IBIC2013 - List of Keywords (injection)

Paper	Title	Other Keywords	Page
MOBL2	Thermalized and Reaccelerated Beams at the National Superconducting Cyclotron Laboratory	ion, acceleration, diagnostics, cyclotron	19
	S.J. Williams, T. Baumann, K. Cooper, A. Lapierre, D. Leitner, D.J. Morrissey, G. Perdikakis, J.A. Rodriguez, S. Schwarz, A. Spyrou, M. Steiner, C. Sumithrarachchi NSCL, East Lansing, Michigan, USA W. Wittmer FRIB, East Lansing, Michigan, USA
	Funding: This work is supported by the National Science Foundation under contract number RC100609. The National Superconducting Cyclotron Laboratory at Michigan State University is a Radioactive Ion Beam (RIB) facility providing beams of exotic nuclear species through projectile fragmentation. The Coupled Cyclotron Facility accelerates stable ion beams to ~100 MeV/A which are then fragmented and selected with the A1900 separator. A recent addition to NSCL is the gas stopping facility which thermalizes the high energy beam. The RIBs are extracted at <60keV and selected by A/Q for further transport to the low energy areas, currently consisting of the BECOLA beam cooling and laser spectroscopy system, and LEBIT Penning trap. RIBs up to 6 MeV/A will be provided by the ReA post-accelerator, currently consisting of an EBIT, RFQ and superconducting RF cavities. Energies up to 1.5 MeV/A are presently available, and energy increases will be phased in with the addition of further cryomodules. In a campaign of commissioning experiments, RIBs from a fragmentation facility were thermalized and post-accelerated for the first time. Preliminary results will be presented, focussing on the diagnostic challenges of detecting and characterizing beams over a wide range of energy and rate.
	Slides MOBL2 [2.084 MB]

MOPC05	Beam Diagnostics of SuperKEKB Damping Ring	KEKB, beam-position, extraction, beam-losses	53
	H. Ikeda, A. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama KEK, Ibaraki, Japan
	The KEKB accelerator ceased operation in 2010, and is being upgraded to SuperKEKB. Adopting low emittance and high current beams, the design luminosity is set at 40 times larger than that of KEKB. We are constructing a damping ring (DR) in order to achieve a low-emittance positron beam for injection. Turn-by-turn beam position monitors (BPMs), a transverse feedback system, a synchrotron radiation monitor (SRM), a DCCT, loss monitors using ion chambers, a bunch current monitor and a tune meter will be installed for beam diagnostics at the DR. An overview of the instrumentation of the DR will be presented in this paper.

MOPC18	Development of a High Dynamic Range Beam Position Measurement System Using Logarithmic Amplifiers for the SPS at CERN	SPS, beam-position, proton, CERN	89
	J.L. Gonzalez, T.B. Bogey, C. Deplano, J.-J. Savioz CERN, Geneva, Switzerland
	A new Front-End electronics, based on Logarithmic Amplifiers, is currently being developed for the CERN SPS Multi Orbit POsition System (MOPOS). The aim is to resolve the multi-batch structure of the beams and cope with their large intensity range (> 70 dB). Position and intensity signals are digitized in the Front-End electronics installed in the tunnel. The data are then transmitted over a serial fibre-optic link to a VME Digital Acquisition board located in surface buildings. A first prototype, equipped with a calibration system, has been successfully tested on the SPS under different beam conditions, including single bunch, 25ns and 50ns bunch trains. The system architecture and the first beam measurements are reported in this paper.
	Poster MOPC18 [4.013 MB]

MOPC35	A Beam-Synchronous Gated Peak-Detector for the LHC Beam Observation System	LHC, CERN, longitudinal, synchrotron	147
	T.E. Levens, T. Bohl, U. Wehrle CERN, Geneva, Switzerland
	Measurements of the bunch peak amplitude using the longitudinal wideband wall-current monitor are a vital tool used in the Large Hadron Collider (LHC) beam observation system. These peak-detected measurements can be used to diagnose bunch shape oscillations, for example coherent quadrupole oscillations, that occur at injection and during beam manipulations. Peak-detected Schottky diagnostics can also be used to obtain the synchrotron frequency distribution and other parameters from a bunched beam under stable conditions. For the LHC a beam-synchronous gated peak detector has been developed to allow individual bunches to be monitored without the influence of other bunches circulating in the machine. The requirement for the observation of both low intensity pilot bunches and high intensity bunches for physics requires a detector front-end with a high bandwidth and a large dynamic range while the usage for Schottky measurements requires low noise electronics. This paper will present the design of this detector system as well as initial results obtained during the 2012-2013 LHC run.
	Poster MOPC35 [2.792 MB]

MOPC43	Performance of Detectors using Diamond Sensors at the LHC and CMS	DIAMOND, beam-losses, LHC, luminosity	174
	M. Hempel BTU, Cottbus, Germany T. Baer, A.E. Dabrowski CERN, Geneva, Switzerland E. Griesmayer ATI, Wien, Austria W. Lange, O. Novgorodova DESY Zeuthen, Zeuthen, Germany W. Lohmann DESY, Hamburg, Germany N.J. Odell NU, Evanston, USA D.P. Stickland PU, Princeton, New Jersey, USA
	Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiation fields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pCVD diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses sCVD diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.
	Poster MOPC43 [0.721 MB]

