IBIC2014 - List of Keywords (synchrotron)

Paper	Title	Other Keywords	Page
MOCZB1	A Picosecond Sampling Electronic “KAPTURE” for Terahertz Synchrotron Radiation	synchrotron-radiation, radiation, storage-ring, detector	24
	C.M. Caselle, M. Brosi, S.A. Chilingaryan, T. Dritschler, N. Hiller, V. Judin, A. Kopmann, A.-S. Müller, L. Petzold, J. Raasch, L. Rota, M. Siegel, N.J. Smale, J.L. Steinmann, M. Vogelgesang, M. Weber, S. Wuensch KIT, Eggenstein-Leopoldshafen, Germany
	For a few years, coherent synchrotron radiation (CSR) generated by short electron bunches has been provided at the ANKA light source. Electron bunches can be filled in up to 184 buckets with a distance between two adjacent bunches of 2 ns corresponding to the RF system frequency of 500 MHz. Arbitrary filling patterns are generated to investigate the interaction of adjacent bunches in CSR. To study the THz emission characteristics over multiple revolutions superconducting YBa2Cu3O7−δ (YBCO) film detectors are used. The intrinsic response time of YBCO thin films is in the order of a few picoseconds only. For fast, continuous sampling of these individual ultra-short terahertz pulses, a novel digitizer system has been developed. The KAPTURE (KArlsruhe Pulse Taking Ultra-fast Readout Electronics) consists of a wideband low-noise amplifier, a picosecond pulse sampling card and a GByte transfer data link back-end readout card. High-end graphic processing units (GPUs) perform real-time data analysis. The KAPTURE system was successfully demonstrated for readout of the intensity fluctuations in the CSR at the ANKA Storage Ring detected in THz range. Four samples are recorded in parallel for each fast pulse with programmable sampling times in the range of 3 to 100 psec. A clean jitter phase locked loop (PLL) provides a clock signal with high temporal accuracy. The back-end card receives the 4 digital samples every 2 ns with 12 bits resolution and transmits the data to the data analysis unit. The readout board is based on programmable logic FPGA and DDR3 memories for on-line data preprocessing and temporary storage. The data is transmitted to the GPU computing node by a fast data transfer links based on a bus master DMA engine connected to PCI express endpoint logic to ensure a continuous high data throughput of up to 4 GByte/s. This heterogeneous real-time system architecture based on FPGA and GPU is used for on-line pulse reconstruction and evaluations and calculates the peak amplitude of each pulse and the time between consecutive bunches with a picosecond time resolution. A Fast Fourier Transform (FFT) is performed on-line for the frequency analysis of the CSR undulations. With the presented acquisition system it was possible to resolve the bursting behavior of single bunches even in a multi-bunch environment to study the bunch-bunch-interactions at ANKA. First results obtained have already been published in the synchrotron machine physic community. The monitoring of bursting for different ANKA parameters using KAPTURE system opens up new analysis and diagnostics possibilities for electron storage rings operating at short bunch lengths.
	Slides MOCZB1 [11.326 MB]
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MOPF30	Diagnostics of the TPS Booster Synchrotron for Beam Commissioning	booster, injection, EPICS, radiation	114
	K.T. Hsu, J. Chen, Y.-S. Cheng, P.C. Chiu, S.Y. Hsu, K.H. Hu, C.H. Huang, C.H. Kuo, D. Lee, C.Y. Liao, C.Y. Wu NSRRC, Hsinchu, Taiwan
	Booster synchrotron for the Taiwan photon source project is in commissioning. Diagnostics which consist of screen monitors, intensity monitors, beam position monitors, tune monitors, visible light synchrotron radiation monitors and radiation-sensing field-effect transistors are integrated with accelerator control system. Integration and functionality check were done recently. Details of these diagnostics and preliminary test results will be summarized in this report.
	Poster MOPF30 [1.036 MB]
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MOPD05	Dual Transverse and Longitudinal Streak Camera Imaging at ELSA	damping, cavity, diagnostics, electron	144
	M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, M. Schedler ELSA, Bonn, Germany
	Funding: Funded by the German Research Foundation (DFG) within Colaborative Research Center (SFB/TRR) 16 The electron pulse stretcher ring ELSA located at Bonn University provides 0.5 – 3.5 GeV polarized and non-polarized electron beams for external experimental stations. A streak camera system has been installed to capture time resolved images of beam dynamics ranging from nanoseconds to several milliseconds. Particular attention was drawn to the capability of simultaneous imaging of both transverse beam dimensions, hence providing information of all spatial dimensions in one synchroscan or slow sweep measurement. Incoherent and coherent beam instabilities, especially at high stored beam currents, are subject of analysis due to the planned intensity upgrade towards 200 mA for standard operation. The current resolution performance of the imaging system and machine relevant measurements are presented.
