IBIC2013 - List of Keywords (beam-position)

Paper	Title	Other Keywords	Page
MOPC05	Beam Diagnostics of SuperKEKB Damping Ring	KEKB, extraction, injection, 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.

MOPC06	Beam Diagnostics System for a Photo-Neutron Source Driven by 15MeV Electron Linac	electron, linac, diagnostics, BPM	57
	Y.B. Yan, J. Chen, Z.C. Chen, Y.B. Leng, L.Y. Yu, R.X. Yuan, W.M. Zhou SINAP, Shanghai, People's Republic of China
	A photo-neutron source driven by 15MeV electron LINAC is under construction at Shanghai Institute of Applied Physics (SINAP). Several kinds of beam monitors (BPM, Profile and ICT) have been installed. The stripline beam position monitor with eight electrodes was designed, also for energy spread measurement. Due to the multi-bunch operation mode, a custom RF front end was adopted, which down-converts the signal from 2856MHz to 500MHz and then brings it to Libera Single Pass E. The beam position monitor was based on the integrated step-servo motor and GigE Vision camera. For the beam charge measurement we used the ICT from Bergoz and scope from Agilent. The detail of the whole beam diagnostics system development will be reported in this paper.

MOPC10	Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector	undulator, DIAMOND, radiation, photon	67
	P. Ilinski BNL, Upton, Long Island, New York, USA
	Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPC12	Development of the New Electronic Instrumentation for the LIPAc/IFMIF Beam Position Monitors	BPM, diagnostics, instrumentation, controls	71
	A. Guirao, D. Jimenez, L.M. Martinez Fresno, J. Molla, I. Podadera CIEMAT, Madrid, Spain
	Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654. Among all the LIPAc/IFMIF accelerator diagnostics instrumentation, the Beam Position Monitors are a cornerstone for its operation. A new approach for the LIPAc/IFMIF beam position monitors acquisition electronics is proposed for the twenty BPM stations distributed along the accelerator. The new system under development is a fully digital instrumentation which incorporates automatic calibration of the monitors' signals and allows monitoring of both fundamental and second signal harmonics. The current state of the development and first experimental results of the system on the test bench will be presented.

MOPC17	Calibration of a Non-Linear Beam Position Monitor Electronics by Switching Electrode Signals	BPM, LHC, SPS, CERN	85
	M. Gasior CERN, Geneva, Switzerland
	Button electrode signals from beam position monitors embedded into new LHC collimators will be individually processed with front-end electronics based on compensated diode detectors and digitized with 24-bit audio-range ADCs. This scheme allows sub-micrometre beam orbit resolution to be achieved with simple hardware and no external timing. As the diode detectors only operate in a linear regime with large amplitude signals, offset errors of the electronics cannot be calibrated in the classical way with no input. This paper describes the algorithms developed to calibrate the offset and gain asymmetry of these nonlinear electronic channels. Presented algorithm application examples are based on measurements performed with prototype diode orbit systems installed on the CERN SPS and LHC machines.

MOPC18	Development of a High Dynamic Range Beam Position Measurement System Using Logarithmic Amplifiers for the SPS at CERN	SPS, injection, 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]

MOPC19	Status of the Beam Position Monitors for LIPAc	pick-up, BPM, simulation, linac	93
	I. Podadera, F.M. De Aragon, A. Guirao, D. Jimenez, A. Lara, L.M. Martinez, J. Molla CIEMAT, Madrid, Spain
	Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654. The LIPAc accelerator will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. Several types of Beam Position Monitors BPM’s- are placed in each section of the accelerator to ensure a good beam transport and minimize beam losses. Prototypes of almost all the BPM’s have been already fabricated. Acceptance tests have been carried out on each device. The output of the vacuum leak tests and electrical tests will be analyzed in this contribution. In addition, the test bench to characterize the BPM’s has been upgraded and validated using some prototypes in order to obtain a better global measurement accuracy of the electrical center offset. The test bench can be used to crosscheck the simulations with the real response of each BPM. The result of the comparison will be discussed in detail.

MOPC21	Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring	BPM, linac, proton, single-bunch	101
	M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh GSI, Darmstadt, Germany W. Ackermann TEMF, TU Darmstadt, Darmstadt, Germany M.H. Almalki IAP, Frankfurt am Main, Germany M.H. Almalki KACST, Riyadh, Kingdom of Saudi Arabia B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic I-Tech, Solkan, Slovenia C.S. Simon CEA/DSM/IRFU, France
	The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne⁴⁺ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.
	Poster MOPC21 [1.622 MB]

MOPC25	About BPMS to be Used for PAL-XFEL	BPM, pick-up, XFEL, electron	112
	H. J. Choi, H.-S. Kang, C. Kim, S.H. Kim, S.J. Lee, S.J. Park, H. Yang PAL, Pohang, Kyungbuk, Republic of Korea
	Pohang Accelerator Laboratory (PAL) has been building the X-Ray Free Electron Laser (XFEL), a fourth-generation accelerator, and the construction will be complete in 2015. To successfully construct the XFEL, PAL built an injection test facility (ITF) in 2012, and the facility is in operation. The ITF examines the efficiency of various diagnostic units through extended tests. A BPM is a diagnostic unit that measures the position of an electron bunch. There are various kinds of BPM, and they have different merits and demerits. A user can select any kind of BPM that is appropriate for their purpose, and install it after going through various design and production processes. In order to measure the position of an electron bunch, a cavity BPM is installed at an undulator of PAL-XFEL and a stripline BPM is installed at an accelerator. The efficiency of the stripline BPM was tested at the ITF. The X-band cavity BPM was produced and is being tested at the ITF. This paper aims to introduce the specification and properties of the cavity BPM and stripline BPM to be installed at PAL-XFEL, and explain the physical concept and the way of measuring necessary for designing a stripline pickup.

