DIPAC2011 - List of Keywords (pick-up)

Paper	Title	Other Keywords	Page
MOOC01	Overview of Recent Trends and Developments for BPM Systems	cavity, coupling, monitoring, linac	18
	M. Wendt Fermilab, Batavia, USA
	Beam position monitoring (BPM) systems are the workhorse beam diagnostics for almost any kind of charged particle accelerator; linear, circular or transport-lines, operating with leptons, hadrons or heavy ions. The BPMs are essential for beam commissioning, accelerator fault analysis and trouble shooting, machine optics and lattice measurements, and finally for the accelerator optimization to achieve the ultimate beam quality. This presentation summarizes the efforts of the beam instrumentation community on recent developments and advances on BPM technologies, i.e. BPM pickup monitors and front-end electronics (analog and digital). Principles, examples, and state-of-the-art status on various BPM techniques are outlined, serving hadron and heavy ion machines, sync light synchrotron's, as well as electron linacs for FEL or HEP applications.
	Slides MOOC01 [4.123 MB]

MOOC03	The Fermi@Elettra Cavity BPM System: Description and Commissioning Results	cavity, controls, FEL, undulator	26
	M. Ferianis, A.O. Borga, P. Craievich, R. De Monte, G. Gaio, M. Predonzani ELETTRA, Basovizza, Italy M. Dal Forno DIEIT, Trieste, Italy
	The Fermi@elettra cavity BPM (C-BPM) system is based on an original implementation of the C-BPM scheme as the pick-up, operating at 6.5GHz, is coupled to a dedicated, self-calibrating electronics based on a novel concept. The system has been developed in-house; both the E-M and the mechanical design of the pick-up have been carried out, including an original frequency tuning scheme. The detector electronics directly obtains the envelope of the sum and difference signals by means of an RF 180° hybrid; no mixer for the RF signal down conversion is used. The detector is based on 3 blocks: an RF front-end, a baseband analogue transmission module and a digital back-end unit, based on a micro-TCA platform. The digital back-end is equipped with a powerful Virtex 5 FPGA and several real-time tasks have been implemented on it, including intra-pulse calibration. Ten C-BPM stations have been installed so far, fully integrated in the FERMI control System, enabling a real-time control of this key FEL diagnostics. Results on performances with beam are also presented; the scale factor of C-BPMs is obtained with beam, as two-axis micrometer translation stages have been installed.
	Slides MOOC03 [2.733 MB]

MOPD01	Beam Diagnostics for the NSLS-II Booster	booster, betatron, vacuum, controls	29
	V.V. Smaluk BINP, Novosibirsk, Russia E.A. Bekhtenev, V.P. Cherepanov, G.V. Karpov, V. Kuzminykh, O.I. Meshkov BINP SB RAS, Novosibirsk, Russia I. Pinayev, O. Singh, K. Vetter BNL, Upton, Long Island, New York, USA
	For successful commissioning and effective operation of the projected NSLS-II Booster, a set of beam diagnostic instruments has been designed. Fluorescent screens are used for the Booster commissioning and troubleshooting. Closed orbit is measured using electrostatic BPMs with turn-by-turn capability. The circulating current and beam lifetime are measured using a DC current transformer. The fill pattern is monitored by a fast current transformer. Visible synchrotron radiation is registered for observation of the beam image. Betatron tunes are measured using two pairs of striplines, the first pair is for beam excitation and the second one – for beam response measurement. Design and performance of the Booster beam instrumentation are described.

MOPD05	Beam Diagnostic Layout for SIS100 at FAIR	ion, diagnostics, proton, beam-losses	41
	M. Schwickert, P. Forck, T. Hoffmann, P. Kowina, H. Reeg GSI, Darmstadt, Germany
	The SIS100 heavy ion synchrotron will be the central machine of the FAIR (Facility for Antiprotons and Ions Research) project currently designed at GSI. The unique features of SIS100, like e.g. the acceleration of high intensity beams of 2.5·10¹³ protons and 5·10¹¹ Uranium ions near the space charge limit, the anticipated large tune spread, extreme UHV conditions of the cryogenic system for superconducting magnets and fast ramp rates of 4 T/s, make challenging demands on the beam diagnostic components. This contribution describes the conceptual design for SIS100 beam diagnostics and reports on the present status of prototype studies. Exemplarily the progress concerning beam position monitors, beam current transformers and beam-loss monitors is presented.