MOPC45	A Prototype Readout System for the Diamond Beam Loss Monitors at LHC	beam-losses, DIAMOND, LHC, proton	182
	E. Effinger, T. Baer, B. Dehning, R. Schmidt CERN, Geneva, Switzerland H. Frais-Kölbl FH WN, Wiener Neustadt, Austria E. Griesmayer ATI, Wien, Austria P. Kavrigin CIVIDEC Instrumentation, Wien, Austria
	Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. Results from specimen LHC loss measurements are presented in this talk. The bunch-to-bunch loss measurements make full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. The data processing is done with a dedicated readout system, which was designed and optimized for particular applications with the diamond beam loss monitors. This FPGA-based system provides on-line, real-time, and dead-time-free data processing. Several examples are presented: the Time Loss Histogram with 1.6 ns binning provides beam loss measurements that are synchronized with the revolution period throughout the full operational LHC cycle. The Post Mortem Recorder with a sampling frequency of 1 GS/s allows beam-loss-based tune estimates for all bunches in parallel. Future applications and upgrades are discussed.
	Poster MOPC45 [0.778 MB]

MOPF15	Advanced uses of a Current Transformer and a Multi-Wire Profile Monitor for Online Monitoring of the Stripper Foil Degradation in the 3-GeV RCS of J-PARC	monitoring, proton, target, linac	239
	P.K. Saha, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, M. Kinsho, K. Okabe, R. Saeki, K. Yamamoto, Y. Yamazaki, M. Yoshimoto JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	We have established advanced and sophisticated uses of a Current Transformer (CT) and a Multi-Wire Profile Monitor (MWPM) for measuring as well as online monitoring of the stripper foil degradation during user operation of the 3-GeV Rapid Cycling Synchrotron (RCS) in Japan Proton Accelerator Research Complex (J-PARC). An incoming negative hydrogen beam from the Linac is stripped to a proton beam by using a stripper foil placed in the RCS injection area. Foil degradation such as, foil thinning and pinhole formation are believed to be signs of a foil breaking. A sudden foil breaking is not only a load on the accelerator downtime but also raises maintenance issues. In a high intensity accelerator like RCS, a proper monitoring system of the foil is thus important in order to avoid such above issues by replacing the foil with a new one in the scheduled maintenance day. The thickness of the stipper foil used for the present 181 MeV injection energy is 200 ug/cm², where a change of foil thickness as low as 1% or even less has already been successfully monitored by utilizing the presented method. Measured data for the last 6 months operation of the RCS will be presented.
	Poster MOPF15 [1.591 MB]

MOPF19	Injection Efficiency Monitoring System at the Australian Synchrotron	booster, synchrotron, extraction, background	248
	E.D. van Garderen, S.A. Griffiths, G. LeBlanc, S. Murphy, A. Rhyder, A. C. Starritt ASCo, Clayton, Victoria, Australia M.J. Boland SLSA, Clayton, Australia
	The Australian Synchrotron upgraded its user mode from decay mode to top-up mode in May 2012. To monitor the beam charge passing through the accelerator systems at key transfer points the transmission efficiency system has been upgraded. The original system could only measure the efficiency of the booster to storage ring injection. The new one calculates intermediate efficiencies between six points along the injection system, from the electron gun to the booster-to-storage ring transfer line. This is helpful to diagnose in real-time shot-to-shot the performance of the pulsed magnets, ramped magnets and ramped RF systems and their associated triggers. A software-based injection efficiency interlock has also been introduced, that can inhibit the gun when the machine settings are not optimal. This article details the architecture of the injection efficiency system and lists the improvements on the machine that have been carried out to obtain high quality data.

TUBL2	A 4 GS/s Feedback Processing System for Control of Intra-Bunch Instabilities	feedback, SPS, controls, kicker	323
	J.D. Fox, J.M. Cesaratto, J.E. Dusatko, J.J. Olsen, K.M. Pollock, C.H. Rivetta, O. Turgut SLAC, Menlo Park, California, USA W. Höfle CERN, Geneva, Switzerland
	Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research program ( LARP) We present the architecture and implementation overview of a digital signal processing system developed to study control of Electron-Cloud and Transverse Mode coupling instabilities in the CERN SPS. The system is based on a reconfigurable processing architecture which samples vertical bunch motion and applies correction signals at a 4 GS/s rate, allowing 16 samples across a single 5 ns SPS RF bucket. The system requires wideband beam pickups and a vertical kicker structure with GHz bandwidth. This demonstration system implements a general purpose 16 tap FIR control filter for each sample. We present results from SPS machine studies showing the impact of wideband feedback to excite/damp internal modes of vertical motion as well as stabilize an unstable beam. These results highlight the challenges of intra-bunch feedback and show proof of principle feasibility of the architecture.
	Slides TUBL2 [12.154 MB]

TUPC16	Bunch-by-Bunch Feedback and Diagnostics at BESSY II	feedback, longitudinal, beam-losses, kicker	399
	A. Schälicke, F. Falkenstern, R. Müller HZB, Berlin, Germany
	At the light source BESSY II new digital bunch-by-bunch feedback systems have been put into operation in January 2013, replacing the existing analog as well as the obsolete digital systems. From the first days of operation the new system successfully suppresses transverse and longitudinal beam instabilities in wide range of machine parameters. The system offers also many new diagnostics opportunities, these include the analysis of instability modes, measurement of the feedback loop gain, and determination of the transfer function. A method to systematically optimise the output amplifier response function with the help of shaper coefficients for the optimal bunch separation has been developed. In addition the analysis of the input data stream allows a passive determination of machine properties like betatron and synchrotron frequencies as well as the longitudinal phases for every bunch. The integration of external triggers permits the analysis of postmortem data, the characterisation of beam-loss events, and monitoring of the injection process. In this contribution first operational experience, the developed data analysis techniques and experimental data will be presented.
	Poster TUPC16 [56.767 MB]