TUPC10	Operation of Diamond Light Source XBPMs with Zero Bias	electron, DIAMOND, photon, synchrotron	376
	C. Bloomer, G. Rehm Diamond, Oxfordshire, United Kingdom
	Tungsten blade X-ray Beam Position Monitors (XBPMs) have been used at Diamond Light Source since 2007, however a long-standing problem with these devices has been the growth of leakage current through the ceramic insulation within the XBPMs over time, often becoming greater than 10% of the signal current after a few years of operation. The growth of these leakage currents has been found to be exacerbated by the application of a negative bias (-70V) to the tungsten blades, a bias suggested for optimum position sensitivity. This bias is applied in order to accelerate free electrons away from the surface of the blades and to prevent cross-talk, however, we have found that the operation of the XBPMs without bias has negligible impact on our measurements. Removal of the bias has been found to prevent the growth of leakage currents over time, and can also significantly reduce the cost of our signal acquisition by removing the need for a low-current amplifier with a bias supply.
	Poster TUPC10 [0.455 MB]

TUPC12	Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam	BPM, CLIC, CTF3, impedance	384
	A. Benot-Morell, L. Søby, M. Wendt CERN, Geneva, Switzerland A. Benot-Morell, A. Faus-Golfe IFIC, Valencia, Spain J.M. Nappa, S. Vilalte IN2P3-LAPP, Annecy-le-Vieux, France S.R. Smith SLAC, Menlo Park, California, USA
	Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515 In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.
	Poster TUPC12 [1.729 MB]

TUPC13	System Overview and Design Considerations of the BPM System of the ESS Linac	BPM, target, linac, ESS	388
	H. Hassanzadegan, A. Jansson, R. Zeng ESS, Lund, Sweden A.J. Johansson Lund University, Lund, Sweden K. Strniša Cosylab, Ljubljana, Slovenia A. Young SLAC, Menlo Park, California, USA
	The ESS Linac will include in total more than 140 Beam Position Monitors of different sizes and types. The BPM system needs to measure the beam position, phase and intensity in all foreseen beam modes with a pulse rate of 14 Hz, duration of 2.86 ms and amplitude ranging form 5 mA to 62.5 mA. With respect to the BPM connection to the Machine Interlock System, the total response time must be less than 10 us. The signal level variations from one BPM to another along the Linac should be as small as possible to meet the requirements on the analog gain of the front-end electronics and the dynamic range of the digitizer card input. The other requirement is that the BPM system needs to give at least a rough estimation of the beam position and phase, even if the beam is significantly debouched, ex. during the Linac tuning phase. These requirements and their impact on the design of the BPM detector, the analog front-end electronics and the selection of the digitizer card are discussed in this paper along with a general description of the BPM system.
	Poster TUPC13 [3.050 MB]

TUPC14	Development of a Low-Beta Button BPM for PXIE Project	BPM, simulation, pick-up, longitudinal	392
	A. Lunin, N. Eddy, T.N. Khabiboulline, V.A. Lebedev, V.P. Yakovlev Fermilab, Batavia, USA
	The button BPM is under development for a low beta section of the Project X Injector Experiment (PXIE) at Fermilab. The presented paper includes an analytical estimation of the BPM performance as well a direct wakefield simulation with CST Particle Studio (on a hexahedral mesh). In addition we present a novel approach of a low beta beam interaction with BPM electrodes realized with ANSYS HFSS TD-solver on unstructured tetrahedral mesh. Both methods show a good agreement of BPM output signals for various beam parameters. Finally we describe the signal processing scheme and the electronics we are going to use.
	Poster TUPC14 [1.051 MB]

TUPC15	BPM Electronics Upgrade for the Fermilab H⁻ Linac Based Upon Custom Downconverter Electronics	linac, BPM, controls, booster	396
	E.S.M. McCrory, N. Eddy, F.G.G. Garcia, S.U. Hansen, T. Kiper, M.Z. Sliczniak Fermilab, Batavia, USA
	As part of the Fermilab Proton Improvement Plan, the readout electronics for the Fermilab H⁻ Linac has been upgraded. The new custom electronics provide a low cost solution to process the 2nd harmonic of the RF at 402.5MHz. A single 4 channel NIM-bin module is used to readout each 4 plate stripline BPM pickup with each module being locked to an external 805MHz machine reference from the low level RF. For each BPM a number of measurements are provided including average horizontal and vertical position, average intensity, and average relative phase for variable pulse lengths from a few μs up to 50~usec. The system is being exploited in a number of ways with new operations applications.
	Poster TUPC15 [1.731 MB]

TUPC19	First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam	single-bunch, BPM, dipole, pick-up	411
	F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler JAI, Egham, Surrey, United Kingdom W. Farabolini, T. Lefèvre, L. Søby, M. Wendt CERN, Geneva, Switzerland
	Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.

TUPC22	Cavity Beam Position Monitor in Multiple Bunch Operation for the ATF2 Interaction Point Region	BPM, feedback, collider, single-bunch	419
	Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, S.T. Boogert, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin, C. Perry JAI, Oxford, United Kingdom J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White SLAC, Menlo Park, California, USA Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa KEK, Ibaraki, Japan
	The Accelerator Test Facility 2 (ATF2) at KEK, Japan, is a scaled test beam line for the international linear collider (ILC) final focus system. There are two goals: firstly, to demonstrate focusing to 37 nm vertical beam size; secondly, to achieve a few nanometer level beam orbit stability at the focus point (the Interaction Point (IP)) in the vertical plane. High-resolution beam position monitors around the IP area (IPBPMs) have been developed in order to measure the electron beam position in that region with a resolution of a few nanometers in the vertical plane. Currently, the standard operation mode at ATF2 is single bunch, however, multiple bunch operation with a bunch spacing similar to the one foreseen for the ILC (around 300 ns) is also possible. IPBPMs have a low Q value resulting in a decay time of about 30 ns, and so should be able to measure the beam position of individual bunches without any significant performance degradation. The IPBPMs in the ATF2 extraction beam line have been tested in multibunch regime. This paper analyses the signals, processing methods and results for this mode.
	Poster TUPC22 [1.050 MB]

TUPC29	Grounded Coplanar Waveguide Transmission Lines as Pickups for Beam Position Monitoring in Particle Accelerators	pick-up, XFEL, simulation, coupling	438
	A. Penirschke, A. Angelovski, R. Jakoby TU Darmstadt, Darmstadt, Germany C. Gerth, U. Mavrič, D. Nölle, C. Sydlo, S. Vilcins DESY, Hamburg, Germany
	Funding: The work was supported by the MSK group at DESY Hamburg. The authors would like to thank the CST AG for providing the CST Software Package. Energy beam position monitors (EBPM) based on grounded co-planar waveguide (GCPW) transmission lines have been designed for installation in the dispersive sections of the bunch compressor chicanes at the European XFEL. In combination with beam position monitors at the entrance and exit of the bunch compressor chicanes, measurements of the beam energy with single bunch resolution are feasible. The EBPM consists of transversely mounted stripline pickups in a rectangular beam pipe section. The signal detection for the measurement of the phases of the pulses at each end of the pickups is based on the standard down-conversion and phase detection scheme used for the low-level RF-system. A measurement resolution within the lower micrometer range can be achieved for input signal reflections at the pickup of less than -25 dB at 3 GHz. In this paper, simulation results of a novel pickup geometry utilized with GCPW pickup structures and optimized transitions to perpendicular mounted coaxial connectors are presented. The simulation results exhibit small reflection coefficients with reflected signal components having less than 2% of the peak voltage signal.

