F. Pérez CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	The ALBA Storage Ring is a 3GeV 3rd Generation Synchrotron Light Source whose 1st phase commissioning took place in Spring 2011. The machine is equipped with 123 BPMs, striplines, several fluorescent screens, FCT and DCCT, 128 BLMs, and two front ends strictly used for electron beam diagnostics (pinhole and streak camera). This paper presents an overview of the Diagnostics elements installed in the machine and our experience during the commissioning.
	Slides TUOA02 [5.476 MB]

TUPD20	Pre-amplifier Impedance Matching for Cryogenic BPMs	cryogenics, impedance, vacuum, quadrupole	347
	P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann GSI, Darmstadt, Germany N. Sobel, F. Völklein Hochschule RheinMain, Wiesbaden, Germany
	Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.
	Poster TUPD20 [0.655 MB]

TUPD21	Frontend Measurements and Optimizations at Libera Brilliance BPM Electronics during Commissioning of the Petra III Synchrotron Light Source	brilliance, controls, instrumentation, feedback	350
	F. Schmidt-Föhre, G. Kube, J.M. Maass, K. Wittenburg DESY, Hamburg, Germany
	New 3rd generation synchrotron light sources like Petra III utilize high-accuracy beam position measurement (BPM) systems to achieve the desired precision for beam position measurement and control, as needed for electron/positron beam stability and brilliance of the delivered photon beam. To reach the design goals, specifically adapted and parameterized commercial-of-the-shelf (COTS) Libera Brilliance BPM processor electronics are used within the Petra III BPM system. Quality of the acquired position measurement and orbit control data is highly dependent on the properties and setup of the analog and digital frontend of such BPM electronics. This paper shows influences and optimizations at the BPM system frontend of the Petra III light-source in reference to corresponding measurements done during the accelerator commissioning phase.

TUPD33	Coherent Resonant Diffraction Radiation from Inclined Grating as a Tool for Bunch Length Diagnostics	radiation, diagnostics, electron, vacuum	377
	L.G. Sukhikh, G. Kube DESY, Hamburg, Germany A. Potylitsyn Tomsk Polytechnic University, Tomsk, Russia V. Schlott PSI, Villigen, Switzerland
	There exists considerable interest in studying new types of non-invasive bunch length diagnostics for sub-picosecond bunches. In this context coherent Smith-Purcell radiation (CSPR) is a good candidate because the use of grating causes wavelength dispersive radiation emission, i.e. a CSPR based monitor does not require any additional spectrometer. In contrast to existing CSPR monitors a new scheme is proposed with two detectors placed at fixed positions, and a wavelength scan is performed by scanning the tilt angle between grating surface and beam axis. In this scheme the information of both detectors, positioned opposite to each other and perpendicular to the beam axis, can be combined by taking the intensity ratio of the signals from both detectors. The advantage of such diagnostics scheme is that one has not to rely on absolute values of the radiation yield, avoiding the need to know the sensitivity of each detector with high accuracy. In contrast to CSPR which is emitted from a grating oriented parallel to the beam, the effect is termed coherent resonant diffraction radiation when the grating is tilted. In the report we present simulation results and detailed experimental plan.

TUPD39	Observation of Synchrotron Radiation Using Low Noise Block (LNB) at ANKA	radiation, storage-ring, synchrotron-radiation, vacuum	389
	V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale KIT, Karlsruhe, Germany F. Caspers CERN, Geneva, Switzerland
	Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contact number VH-NG-320 Generally Coherent Synchrotron Radiation (CSR) is emitted for wavelengths longer than or equal the bunch length, so for CSR in the THz-range short bunches are required. There are two types of detectors in this range of the spectrum: slow detectors like a golay cell or pyrometric detectors (used for e.g. imaging, spectroscopy) and fast detectors like superconducting bolometer detector systems and Schottky Barrier diodes (used for e.g. the investigation of dynamic processes in accelerator physics). The hot electron bolometer (HEB) detector system is a member of second group. It is very fast and has broad spectral characteristics, but unfortunately very expensive and have to be cooled using liquid helium. If the broad spectral response is not important, it will be suitably to use a Schottky Barrier diode instead. These detectors are massively cheaper but also slower. As an alternative to a Schottky diode a LNB (Low Noise Block) can be also used. It is usually used in standard TV-SAT-receivers. Due to mass production LNBs became very cheap, moreover they are optimized to detect very low intensity "noise-like" signals. In this paper we present our experience with a LNB at ANKA.