TUPF01	Proton Emittance Measurements in the Brookhaven AGS	emittance, AGS, IPM, space-charge	492
	H. Huang, R. Connolly, C.W. Dawson, D.M. Gassner, C.E. Harper, S.E. Jao, W. Meng, F. Méot, R.J. Michnoff, M.G. Minty, V. Schoefer, T. Summers, S. Tepikian, K. Yip, K. Zeno 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. High luminosity and high polarization in RHIC require good control and measurement of emittance in its injector, the Brookhaven AGS. In the past, the AGS emittance has been measured by using an ion collecting IPM during the whole cycle and a multi-wire at injection. The beam profiles from this IPM are distorted by space charge forces at higher energy, which makes the emittance determination very hard. In addition, helical superconducting snake magnets and near integer vertical tune for polarized proton operation distort the lattice in the AGS and introduce large beta beating. For more precise measurements of the emittance, we need TBT measurements near injection and beta function measurements at the location of devices used to measure the emittance. A Polarimeter target has been used as flying wire for proton emittance measurement. A new type electron collecting IPM has been installed and tested in the AGS with proton beam. The Beta functions at the IPM locations have been measured with Orbit Response Matrix (ORM) methods and with a local corrector at IPM. This paper summarizes our current understanding of AGS emittances and plans for further improvements.

WEPC13	Optimisation of the SVD Treatment in the Fast Orbit Correction of the ESRF Storage Ring	BPM, ESRF, feedback, storage-ring	694
	E. Plouviez, F. Epaud, L. Farvacque, J.M. Koch ESRF, Grenoble, France
	The ESRF fast orbit correction system has been in operation since May 2012. The orbit correction scheme relies classically on the calculation of a correction orbit based on the SVD analysis of the response matrix of our 224 BPMs to each of our 96 correctors. The rate of the calculation of the corrections is 10 KHz; we use a PI loop achieving a bandwidth of 150Hz completed with a narrow band pass filter with extra gain at 50Hz. In order to make the best use of the correctors dynamic range and of the resolution of the calculation, it can be useful to limit the bandwidth of loop for the highest order vectors of the SVD, or even to totally remove some of these vectors from the correction down to DC. Removing some of the eigen vectors while avoiding that the loop becomes unstable usually increases a lot the complexity of the matrix calculations: we have developed an algorithm which overcomes this problem; The test of this algorithm is presented. We present also the beneficial effect at high frequency of the limitation of the gain of the correction of the highest SVD eigen vectors on the demand of the peak strength of the correctors and on the resolution of the correction calculation.
	Poster WEPC13 [0.974 MB]

WEPC16	The Design of BPM Electronic System for CSNS RCS	pick-up, BPM, extraction, beam-position	706
	W. Lu, H.Y. Sheng, X.C. Tian, J.W. Zhao, Y.B. Zhao IHEP, Bejing, People's Republic of China
	A Beam Position Monitor (BPM) system has been designed for the Rapid Cycling Synchrotron (RCS) at the China Spallation Neutron Source (CSNS) to acquire beam position information. This article introduces the design and implementation of the BPM electronic system. The challenge of designing the BPM electronics is to acquire and process the signal with large dynamic range (5.8mV~32V) and changing width (80ns to 500ns). The analog circuit described in this paper, which is constructed of a single-stage operational amplifier and an analog switch, can cover the input signal with large dynamic range. Because of the minimum bunch length (80ns) and the requirement of position resolution, a 14 bit 250MHz ADC is adopted to digitize the signal. Besides, for BPM system, the demand of an accurate real-time position monitoring is mandatory. The algorithm developed in an FPGA is able to make Bunch-by-Bunch position calculation and Closed Orbit position calculation in real time. Also, some preliminary test results will be presented and discussed, which show that the resolution of Bunch-by-Bunch position is 0.8mm when the input signal is 5.8mV and the resolution of Closed Orbit position is 50um.
	Poster WEPC16 [0.937 MB]

WEPC19	Performance of Injection Beam Position Monitors in the J-PARC RCS	linac, BPM, monitoring, bunching	716
	N. Hayashi, P.K. Saha JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	It is important to monitor the injected beam trajectory and position into a synchrotron ring. In the J-PARC RCS, there are two specialized beam position monitors (BPM) in the first arc section in order to perform continuous monitoring. They detect the linac RF frequency 324 MHz or its second harmonics, these contributions quickly decrease after a few turns in the ring. Therefore, they are sensitive only just injected beam. The RCS adopts the multi-turn injection and transverse painting. These monitors are useful to check the beam behavior on-line.

WEPC28	Bunch By Bunch Transverse Beam Position Observation and Analyze During Injection at SSRF	kicker, transverse, betatron, storage-ring	746
	Y.B. Leng, Y.B. Yan, Y. Yang, R.X. Yuan, N. Zhang SSRF, Shanghai, People's Republic of China
	Funding: Work supported by National Science Foundation of China (No. 11075198) Top-up operation has been performed at SSRF since Dec. 2012. Orbit disturbance every 10 minutes decreased the quality of synchrotron radiation. In order to minimize this disturbance the tilts and the timing of injection kickers need to be tuning carefully based on real beam information. A set of button type pick-up and a scope based IOC were employed to capture the transient beam movement with bunch by bunch rate during injection. Several sets of observation and analyze will be discussed in this paper.