MOPD06	Capabilities and Performance of the LHC Schottky Monitors	injection, emittance, impedance, proton	44
	M. Favier, T.B. Bogey, F. Caspers, O.R. Jones CERN, Geneva, Switzerland J. Cai, E.S.M. McCrory, R.J. Pasquinelli Fermilab, Batavia, USA A. Jansson ESS, Lund, Sweden
	The LHC Schottky system has been under commissioning since summer 2010. This non destructive observation relies on a slotted waveguide structure resonating at 4.8GHz. Four monitors, one for each plane of the two counter-rotating LHC beams, are used to measure the transverse Schottky sidebands Electronic gating allows selective bunch-by-bunch measurements, while a triple down-mixing scheme combined with heavy filtering gives an instantaneous dynamic range of over 100dB within a 20kHz bandwidth. Observations of both proton and lead ion Schottky spectra will be discussed along with a comparison of predicted and measured performance.
	Poster MOPD06 [3.484 MB]

MOPD08	Beam Diagnostics in the J-PARC Linac for ACS Upgrade	linac, diagnostics, acceleration, simulation	50
	A. Miura, S. Sato JAEA/J-PARC, Tokai-mura, Japan Z. Igarashi, M. Ikegami, T. Miyao, T. Toyama KEK, Ibaraki, Japan T. Tomisawa JAEA/LINAC, Ibaraki-ken, Japan
	J-PARC had developed the beam diagnostic devices for the current J-PARC linac and has used them since the operation start. J-PARC linac began the energy upgrade project since 2009 and 21 ACS cavities will be installed. In this project, many cavities and related devices are newly installed in the ACS section and its downstream part. Because the beam parameters are updated, new beam diagnostic devices are fabricated and current diagnostic devices are developed. Beam position monitors (BPM) are newly designed and fabricated, based on the computer simulation and bench test. Because the gas proportional BLMs as the current BLM are sensitive to background noise of X-ray emitted from RF cavities, it is difficult to recognize real beam loss. We need to subtract an X-ray noise from the signal from BLM, another candidate BLMs have been tried to measure the beam loss. In addition, the bunch shape monitor for the longitudinal tuning has been developed in the corroboration with the institute for nuclear research, Russia. In this paper, we describe the new developed devices and their development process, especially for beam loss monitor and the developing bunch shape monitor.

MOPD10	A Calibration Method for the RF Front-end Asymmetry of the DBPM Processor	target, controls, instrumentation, factory	56
	X. Yi, L.W. Lai, Y.B. Leng, Y.B. Yan, N. Zhang SSRF, Shanghai, People's Republic of China Z.C. Chen SINAP, Shanghai, People's Republic of China
	Digital Beam Position Monitor (DBPM) processor, designed to measure the beam positions in the LINAC, booster and the storage ring of a particle accelerator, has been used in many synchrotron radiation facilities. Channels asymmetry, which deteriorates the performance of the DBPM, is inevitable since the RF front-end needs four exactly same blocks. Recently, an RF front-end board for DBPM has been made with calibration circuit which clears the switching noise. The calibration method will be described in detail, including an overview of the RF board. The beam current dependence, which is sensitive to channels asymmetry, decreases from 160μm to 25μm after the calibration in the lab test.
	Poster MOPD10 [1.682 MB]