TUPD51	Ionization Profile Monitors - IPM @ GSI	high-voltage, ion, electron, space-charge	419
	T. Giacomini, P. Forck GSI, Darmstadt, Germany J.G. De Villiers iThemba LABS, Somerset West, South Africa J. Dietrich FZJ, Jülich, Germany D.A. Liakin ITEP, Moscow, Russia
	The Ionization Profile Monitor in the SIS18 is frequently used for machine development. The permanent availability and the elaborated software user interface make it easy and comfortable to use. Additional to the beam profile data the device records the data of synchrotron dc current, dipole ramp and accelerating rf properties. The trend curves of these data are shown correlated to the beam profile evolution for a full synchrotron cycle from injection to extraction with 100 profiles/s. The reliable function is based on the optimized in-vacuum hardware design, like the stable high voltage connections, the electric field box with very uniform field distribution and the uv-light based calibration system. The permanent availability is based on the convenient software interface using the Qt library. A new IPM generation was recently commissioned in the experimental storage ring ESR at GSI and one in the COSY ring at FZ-Jülich. These monitors are enhancements of the SIS18 multiwire IPM but equipped with an especially developed large area 50x100 mm² optical particle detector of rectangular shape that is readout by a digital camera through a viewport.

TUPD72	Advancements in the Base-Band-Tune and Chromaticity Instrumentation and Diagnostics Systems during LHC's First Year of Operation	diagnostics, feedback, resonance, monitoring	476
	R.J. Steinhagen, M. Gasior, S. Jackson CERN, Geneva, Switzerland
	The Base-Band-Tune (BBQ) system is an integral part of day-to-day LHC operation, used for tune and chromaticity diagnostics and feedback and giving unprecedented precision with good reliability. This contribution summarises the system's overall performance and documents the various improvements of the analogue front-end circuitry, digital post-processing and integration that were necessary in response to issues arising during high-intensity physics operation. The result of beam studies undertaken are presented, which have established a better understanding of the detection principle since its first introduction in 2005.
	Poster TUPD72 [0.794 MB]

TUPD78	SOLEIL Beam Orbit Stability Improvements	photon, feedback, kicker, electron	488
	N. Hubert, L. Cassinari, J.-C. Denard, P. Lebasque, L.S. Nadolski, D. Pédeau SOLEIL, Gif-sur-Yvette, France
	SOLEIL beam orbit stability is being significantly improved. A first effort was set on long term stability for specific beamlines (new 160 m long Nanoscopium and Hard X-rays beamlines). BPM and XBPM steel supports will be replaced for reducing their sensitiveness to temperature drift. Thermal expansion of INVAR and fused Silica stands has been measured. INVAR has been selected for the new BPM supports. A second effort aimed at improving the orbit stability of beamlines based on bending magnets. We plan to use their first XBPM in the global orbit feedback loops (slow and fast). For that purpose new XBPM electronics called Libera photons will be used. Soleil, having contributed to the development, tested extensively the first series. A third effort focused on noise source location. An application developed in-house has identified localized orbit perturbation sources introducing spurious spectrum lines at 46, 50 and 54 Hz on the orbit. They originate from fans rotating close to ceramics chambers of kickers, FCT and shaker. Their suppression decreases the vertical integrated noise down to 300 nm in the DC-500Hz frequency range.

TUPD81	The Petra III Multibunch Feedback System	feedback, kicker, cavity, impedance	494
	J. Klute, K. Balewski, A. Delfs, H.T. Duhme, M. Ebert, Ru. Neumann, F. Obier DESY, Hamburg, Germany
	In order to fulfill the demands of a high brilliance synchrotron light source like PETRA III different feedback systems are required. The high brilliance is accomplished by high beam current of 100 mA and very small transverse emittances. The current in PETRA is limited by coupled bunch instabilities to rather low values and powerful longitudinal and transverse feedback systems are necessary to achieve the design current. A careful design of the feedback is required in order to avoid any kind of beam quality degradation such as beam blow up due to noise. Additional requirements on signal processing are: very high dynamic range, adaptive signal adjustment, very high sensitivity to beam oscillations, high resolution and very high bandwidth. This contribution will describe the most important components and their properties. Results of the feedback operation will be presented and discussed. The design current of 100mA has been achieved without the indication of emittance growth and the feedback has been operated reliably during the fast user period.

TUPD86	RF Reference Distribution and Timing System for the Taiwan Photon Source	gun, linac, controls, booster	506
	C.Y. Wu, Y.-T. Chang, J. Chen, Y.-S. Cheng, P.C. Chiu, K.T. Hsu, K.H. Hu, C.H. Kuo, C.-Y. Liao NSRRC, Hsinchu, Taiwan
	Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m (24 straight sections for installation of insertion devices), radio-frequency cavities and electron beam from the 150 MeV linac system which being in construction at National Synchrotron Radiation Research Center (NSRRC) campus. A high stability of the novel fiber based 500 MHz RF reference distribution is required and planned to use. Timing system for the TPS will be an event based system. It is based on 6U CompactPCI form factor from Micro-Research Finland Oy. Prototyping of the RF distribution and event system are on progress in this direction. The preliminary test results and implementation details will summary in this report.