	Poster MOPD05 [6.133 MB]
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MOPD11	Near-Saturation Single-Photon Avalanche Diode Afterpulse and Sensitivity Correction Scheme for the LHC Longitudinal Density Monitor	photon, detector, laser, synchrotron-radiation	169
	M. Palm, E. Bravin, S. Mazzoni CERN, Geneva, Switzerland
	Funding: CERN Single-Photon Avalanche Diodes (SPADs) monitor the longitudinal density of the LHC beams by measuring the temporal distribution of synchrotron radiation. The relative population of nominally empty RF-buckets (satellites or ghosts) with respect to filled bunches is a key figure for the luminosity calibration of the LHC experiments. Since afterpulsing from a main bunch avalanche can be as high as, or higher than, the signal from satellites or ghosts, an accurate correction algorithm is needed. Furthermore, to reduce the integration time, the amount of light sent to the SPAD is enough so that pile-up effects and afterpulsing cannot be neglected. The SPAD sensitivity has also been found to vary at the end of the active quenching phase. We present a method to characterize and correct for SPAD deadtime, afterpulsing and sensitivity variation near saturation, together with laboratory benchmarking.
	Poster MOPD11 [6.756 MB]
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TUIXB1	The Beam Instrumentation and Diagnostic Challenges for LHC Operation at High Energy	electron, detector, emittance, quadrupole	216
	O.R. Jones CERN, Geneva, Switzerland
	This contribution will present the role of beam instrumentation and diagnostics in facing the challenges posed by running the LHC close to its design energy of 7TeV. Machine protection will be ever more critical, with the quench level of the magnets significantly reduced, so relying heavily on the beam loss system and abort gap monitor interlocks on the beam position and fast beam current change system. Non-invasive profile monitoring also becomes more of a challenge, with standard synchrotron light imaging limited by diffraction and rest gas ionisation monitoring dominated by space charge effects. There is also a requirement to better understand beam instabilities, of which several were observed during Run I, leading to the need for synchronised bunch-by-bunch, turn-by-turn information from many distributed instrumentation systems. All of these challenges will be discussed along with the strategies adopted to overcome them.
	Slides TUIXB1 [7.329 MB]
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TUCZB2	Measurements of Small Vertical Beamsize using a Coded Aperture at Diamond Light Source	electron, radiation, detector, synchrotron-radiation	279
	C. Bloomer, G. Rehm DLS, Oxfordshire, United Kingdom J.W. Flanagan KEK, Ibaraki, Japan
	Diamond Light Source produces a low emittance 3GeV electron beam which is now regularly operated at 8pm.rad vertical emittance. This corresponds to a vertical beamsize of just 13um in the dipole, which is at a high vertical beta location and routinely used for observing the synchrotron radiation using a pinhole camera. Deconvolution of the images from the pinhole camera to maximise resolution is limited by uncertainly regarding the precise shape of the pinhole, resulting in uncertainty on its computed point spread function. Recently a coded aperture has been installed which offers the potential to improve upon the traditional pinhole measurement by offering both higher resolution and increased flux seen through a larger total aperture, however, at the cost of significantly more complex analysis of the recorded images. A comparison of results obtained using the coded aperture and those achieved using the conventional pinhole is presented.
	Slides TUCZB2 [4.199 MB]
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TUPF02	Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches	electron, simulation, synchrotron-radiation, collider	294
	P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic BNL, Upton, Long Island, New York, USA
	Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.
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TUPF21	NSLS2 Visible Synchrotron Light Monitor Diagnostic Beamline Commissioning	storage-ring, radiation, dipole, injection	369
	W.X. Cheng, B. Bacha, Y. Hu, O. Singh, H. Xu BNL, Upton, Long Island, New York, USA
	Visible Synchrotron Light Monitor (SLM) beamline has been designed and constructed at NSLS2 storage ring, to characterize the electron beam profile at various machine conditions. Due to carefully alignment, SLM beamline was able to see the first light even before beam circulating the ring. Besides a normal CCD camera to monitor the beam profile, streak camera and gated camera are used to measure the longitudinal and transverse profile to understand the beam dynamics. Measurement results from these cameras will be present in this paper.
	Poster TUPF21 [1.631 MB]
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TUPF23	Beam Size Measurements using Synchrotron Radiation Interferometry at ALBA	radiation, extraction, synchrotron-radiation, vacuum	374