TUPC31	New Design of High Order Modes Electronics in MTCA.4 Standard for FLASH and the European XFEL	XFEL, DESY, monitoring, alignment	443
	S. Bou Habib, A. Abramowicz Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland N. Baboi, H. Schlarb DESY, Hamburg, Germany
	At free-electron linear accelerators, various High Order Modes (HOM) - both monopole and dipole - are excited. Extensive studies at DESY have shown that monitoring and analysis of some of these modes can be used for different applications including Beam Position Monitors (BPMs) and the reduction of wake-fields, the measurement of the beam phase with-respect-to RF signal in cavities, and the measurement of cavity alignment in the 1.3 GHz cryo-modules. Three frequencies were chosen for further experiments: the 1.3 GHz base frequency from the klystron, the 1.7 GHz dipole mode and the 2.4 GHz monopole mode. In order to realize the monitoring and analysis requirements, very high resolution measurements in amplitude, phase and shape (time resolution) are required for all three frequencies simultaneously. In this paper, we present the new HOM electronics prototype including a microstrip and stripline RF tri-passband filter design and measurements and the specialized MTCA.4 Rear Transition Module for HOM measurements with an ultra-fast high-resolution AMC digitizer.
	Poster TUPC31 [1.226 MB]

TUPC35	Upgrade of the Read-out Electronics for the Energy Beam Position Monitors at FLASH and European XFEL	pick-up, XFEL, DESY, SNR	454
	U. Mavrič, C. Gerth, H. Schlarb DESY, Hamburg, Germany A. Piotrowski TUL-DMCS, Łódź, Poland
	The dispersive sections of magnetic bunch compressor chicanes at free-electron lasers are excellent candidates for beam energy measurements. In the rectangular beamline sections of the bunch compressors at FLASH, energy beam position monitors (EBPM) with transversely mounted stripline pickups are installed. In this paper, we present the upgrade of the read-out electronics for signal detection of the EBPM installed at FLASH. The system is based on the MTCA.4 standard and reuses already available MTCA.4 compliant modules. This is also true for gateware and software development which fits into standard MTCA.4 framework development. The performance of the instrument was studied at FLASH during user operation and the results are presented.

WEBL2	Applications of Stripline and Cavity Beam Position Monitors in Low-Latency, High-Precision, Intra-Train Feedback Systems	feedback, BPM, kicker, extraction	630
	M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry JAI, Oxford, United Kingdom
	Two, low-latency, sub-micron beam position monitoring (BPM) systems have been developed and tested with beam at the KEK Accelerator Test Facility (ATF2). One system (‘upstream’), based on stripline BPMs uses fast analogue front-end signal processing and has demonstrated a position resolution as low as 400nm for beam intensities of ~1 nC, with single-pass beam. The other (‘IP’) system, based on low-Q cavity BPMs and utilising custom signal processing electronics designed for low latency, provides a single pass resolution of approximately 100nm. The BPM position data are digitised by fast ADCs on a custom FPGA-based feedback controller and used in three modes: 1) the upstream BPM data are used to drive a pair of local kickers nominally orthogonal in phase in closed-loop feedback mode; 2) the upstream BPM data are used to drive a downstream kicker in the ATF2 final focus region in feedforward mode; 3) the IP cavity BPM data are used to drive a local downstream kicker in the ATF2 final focus region in closed-loop feedback mode. In each case the beam jitter is measured downstream of the final focus system with the IP cavity BPMs. The relative performance of these systems is compared.
	Slides WEBL2 [1.934 MB]

WEPC11	Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System	radiation, SPS, CERN, BPM	686
	C. Deplano, J. Albertone, T.B. Bogey, J.L. Gonzalez, J.-J. Savioz CERN, Geneva, Switzerland
	A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.
	Poster WEPC11 [3.299 MB]

WEPC14	Development of High Precision Beam Position Monitor Readout System with Narrow Bandpass Filters for the KEKB Injector Linac Towards the SuperKEKB	BPM, positron, linac, KEKB	698
	R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada KEK, Ibaraki, Japan
	The SuperKEKB accelerator complexes are now being upgraded to bring the world highest luminosity (L=8x10³⁵/cm²/s). Hence, the KEKB Injector Linac is required to produce: electron: 20 mm mrad (7GeV, 5nC), positron: 10 mm mrad (4GeV, 4nC). To achieve this, the accelerator components have to be aligned within ± 0.1mm (1 σ). BPM is essential instrumentation for Beam Based Alignment, and is required one magnitude better position resolution to get better alignment results. Since current BPM readout system using oscilloscopes has ~50um position resolution, we decided to develop high precision BPM readout system with narrow bandpass filters. It handles two bunches with 96ns interval and has a dynamic range between 0.1nC (for photon factory) to 10nC (positron primary). To achieve these criteria, we adopt semiconductor attenuators and optimized two-stage Bessel filters at 300MHz center frequency to meet both time and frequency domain constraints. To correct position drift due to gain imbalance during operation, calibration pulses are output to the BPM between beam cycles (20ms). The beam position and charge calculations are performed by onboard FPGA to achieve fast readout cycle.
	Poster WEPC14 [3.039 MB]

WEPC16	The Design of BPM Electronic System for CSNS RCS	pick-up, BPM, extraction, injection	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]

WEPC18	Development of Compact Electronics Dedicated to Beam Position Monitors in Injectors and Boosters	booster, ESRF, BPM, controls	713
	G. Jug, M. Cargnelutti I-Tech, Solkan, Slovenia K.B. Scheidt ESRF, Grenoble, France
	The need for state-of-the-art electronics for data-acquisition and processing of BPM signals in Injector and/or Booster Synchrotrons is being addressed in a development that aims at making such system available with less complexity and yet fulfilling precisely the needs of such specific BPMs. The ESRF Booster Synchrotron uses 75 BPMs in its 300m circumference to measure the orbit along its acceleration cycle of 50 milliseconds for the electron beam from 0.2 to 6GeV. The 25 year old electronics of these BPMs are in need of replacement. While BPM developments in recent years have focused on devices for Storage Rings that face extreme requirements like sub-micron drift with time, beam intensity, etc. that result in complicated implementation schemes. This new development combines both the simplification in the measurement concept and the implementation of novelties like compact design integrating RF electronics, with power-over-Ethernet supply and passive cooling, a powerful System-on-Chip engine and easy communication via SCPI commands. This paper will present the full design concept and its aimed functionalities as a BPM device that should offer an excellent price/performance ratio.