TUPD88	A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron	electron, gun, proton, diagnostics	512
	A. Pertica, S.J. Payne STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.
	Poster TUPD88 [1.793 MB]

TUPD94	Monitoring of GeV Deuteron Beam Parameters in ADS Experiments at the Nuclotron (JINR, Dubna)	target, neutron, proton, monitoring	530
	A.A. Safronava, A.A. Patapenka JIPNR-Sosny NASB, Minsk, Belarus V.V. Sotnikov, V.A. Voronko NSC/KIPT, Kharkov, Ukraine O. Svoboda NPI, Řež near Prague, Czech Republic W. Westmeier Philipps-Universität, Marburg, Germany
	The quality of beam instrumentation is very important in the experiments on accelerator driven systems (ADS) aiming to investigate spatial and energy distribution of neutrons inside and outside the subcritical setups comprising spallation neutron sources irradiated by relativistic beams. An important source of systematic uncertainties of the experimental data is the inaccuracy of determination of the beam parameters such as total intensity of the extracted beam, beam position at the target, fraction of the beam hitting the target and beam shape. This paper reviews the experimental techniques and measurement tools for deuteron beam monitoring used within the “Energy plus Transmutation” collaboration in the ADS experiments at the accelerator complex of Nuclotron (JINR, Russia): - activation technique using Al monitors for measurement of the total intensity of the extracted beam; - solid nuclear track detectors method and activation technique using segmented activation Cu foils for determination of beam profile and position at the target.
	Poster TUPD94 [13.019 MB]

WEOB03	Single-shot Resolution of X-ray Monitor using Coded Aperture Imaging	photon, emittance, synchrotron-radiation, optics	561
	J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda, T.M. Mitsuhashi KEK, Ibaraki, Japan J.P. Alexander, M.A. Palmer, D.P. Peterson, N.T. Rider CLASSE, Ithaca, New York, USA G.S. Varner UH, Honolulu, HI, USA
	We report on tests of an x-ray beam size monitor based on coded aperture imaging. This technique uses a mask pattern to modulate incoming light, with the resulting image being deconvolved through the mask and detector responses, including the effects of diffraction and attenuation materials in the path, over the spectral and angular distribution of the synchrotron radiation generated by the beam. We have tested mask patterns called URA masks, which have relatively flat spatial frequency response, and an open aperture of 50% for high-flux throughput, enabling single-shot (bunch-by-bunch, turn-by-turn) measurements without the need for heat-sensitive mirrors. Bunch size measurements of ~10 micron bunches with single-shot (statistics-dominated) resolutions of ~2.5 microns have been demonstrated at CesrTA, and single-shot measurements with similar or better resolution of beams in the ~5 micron range are being aimed for at the ATF2. A beam-size monitor based on these principles is also being designed for the SuperKEKB low-emittance rings. We will present estimated single-shot resolutions, along with a comparison to single-shot resolution measurements made at CesrTA.
	Slides WEOB03 [1.694 MB]

Paper

Title

Other Keywords

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MOPD02

The CNAO Qualification Monitor

extraction, power-supply, proton, controls

32

C. Viviani, G. Balbinot, J. Bosser, M. Caldara, H. Caracciolo, M.A. Garella, V. Lante, A. Parravicini, M. Pullia
CNAO Foundation, Milan, Italy

The CNAO (Centro Nazionale di Adroterapia Oncologica) Foundation is the first Italian center for deep hadrontherapy. It will treat patients using Protons and Carbon ions in the next coming months. Patient safety is the first priority and many diagnostics devices have been developed to guarantee it. This work presents the so-called Qualification Monitor (QM). It is mounted in the common part of the four extraction lines, in front of the Chopper Dump, and it aims to qualify the extracted beam profile and intensity, before sending it to the treatment rooms. It is made of two different detectors: the first one, called Qualification Profile Monitor (QPM), is made by two dimensional harp of scintillating fibers to measure horizontal and vertical profiles. The second one, named Qualification Intensity Monitor (QIM) is a scintillating plate for intensity measurement. At the beginning of each extracted spill the beam is dumped on the Chopper Dump and it hit the QM. Only a positive result from beam qualification allows to switch on Chopper magnets and to send the beam to the patient. The QM is working with beam from some months, first results and future upgrades are presented.

MOPD07

Newly Installed Beam Diagnostics at the Australian Synchrotron

injection, booster, diagnostics, linac

47

E.D. van Garderen, M.J. Boland, G. LeBlanc, B. Mountford, A. Rhyder, A. C. Starritt, A. Walsh, K. Zingre
ASCo, Clayton, Victoria, Australia

The Australian Synchrotron (AS) is aiming at implementing Top-Up operations in 2012. To reduce costs only one of the two klystrons in the linac will be used. The electron beam in the linac will only be accelerated to 80 MeV, instead of 100 MeV achieved currently. The injection system will need to be recommissioned. The beam position monitors in the booster have been upgraded and YAG:Ce screens have been added to the booster-to-storage ring (BTS) transfer line. In addition the injection efficiency will be optimized and monitored. For this purpose another Fast Current Transformer has also been installed at the end of the BTS.