MOPD13	Mode Selective Waveguide BPM	coupling, cavity, simulation, impedance	65
	A. Lyapin JAI, Egham, Surrey, United Kingdom
	I propose a mode-selective waveguide Beam Position Monitor (BPM). It uses waveguide couplers arranged at the beampipe to create boundary conditions similar to those in slot-coupled cavity BPMs. This structure allows to couple to the differential waveguide mode co-propagating with the beam, and reject the usually much stronger monopole component of the field. As the full dynamic range of the processing electronics can be used for position measurements, and a waveguide is a native high-pass filter, such a BPM is expected to outperform stripline and button BPMs in terms of both spacial and time resolution. In this paper I give some details on the basic principle and the first simulation results and discuss possible ways of signal processing.
	Poster MOPD13 [3.052 MB]

MOPD14	Calibration of the Electrostatic Beam Position Monitors for VEPP-2000	vacuum, electron, optics, positron	68
	Yu. A. Rogovsky, I. Nesterenko BINP SB RAS, Novosibirsk, Russia
	The basic requirement for the VEPP-2000 Beam Position Monitor (BPM) is the measurement of the beam orbit with 0.1 mm precision. To improve the measurement accuracy, the response of the electrostatic BPMs (pickups) were mapped in the laboratory before they were installed in the VEPP-2000 ring. The wire method for the sensitivity calibration and position-to-signal mapping is used. The test stand consists of high frequency coaxial switches to select each pickup electrode, movable antenna to simulate the beam, signal source, spectrum analyzer to measure the pickup signals, and analysis software. This calibration showed possibility of required accuracy. During calibration the electrical center of the different BPMs was measured with respect to the mechanical center. Conversion between the BPM signal and the actual beam position is done by using polynomial expansions fit to the mapping data within ± 6 mm square. Results for these portions of the calibration are presented.
	Poster MOPD14 [0.393 MB]

MOPD15	Electromagnetic Simulations of an Embedded BPM in Collimator Jaws	simulation, collimation, alignment, proton	71
	A.A. Nosych, C.B. Boccard, M. Gasior CERN, Geneva, Switzerland
	Next generation of the LHC collimators will be equipped with button beam position monitors (BPMs) embedded into the collimator jaws. Such a solution will improve the accuracy of the jaw alignment with respect to the beam and reduce the beam time necessary for the collimator setup. This paper describes results of electromagnetic simulations of the jaw BPMs performed with the CST Particle Studio suite, aimed at characterisation of the BPMs as well as the simulation software itself. The results are compared to the measurements obtained with beam on a prototype system installed in the CERN SPS.
	Poster MOPD15 [6.439 MB]

MOPD20	Applicability of the AM-PM Conversion Method to Beam Position Monitoring of Electron Beams accelerated in S-Band Frequency Range	electron, insertion, controls, monitoring	86
	M. Ruf, P. Quednau, L. Schmidt U. Erlangen-Nurnberg LHFT, Erlangen, Germany S. Setzer Siemens Med, Erlangen, Germany
	Funding: Work supported by Bayerische Forschungsstiftung in the project "MEDieMAS - Effiziente Bestrahlungsgeräte für Krebstherapie (Efficient radiation systems for cancer therapy)", file number AZ-735-07 In this paper, the applicability of the amplitude-to-phase-conversion (AM-PM) method to beam position monitoring (BPM) purposes in S-Band frequency range is investigated. The proof-of-principle experiment is done by AM-PM-processing of capacitive pickup signals generated by a 6 MeV S-Band electron beam. It is demonstrated that the AM-PM-output pulsed DC signal is proportional to transverse beam offsets. Furthermore, design considerations and selection criteria of appropriate RF devices are described. Additionally, results of cold measurements of a planar 2-channel AM-PM-receiver module are presented indicating that the applicability will also be given for even higher frequency ranges.