	L. Torino, U. Iriso ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain T.M. Mitsuhashi KEK, Ibaraki, Japan
	First tests to measure the transverse beam size using interferometry at ALBA showed that the measurement reliability was limited by the inhomogeneous light wavefront arriving at the double slit system. For this reason, the optical components guiding the synchrotron radiation have been exchanged, and detailed quality checks have been carried out using techniques like the Fizeau interferometry or Hartmann mask tests. We report the results of the analysis of the optical elements installed in the beamline, and the beam size measurements performed using double slit interferometry in both horizontal and vertical planes.
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TUPD10	An Ultrafast Linear Array Detector for Single-Shot Electro-Optical Bunch Profile Measurements	detector, FPGA, laser, radiation	435
	L. Rota, C.M. Caselle, N. Hiller, A.-S. Müller, M. Weber KIT, Eggenstein-Leopoldshafen, Germany
	A new spectrometer system has been developed at ANKA for near-field single-shot Electro-Optical (EO) bunch profile measurements with a frame rate of 5 Mfps. The frame rate of commercial line detectors is limited to several tens of kHz, unsuitable for measuring fast dynamic changes of the bunch conditions. The new system aims to realize continuous data acquisition and over long observation periods without dead time. InGaAs or Si linear array pixel sensors are used to detect the near IR and visible spectrum radiation. The detector signals are fed via wire-bonding connections to the GOTTHARD ASIC, a charge-sensitive amplifier with analog outputs. The front-end board is also equipped with an array of fast ADCs. The digital samples are then acquired by an FPGA-based readout card and transmitted to an external DAQ system via a high-speed PCI-Express data link. The DAQ system uses high-end Graphics Processors Units (GPUs) to perform a real-time analysis of the beam conditions. In this paper we present the concept, the first prototype and the low-noise layout techniques used for fast linear detectors.
	Poster TUPD10 [5.159 MB]
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WECZB3	Measurement of Beam Losses Using Optical Fibers at the Australian Synchrotron	electron, detector, beam-losses, emittance	515
	E. Nebot Del Busto, C.P. Welsch The University of Liverpool, Liverpool, United Kingdom M.J. Boland ASCo, Clayton, Victoria, Australia M.J. Boland, R.P. Rassool The University of Melbourne, Melbourne, Victoria, Australia E.B. Holzer, M. Kastriotou, E. Nebot Del Busto CERN, Geneva, Switzerland P.D. Jackson University of Adelaide, Adelaide, Australia J. Schmidt Albert-Ludwig Universität Freiburg, Freiburg, Germany C.P. Welsch Cockcroft Institute, Warrington, Cheshire, United Kingdom
	The unprecedented requirements that new machines are setting on their diagnostic systems are leading to the development of a new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detectors. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over the long distances of beam lines. In this document, we study the feasibility of a beam loss monitor (BLM) system based on optical fibers as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record lowest transverse emittance (below 1 pm rad). Ultra low transverse sizes and large amounts of synchrotron radiation provide an environment very similar to that expected in the CLIC damping rings. A qualitative benchmark of beam losses under damping ring-like conditions is presented here. A wide range of beam loss rates can be achieved by modifying the bunch charge, horizontal/vertical coupling and dynamic aperture as well as via beam scrapers. The controlled beam losses are observed by means of the Cherenkov light produced in a 365 um core Silica fiber. The output light is coupled to different types of photo sensors namely: Multi Pixel Photon Counters (MPPCs), standard PhotoMulTiplier (PMT) tubes and Avalanche PhotoDiodes (APD). A detailed comparison of the sensitivities and time resolution obtained with the different read-outs are discussed in this contribution.
	Slides WECZB3 [2.755 MB]
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WEPF03	Upgrade of the Fast Beam Intensity Measurement System for the CERN PS Complex	controls, shielding, proton, vacuum	525
	D. Belohrad, J.C.A. Allica, M. Andersen, W. Andreazza, G. Favre, N. Favre, L.K. Jensen, L. Lenardon, W. Vollenberg CERN, Geneva, Switzerland
	The CERN Proton Synchrotron complex (CPS) has been operational for over 50 years. During this time the Fast Beam Current Transformers (FBCTs) have only been repaired when they ceased to function, or individually modified to cope with new requests. This strategy resulted in a large variation of designs, making their maintenance difficult and limiting the precision with which comparisons could be made between transformers for the measurement of beam intensity transmission. During the first long shut-down of the CERN LHC and its injectors (LS1) these systems have undergone a major consolidation, with detectors and acquisition electronics upgraded to provide a uniform measurement system throughout the PS complex. This paper discusses the solutions used and analyses the first beam measurement results.