MOPD16

Advanced Digital Signal Processing for Effective Beam Position Monitoring

antiproton, monitoring, heavy-ion, proton

74

D.A. Liakin
ITEP, Moscow, Russia
P. Forck, K. Lang, R. Singh
GSI, Darmstadt, Germany

A latest experience in digital signal processing of BPM data obtained in synchrotrons of ITEP and GSI is discussed. The data in ITEP was collected by BPM processor prototype while the SIS18 in GSI uses a renovated digital system. Due to different concept of BPM architectures on those facilities it is possible to compare algorithms oriented to certain hardware. Several algorithms of position detection are compared to each other. Performances of ‘collective’ and partly distributed algorithms are estimated. Data reduction methods and visualization solutions are considered. Finally low- and wideband data evaluation for longitudinal phase space is presented.

Poster MOPD16 [13.416 MB]

MOPD22

Beam Based Gain Calibration of Beam Position Monitors at J-PARC MR

simulation, ion, pick-up

92

M. Tejima, T. Toyama
KEK, Ibaraki, Japan
S. Hatakeyama
JAEA/J-PARC, Tokai-mura, Japan

The output data from a beam position monitor (BPM) system usually was calibrated on the test bench and so on. The gain of the output data may drift due to unpredictable imbalance among output signals from the pickup electrodes, because they must travel through separate paths,cables, connectors, attenuators, switches, and then are measured by detectors. The gain calibration has been tried to apply for the BPM system in J-PARC Main Ring. This paper reports the result of beam based gain callibration to estimate the imbalance, which was performed measuring the response from four output data of a BPM head.

MOPD28

Loss Factor Measurement using Time Correlated Single Photon Counting of Synchrotron Radiation

photon, cavity, storage-ring, vacuum

110

G. Rehm, C. Bloomer, C.A. Thomas
Diamond, Oxfordshire, United Kingdom

A method to derive the total loss factor from the variation of SR photon arrival times with bunch charge has been developed. A time correlated single photon counting system is used operationally for fill pattern and bunch purity measurements. By fitting the individual peaks in the photon arrival time histogram, their relative timing can be retrieved with ps resolution and reproducibility. For a measurement of the loss factor, a fill pattern comprising a range of different bunch charges is stored and then their timing relative to the RF buckets is charted against charge. Examples of measurements illustrate the variation of loss factor with RF voltage and change in Insertion Device gap.

MOPD30

Bunch Length Measurement for PETRA III Light Source Storage Ring

ion, extraction, vacuum, radiation

113

H.-C. Schröder, A. Affeldt, H.P. Gausepohl, G. Kube, G. Priebe
DESY, Hamburg, Germany

To fulfill the demand for a very high brilliance synchrotron light source, it is required, that the individual particle bunches, used to create the synchrotron light in special undulator sections, do not exceed certain limits in linear dimension and divergence during the storage time. The bunch length measurement in the visible region of the spectrum is the sole system to measure the longitudinal beam parameter needed for a complete description of the behavior of the PETRAIII positron beam. A detailed description of the dipole magnet visible synchrotron light extraction, the light transport and the analysis by means of a Streak Camera System (SCS) in the context of the PETRAIII storage ring is given. The influence of the custom designed apochromatic refractive optics transport line on the time resolution of the bunch length measurement is discussed and values are given. The final time resolution of the whole system transport optics and Streak camera is shown to be not bigger than 4 ps. Several measurements from PETRAIII runs are presented and results of the bunch length measurements are shown. The typical bunch length measured is about 40 ps.

Poster MOPD30 [6.402 MB]

MOPD32

Bunch Length Measurement from Power Fluctuation at Diamond

radiation, cavity, synchrotron-radiation, lattice

119

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

Bunch length can be measured using the visible light power fluctuation statistics of an individual bunch. This method developed at ALS has been implemented at Diamond with further improvement on the detection method and the speed of the measurement. In this paper, we firstly report on the development and implementation of the method. We will show the performance of several detector diodes used and the limits of the method. Validation of the method will be demonstrated against streak camera measurement with picosecond long bunches. Before concluding, we will discuss about the strengths and weaknesses of the method.

MOPD51

Progress with the Scintillation Profile Monitor at COSY

vacuum, proton, power-supply, target

164

V. Kamerdzhiev, J. Dietrich, F. Klehr, K. Reimers
FZJ, Jülich, Germany

After successful demonstration measurements with the Scintillation Profile Monitor at COSY, a dedicated vacuum chamber with two vacuum windows and supporting vacuum ports was installed in the COSY synchrotron. The chamber is blackened inside to suppress light reflection. Since residual gas pressure is too low to support reliable profile measurements based on beam induced scintillation, a piezo-electric dosing valve was installed allowing fast injections of defined amount of nitrogen. A 32-channel photomultiplier is used to detect light. Beam profile measurements and first operational experience are reported.

