IBIC2014 - List of Keywords (synchrotron-radiation)

Paper	Title	Other Keywords	Page
MOCZB1	A Picosecond Sampling Electronic “KAPTURE” for Terahertz Synchrotron Radiation	synchrotron, 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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MOPD11	Near-Saturation Single-Photon Avalanche Diode Afterpulse and Sensitivity Correction Scheme for the LHC Longitudinal Density Monitor	photon, detector, laser, synchrotron	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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TUCZB2	Measurements of Small Vertical Beamsize using a Coded Aperture at Diamond Light Source	electron, radiation, detector, synchrotron	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, collider, synchrotron	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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TUPF23	Beam Size Measurements using Synchrotron Radiation Interferometry at ALBA	radiation, extraction, synchrotron, 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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TUPD08	YAG:Ce Screen Monitor Using a Gated CCD Camera	timing, emittance, radiation, collider	426
	T. Naito, T.M. Mitsuhashi KEK, Ibaraki, Japan
	Due to its good spatial resolution, the YAG:Ce screen monitor is often used for small beam profile measurement in the Linac and beam transport line. We constructed a high-resolution YAG:Ce screen monitor at KEK-ATF2 for the observation of small size beams a. We tested two types of screens, one is powder YAG:Ce and the other is single crystal YAG:Ce. Both screens have 50μm thickness. To escape from strong COTR, we applied delayed timing of the gate for the CCD camera. A microscope having a spatial resolution of 6μm was set outside of a vacuum chamber to observe the scintillation light from the YAG:Ce screen. The results of the difference between the two screens, the camera performance with delayed gate, and the optical performance of the microscope will be presented in this session.
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WEPD17	Commissioning Results of MicroTCA.4 Stripline BPM System	electronics, synchrotron, linac, 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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Paper

Title

Other Keywords

Page

MOCZB1

A Picosecond Sampling Electronic “KAPTURE” for Terahertz Synchrotron Radiation

synchrotron, 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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MOPD11

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

photon, detector, laser, synchrotron

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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TUCZB2

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

electron, radiation, detector, synchrotron

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, collider, synchrotron

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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reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPF23

Beam Size Measurements using Synchrotron Radiation Interferometry at ALBA

radiation, extraction, synchrotron, 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.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

TUPD08

YAG:Ce Screen Monitor Using a Gated CCD Camera

timing, emittance, radiation, collider

426

T. Naito, T.M. Mitsuhashi
KEK, Ibaraki, Japan

Due to its good spatial resolution, the YAG:Ce screen monitor is often used for small beam profile measurement in the Linac and beam transport line. We constructed a high-resolution YAG:Ce screen monitor at KEK-ATF2 for the observation of small size beams a. We tested two types of screens, one is powder YAG:Ce and the other is single crystal YAG:Ce. Both screens have 50μm thickness. To escape from strong COTR, we applied delayed timing of the gate for the CCD camera. A microscope having a spatial resolution of 6μm was set outside of a vacuum chamber to observe the scintillation light from the YAG:Ce screen. The results of the difference between the two screens, the camera performance with delayed gate, and the optical performance of the microscope will be presented in this session.

Export •

reference for this paper to ※ LaTeX, ※ Text, ※ IS/RefMan, ※ EndNote (xml)

WEPD17

Commissioning Results of MicroTCA.4 Stripline BPM System

electronics, synchrotron, linac, 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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