	Poster WEPF03 [7.547 MB]
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WEPF31	Sensor Studies for DC Current Transformer Application	ion, storage-ring, instrumentation, feedback	624
	E. Soliman, K. Hofmann TU Darmstadt, Darmstadt, Germany H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	DC Current Transformers (DCCTs) are known since decades as non-intercepting standard tools for online beam current measurement in synchrotrons and storage rings. In general, the measurement principle of commonly used DCCTs is to introduce a modulating AC signal for a pair of ferromagnetic toroid. A passing DC ion beam leads to an asymmetric shift of the hysteresis curves of the toroid pair. However, a drawback for this measurement principle is found at certain revolution frequencies in ring accelerators, when interference caused by the modulating frequency and its harmonics leads to inaccurate readings by the DCCT. Recent developments of magnetic field sensors allow for new approaches towards a DCCT design without using the modulation principle. This paper shows a review of different kinds of usable magnetic sensors, their characteristics and how they could be used in novel DCCT instruments.
	Poster WEPF31 [4.396 MB]
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WEPD17	Commissioning Results of MicroTCA.4 Stripline BPM System	electronics, linac, synchrotron-radiation, booster	680
	C. Xu, S. Allison, S. L. Hoobler, D.J. Martin, J.J. Olsen, T. Straumann, A. Young SLAC, Menlo Park, California, USA H.-S. Kang, C. Kim, S.J. Lee, G. Mun PAL, Pohang, Kyungbuk, Republic of Korea
	Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357, DE-AC02-76SF00515, and WFOA13-197 SLAC National Accelerator Laboratory is a premier photon science laboratory. SLAC has a Free Electron Laser facility that will produce 0.5 to 77 Angstroms x-rays and a synchrotron light source facility. In order to achieve this high level of performance, the beam position measurement system needs to be accurate so the electron beam bunch can be stable. We have designed a general purpose stripline Beam Position Monitor (BPM) system that has a dynamic range of 10pC to 1nC bunch charge. The BPM system uses the MicroTCA (Micro Telecommunication Computing Architecture) for physics platform that consists of a 14-bit 250 MSPS ADC module (SIS8300 from Struck) that uses the Zone 3 A1.x classification for the Rear Transition Module (RTM). This paper will discuss the commissioning result at SLAC LCLS-I, SLAC SSRL, and Pohang Accelerator Laboratory. The RTM architecture includes a bandpass filter at 300MHz with 30 MHz bandwidth, and an automated BPM calibration process. The RTM communicates with the AMC FPGA using a QSPI interface over the zone 3 connection.
	Poster WEPD17 [5.087 MB]
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WEPD21	BPM Data Correction at SOLEIL	electronics, vacuum, storage-ring, simulation	684
	N. Hubert, B. Béranger, L.S. Nadolski SOLEIL, Gif-sur-Yvette, France
	In a synchrotron light source like SOLEIL, Beam Position Monitors (BPM) are optimized to have the highest sensitivity for an electron beam passing nearby their mechanical center. Nevertheless, this optimization is done to the detriment of the response linearity when the beam is off-centered for dedicated machine physic studies. To correct the geometric non linearity of the BPM, we have applied an algorithm based on a boundary element method. Moreover the BPM electronics is able to provide position data at a turn by turn rate. Unfortunately the filtering process in this electronics mixes the information from one turn to the neighboring turns. An additional demixing algorithm has been set-up to correct this artefact. The paper reports on performances and limitations of those two algorithms that are used at SOLEIL to correct the BPM data.
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WEPD22	Design of a New Blade-Type XBPM	photon, insertion, insertion-device, undulator	687
	N. Hubert, N. Béchu, L. Cassinari, J. Da Silva Castro, J.-C. Denard, M. Labat, J.L. Marlats, A. Mary SOLEIL, Gif-sur-Yvette, France S.R. Marques, R.T. Neuenschwander LNLS, Campinas, Brazil
	A new photon Beam Position Monitor (X-BPM) design has been developed in collaboration between the Brazilian Synchrotron Light Laboratory (LNLS) and SOLEIL Synchrotron. This blade-type X-BPM has been carefully studied in order to minimize beam current dependence and temperature dependence. The main advantages of the design are a good stability than the standard X-BPMs initially installed at SOLEIL. This new design is used for the new X-BPMs installed at SOLEIL and is being considered for the bending magnet front-ends of the future SIRIUS light source. A first “double” unit has been constructed by LNLS for the two canted Anatomix and Nanoscopium SOLEIL beamlines, and has been installed at SOLEIL in May 2014. Design and first results are presented.
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Paper