MOPD61

Vertical Emittance Measurement at the ESRF

emittance, radiation, photon, dipole

188

F. Ewald, P. Elleaume, L. Farvacque, A. Franchi, D. Robinson, K.B. Scheidt, A. Snigirev, I. Snigireva
ESRF, Grenoble, France

In the short term the ESRF aims to reach emittances of less than 2 pm. We review the existing emittance diagnostics – X-ray projection monitors and pinhole cameras – and evaluate their ability to resolve such ultra-small vertical emittances. Even though these devices are reliable and show good agreement between measurements and theoretical predictions down to vertical emittance values of less than 10 pm, they will reach their limit of resolution for emittances decreasing below a few picometers. In addition to the existing emittance diagnostics, a new device was installed that images bending magnet radiation using compound refractive lenses (CRLs).

MOPD66

Upgrade of the CERN PSB/CPS Fast Intensity Measurements

linac, proton, booster, status

200

A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby
CERN, Geneva, Switzerland
G. Kasprowicz
CREOTECH Ltd., Warsaw, Poland

The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

MOPD71

Using the Transverse Digital Damper as a Real-time Tune Monitor for the Booster Synchrotron at Fermilab

booster, damping, kicker, controls

209

N. Eddy, O. Lysenko
Fermilab, Batavia, USA

The Fermilab Booster is a fast ramping (15Hz) synchrotron which accelerates protons from 400MeV to 8GeV. During commissioning of a transverse digital damper system, it was shown that the damper could provide a measurement of the the machine tune throughout the cycle by exciting just 1 of the 84 bunches with minimal impact on the machine operation. The algorithms used to make the measurement have been incorporated into the damper FPGA firmware allowing for real-time tune monitoring of all Booster cycles.
Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.

MOPD79

An FPGA-based Turn-by-Turn Beam Position Monitoring System for Studying Multiple Bunch Beams in the ATF Damping Ring

injection, extraction, damping, feedback

230

G.B. Christian, D.R. Bett, B. Constance, M.R. Davis
JAI, Oxford, United Kingdom
R. Apsimon, P. Burrows, A. Gerbershagen, C. Perry
Oxford University, Physics Department, Oxford, Oxon, United Kingdom
J. Resta-López
IFIC, Valencia, Spain

Instabilities associated with beam-size blow-up have previously been observed with multi-bunch beam in the damping ring (DR) of the KEK Accelerator Test Facility (ATF). A system has been developed to monitor such instabilities, utilising an ATF stripline beam position monitor (BPM) in the DR, and BPM processor hardware designed for the FONT upstream feedback system in the ATF extraction line. The system is designed to record the horizontal and/or vertical positions of up to three bunches in the DR in single-bunch multi-train mode or the head bunch of up to three trains in multi-bunch mode, with a bunch spacing of 5.6 ns. The FPGA firmware and data acquisition software were modified to record turn-by-turn data for up to six channels and 1–3 bunches in the DR. The maximum memory configuration on the FPGA allows 131071 bunch-turn-channels of data to be recorded from a particular machine pulse, and the system has the capability to select only certain turns at a regular interval in which to record data, in order to zoom out and cover the entire period of the damping cycle at the ATF. An overview of the system and initial results will be presented.

MOPD86

Development of FESA-based Data Acquisition and Control for FAIR

controls, diagnostics, high-voltage, power-supply

248

R. Haseitl, H. Bräuning, T. Hoffmann, K. Lang, R. Singh
GSI, Darmstadt, Germany

GSI has selected the CERN Front End Software Architecture (FESA) to operate future beam diagnostic devices for the upcoming FAIR facility. The FESA framework is installed and operational at the GSI site, giving equipment specialists the possibility to develop FESA classes for device control and data acquisition. This contribution outlines first developments of FESA-based systems for various applications. Prototype DAQ systems based on FESA are the BPM system of the synchrotron SIS18 with data rates up to 7 GBit/s and a large scaler setup for particle counters called LASSIE. FESA classes that address gigabit Ethernet cameras are used for video imaging tasks like scintillator screen observation. Control oriented FESA classes access industrial Programmable Logic Controllers (PLCs) for the slow control of beam diagnostic devices. To monitor temperatures and set fan speeds of VME crates, a class communicating over the CAN bus has been developed.