WEPC33	Upgrade of Beam Phase Monitors for the ESRF Injector and Storage Ring	storage-ring, booster, BPM, ESRF	757
	K.B. Scheidt, B. Joly ESRF, Grenoble, France
	The measurement of the phase relation between the stored beam in the Storage Ring and the beam circulating in the Booster Synchrotron is now done with high precision and at high speed using a single unit of commercial BPM electronics. The quadrature demodulation, driven by a common PLL, done in these digital electronics on each of its four RF input channels makes the relative measurement of the I/Q components, hence phase relation, easy and strait forward. The RF signals of the relatively low current Booster come from two stripline outputs while that of the Storage Ring from two small BPM buttons. Treating simultaneously four signals, thus with a redundancy of two to measure the phase between two sources, allows to perform intrinsic shot-to-shot cross verifications on resolution and reproducibility. The long-term stability of this device has also been successfully assessed by independent verifications against time and temperature drifts. An identical unit has now been added for phase measurements between the Storage Ring beam and the RF cavity signals. Results with beam and assessment of its scope of performance will be presented on both systems.
	Poster WEPC33 [0.836 MB]

WEPC34	Time Trend Observation of Certain Remarked Bunches using a Streak Camera	synchrotron, longitudinal, damping, KEK	761
	T. Naito, S. Araki, H. Hayano, K. Kubo, S. Kuroda, T.M. Mitsuhashi, T. Okugi, S. Sakanaka, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	Funding: This work is supported by Japan-U.S. cooperative program . A streak camera with two dimensional sweep function can measure the trend of the longitudinal beam profile in the ring. In the case of the multi-bunch measurement, the different bunch profile sit on same timing, thus, we can not distinguish the behavior of each bunch. We have developed a trigger circuit to measure the bunch-by-bunch longitudinal beam profile, which uses non integer sweep frequency for the acceleration frequency. The bunch profile of each bunch sit on different position in this measurement. We observed the increment of the synchrotron oscillation amplitude from the first bunch to the 20th bunch in the KEK-ATF Damping Ring by using this system. This paper describes the hardware and the measurement results.

WEPC39	First Tests of the Top-up Gating at Synchrotron SOLEIL	SOLEIL, synchrotron, storage-ring, kicker	775
	J.P. Ricaud, L. Cassinari, P. Dumas, P. Lebasque, A. Nadji SOLEIL, Gif-sur-Yvette, France
	Since 2006, Synchrotron SOLEIL is delivering photons to its beamlines. Until 2012, thanks to the excellent performances of the injection system of the storage ring, the perturbation on the position of the stored beam was small enough to be accepted by the users. For some specific experiments, few beamlines expressed their wish to be able to stop their data acquisition during the injection. To fulfill this need, the diagnostics group of Synchrotron SOLEIL has designed the “TimEX3” board which was integrated into the timing system allowing the gating of the Top-up injection. This design was released as open hardware. Towards this aim, we decided to design it with the open source and free EDA software “KiCad”, and to make it available under the CERN’s Open Hardware Repository.
	Poster WEPC39 [0.521 MB]

WEPF29	The LHC Fast Beam Current Change Monitor	LHC, CERN, FIR, beam-losses	887
	D. Belohrad, J.M. Belleman, L.K. Jensen, M. Krupa, A. Topaloudis CERN, Geneva, Switzerland
	The modularity of the Large Hadron Collider’s (LHC) machine protection system (MPS) allows for the integration of several beam diagnostic instruments. These instruments have not necessarily been designed to have protection functionality, but MPS can still use them to increase the redundancy and reliability of the machine. The LHC fast beam current change monitor (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates the magnitude of the beam signal provided by the FBCT, looks for a change over specific time intervals, and triggers a beam dump interlock if losses exceed an energy-dependent threshold. The first prototype of the FBCCM was installed in the LHC during the 2012-2013 run. The aim of this article is to present the FBCCM system and the results obtained, analyse its current performance and provide an outlook for the final system which is expected to be operational after the long LHC shutdown.

THAL3	Charge Distribution Measurements at ALBA	photon, synchrotron, electron, BPM	925
	L. Torino, U. Iriso CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain
	Two different set-ups are used to perform quantitative measurements of the charge distribution at ALBA. The first consists in a real-time analysis of data coming from the Fast Current Transformer or from the buttons of a Beam Position Monitor installed in the Storage Ring. The second is performed at the diagnostic visible beamline Xanadu, using a Photomultiplier that measures the temporal distribution of synchrotron light. In both cases a quantitative estimation of the charge distribution is obtained after a dedicated data treatment and beam current measurements from the DCCT. We compare results with both methods, and discuss differences and limitations with respect to bunch purity measurements with the Time Correlated Single Photon Counting technique.
	Slides THAL3 [15.369 MB]

Paper

Title

Other Keywords

Page

MOBL2

Thermalized and Reaccelerated Beams at the National Superconducting Cyclotron Laboratory

ion, acceleration, diagnostics, cyclotron

19

S.J. Williams, T. Baumann, K. Cooper, A. Lapierre, D. Leitner, D.J. Morrissey, G. Perdikakis, J.A. Rodriguez, S. Schwarz, A. Spyrou, M. Steiner, C. Sumithrarachchi
NSCL, East Lansing, Michigan, USA
W. Wittmer
FRIB, East Lansing, Michigan, USA