Title

Other Keywords

Page

MOCZB1

A Picosecond Sampling Electronic “KAPTURE” for Terahertz Synchrotron Radiation

synchrotron-radiation, radiation, storage-ring, detector

24

C.M. Caselle, M. Brosi, S.A. Chilingaryan, T. Dritschler, N. Hiller, V. Judin, A. Kopmann, A.-S. Müller, L. Petzold, J. Raasch, L. Rota, M. Siegel, N.J. Smale, J.L. Steinmann, M. Vogelgesang, M. Weber, S. Wuensch
KIT, Eggenstein-Leopoldshafen, Germany

For a few years, coherent synchrotron radiation (CSR) generated by short electron bunches has been provided at the ANKA light source. Electron bunches can be filled in up to 184 buckets with a distance between two adjacent bunches of 2 ns corresponding to the RF system frequency of 500 MHz. Arbitrary filling patterns are generated to investigate the interaction of adjacent bunches in CSR. To study the THz emission characteristics over multiple revolutions superconducting YBa2Cu3O7−δ (YBCO) film detectors are used. The intrinsic response time of YBCO thin films is in the order of a few picoseconds only. For fast, continuous sampling of these individual ultra-short terahertz pulses, a novel digitizer system has been developed. The KAPTURE (KArlsruhe Pulse Taking Ultra-fast Readout Electronics) consists of a wideband low-noise amplifier, a picosecond pulse sampling card and a GByte transfer data link back-end readout card. High-end graphic processing units (GPUs) perform real-time data analysis. The KAPTURE system was successfully demonstrated for readout of the intensity fluctuations in the CSR at the ANKA Storage Ring detected in THz range. Four samples are recorded in parallel for each fast pulse with programmable sampling times in the range of 3 to 100 psec. A clean jitter phase locked loop (PLL) provides a clock signal with high temporal accuracy. The back-end card receives the 4 digital samples every 2 ns with 12 bits resolution and transmits the data to the data analysis unit. The readout board is based on programmable logic FPGA and DDR3 memories for on-line data preprocessing and temporary storage. The data is transmitted to the GPU computing node by a fast data transfer links based on a bus master DMA engine connected to PCI express endpoint logic to ensure a continuous high data throughput of up to 4 GByte/s. This heterogeneous real-time system architecture based on FPGA and GPU is used for on-line pulse reconstruction and evaluations and calculates the peak amplitude of each pulse and the time between consecutive bunches with a picosecond time resolution. A Fast Fourier Transform (FFT) is performed on-line for the frequency analysis of the CSR undulations. With the presented acquisition system it was possible to resolve the bursting behavior of single bunches even in a multi-bunch environment to study the bunch-bunch-interactions at ANKA. First results obtained have already been published in the synchrotron machine physic community. The monitoring of bursting for different ANKA parameters using KAPTURE system opens up new analysis and diagnostics possibilities for electron storage rings operating at short bunch lengths.

Slides MOCZB1 [11.326 MB]

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MOPF30

Diagnostics of the TPS Booster Synchrotron for Beam Commissioning

booster, injection, EPICS, radiation

114

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

Booster synchrotron for the Taiwan photon source project is in commissioning. Diagnostics which consist of screen monitors, intensity monitors, beam position monitors, tune monitors, visible light synchrotron radiation monitors and radiation-sensing field-effect transistors are integrated with accelerator control system. Integration and functionality check were done recently. Details of these diagnostics and preliminary test results will be summarized in this report.

Poster MOPF30 [1.036 MB]

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MOPD05

Dual Transverse and Longitudinal Streak Camera Imaging at ELSA

damping, cavity, diagnostics, electron

144

M.T. Switka, F. Frommberger, P. Hänisch, W. Hillert, M. Schedler
ELSA, Bonn, Germany

Funding: Funded by the German Research Foundation (DFG) within Colaborative Research Center (SFB/TRR) 16
The electron pulse stretcher ring ELSA located at Bonn University provides 0.5 – 3.5 GeV polarized and non-polarized electron beams for external experimental stations. A streak camera system has been installed to capture time resolved images of beam dynamics ranging from nanoseconds to several milliseconds. Particular attention was drawn to the capability of simultaneous imaging of both transverse beam dimensions, hence providing information of all spatial dimensions in one synchroscan or slow sweep measurement. Incoherent and coherent beam instabilities, especially at high stored beam currents, are subject of analysis due to the planned intensity upgrade towards 200 mA for standard operation. The current resolution performance of the imaging system and machine relevant measurements are presented.

Poster MOPD05 [6.133 MB]

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MOPD11

Near-Saturation Single-Photon Avalanche Diode Afterpulse and Sensitivity Correction Scheme for the LHC Longitudinal Density Monitor

photon, detector, laser, synchrotron-radiation

169

M. Palm, E. Bravin, S. Mazzoni
CERN, Geneva, Switzerland

Funding: CERN
Single-Photon Avalanche Diodes (SPADs) monitor the longitudinal density of the LHC beams by measuring the temporal distribution of synchrotron radiation. The relative population of nominally empty RF-buckets (satellites or ghosts) with respect to filled bunches is a key figure for the luminosity calibration of the LHC experiments. Since afterpulsing from a main bunch avalanche can be as high as, or higher than, the signal from satellites or ghosts, an accurate correction algorithm is needed. Furthermore, to reduce the integration time, the amount of light sent to the SPAD is enough so that pile-up effects and afterpulsing cannot be neglected. The SPAD sensitivity has also been found to vary at the end of the active quenching phase. We present a method to characterize and correct for SPAD deadtime, afterpulsing and sensitivity variation near saturation, together with laboratory benchmarking.