Poster MOPD86 [3.137 MB]

MOPD96

The Mirror Mounting of a Fast Switching Mirror Unit at FLASH

laser, site, target, simulation

269

F. Perlick, A. Donat, R. Heller, J. Nagler, M. Sachwitz, L.V. Vu
DESY Zeuthen, Zeuthen, Germany

To provide different beam lines with laser light from one source, a fast switching mirror unit that allows permanent switching with a frequency of up to 2.5 Hz was developed. One part of the study deals with the mirror and the design of its mounting in the chamber. The challenge lies in achieving a firm mounting of the mirror without significant mirror deformation, since the users demand only very few divergence of the laser beam at the test sites. The newest design of the mounting brought considerable improvement with regard to the pitching and the torsion of the mirror, which have an important impact on the beam divergence.

TUOA02

Diagnostics during the ALBA Storage Ring Commissioning

diagnostics, injection, kicker, storage-ring

280

U. Iriso, M. Alvarez, F.F.B. Fernandez, A. Olmos, F. Pérez
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

The ALBA Storage Ring is a 3GeV 3rd Generation Synchrotron Light Source whose 1st phase commissioning took place in Spring 2011. The machine is equipped with 123 BPMs, striplines, several fluorescent screens, FCT and DCCT, 128 BLMs, and two front ends strictly used for electron beam diagnostics (pinhole and streak camera). This paper presents an overview of the Diagnostics elements installed in the machine and our experience during the commissioning.

Slides TUOA02 [5.476 MB]

TUPD20

Pre-amplifier Impedance Matching for Cryogenic BPMs

cryogenics, impedance, vacuum, quadrupole

347

P. Kowina, M. Freimuth, K. Gütlich, W. Kaufmann, H. Rödl, J. Wießmann
GSI, Darmstadt, Germany
N. Sobel, F. Völklein
Hochschule RheinMain, Wiesbaden, Germany

Beam Position Monitors (BPMs) for the FAIR fast-ramped super conducting synchrotron SIS-100 will be installed inside the cryostats of quadrupole magnets. This contribution focuses on the coupling path between BPM electrodes and low noise amplifiers installed outside the cryostat. Matching transformers (MT) meet well the requirements of reflection free signal transfer through the relative long lines without loading the capacitive BPM by 50 Ohm. Different transformers based on toroidal cores made out of Vitroperm-500F nanocrystalline were tested. The form of windings and circuit geometry were optimized to improve linearity allow for resonance-free transmission over a required frequency range from 0.1 MHz to 80 MHz. The MTs have to be balanced pair wise within 0.1 dB and the geometry of windings has to be mechanically stabilized using e.g. epoxy resin. A choice of different epoxy types and their suitability for cryogenic operation was tested in liquid Nitrogen and liquid Helium.

Poster TUPD20 [0.655 MB]

TUPD21

Frontend Measurements and Optimizations at Libera Brilliance BPM Electronics during Commissioning of the Petra III Synchrotron Light Source

brilliance, controls, instrumentation, feedback

350

F. Schmidt-Föhre, G. Kube, J.M. Maass, K. Wittenburg
DESY, Hamburg, Germany

New 3rd generation synchrotron light sources like Petra III utilize high-accuracy beam position measurement (BPM) systems to achieve the desired precision for beam position measurement and control, as needed for electron/positron beam stability and brilliance of the delivered photon beam. To reach the design goals, specifically adapted and parameterized commercial-of-the-shelf (COTS) Libera Brilliance BPM processor electronics are used within the Petra III BPM system. Quality of the acquired position measurement and orbit control data is highly dependent on the properties and setup of the analog and digital frontend of such BPM electronics. This paper shows influences and optimizations at the BPM system frontend of the Petra III light-source in reference to corresponding measurements done during the accelerator commissioning phase.

TUPD33

Coherent Resonant Diffraction Radiation from Inclined Grating as a Tool for Bunch Length Diagnostics

radiation, diagnostics, electron, vacuum

377

L.G. Sukhikh, G. Kube
DESY, Hamburg, Germany
A. Potylitsyn
Tomsk Polytechnic University, Tomsk, Russia
V. Schlott
PSI, Villigen, Switzerland

There exists considerable interest in studying new types of non-invasive bunch length diagnostics for sub-picosecond bunches. In this context coherent Smith-Purcell radiation (CSPR) is a good candidate because the use of grating causes wavelength dispersive radiation emission, i.e. a CSPR based monitor does not require any additional spectrometer. In contrast to existing CSPR monitors a new scheme is proposed with two detectors placed at fixed positions, and a wavelength scan is performed by scanning the tilt angle between grating surface and beam axis. In this scheme the information of both detectors, positioned opposite to each other and perpendicular to the beam axis, can be combined by taking the intensity ratio of the signals from both detectors. The advantage of such diagnostics scheme is that one has not to rely on absolute values of the radiation yield, avoiding the need to know the sensitivity of each detector with high accuracy. In contrast to CSPR which is emitted from a grating oriented parallel to the beam, the effect is termed coherent resonant diffraction radiation when the grating is tilted. In the report we present simulation results and detailed experimental plan.