Funding: This work is supported by the National Science Foundation under contract number RC100609.
The National Superconducting Cyclotron Laboratory at Michigan State University is a Radioactive Ion Beam (RIB) facility providing beams of exotic nuclear species through projectile fragmentation. The Coupled Cyclotron Facility accelerates stable ion beams to ~100 MeV/A which are then fragmented and selected with the A1900 separator. A recent addition to NSCL is the gas stopping facility which thermalizes the high energy beam. The RIBs are extracted at <60keV and selected by A/Q for further transport to the low energy areas, currently consisting of the BECOLA beam cooling and laser spectroscopy system, and LEBIT Penning trap. RIBs up to 6 MeV/A will be provided by the ReA post-accelerator, currently consisting of an EBIT, RFQ and superconducting RF cavities. Energies up to 1.5 MeV/A are presently available, and energy increases will be phased in with the addition of further cryomodules. In a campaign of commissioning experiments, RIBs from a fragmentation facility were thermalized and post-accelerated for the first time. Preliminary results will be presented, focussing on the diagnostic challenges of detecting and characterizing beams over a wide range of energy and rate.

Slides MOBL2 [2.084 MB]

MOPC05

Beam Diagnostics of SuperKEKB Damping Ring

KEKB, beam-position, extraction, beam-losses

53

H. Ikeda, A. Arinaga, J.W. Flanagan, H. Fukuma, H. Ishii, S. Kanaeda, K. Mori, M. Tejima, M. Tobiyama
KEK, Ibaraki, Japan

The KEKB accelerator ceased operation in 2010, and is being upgraded to SuperKEKB. Adopting low emittance and high current beams, the design luminosity is set at 40 times larger than that of KEKB. We are constructing a damping ring (DR) in order to achieve a low-emittance positron beam for injection. Turn-by-turn beam position monitors (BPMs), a transverse feedback system, a synchrotron radiation monitor (SRM), a DCCT, loss monitors using ion chambers, a bunch current monitor and a tune meter will be installed for beam diagnostics at the DR. An overview of the instrumentation of the DR will be presented in this paper.

MOPC18

Development of a High Dynamic Range Beam Position Measurement System Using Logarithmic Amplifiers for the SPS at CERN

SPS, beam-position, proton, CERN

89

J.L. Gonzalez, T.B. Bogey, C. Deplano, J.-J. Savioz
CERN, Geneva, Switzerland

A new Front-End electronics, based on Logarithmic Amplifiers, is currently being developed for the CERN SPS Multi Orbit POsition System (MOPOS). The aim is to resolve the multi-batch structure of the beams and cope with their large intensity range (> 70 dB). Position and intensity signals are digitized in the Front-End electronics installed in the tunnel. The data are then transmitted over a serial fibre-optic link to a VME Digital Acquisition board located in surface buildings. A first prototype, equipped with a calibration system, has been successfully tested on the SPS under different beam conditions, including single bunch, 25ns and 50ns bunch trains. The system architecture and the first beam measurements are reported in this paper.

Poster MOPC18 [4.013 MB]

MOPC35

A Beam-Synchronous Gated Peak-Detector for the LHC Beam Observation System

LHC, CERN, longitudinal, synchrotron

147

T.E. Levens, T. Bohl, U. Wehrle
CERN, Geneva, Switzerland

Measurements of the bunch peak amplitude using the longitudinal wideband wall-current monitor are a vital tool used in the Large Hadron Collider (LHC) beam observation system. These peak-detected measurements can be used to diagnose bunch shape oscillations, for example coherent quadrupole oscillations, that occur at injection and during beam manipulations. Peak-detected Schottky diagnostics can also be used to obtain the synchrotron frequency distribution and other parameters from a bunched beam under stable conditions. For the LHC a beam-synchronous gated peak detector has been developed to allow individual bunches to be monitored without the influence of other bunches circulating in the machine. The requirement for the observation of both low intensity pilot bunches and high intensity bunches for physics requires a detector front-end with a high bandwidth and a large dynamic range while the usage for Schottky measurements requires low noise electronics. This paper will present the design of this detector system as well as initial results obtained during the 2012-2013 LHC run.

Poster MOPC35 [2.792 MB]

MOPC43

Performance of Detectors using Diamond Sensors at the LHC and CMS

DIAMOND, beam-losses, LHC, luminosity

174

M. Hempel
BTU, Cottbus, Germany
T. Baer, A.E. Dabrowski
CERN, Geneva, Switzerland
E. Griesmayer
ATI, Wien, Austria
W. Lange, O. Novgorodova
DESY Zeuthen, Zeuthen, Germany
W. Lohmann
DESY, Hamburg, Germany
N.J. Odell
NU, Evanston, USA
D.P. Stickland
PU, Princeton, New Jersey, USA

Diamond detectors are used as beam loss and luminosity monitors for CMS and LHC. A time resolution in the nanosecond range allows to detect beam losses and luminosities of single bunches. The radiation hardness and negligible temperature dependence allow the usage of diamond sensors in high radiation fields without cooling. Two different diamond detector types are installed at LHC and CMS. One is based on pCVD diamonds and installed at different locations in the LHC tunnel for beam loss monitoring. Measurements of these detectors are used to perform a bunch-by-bunch beam loss analysis. They allow to disentangle the origin of beam losses. The second type uses sCVD diamonds and is located inside CMS for van-der-Meer scan, beam halo and online luminosity monitoring and around the LHC tunnel for beam loss observation. Results on the performance of these detectors will be presented and examples of the use for analyzing the beam conditions will be given. In order to persist the enhanced requirements of the LHC after the long shutdown, e.g. higher luminosity, an upgrade of the detectors is required. The concept of the new detectors will be presented and first results will be shown.