WEPC23	Design of an Ultra-Compact Stripline BPM Receiver using MicroTCA for LCLS-II at SLAC	BPM, SLAC, LCLS, linac	731
	C. Xu, S. Babel, S. L. Hoobler, R.S. Larsen, J.J. Olsen, S.R. Smith, T. Straumann, D. Van Winkle, A. Young SLAC, Menlo Park, California, USA
	Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515 The Linac Coherent Light Source II (LCLS II) is a free electron laser (FEL) light source. LCLS II will be able to produce 0.5 to 77 Angstroms soft and hard x-rays. In order to achieve this high level of performance, the electron beam needs to be stable and accurate. The LCLS II stripline BPM system has a dynamic range of 10pC to 1nC beam charge. The system has a 3.5 micrometer resolution at 250pC beam charge in an one inch diameter stripline BPM structure. The BPM system uses the MicroTCA physics platform that consists of analog front-end (AFE) and 16-bit analog to digital convertor (ADC) module. The paper will discuss the hardware design, architecture, and performance measurements on the SLAC LINAC. The hardware architecture includes bandpass filter at 300MHz with 15 MHz band-width, and BPM calibration process without communicating with the CPU module. The system will be able to process multibunch beams with 40ns spacing.
	Poster WEPC23 [1.769 MB]

WEPC25	Optimisation of a Split Plate Position Monitor for the ISIS Proton Synchrotron	coupling, BPM, simulation, proton	739
	C.C. Wilcox, J.C. Medland, S.J. Payne, A. Pertica, M.A. Probert STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	A new Beam Position Monitor (BPM) has been designed for the ISIS proton accelerator facility at the Rutherford Appleton Laboratory in the UK. The new monitor, which will be installed in the beam line to Target 1, is of a ‘split plate’ design which utilises two pairs of electrodes to allow the beam position to be measured simultaneously in the horizontal and vertical planes. Simulations carried out using the CST low frequency solver have highlighted the inaccuracies in the measured beam position caused by strong inter-electrode coupling in such a monitor. This coupling, along with imbalanced electrode capacitances, leads to reduced sensitivity to changes in beam position as well as producing a positional offset error. This paper describes how the problems associated with inter-electrode coupling have been removed with the addition of grounded rings placed between each of the four electrodes. The design and positioning of the rings also ensured that the four electrode capacitances were matched. The results are presented both as CST simulations of ‘thin wire’ beam position measurements and results from bench measurements of a prototype dual plane BPM.

WEPF04	A New Compact Design of a Three-Dimensional Ionization Profile Monitor (IPM)	IPM, laser, DESY, simulation	811
	H.F. Breede, H.-J. Grabosch, M. Sachwitz, L.V. Vu DESY Zeuthen, Zeuthen, Germany
	FLASH at DESY in Hamburg is a linear accelerator, which uses superconducting technology to produce soft x-ray laser light ranging from 4.1 to 45 nm. To ensure the operation stability of FLASH, monitoring of the beam is mandatory. Two Ionization Profile Monitors (IPM) detect the lateral x and y position changes. The functional principle of the IPM is based on the detection of particles, generated by interaction of the beam with the residual gas in the beam line. The newly designed IPM enables the combined determination of the horizontal and vertical position as well as the profile. This is made possible by a compact monitor, consisting of a cage in a vacuum chamber, two micro-channel plates (MCP) and two repeller plates with toggled electric fields at the opposite sides of the MCPs. The particles created by the FEL beam, drift in a homogenous electrical field towards the respective MCP, which produces an image of the beam profile on an attached phosphor screen. A camera for each MCP is used for evaluation. This indirect detection scheme operates over a wide dynamic range and allows the detection of the center of gravity and the shape of the beam. The final design is presented.
	Poster WEPF04 [3.643 MB]

Paper

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MOPC05

Beam Diagnostics of SuperKEKB Damping Ring

KEKB, extraction, injection, 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.

MOPC06

Beam Diagnostics System for a Photo-Neutron Source Driven by 15MeV Electron Linac

electron, linac, diagnostics, BPM

57

Y.B. Yan, J. Chen, Z.C. Chen, Y.B. Leng, L.Y. Yu, R.X. Yuan, W.M. Zhou
SINAP, Shanghai, People's Republic of China

A photo-neutron source driven by 15MeV electron LINAC is under construction at Shanghai Institute of Applied Physics (SINAP). Several kinds of beam monitors (BPM, Profile and ICT) have been installed. The stripline beam position monitor with eight electrodes was designed, also for energy spread measurement. Due to the multi-bunch operation mode, a custom RF front end was adopted, which down-converts the signal from 2856MHz to 500MHz and then brings it to Libera Single Pass E. The beam position monitor was based on the integrated step-servo motor and GigE Vision camera. For the beam charge measurement we used the ICT from Bergoz and scope from Agilent. The detail of the whole beam diagnostics system development will be reported in this paper.

MOPC10

Optimization of NSLS-II Blade X-ray Beam Position Monitors: From Photoemission Type to Diamond Detector

undulator, DIAMOND, radiation, photon

67

P. Ilinski
BNL, Upton, Long Island, New York, USA

Optimization of blade type X-ray Beam Position Monitors (XBPM) was performed for NSLS-II undulator IVU20. Blade material, conﬁguration and operation principle were analyzed. Optimization is based on calculation of the XBPM signal spatial distribution. Along with standard photo-emission blades, Diamond Detector Blade (DDB) was examined as XBPM signal source. Analyses revealed, that Diamond Detector Blade XBPM would allow to overcome drawbacks of the photo-emission type XBPMs.