TUPD39

Observation of Synchrotron Radiation Using Low Noise Block (LNB) at ANKA

radiation, storage-ring, synchrotron-radiation, vacuum

389

V. Judin, N. Hiller, A. Hofmann, E. Huttel, B. Kehrer, M. Klein, S. Marsching, A.-S. Müller, N.J. Smale
KIT, Karlsruhe, Germany
F. Caspers
CERN, Geneva, Switzerland

Funding: Work supported by the Initiative and Networking Fund of the Helmholtz Association under contact number VH-NG-320
Generally Coherent Synchrotron Radiation (CSR) is emitted for wavelengths longer than or equal the bunch length, so for CSR in the THz-range short bunches are required. There are two types of detectors in this range of the spectrum: slow detectors like a golay cell or pyrometric detectors (used for e.g. imaging, spectroscopy) and fast detectors like superconducting bolometer detector systems and Schottky Barrier diodes (used for e.g. the investigation of dynamic processes in accelerator physics). The hot electron bolometer (HEB) detector system is a member of second group. It is very fast and has broad spectral characteristics, but unfortunately very expensive and have to be cooled using liquid helium. If the broad spectral response is not important, it will be suitably to use a Schottky Barrier diode instead. These detectors are massively cheaper but also slower. As an alternative to a Schottky diode a LNB (Low Noise Block) can be also used. It is usually used in standard TV-SAT-receivers. Due to mass production LNBs became very cheap, moreover they are optimized to detect very low intensity "noise-like" signals. In this paper we present our experience with a LNB at ANKA.

TUPD51

Ionization Profile Monitors - IPM @ GSI

high-voltage, ion, electron, space-charge

419

T. Giacomini, P. Forck
GSI, Darmstadt, Germany
J.G. De Villiers
iThemba LABS, Somerset West, South Africa
J. Dietrich
FZJ, Jülich, Germany
D.A. Liakin
ITEP, Moscow, Russia

The Ionization Profile Monitor in the SIS18 is frequently used for machine development. The permanent availability and the elaborated software user interface make it easy and comfortable to use. Additional to the beam profile data the device records the data of synchrotron dc current, dipole ramp and accelerating rf properties. The trend curves of these data are shown correlated to the beam profile evolution for a full synchrotron cycle from injection to extraction with 100 profiles/s. The reliable function is based on the optimized in-vacuum hardware design, like the stable high voltage connections, the electric field box with very uniform field distribution and the uv-light based calibration system. The permanent availability is based on the convenient software interface using the Qt library. A new IPM generation was recently commissioned in the experimental storage ring ESR at GSI and one in the COSY ring at FZ-Jülich. These monitors are enhancements of the SIS18 multiwire IPM but equipped with an especially developed large area 50x100 mm² optical particle detector of rectangular shape that is readout by a digital camera through a viewport.

TUPD72

Advancements in the Base-Band-Tune and Chromaticity Instrumentation and Diagnostics Systems during LHC's First Year of Operation

diagnostics, feedback, resonance, monitoring

476

R.J. Steinhagen, M. Gasior, S. Jackson
CERN, Geneva, Switzerland

The Base-Band-Tune (BBQ) system is an integral part of day-to-day LHC operation, used for tune and chromaticity diagnostics and feedback and giving unprecedented precision with good reliability. This contribution summarises the system's overall performance and documents the various improvements of the analogue front-end circuitry, digital post-processing and integration that were necessary in response to issues arising during high-intensity physics operation. The result of beam studies undertaken are presented, which have established a better understanding of the detection principle since its first introduction in 2005.

Poster TUPD72 [0.794 MB]

TUPD78

SOLEIL Beam Orbit Stability Improvements

photon, feedback, kicker, electron

488

N. Hubert, L. Cassinari, J.-C. Denard, P. Lebasque, L.S. Nadolski, D. Pédeau
SOLEIL, Gif-sur-Yvette, France

SOLEIL beam orbit stability is being significantly improved. A first effort was set on long term stability for specific beamlines (new 160 m long Nanoscopium and Hard X-rays beamlines). BPM and XBPM steel supports will be replaced for reducing their sensitiveness to temperature drift. Thermal expansion of INVAR and fused Silica stands has been measured. INVAR has been selected for the new BPM supports. A second effort aimed at improving the orbit stability of beamlines based on bending magnets. We plan to use their first XBPM in the global orbit feedback loops (slow and fast). For that purpose new XBPM electronics called Libera photons will be used. Soleil, having contributed to the development, tested extensively the first series. A third effort focused on noise source location. An application developed in-house has identified localized orbit perturbation sources introducing spurious spectrum lines at 46, 50 and 54 Hz on the orbit. They originate from fans rotating close to ceramics chambers of kickers, FCT and shaker. Their suppression decreases the vertical integrated noise down to 300 nm in the DC-500Hz frequency range.