Poster MOPC43 [0.721 MB]

MOPC45

A Prototype Readout System for the Diamond Beam Loss Monitors at LHC

beam-losses, DIAMOND, LHC, proton

182

E. Effinger, T. Baer, B. Dehning, R. Schmidt
CERN, Geneva, Switzerland
H. Frais-Kölbl
FH WN, Wiener Neustadt, Austria
E. Griesmayer
ATI, Wien, Austria
P. Kavrigin
CIVIDEC Instrumentation, Wien, Austria

Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. Results from specimen LHC loss measurements are presented in this talk. The bunch-to-bunch loss measurements make full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. The data processing is done with a dedicated readout system, which was designed and optimized for particular applications with the diamond beam loss monitors. This FPGA-based system provides on-line, real-time, and dead-time-free data processing. Several examples are presented: the Time Loss Histogram with 1.6 ns binning provides beam loss measurements that are synchronized with the revolution period throughout the full operational LHC cycle. The Post Mortem Recorder with a sampling frequency of 1 GS/s allows beam-loss-based tune estimates for all bunches in parallel. Future applications and upgrades are discussed.

Poster MOPC45 [0.778 MB]

MOPF15

Advanced uses of a Current Transformer and a Multi-Wire Profile Monitor for Online Monitoring of the Stripper Foil Degradation in the 3-GeV RCS of J-PARC

monitoring, proton, target, linac

239

P.K. Saha, H. Harada, S. Hatakeyama, N. Hayashi, H. Hotchi, M. Kinsho, K. Okabe, R. Saeki, K. Yamamoto, Y. Yamazaki, M. Yoshimoto
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

We have established advanced and sophisticated uses of a Current Transformer (CT) and a Multi-Wire Profile Monitor (MWPM) for measuring as well as online monitoring of the stripper foil degradation during user operation of the 3-GeV Rapid Cycling Synchrotron (RCS) in Japan Proton Accelerator Research Complex (J-PARC). An incoming negative hydrogen beam from the Linac is stripped to a proton beam by using a stripper foil placed in the RCS injection area. Foil degradation such as, foil thinning and pinhole formation are believed to be signs of a foil breaking. A sudden foil breaking is not only a load on the accelerator downtime but also raises maintenance issues. In a high intensity accelerator like RCS, a proper monitoring system of the foil is thus important in order to avoid such above issues by replacing the foil with a new one in the scheduled maintenance day. The thickness of the stipper foil used for the present 181 MeV injection energy is 200 ug/cm², where a change of foil thickness as low as 1% or even less has already been successfully monitored by utilizing the presented method. Measured data for the last 6 months operation of the RCS will be presented.

Poster MOPF15 [1.591 MB]

MOPF19

Injection Efficiency Monitoring System at the Australian Synchrotron

booster, synchrotron, extraction, background

248

E.D. van Garderen, S.A. Griffiths, G. LeBlanc, S. Murphy, A. Rhyder, A. C. Starritt
ASCo, Clayton, Victoria, Australia
M.J. Boland
SLSA, Clayton, Australia

The Australian Synchrotron upgraded its user mode from decay mode to top-up mode in May 2012. To monitor the beam charge passing through the accelerator systems at key transfer points the transmission efficiency system has been upgraded. The original system could only measure the efficiency of the booster to storage ring injection. The new one calculates intermediate efficiencies between six points along the injection system, from the electron gun to the booster-to-storage ring transfer line. This is helpful to diagnose in real-time shot-to-shot the performance of the pulsed magnets, ramped magnets and ramped RF systems and their associated triggers. A software-based injection efficiency interlock has also been introduced, that can inhibit the gun when the machine settings are not optimal. This article details the architecture of the injection efficiency system and lists the improvements on the machine that have been carried out to obtain high quality data.

TUBL2

A 4 GS/s Feedback Processing System for Control of Intra-Bunch Instabilities

feedback, SPS, controls, kicker

323

J.D. Fox, J.M. Cesaratto, J.E. Dusatko, J.J. Olsen, K.M. Pollock, C.H. Rivetta, O. Turgut
SLAC, Menlo Park, California, USA
W. Höfle
CERN, Geneva, Switzerland

Funding: Work supported by the U.S. Department of Energy under contract DE-AC02-76SF00515 and the US LHC Accelerator Research program ( LARP)
We present the architecture and implementation overview of a digital signal processing system developed to study control of Electron-Cloud and Transverse Mode coupling instabilities in the CERN SPS. The system is based on a reconfigurable processing architecture which samples vertical bunch motion and applies correction signals at a 4 GS/s rate, allowing 16 samples across a single 5 ns SPS RF bucket. The system requires wideband beam pickups and a vertical kicker structure with GHz bandwidth. This demonstration system implements a general purpose 16 tap FIR control filter for each sample. We present results from SPS machine studies showing the impact of wideband feedback to excite/damp internal modes of vertical motion as well as stabilize an unstable beam. These results highlight the challenges of intra-bunch feedback and show proof of principle feasibility of the architecture.