MOPC12

Development of the New Electronic Instrumentation for the LIPAc/IFMIF Beam Position Monitors

BPM, diagnostics, instrumentation, controls

71

A. Guirao, D. Jimenez, L.M. Martinez Fresno, J. Molla, I. Podadera
CIEMAT, Madrid, Spain

Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654.
Among all the LIPAc/IFMIF accelerator diagnostics instrumentation, the Beam Position Monitors are a cornerstone for its operation. A new approach for the LIPAc/IFMIF beam position monitors acquisition electronics is proposed for the twenty BPM stations distributed along the accelerator. The new system under development is a fully digital instrumentation which incorporates automatic calibration of the monitors' signals and allows monitoring of both fundamental and second signal harmonics. The current state of the development and first experimental results of the system on the test bench will be presented.

MOPC17

Calibration of a Non-Linear Beam Position Monitor Electronics by Switching Electrode Signals

BPM, LHC, SPS, CERN

85

M. Gasior
CERN, Geneva, Switzerland

Button electrode signals from beam position monitors embedded into new LHC collimators will be individually processed with front-end electronics based on compensated diode detectors and digitized with 24-bit audio-range ADCs. This scheme allows sub-micrometre beam orbit resolution to be achieved with simple hardware and no external timing. As the diode detectors only operate in a linear regime with large amplitude signals, offset errors of the electronics cannot be calibrated in the classical way with no input. This paper describes the algorithms developed to calibrate the offset and gain asymmetry of these nonlinear electronic channels. Presented algorithm application examples are based on measurements performed with prototype diode orbit systems installed on the CERN SPS and LHC machines.

MOPC18

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

SPS, injection, 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]

MOPC19

Status of the Beam Position Monitors for LIPAc

pick-up, BPM, simulation, linac

93

I. Podadera, F.M. De Aragon, A. Guirao, D. Jimenez, A. Lara, L.M. Martinez, J. Molla
CIEMAT, Madrid, Spain

Funding: Work partially supported by the Spanish Ministry of Science and Innovation under project AIC10-A-000441 and AIC-A-2011-0654.
The LIPAc accelerator will be a 9 MeV, 125 mA CW deuteron accelerator which aims to validate the technology that will be used in the future IFMIF accelerator. Several types of Beam Position Monitors BPM’s- are placed in each section of the accelerator to ensure a good beam transport and minimize beam losses. Prototypes of almost all the BPM’s have been already fabricated. Acceptance tests have been carried out on each device. The output of the vacuum leak tests and electrical tests will be analyzed in this contribution. In addition, the test bench to characterize the BPM’s has been upgraded and validated using some prototypes in order to obtain a better global measurement accuracy of the electrical center offset. The test bench can be used to crosscheck the simulations with the real response of each BPM. The result of the comparison will be discussed in detail.

MOPC21

Layout of the BPM System for p-LINAC at FAIR and the Digital Methods for Beam Position and Phase Monitoring

BPM, linac, proton, single-bunch

101

M.H. Almalki, G. Clemente, P. Forck, L. Groening, W. Kaufmann, P. Kowina, C. Krüger, R. Singh
GSI, Darmstadt, Germany
W. Ackermann
TEMF, TU Darmstadt, Darmstadt, Germany
M.H. Almalki
IAP, Frankfurt am Main, Germany
M.H. Almalki
KACST, Riyadh, Kingdom of Saudi Arabia
B.B. Baricevic, R. Hrovatin, P.L. Lemut, M. Znidarcic
I-Tech, Solkan, Slovenia
C.S. Simon
CEA/DSM/IRFU, France

The planned Proton LINAC at the FAIR facility will provide a beam current from 35 to 70 mA accelerated to 70 MeV by novel CH-type DTLs. Four-fold button Beam Position Monitor (BPM) will be installed at 14 locations along the LINAC and some of these BPMs are mounted only about 40 mm upstream of the CH cavities. The coupling of the RF accelerating field to the BPMs installed close to the CH cavities was numerically investigated. For the digital signal processing using I/Q demodulation a 'Libera Single Pass H' is foreseen. The properties of this digitization and processing scheme were characterized by detailed lab-based tests. Moreover, the performance was investigated by a 80 μA Ne⁴⁺ beam at 1.4 MeV / u and compared to a time-domain approach and successive FFT calculation. In particular, concerning the phase determination significant deviations between the methods were observed and further investigations to understand the reason are ongoing.

Poster MOPC21 [1.622 MB]

MOPC25

About BPMS to be Used for PAL-XFEL

BPM, pick-up, XFEL, electron

112

H. J. Choi, H.-S. Kang, C. Kim, S.H. Kim, S.J. Lee, S.J. Park, H. Yang
PAL, Pohang, Kyungbuk, Republic of Korea

Pohang Accelerator Laboratory (PAL) has been building the X-Ray Free Electron Laser (XFEL), a fourth-generation accelerator, and the construction will be complete in 2015. To successfully construct the XFEL, PAL built an injection test facility (ITF) in 2012, and the facility is in operation. The ITF examines the efficiency of various diagnostic units through extended tests. A BPM is a diagnostic unit that measures the position of an electron bunch. There are various kinds of BPM, and they have different merits and demerits. A user can select any kind of BPM that is appropriate for their purpose, and install it after going through various design and production processes. In order to measure the position of an electron bunch, a cavity BPM is installed at an undulator of PAL-XFEL and a stripline BPM is installed at an accelerator. The efficiency of the stripline BPM was tested at the ITF. The X-band cavity BPM was produced and is being tested at the ITF. This paper aims to introduce the specification and properties of the cavity BPM and stripline BPM to be installed at PAL-XFEL, and explain the physical concept and the way of measuring necessary for designing a stripline pickup.

TUPC10

Operation of Diamond Light Source XBPMs with Zero Bias

electron, DIAMOND, photon, synchrotron

376

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

Tungsten blade X-ray Beam Position Monitors (XBPMs) have been used at Diamond Light Source since 2007, however a long-standing problem with these devices has been the growth of leakage current through the ceramic insulation within the XBPMs over time, often becoming greater than 10% of the signal current after a few years of operation. The growth of these leakage currents has been found to be exacerbated by the application of a negative bias (-70V) to the tungsten blades, a bias suggested for optimum position sensitivity. This bias is applied in order to accelerate free electrons away from the surface of the blades and to prevent cross-talk, however, we have found that the operation of the XBPMs without bias has negligible impact on our measurements. Removal of the bias has been found to prevent the growth of leakage currents over time, and can also significantly reduce the cost of our signal acquisition by removing the need for a low-current amplifier with a bias supply.