Poster MOPD11 [6.756 MB]

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TUIXB1

The Beam Instrumentation and Diagnostic Challenges for LHC Operation at High Energy

electron, detector, emittance, quadrupole

216

O.R. Jones
CERN, Geneva, Switzerland

This contribution will present the role of beam instrumentation and diagnostics in facing the challenges posed by running the LHC close to its design energy of 7TeV. Machine protection will be ever more critical, with the quench level of the magnets significantly reduced, so relying heavily on the beam loss system and abort gap monitor interlocks on the beam position and fast beam current change system. Non-invasive profile monitoring also becomes more of a challenge, with standard synchrotron light imaging limited by diffraction and rest gas ionisation monitoring dominated by space charge effects. There is also a requirement to better understand beam instabilities, of which several were observed during Run I, leading to the need for synchronised bunch-by-bunch, turn-by-turn information from many distributed instrumentation systems. All of these challenges will be discussed along with the strategies adopted to overcome them.

Slides TUIXB1 [7.329 MB]

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TUCZB2

Measurements of Small Vertical Beamsize using a Coded Aperture at Diamond Light Source

electron, radiation, detector, synchrotron-radiation

279

C. Bloomer, G. Rehm
DLS, Oxfordshire, United Kingdom
J.W. Flanagan
KEK, Ibaraki, Japan

Diamond Light Source produces a low emittance 3GeV electron beam which is now regularly operated at 8pm.rad vertical emittance. This corresponds to a vertical beamsize of just 13um in the dipole, which is at a high vertical beta location and routinely used for observing the synchrotron radiation using a pinhole camera. Deconvolution of the images from the pinhole camera to maximise resolution is limited by uncertainly regarding the precise shape of the pinhole, resulting in uncertainty on its computed point spread function. Recently a coded aperture has been installed which offers the potential to improve upon the traditional pinhole measurement by offering both higher resolution and increased flux seen through a larger total aperture, however, at the cost of significantly more complex analysis of the recorded images. A comparison of results obtained using the coded aperture and those achieved using the conventional pinhole is presented.

Slides TUCZB2 [4.199 MB]

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TUPF02

Proposed Pulse Stretching of BPM Signals for the Position Determination of Very Short and Closely Spaced Bunches

electron, simulation, synchrotron-radiation, collider

294

P. Thieberger, S.J. Brooks, K. Hamdi, R.L. Hulsart, G.J. Mahler, R.J. Michnoff, M.G. Minty, D. Trbojevic
BNL, Upton, Long Island, New York, USA

Funding: Work supported by Brookhaven Science Associates, LLC under contract No. DE-AC02-98CH10886 with the U.S. Department of Energy
A proposal for a future ultra relativistic polarized electron-proton collider (eRHIC) is based in part on the transport of multiple electron beams of different energies through two FFAG beam transports around the 3834 m long RHIC tunnel circumference in order to recirculate them through an Energy Recovery Linac for their stepwise acceleration and deceleration. For each of these transports, the beams will travel in a common vacuum chamber, horizontally separated from each other by a few mm. Determining the position of the individual bunches is challenging due to their very short length (~12 ps rms) and their temporal proximity (less than 4 ns in some cases). Providing pulses adequate for accurate sampling is further complicated by the less-than-ideal response of long coaxial cables. Here we propose two approaches to produce enhanced, i.e. stretched pulse shapes of limited duration; one based on specially shaped BPM electrodes and the other one on analog integration of more conventional stripline BPM signals. In both cases, signals can be generated which contain relatively flat portions which should be easier to sample with good precision without requiring picoseconds timing accuracy.

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TUPF21

NSLS2 Visible Synchrotron Light Monitor Diagnostic Beamline Commissioning

storage-ring, radiation, dipole, injection

369

W.X. Cheng, B. Bacha, Y. Hu, O. Singh, H. Xu
BNL, Upton, Long Island, New York, USA

Visible Synchrotron Light Monitor (SLM) beamline has been designed and constructed at NSLS2 storage ring, to characterize the electron beam profile at various machine conditions. Due to carefully alignment, SLM beamline was able to see the first light even before beam circulating the ring. Besides a normal CCD camera to monitor the beam profile, streak camera and gated camera are used to measure the longitudinal and transverse profile to understand the beam dynamics. Measurement results from these cameras will be present in this paper.