Slides TUBL2 [12.154 MB]

TUPC16

Bunch-by-Bunch Feedback and Diagnostics at BESSY II

feedback, longitudinal, beam-losses, kicker

399

A. Schälicke, F. Falkenstern, R. Müller
HZB, Berlin, Germany

At the light source BESSY II new digital bunch-by-bunch feedback systems have been put into operation in January 2013, replacing the existing analog as well as the obsolete digital systems. From the first days of operation the new system successfully suppresses transverse and longitudinal beam instabilities in wide range of machine parameters. The system offers also many new diagnostics opportunities, these include the analysis of instability modes, measurement of the feedback loop gain, and determination of the transfer function. A method to systematically optimise the output amplifier response function with the help of shaper coefficients for the optimal bunch separation has been developed. In addition the analysis of the input data stream allows a passive determination of machine properties like betatron and synchrotron frequencies as well as the longitudinal phases for every bunch. The integration of external triggers permits the analysis of postmortem data, the characterisation of beam-loss events, and monitoring of the injection process. In this contribution first operational experience, the developed data analysis techniques and experimental data will be presented.

Poster TUPC16 [56.767 MB]

TUPF01

Proton Emittance Measurements in the Brookhaven AGS

emittance, AGS, IPM, space-charge

492

H. Huang, R. Connolly, C.W. Dawson, D.M. Gassner, C.E. Harper, S.E. Jao, W. Meng, F. Méot, R.J. Michnoff, M.G. Minty, V. Schoefer, T. Summers, S. Tepikian, K. Yip, K. Zeno
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.
High luminosity and high polarization in RHIC require good control and measurement of emittance in its injector, the Brookhaven AGS. In the past, the AGS emittance has been measured by using an ion collecting IPM during the whole cycle and a multi-wire at injection. The beam profiles from this IPM are distorted by space charge forces at higher energy, which makes the emittance determination very hard. In addition, helical superconducting snake magnets and near integer vertical tune for polarized proton operation distort the lattice in the AGS and introduce large beta beating. For more precise measurements of the emittance, we need TBT measurements near injection and beta function measurements at the location of devices used to measure the emittance. A Polarimeter target has been used as flying wire for proton emittance measurement. A new type electron collecting IPM has been installed and tested in the AGS with proton beam. The Beta functions at the IPM locations have been measured with Orbit Response Matrix (ORM) methods and with a local corrector at IPM. This paper summarizes our current understanding of AGS emittances and plans for further improvements.

WEPC13

Optimisation of the SVD Treatment in the Fast Orbit Correction of the ESRF Storage Ring

BPM, ESRF, feedback, storage-ring

694

E. Plouviez, F. Epaud, L. Farvacque, J.M. Koch
ESRF, Grenoble, France

The ESRF fast orbit correction system has been in operation since May 2012. The orbit correction scheme relies classically on the calculation of a correction orbit based on the SVD analysis of the response matrix of our 224 BPMs to each of our 96 correctors. The rate of the calculation of the corrections is 10 KHz; we use a PI loop achieving a bandwidth of 150Hz completed with a narrow band pass filter with extra gain at 50Hz. In order to make the best use of the correctors dynamic range and of the resolution of the calculation, it can be useful to limit the bandwidth of loop for the highest order vectors of the SVD, or even to totally remove some of these vectors from the correction down to DC. Removing some of the eigen vectors while avoiding that the loop becomes unstable usually increases a lot the complexity of the matrix calculations: we have developed an algorithm which overcomes this problem; The test of this algorithm is presented. We present also the beneficial effect at high frequency of the limitation of the gain of the correction of the highest SVD eigen vectors on the demand of the peak strength of the correctors and on the resolution of the correction calculation.

Poster WEPC13 [0.974 MB]

WEPC16

The Design of BPM Electronic System for CSNS RCS

pick-up, BPM, extraction, beam-position

706

W. Lu, H.Y. Sheng, X.C. Tian, J.W. Zhao, Y.B. Zhao
IHEP, Bejing, People's Republic of China

A Beam Position Monitor (BPM) system has been designed for the Rapid Cycling Synchrotron (RCS) at the China Spallation Neutron Source (CSNS) to acquire beam position information. This article introduces the design and implementation of the BPM electronic system. The challenge of designing the BPM electronics is to acquire and process the signal with large dynamic range (5.8mV~32V) and changing width (80ns to 500ns). The analog circuit described in this paper, which is constructed of a single-stage operational amplifier and an analog switch, can cover the input signal with large dynamic range. Because of the minimum bunch length (80ns) and the requirement of position resolution, a 14 bit 250MHz ADC is adopted to digitize the signal. Besides, for BPM system, the demand of an accurate real-time position monitoring is mandatory. The algorithm developed in an FPGA is able to make Bunch-by-Bunch position calculation and Closed Orbit position calculation in real time. Also, some preliminary test results will be presented and discussed, which show that the resolution of Bunch-by-Bunch position is 0.8mm when the input signal is 5.8mV and the resolution of Closed Orbit position is 50um.

Poster WEPC16 [0.937 MB]

WEPC19

Performance of Injection Beam Position Monitors in the J-PARC RCS

linac, BPM, monitoring, bunching

716

N. Hayashi, P.K. Saha
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

It is important to monitor the injected beam trajectory and position into a synchrotron ring. In the J-PARC RCS, there are two specialized beam position monitors (BPM) in the first arc section in order to perform continuous monitoring. They detect the linac RF frequency 324 MHz or its second harmonics, these contributions quickly decrease after a few turns in the ring. Therefore, they are sensitive only just injected beam. The RCS adopts the multi-turn injection and transverse painting. These monitors are useful to check the beam behavior on-line.