Poster TUPC10 [0.455 MB]

TUPC12

Status of the Stripline Beam Position Monitor Development for the CLIC Drive Beam

BPM, CLIC, CTF3, impedance

384

A. Benot-Morell, L. Søby, M. Wendt
CERN, Geneva, Switzerland
A. Benot-Morell, A. Faus-Golfe
IFIC, Valencia, Spain
J.M. Nappa, S. Vilalte
IN2P3-LAPP, Annecy-le-Vieux, France
S.R. Smith
SLAC, Menlo Park, California, USA

Funding: MINECO contract FPA2010-21456-C02-01, SEIC-2010-00028, U.S. Department of Energy contract DE-AC02-76SF00515
In collaboration with SLAC, LAPP and IFIC, a first prototype of a strip-line Beam Position Monitor (BPM) for the CLIC Drive Beam and its associated readout electronics has been successfully tested in the CLIC Test Facility linac (CTF3) at CERN. In addition, a modified prototype with downstream terminated strip-lines is under development to better suppress any unwanted RF signal interference. This paper presents the results of the beam tests, the most relevant design aspects for the modified strip-line BPM version and its expected performance.

Poster TUPC12 [1.729 MB]

TUPC13

System Overview and Design Considerations of the BPM System of the ESS Linac

BPM, target, linac, ESS

388

H. Hassanzadegan, A. Jansson, R. Zeng
ESS, Lund, Sweden
A.J. Johansson
Lund University, Lund, Sweden
K. Strniša
Cosylab, Ljubljana, Slovenia
A. Young
SLAC, Menlo Park, California, USA

The ESS Linac will include in total more than 140 Beam Position Monitors of different sizes and types. The BPM system needs to measure the beam position, phase and intensity in all foreseen beam modes with a pulse rate of 14 Hz, duration of 2.86 ms and amplitude ranging form 5 mA to 62.5 mA. With respect to the BPM connection to the Machine Interlock System, the total response time must be less than 10 us. The signal level variations from one BPM to another along the Linac should be as small as possible to meet the requirements on the analog gain of the front-end electronics and the dynamic range of the digitizer card input. The other requirement is that the BPM system needs to give at least a rough estimation of the beam position and phase, even if the beam is significantly debouched, ex. during the Linac tuning phase. These requirements and their impact on the design of the BPM detector, the analog front-end electronics and the selection of the digitizer card are discussed in this paper along with a general description of the BPM system.

Poster TUPC13 [3.050 MB]

TUPC14

Development of a Low-Beta Button BPM for PXIE Project

BPM, simulation, pick-up, longitudinal

392

A. Lunin, N. Eddy, T.N. Khabiboulline, V.A. Lebedev, V.P. Yakovlev
Fermilab, Batavia, USA

The button BPM is under development for a low beta section of the Project X Injector Experiment (PXIE) at Fermilab. The presented paper includes an analytical estimation of the BPM performance as well a direct wakefield simulation with CST Particle Studio (on a hexahedral mesh). In addition we present a novel approach of a low beta beam interaction with BPM electrodes realized with ANSYS HFSS TD-solver on unstructured tetrahedral mesh. Both methods show a good agreement of BPM output signals for various beam parameters. Finally we describe the signal processing scheme and the electronics we are going to use.

Poster TUPC14 [1.051 MB]

TUPC15

BPM Electronics Upgrade for the Fermilab H⁻ Linac Based Upon Custom Downconverter Electronics

linac, BPM, controls, booster

396

E.S.M. McCrory, N. Eddy, F.G.G. Garcia, S.U. Hansen, T. Kiper, M.Z. Sliczniak
Fermilab, Batavia, USA

As part of the Fermilab Proton Improvement Plan, the readout electronics for the Fermilab H⁻ Linac has been upgraded. The new custom electronics provide a low cost solution to process the 2nd harmonic of the RF at 402.5MHz. A single 4 channel NIM-bin module is used to readout each 4 plate stripline BPM pickup with each module being locked to an external 805MHz machine reference from the low level RF. For each BPM a number of measurements are provided including average horizontal and vertical position, average intensity, and average relative phase for variable pulse lengths from a few μs up to 50~usec. The system is being exploited in a number of ways with new operations applications.

Poster TUPC15 [1.731 MB]

TUPC19

First Beam Tests of a Prototype Cavity Beam Position Monitor for the CLIC Main Beam

single-bunch, BPM, dipole, pick-up

411

F.J. Cullinan, S.T. Boogert, A. Lyapin, J.R. Towler
JAI, Egham, Surrey, United Kingdom
W. Farabolini, T. Lefèvre, L. Søby, M. Wendt
CERN, Geneva, Switzerland

Beam position monitors (BPMs) throughout the CLIC (Compact Linear Collider) main linac and beam delivery system must routinely operate at 50 nm resolution and be able to make multiple position measurements within a single 156 ns long bunch train. A prototype cavity beam position monitor, designed to demonstrate this performance, has been tested on the probe beamline of CTF3 (the CLIC Test Facility). Sensitivity measurements of the dipole mode position cavity and of the monopole mode reference cavity have been made. The characteristics of signals from short and long bunch trains and the dominant systematic effects have also been studied.

TUPC22

Cavity Beam Position Monitor in Multiple Bunch Operation for the ATF2 Interaction Point Region

BPM, feedback, collider, single-bunch

419

Y.I. Kim, D.R. Bett, N. Blaskovic Kraljevic, S.T. Boogert, P. Burrows, G.B. Christian, M.R. Davis, A. Lyapin, C. Perry
JAI, Oxford, United Kingdom
J.C. Frisch, D.J. McCormick, J. Nelson, G.R. White
SLAC, Menlo Park, California, USA
Y. Honda, T. Tauchi, N. Terunuma, J. Urakawa
KEK, Ibaraki, Japan

The Accelerator Test Facility 2 (ATF2) at KEK, Japan, is a scaled test beam line for the international linear collider (ILC) final focus system. There are two goals: firstly, to demonstrate focusing to 37 nm vertical beam size; secondly, to achieve a few nanometer level beam orbit stability at the focus point (the Interaction Point (IP)) in the vertical plane. High-resolution beam position monitors around the IP area (IPBPMs) have been developed in order to measure the electron beam position in that region with a resolution of a few nanometers in the vertical plane. Currently, the standard operation mode at ATF2 is single bunch, however, multiple bunch operation with a bunch spacing similar to the one foreseen for the ILC (around 300 ns) is also possible. IPBPMs have a low Q value resulting in a decay time of about 30 ns, and so should be able to measure the beam position of individual bunches without any significant performance degradation. The IPBPMs in the ATF2 extraction beam line have been tested in multibunch regime. This paper analyses the signals, processing methods and results for this mode.