Poster TUPF21 [1.631 MB]

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TUPF23

Beam Size Measurements using Synchrotron Radiation Interferometry at ALBA

radiation, extraction, synchrotron-radiation, vacuum

374

L. Torino, U. Iriso
ALBA-CELLS Synchrotron, Cerdanyola del Vallès, Spain
T.M. Mitsuhashi
KEK, Ibaraki, Japan

First tests to measure the transverse beam size using interferometry at ALBA showed that the measurement reliability was limited by the inhomogeneous light wavefront arriving at the double slit system. For this reason, the optical components guiding the synchrotron radiation have been exchanged, and detailed quality checks have been carried out using techniques like the Fizeau interferometry or Hartmann mask tests. We report the results of the analysis of the optical elements installed in the beamline, and the beam size measurements performed using double slit interferometry in both horizontal and vertical planes.

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TUPD10

An Ultrafast Linear Array Detector for Single-Shot Electro-Optical Bunch Profile Measurements

detector, FPGA, laser, radiation

435

L. Rota, C.M. Caselle, N. Hiller, A.-S. Müller, M. Weber
KIT, Eggenstein-Leopoldshafen, Germany

A new spectrometer system has been developed at ANKA for near-field single-shot Electro-Optical (EO) bunch profile measurements with a frame rate of 5 Mfps. The frame rate of commercial line detectors is limited to several tens of kHz, unsuitable for measuring fast dynamic changes of the bunch conditions. The new system aims to realize continuous data acquisition and over long observation periods without dead time. InGaAs or Si linear array pixel sensors are used to detect the near IR and visible spectrum radiation. The detector signals are fed via wire-bonding connections to the GOTTHARD ASIC, a charge-sensitive amplifier with analog outputs. The front-end board is also equipped with an array of fast ADCs. The digital samples are then acquired by an FPGA-based readout card and transmitted to an external DAQ system via a high-speed PCI-Express data link. The DAQ system uses high-end Graphics Processors Units (GPUs) to perform a real-time analysis of the beam conditions. In this paper we present the concept, the first prototype and the low-noise layout techniques used for fast linear detectors.

Poster TUPD10 [5.159 MB]

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WECZB3

Measurement of Beam Losses Using Optical Fibers at the Australian Synchrotron

electron, detector, beam-losses, emittance

515

E. Nebot Del Busto, C.P. Welsch
The University of Liverpool, Liverpool, United Kingdom
M.J. Boland
ASCo, Clayton, Victoria, Australia
M.J. Boland, R.P. Rassool
The University of Melbourne, Melbourne, Victoria, Australia
E.B. Holzer, M. Kastriotou, E. Nebot Del Busto
CERN, Geneva, Switzerland
P.D. Jackson
University of Adelaide, Adelaide, Australia
J. Schmidt
Albert-Ludwig Universität Freiburg, Freiburg, Germany
C.P. Welsch
Cockcroft Institute, Warrington, Cheshire, United Kingdom

The unprecedented requirements that new machines are setting on their diagnostic systems are leading to the development of a new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detectors. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over the long distances of beam lines. In this document, we study the feasibility of a beam loss monitor (BLM) system based on optical fibers as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record lowest transverse emittance (below 1 pm rad). Ultra low transverse sizes and large amounts of synchrotron radiation provide an environment very similar to that expected in the CLIC damping rings. A qualitative benchmark of beam losses under damping ring-like conditions is presented here. A wide range of beam loss rates can be achieved by modifying the bunch charge, horizontal/vertical coupling and dynamic aperture as well as via beam scrapers. The controlled beam losses are observed by means of the Cherenkov light produced in a 365 um core Silica fiber. The output light is coupled to different types of photo sensors namely: Multi Pixel Photon Counters (MPPCs), standard PhotoMulTiplier (PMT) tubes and Avalanche PhotoDiodes (APD). A detailed comparison of the sensitivities and time resolution obtained with the different read-outs are discussed in this contribution.

Slides WECZB3 [2.755 MB]

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WEPF03

Upgrade of the Fast Beam Intensity Measurement System for the CERN PS Complex

controls, shielding, proton, vacuum

525

D. Belohrad, J.C.A. Allica, M. Andersen, W. Andreazza, G. Favre, N. Favre, L.K. Jensen, L. Lenardon, W. Vollenberg
CERN, Geneva, Switzerland

The CERN Proton Synchrotron complex (CPS) has been operational for over 50 years. During this time the Fast Beam Current Transformers (FBCTs) have only been repaired when they ceased to function, or individually modified to cope with new requests. This strategy resulted in a large variation of designs, making their maintenance difficult and limiting the precision with which comparisons could be made between transformers for the measurement of beam intensity transmission. During the first long shut-down of the CERN LHC and its injectors (LS1) these systems have undergone a major consolidation, with detectors and acquisition electronics upgraded to provide a uniform measurement system throughout the PS complex. This paper discusses the solutions used and analyses the first beam measurement results.