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

MOPD24	A High-resolution Diode-based Orbit Measurement System – Prototype Results from the LHC	feedback, vacuum, injection, coupling	98
	M. Gasior, J. Olexa, R.J. Steinhagen CERN, Geneva, Switzerland
	The prototype of a high resolution beam position monitor (BPM) electronics based on diode peak detectors was tested with LHC beams. In this technique developed at CERN the short beam pulses from each BPM electrode are converted into slowly varying signals by compensated diode peak detectors. The slow signals can be digitised with a laboratory voltmeter or high resolution ADC. As presented in the paper, this technique allows resolutions in the order of 1 ppm of the BPM aperture to be achieved with a measurement rate in the Hz range. Ongoing developments and future prospects for the technique are also discussed.
	Poster MOPD24 [2.055 MB]

MOPD26	Testing of New Hadron Beam Phase and Position Monitor at CIEMAT Laboratory	instrumentation, controls, monitoring, feedback	104
	M. Znidarcic, B.B. Baricevic, R. Hrovatin I-Tech, Solkan, Slovenia J.M. Carmona, A. Ibarra, I. Podadera CIEMAT, Madrid, Spain
	The Libera Single Pass H is the new instrumentation intended for phase, position and charge monitoring in hadron and heavy ion LINACs and transfer lines. Initial measurements and verification of the instrumentation performance were conducted in the laboratory at Instrumentation Technologies. Characterization measurements of the same electronics were later carried out at CIEMAT laboratory. The measurements were performed on a CIEMAT wire test bench with the 175 MHz pulsed signal connected to the wire. Different measurements were performed on the test bench; First, by moving the wire over larger displacements and checking the position and, later, by changing the signal phase and performing the phase shift measurement. This article discusses the new Libera Single Pass H electronics, the tests carried out in the test bench and the performance obtained.

MOPD27	A Sensitive Resonant Schottky Pick-Up for the ESR Storage Ring at GSI	ion, electron, vacuum, impedance	107
	F. Nolden, P. Hülsmann, P. Moritz, C. Peschke, P. Petri, M. Steck, H. Weick GSI, Darmstadt, Germany Yu.A. Litvinov MPI-K, Heidelberg, Germany M.S. Sanjari IKF, Frankfurt am Main, Germany J.X. Wu, Y.D. Zang, S.H. Zhang, T.C. Zhao IMP, Lanzhou, People's Republic of China
	A cavity-like Schottky detector for the heavy ion storage ring ESR at GSI is presented. It works at resonant frequencies around 245 MHz, its loaded Q value is 511, and its loaded R/Q value is roughly 55 Ohms. It features both a very good sensitivity even for beams with single circulating ions and the possibility to take valuable spectra in short time. A few experiments with the new device are presented which show clearly that the device offers new experimental opportunities, both for accelerator diagnostics and nuclear physics experiments. A similar device will be built into the CSRe storage ring at IMP.

MOPD33	Pickup Design for a High Resolution Bunch Arrival Time Monitor for FLASH and XFEL	simulation, electron, vacuum, laser	122
	A. Angelovski, R. Jakoby, A. Kuhl, A. Penirschke, S. Schnepp TU Darmstadt, Darmstadt, Germany M.K. Bock, M. Bousonville, P. Gessler, H. Schlarb DESY, Hamburg, Germany J. Rönsch-Schulenburg, J. Roßbach Uni HH, Hamburg, Germany T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Funded by the Federal Ministry of Education and Research (BMBF): 05K10RDA "Weiterentwickung eines Ankunftszeitmonitors" The Free Electron Laser in Hamburg (FLASH) is currently equipped with four Bunch Arrival time Monitors (BAM’s) which are part of the optical synchronization system [1-2]. FLASH usually works with bunch charges of 0.2 to 1 nC, but for a variety of future experiments, the system needs to operate with bunch charges in the range of 10 to 20 pC. Below 0.2 nC the sensitivity of such a BAM scales approximately linearly with the bunch charge and therefore the system no longer fulfills the time resolution requirements for these low charges. For the low bunch charge regime operation, the bandwidth has to be increased substantially. This paper shows a new design of a high frequency button pickup that can operate in a frequency band from DC up to 40 GHz. The design criteria of the pickup are the voltage slope steepness at the zero-crossing, the maximum amplitude and the ringing of the picked-up voltage. The performance of the designed model is analyzed for fabrication tolerances and orbit variations. Some manufacturing and practical issues are discussed and solutions are offered for improving the results. A full wave simulation with CST PARTICLE STUDIO is performed in order to prove the concept. [1] F. Loehl et. al.,“A Sub 100 fs Electron Bunch Arrival-time Monitor System for FLASH”, THOBFI01, EPAC 2006 [2] F. Loehl et. al.,“A Sub-50 Femtosecond bunch arrival time monitor system for FLASH”, WEPB15, DIPAC 2007
	Poster MOPD33 [27.661 MB]