Poster TUPC22 [1.050 MB]

TUPC29

Grounded Coplanar Waveguide Transmission Lines as Pickups for Beam Position Monitoring in Particle Accelerators

pick-up, XFEL, simulation, coupling

438

A. Penirschke, A. Angelovski, R. Jakoby
TU Darmstadt, Darmstadt, Germany
C. Gerth, U. Mavrič, D. Nölle, C. Sydlo, S. Vilcins
DESY, Hamburg, Germany

Funding: The work was supported by the MSK group at DESY Hamburg. The authors would like to thank the CST AG for providing the CST Software Package.
Energy beam position monitors (EBPM) based on grounded co-planar waveguide (GCPW) transmission lines have been designed for installation in the dispersive sections of the bunch compressor chicanes at the European XFEL. In combination with beam position monitors at the entrance and exit of the bunch compressor chicanes, measurements of the beam energy with single bunch resolution are feasible. The EBPM consists of transversely mounted stripline pickups in a rectangular beam pipe section. The signal detection for the measurement of the phases of the pulses at each end of the pickups is based on the standard down-conversion and phase detection scheme used for the low-level RF-system. A measurement resolution within the lower micrometer range can be achieved for input signal reflections at the pickup of less than -25 dB at 3 GHz. In this paper, simulation results of a novel pickup geometry utilized with GCPW pickup structures and optimized transitions to perpendicular mounted coaxial connectors are presented. The simulation results exhibit small reflection coefficients with reflected signal components having less than 2% of the peak voltage signal.

TUPC31

New Design of High Order Modes Electronics in MTCA.4 Standard for FLASH and the European XFEL

XFEL, DESY, monitoring, alignment

443

S. Bou Habib, A. Abramowicz
Warsaw University of Technology, Institute of Electronic Systems, Warsaw, Poland
N. Baboi, H. Schlarb
DESY, Hamburg, Germany

At free-electron linear accelerators, various High Order Modes (HOM) - both monopole and dipole - are excited. Extensive studies at DESY have shown that monitoring and analysis of some of these modes can be used for different applications including Beam Position Monitors (BPMs) and the reduction of wake-fields, the measurement of the beam phase with-respect-to RF signal in cavities, and the measurement of cavity alignment in the 1.3 GHz cryo-modules. Three frequencies were chosen for further experiments: the 1.3 GHz base frequency from the klystron, the 1.7 GHz dipole mode and the 2.4 GHz monopole mode. In order to realize the monitoring and analysis requirements, very high resolution measurements in amplitude, phase and shape (time resolution) are required for all three frequencies simultaneously. In this paper, we present the new HOM electronics prototype including a microstrip and stripline RF tri-passband filter design and measurements and the specialized MTCA.4 Rear Transition Module for HOM measurements with an ultra-fast high-resolution AMC digitizer.

Poster TUPC31 [1.226 MB]

TUPC35

Upgrade of the Read-out Electronics for the Energy Beam Position Monitors at FLASH and European XFEL

pick-up, XFEL, DESY, SNR

454

U. Mavrič, C. Gerth, H. Schlarb
DESY, Hamburg, Germany
A. Piotrowski
TUL-DMCS, Łódź, Poland

The dispersive sections of magnetic bunch compressor chicanes at free-electron lasers are excellent candidates for beam energy measurements. In the rectangular beamline sections of the bunch compressors at FLASH, energy beam position monitors (EBPM) with transversely mounted stripline pickups are installed. In this paper, we present the upgrade of the read-out electronics for signal detection of the EBPM installed at FLASH. The system is based on the MTCA.4 standard and reuses already available MTCA.4 compliant modules. This is also true for gateware and software development which fits into standard MTCA.4 framework development. The performance of the instrument was studied at FLASH during user operation and the results are presented.

WEBL2

Applications of Stripline and Cavity Beam Position Monitors in Low-Latency, High-Precision, Intra-Train Feedback Systems

feedback, BPM, kicker, extraction

630

M.R. Davis, D.R. Bett, N. Blaskovic Kraljevic, P. Burrows, G.B. Christian, Y.I. Kim, C. Perry
JAI, Oxford, United Kingdom

Two, low-latency, sub-micron beam position monitoring (BPM) systems have been developed and tested with beam at the KEK Accelerator Test Facility (ATF2). One system (‘upstream’), based on stripline BPMs uses fast analogue front-end signal processing and has demonstrated a position resolution as low as 400nm for beam intensities of ~1 nC, with single-pass beam. The other (‘IP’) system, based on low-Q cavity BPMs and utilising custom signal processing electronics designed for low latency, provides a single pass resolution of approximately 100nm. The BPM position data are digitised by fast ADCs on a custom FPGA-based feedback controller and used in three modes: 1) the upstream BPM data are used to drive a pair of local kickers nominally orthogonal in phase in closed-loop feedback mode; 2) the upstream BPM data are used to drive a downstream kicker in the ATF2 final focus region in feedforward mode; 3) the IP cavity BPM data are used to drive a local downstream kicker in the ATF2 final focus region in closed-loop feedback mode. In each case the beam jitter is measured downstream of the final focus system with the IP cavity BPMs. The relative performance of these systems is compared.

Slides WEBL2 [1.934 MB]

WEPC11

Radiation Resistance Testing of Commercial Components for the New SPS Beam Position Measurement System

radiation, SPS, CERN, BPM

686

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

A new Front-End (FE) electronics is under development for the SPS Multi Orbit POsition System (MOPOS). To cover the large dynamic range of beam intensities (70dB) to be measured in the SPS, the beam position monitor signals are processed using logarithmic amplifiers. They are then digitized locally and transmitted via optical fibers over long distances (up to 1km) to VME acquisition boards located in surface buildings. The FE board is designed to be located in the SPS tunnel, where it must cope with a radiation dose rate of up to 100 Gy per year. Analogue components, such as Logarithmic Amplifiers, ADC-Drivers and Voltage regulators, have been tested at PSI for radiation hardness, while several families of bidirectional SFP, both single-fiber and double-fiber, have been tested at both PSI and CNRAD. This paper gives a description of the overall system architecture and presents the results of the radiation hardness tests in detail.