TUPD81

The Petra III Multibunch Feedback System

feedback, kicker, cavity, impedance

494

J. Klute, K. Balewski, A. Delfs, H.T. Duhme, M. Ebert, Ru. Neumann, F. Obier
DESY, Hamburg, Germany

In order to fulfill the demands of a high brilliance synchrotron light source like PETRA III different feedback systems are required. The high brilliance is accomplished by high beam current of 100 mA and very small transverse emittances. The current in PETRA is limited by coupled bunch instabilities to rather low values and powerful longitudinal and transverse feedback systems are necessary to achieve the design current. A careful design of the feedback is required in order to avoid any kind of beam quality degradation such as beam blow up due to noise. Additional requirements on signal processing are: very high dynamic range, adaptive signal adjustment, very high sensitivity to beam oscillations, high resolution and very high bandwidth. This contribution will describe the most important components and their properties. Results of the feedback operation will be presented and discussed. The design current of 100mA has been achieved without the indication of emittance growth and the feedback has been operated reliably during the fast user period.

TUPD86

RF Reference Distribution and Timing System for the Taiwan Photon Source

gun, linac, controls, booster

506

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

Taiwan Photon Source (TPS) is a low-emittance 3-GeV synchrotron light source with circumference of 518.4 m (24 straight sections for installation of insertion devices), radio-frequency cavities and electron beam from the 150 MeV linac system which being in construction at National Synchrotron Radiation Research Center (NSRRC) campus. A high stability of the novel fiber based 500 MHz RF reference distribution is required and planned to use. Timing system for the TPS will be an event based system. It is based on 6U CompactPCI form factor from Micro-Research Finland Oy. Prototyping of the RF distribution and event system are on progress in this direction. The preliminary test results and implementation details will summary in this report.

TUPD88

A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron

electron, gun, proton, diagnostics

512

A. Pertica, S.J. Payne
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.

Poster TUPD88 [1.793 MB]

TUPD94

Monitoring of GeV Deuteron Beam Parameters in ADS Experiments at the Nuclotron (JINR, Dubna)

target, neutron, proton, monitoring

530

A.A. Safronava, A.A. Patapenka
JIPNR-Sosny NASB, Minsk, Belarus
V.V. Sotnikov, V.A. Voronko
NSC/KIPT, Kharkov, Ukraine
O. Svoboda
NPI, Řež near Prague, Czech Republic
W. Westmeier
Philipps-Universität, Marburg, Germany

The quality of beam instrumentation is very important in the experiments on accelerator driven systems (ADS) aiming to investigate spatial and energy distribution of neutrons inside and outside the subcritical setups comprising spallation neutron sources irradiated by relativistic beams. An important source of systematic uncertainties of the experimental data is the inaccuracy of determination of the beam parameters such as total intensity of the extracted beam, beam position at the target, fraction of the beam hitting the target and beam shape. This paper reviews the experimental techniques and measurement tools for deuteron beam monitoring used within the “Energy plus Transmutation” collaboration in the ADS experiments at the accelerator complex of Nuclotron (JINR, Russia): - activation technique using Al monitors for measurement of the total intensity of the extracted beam; - solid nuclear track detectors method and activation technique using segmented activation Cu foils for determination of beam profile and position at the target.

Poster TUPD94 [13.019 MB]

WEOB03

Single-shot Resolution of X-ray Monitor using Coded Aperture Imaging

photon, emittance, synchrotron-radiation, optics

561

J.W. Flanagan, A. Arinaga, H. Fukuma, H. Ikeda, T.M. Mitsuhashi
KEK, Ibaraki, Japan
J.P. Alexander, M.A. Palmer, D.P. Peterson, N.T. Rider
CLASSE, Ithaca, New York, USA
G.S. Varner
UH, Honolulu, HI, USA

We report on tests of an x-ray beam size monitor based on coded aperture imaging. This technique uses a mask pattern to modulate incoming light, with the resulting image being deconvolved through the mask and detector responses, including the effects of diffraction and attenuation materials in the path, over the spectral and angular distribution of the synchrotron radiation generated by the beam. We have tested mask patterns called URA masks, which have relatively flat spatial frequency response, and an open aperture of 50% for high-flux throughput, enabling single-shot (bunch-by-bunch, turn-by-turn) measurements without the need for heat-sensitive mirrors. Bunch size measurements of ~10 micron bunches with single-shot (statistics-dominated) resolutions of ~2.5 microns have been demonstrated at CesrTA, and single-shot measurements with similar or better resolution of beams in the ~5 micron range are being aimed for at the ATF2. A beam-size monitor based on these principles is also being designed for the SuperKEKB low-emittance rings. We will present estimated single-shot resolutions, along with a comparison to single-shot resolution measurements made at CesrTA.

Slides WEOB03 [1.694 MB]