WEPC28

Bunch By Bunch Transverse Beam Position Observation and Analyze During Injection at SSRF

kicker, transverse, betatron, storage-ring

746

Y.B. Leng, Y.B. Yan, Y. Yang, R.X. Yuan, N. Zhang
SSRF, Shanghai, People's Republic of China

Funding: Work supported by National Science Foundation of China (No. 11075198)
Top-up operation has been performed at SSRF since Dec. 2012. Orbit disturbance every 10 minutes decreased the quality of synchrotron radiation. In order to minimize this disturbance the tilts and the timing of injection kickers need to be tuning carefully based on real beam information. A set of button type pick-up and a scope based IOC were employed to capture the transient beam movement with bunch by bunch rate during injection. Several sets of observation and analyze will be discussed in this paper.

WEPC33

Upgrade of Beam Phase Monitors for the ESRF Injector and Storage Ring

storage-ring, booster, BPM, ESRF

757

K.B. Scheidt, B. Joly
ESRF, Grenoble, France

The measurement of the phase relation between the stored beam in the Storage Ring and the beam circulating in the Booster Synchrotron is now done with high precision and at high speed using a single unit of commercial BPM electronics. The quadrature demodulation, driven by a common PLL, done in these digital electronics on each of its four RF input channels makes the relative measurement of the I/Q components, hence phase relation, easy and strait forward. The RF signals of the relatively low current Booster come from two stripline outputs while that of the Storage Ring from two small BPM buttons. Treating simultaneously four signals, thus with a redundancy of two to measure the phase between two sources, allows to perform intrinsic shot-to-shot cross verifications on resolution and reproducibility. The long-term stability of this device has also been successfully assessed by independent verifications against time and temperature drifts. An identical unit has now been added for phase measurements between the Storage Ring beam and the RF cavity signals. Results with beam and assessment of its scope of performance will be presented on both systems.

Poster WEPC33 [0.836 MB]

WEPC34

Time Trend Observation of Certain Remarked Bunches using a Streak Camera

synchrotron, longitudinal, damping, KEK

761

T. Naito, S. Araki, H. Hayano, K. Kubo, S. Kuroda, T.M. Mitsuhashi, T. Okugi, S. Sakanaka, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

Funding: This work is supported by Japan-U.S. cooperative program .
A streak camera with two dimensional sweep function can measure the trend of the longitudinal beam profile in the ring. In the case of the multi-bunch measurement, the different bunch profile sit on same timing, thus, we can not distinguish the behavior of each bunch. We have developed a trigger circuit to measure the bunch-by-bunch longitudinal beam profile, which uses non integer sweep frequency for the acceleration frequency. The bunch profile of each bunch sit on different position in this measurement. We observed the increment of the synchrotron oscillation amplitude from the first bunch to the 20th bunch in the KEK-ATF Damping Ring by using this system. This paper describes the hardware and the measurement results.

WEPC39

First Tests of the Top-up Gating at Synchrotron SOLEIL

SOLEIL, synchrotron, storage-ring, kicker

775

J.P. Ricaud, L. Cassinari, P. Dumas, P. Lebasque, A. Nadji
SOLEIL, Gif-sur-Yvette, France

Since 2006, Synchrotron SOLEIL is delivering photons to its beamlines. Until 2012, thanks to the excellent performances of the injection system of the storage ring, the perturbation on the position of the stored beam was small enough to be accepted by the users. For some specific experiments, few beamlines expressed their wish to be able to stop their data acquisition during the injection. To fulfill this need, the diagnostics group of Synchrotron SOLEIL has designed the “TimEX3” board which was integrated into the timing system allowing the gating of the Top-up injection. This design was released as open hardware. Towards this aim, we decided to design it with the open source and free EDA software “KiCad”, and to make it available under the CERN’s Open Hardware Repository.

Poster WEPC39 [0.521 MB]

WEPF29

The LHC Fast Beam Current Change Monitor

LHC, CERN, FIR, beam-losses

887

D. Belohrad, J.M. Belleman, L.K. Jensen, M. Krupa, A. Topaloudis
CERN, Geneva, Switzerland

The modularity of the Large Hadron Collider’s (LHC) machine protection system (MPS) allows for the integration of several beam diagnostic instruments. These instruments have not necessarily been designed to have protection functionality, but MPS can still use them to increase the redundancy and reliability of the machine. The LHC fast beam current change monitor (FBCCM) is an example. It is based on analogue signals from fast beam current transformers (FBCT) used nominally to measure the LHC bunch intensities. The FBCCM calculates the magnitude of the beam signal provided by the FBCT, looks for a change over specific time intervals, and triggers a beam dump interlock if losses exceed an energy-dependent threshold. The first prototype of the FBCCM was installed in the LHC during the 2012-2013 run. The aim of this article is to present the FBCCM system and the results obtained, analyse its current performance and provide an outlook for the final system which is expected to be operational after the long LHC shutdown.

THAL3

Charge Distribution Measurements at ALBA

photon, synchrotron, electron, BPM

925

L. Torino, U. Iriso
CELLS-ALBA Synchrotron, Cerdanyola del Vallès, Spain

Two different set-ups are used to perform quantitative measurements of the charge distribution at ALBA. The first consists in a real-time analysis of data coming from the Fast Current Transformer or from the buttons of a Beam Position Monitor installed in the Storage Ring. The second is performed at the diagnostic visible beamline Xanadu, using a Photomultiplier that measures the temporal distribution of synchrotron light. In both cases a quantitative estimation of the charge distribution is obtained after a dedicated data treatment and beam current measurements from the DCCT. We compare results with both methods, and discuss differences and limitations with respect to bunch purity measurements with the Time Correlated Single Photon Counting technique.

Slides THAL3 [15.369 MB]