Poster WEPF03 [7.547 MB]

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WEPF31

Sensor Studies for DC Current Transformer Application

ion, storage-ring, instrumentation, feedback

624

E. Soliman, K. Hofmann
TU Darmstadt, Darmstadt, Germany
H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

DC Current Transformers (DCCTs) are known since decades as non-intercepting standard tools for online beam current measurement in synchrotrons and storage rings. In general, the measurement principle of commonly used DCCTs is to introduce a modulating AC signal for a pair of ferromagnetic toroid. A passing DC ion beam leads to an asymmetric shift of the hysteresis curves of the toroid pair. However, a drawback for this measurement principle is found at certain revolution frequencies in ring accelerators, when interference caused by the modulating frequency and its harmonics leads to inaccurate readings by the DCCT. Recent developments of magnetic field sensors allow for new approaches towards a DCCT design without using the modulation principle. This paper shows a review of different kinds of usable magnetic sensors, their characteristics and how they could be used in novel DCCT instruments.

Poster WEPF31 [4.396 MB]

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WEPD17

Commissioning Results of MicroTCA.4 Stripline BPM System

electronics, linac, synchrotron-radiation, booster

680

C. Xu, S. Allison, S. L. Hoobler, D.J. Martin, J.J. Olsen, T. Straumann, A. Young
SLAC, Menlo Park, California, USA
H.-S. Kang, C. Kim, S.J. Lee, G. Mun
PAL, Pohang, Kyungbuk, Republic of Korea

Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357, DE-AC02-76SF00515, and WFOA13-197
SLAC National Accelerator Laboratory is a premier photon science laboratory. SLAC has a Free Electron Laser facility that will produce 0.5 to 77 Angstroms x-rays and a synchrotron light source facility. In order to achieve this high level of performance, the beam position measurement system needs to be accurate so the electron beam bunch can be stable. We have designed a general purpose stripline Beam Position Monitor (BPM) system that has a dynamic range of 10pC to 1nC bunch charge. The BPM system uses the MicroTCA (Micro Telecommunication Computing Architecture) for physics platform that consists of a 14-bit 250 MSPS ADC module (SIS8300 from Struck) that uses the Zone 3 A1.x classification for the Rear Transition Module (RTM). This paper will discuss the commissioning result at SLAC LCLS-I, SLAC SSRL, and Pohang Accelerator Laboratory. The RTM architecture includes a bandpass filter at 300MHz with 30 MHz bandwidth, and an automated BPM calibration process. The RTM communicates with the AMC FPGA using a QSPI interface over the zone 3 connection.

Poster WEPD17 [5.087 MB]

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WEPD21

BPM Data Correction at SOLEIL

electronics, vacuum, storage-ring, simulation

684

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

In a synchrotron light source like SOLEIL, Beam Position Monitors (BPM) are optimized to have the highest sensitivity for an electron beam passing nearby their mechanical center. Nevertheless, this optimization is done to the detriment of the response linearity when the beam is off-centered for dedicated machine physic studies. To correct the geometric non linearity of the BPM, we have applied an algorithm based on a boundary element method. Moreover the BPM electronics is able to provide position data at a turn by turn rate. Unfortunately the filtering process in this electronics mixes the information from one turn to the neighboring turns. An additional demixing algorithm has been set-up to correct this artefact. The paper reports on performances and limitations of those two algorithms that are used at SOLEIL to correct the BPM data.

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WEPD22

Design of a New Blade-Type XBPM

photon, insertion, insertion-device, undulator

687

N. Hubert, N. Béchu, L. Cassinari, J. Da Silva Castro, J.-C. Denard, M. Labat, J.L. Marlats, A. Mary
SOLEIL, Gif-sur-Yvette, France
S.R. Marques, R.T. Neuenschwander
LNLS, Campinas, Brazil

A new photon Beam Position Monitor (X-BPM) design has been developed in collaboration between the Brazilian Synchrotron Light Laboratory (LNLS) and SOLEIL Synchrotron. This blade-type X-BPM has been carefully studied in order to minimize beam current dependence and temperature dependence. The main advantages of the design are a good stability than the standard X-BPMs initially installed at SOLEIL. This new design is used for the new X-BPMs installed at SOLEIL and is being considered for the bending magnet front-ends of the future SIRIUS light source. A first “double” unit has been constructed by LNLS for the two canted Anatomix and Nanoscopium SOLEIL beamlines, and has been installed at SOLEIL in May 2014. Design and first results are presented.

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