Poster WEPC11 [3.299 MB]

WEPC14

Development of High Precision Beam Position Monitor Readout System with Narrow Bandpass Filters for the KEKB Injector Linac Towards the SuperKEKB

BPM, positron, linac, KEKB

698

R. Ichimiya, K. Furukawa, F. Miyahara, M. Satoh, T. Suwada
KEK, Ibaraki, Japan

The SuperKEKB accelerator complexes are now being upgraded to bring the world highest luminosity (L=8x10³⁵/cm²/s). Hence, the KEKB Injector Linac is required to produce: electron: 20 mm mrad (7GeV, 5nC), positron: 10 mm mrad (4GeV, 4nC). To achieve this, the accelerator components have to be aligned within ± 0.1mm (1 σ). BPM is essential instrumentation for Beam Based Alignment, and is required one magnitude better position resolution to get better alignment results. Since current BPM readout system using oscilloscopes has ~50um position resolution, we decided to develop high precision BPM readout system with narrow bandpass filters. It handles two bunches with 96ns interval and has a dynamic range between 0.1nC (for photon factory) to 10nC (positron primary). To achieve these criteria, we adopt semiconductor attenuators and optimized two-stage Bessel filters at 300MHz center frequency to meet both time and frequency domain constraints. To correct position drift due to gain imbalance during operation, calibration pulses are output to the BPM between beam cycles (20ms). The beam position and charge calculations are performed by onboard FPGA to achieve fast readout cycle.

Poster WEPC14 [3.039 MB]

WEPC16

The Design of BPM Electronic System for CSNS RCS

pick-up, BPM, extraction, injection

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]

WEPC18

Development of Compact Electronics Dedicated to Beam Position Monitors in Injectors and Boosters

booster, ESRF, BPM, controls

713

G. Jug, M. Cargnelutti
I-Tech, Solkan, Slovenia
K.B. Scheidt
ESRF, Grenoble, France

The need for state-of-the-art electronics for data-acquisition and processing of BPM signals in Injector and/or Booster Synchrotrons is being addressed in a development that aims at making such system available with less complexity and yet fulfilling precisely the needs of such specific BPMs. The ESRF Booster Synchrotron uses 75 BPMs in its 300m circumference to measure the orbit along its acceleration cycle of 50 milliseconds for the electron beam from 0.2 to 6GeV. The 25 year old electronics of these BPMs are in need of replacement. While BPM developments in recent years have focused on devices for Storage Rings that face extreme requirements like sub-micron drift with time, beam intensity, etc. that result in complicated implementation schemes. This new development combines both the simplification in the measurement concept and the implementation of novelties like compact design integrating RF electronics, with power-over-Ethernet supply and passive cooling, a powerful System-on-Chip engine and easy communication via SCPI commands. This paper will present the full design concept and its aimed functionalities as a BPM device that should offer an excellent price/performance ratio.

WEPC23

Design of an Ultra-Compact Stripline BPM Receiver using MicroTCA for LCLS-II at SLAC

BPM, SLAC, LCLS, linac

731

C. Xu, S. Babel, S. L. Hoobler, R.S. Larsen, J.J. Olsen, S.R. Smith, T. Straumann, D. Van Winkle, A. Young
SLAC, Menlo Park, California, USA

Funding: Work supported by U.S. Department of Energy under Contract Numbers DE-AC02-06CH11357 and DE-AC02-76SF00515
The Linac Coherent Light Source II (LCLS II) is a free electron laser (FEL) light source. LCLS II will be able to produce 0.5 to 77 Angstroms soft and hard x-rays. In order to achieve this high level of performance, the electron beam needs to be stable and accurate. The LCLS II stripline BPM system has a dynamic range of 10pC to 1nC beam charge. The system has a 3.5 micrometer resolution at 250pC beam charge in an one inch diameter stripline BPM structure. The BPM system uses the MicroTCA physics platform that consists of analog front-end (AFE) and 16-bit analog to digital convertor (ADC) module. The paper will discuss the hardware design, architecture, and performance measurements on the SLAC LINAC. The hardware architecture includes bandpass filter at 300MHz with 15 MHz band-width, and BPM calibration process without communicating with the CPU module. The system will be able to process multibunch beams with 40ns spacing.

Poster WEPC23 [1.769 MB]

WEPC25

Optimisation of a Split Plate Position Monitor for the ISIS Proton Synchrotron

coupling, BPM, simulation, proton

739

C.C. Wilcox, J.C. Medland, S.J. Payne, A. Pertica, M.A. Probert
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

A new Beam Position Monitor (BPM) has been designed for the ISIS proton accelerator facility at the Rutherford Appleton Laboratory in the UK. The new monitor, which will be installed in the beam line to Target 1, is of a ‘split plate’ design which utilises two pairs of electrodes to allow the beam position to be measured simultaneously in the horizontal and vertical planes. Simulations carried out using the CST low frequency solver have highlighted the inaccuracies in the measured beam position caused by strong inter-electrode coupling in such a monitor. This coupling, along with imbalanced electrode capacitances, leads to reduced sensitivity to changes in beam position as well as producing a positional offset error. This paper describes how the problems associated with inter-electrode coupling have been removed with the addition of grounded rings placed between each of the four electrodes. The design and positioning of the rings also ensured that the four electrode capacitances were matched. The results are presented both as CST simulations of ‘thin wire’ beam position measurements and results from bench measurements of a prototype dual plane BPM.

WEPF04

A New Compact Design of a Three-Dimensional Ionization Profile Monitor (IPM)

IPM, laser, DESY, simulation

811

H.F. Breede, H.-J. Grabosch, M. Sachwitz, L.V. Vu
DESY Zeuthen, Zeuthen, Germany

FLASH at DESY in Hamburg is a linear accelerator, which uses superconducting technology to produce soft x-ray laser light ranging from 4.1 to 45 nm. To ensure the operation stability of FLASH, monitoring of the beam is mandatory. Two Ionization Profile Monitors (IPM) detect the lateral x and y position changes. The functional principle of the IPM is based on the detection of particles, generated by interaction of the beam with the residual gas in the beam line. The newly designed IPM enables the combined determination of the horizontal and vertical position as well as the profile. This is made possible by a compact monitor, consisting of a cage in a vacuum chamber, two micro-channel plates (MCP) and two repeller plates with toggled electric fields at the opposite sides of the MCPs. The particles created by the FEL beam, drift in a homogenous electrical field towards the respective MCP, which produces an image of the beam profile on an attached phosphor screen. A camera for each MCP is used for evaluation. This indirect detection scheme operates over a wide dynamic range and allows the detection of the center of gravity and the shape of the beam. The final design is presented.

Poster WEPF04 [3.643 MB]