MOPD34	Analysis of New Pickup Designs for the FLASH and XFEL Bunch Arrival Time Monitor System	simulation, laser, electron, vacuum	125
	A. Kuhl, A. Angelovski, R. Jakoby, A. Penirschke, S. Schnepp TU Darmstadt, Darmstadt, Germany M.K. Bock, M. Bousonville, P. Gessler, H. Schlarb DESY, Hamburg, Germany J. Rönsch-Schulenburg, J. Roßbach Uni HH, Hamburg, Germany T. Weiland TEMF, TU Darmstadt, Darmstadt, Germany
	Funding: Funded by the Federal Ministry of Education and Research (BMBF): 05K10RDA "Weiterentwickung eines Ankunftszeitmonitors" The Free Electron Laser in Hamburg (FLASH) is equipped with Bunch Arrival time Monitors (BAM)[1], which provide for a time resolution of less than 10 fs for bunch charges higher than 0.2 nC. Future experiments, however, will aim at generating FEL light pulses from bunch charges of 10-20 pC. The sensitivity of the measurement system is defined by the slope of the pickup signal at the zero crossing and scales close to linear with the bunch charge. The requirements on the time resolution will no longer be fulfilled when operating at decreased bunch charges. Several designs have been developed in CST PARTICLE STUDIO®, each having an increased bandwidth larger than 40 GHz for meeting the requirements when operating at low bunch charges. Furthermore, new post-processing functions for the automatic evaluation of the signal slope and the ringing in the detected voltage signal have been developed and implemented within the CST software for defining optimization goals of the built-in optimizer for determining free design parameters. Results of the new designs are presented and compared with the current BAM pickup. [1] M.K. Bock et.al., "Recent Developments of the Beam Arrival Time Monitor with Femtosecond Resolution at FLASH", WEOCMH02, IPAC 2010
	Poster MOPD34 [3.112 MB]

MOPD35	Improved Signal Treatment for Capacitive Linac Pick-Ups	DTL, rfq, linac, radio-frequency	128
	A. Reiter, C.M. Kleffner, B. Schlitt GSI, Darmstadt, Germany
	Phase probes are a crucial diagnostic tool for pulsed particle beams of linear accelerators. In this contribution we present a simple, but very effective analysis procedure which has been established in various applications during commissioning campaigns of injector linacs for medical facilities. These injectors consist of a 400 keV/u radio-frequency quadrupole followed by a 7 MeV/u inter-digital drift tube linac, both operating at 216.8 MHz. At GSI, the new analysis was recently applied at the HITRAP decelerator, also with promising results. The data analysis exploits the periodic nature of sampling process and bunch signal improving the detector sensitivity and achieving an effective resolution of < 10 ps. If the macro-pulse is sufficiently long, the quality of the data can be improved further by a statistical average of subsequent data blocks acquired within one single macro-pulse. The latter is important for experiments with low beam intensity and low repetition rate like HITRAP where averaging over many macro-pulses is cumbersome.

MOPD65	Sensitivity Optimization of the Standard Beam Current Monitors for XFEL and FLASH II	monitoring, impedance, diagnostics, ion	197
	M. Werner, J. Lund-Nielsen, Re. Neumann, N. Wentowski DESY, Hamburg, Germany
	There is a tendency to operate 4th generation SASE driven light sources at very low charge in order to further shorten the pulse length. Therefore the operation range of XFEL and FLASH II was extended to a charge range of as low as 20 pC to 1 nC. For a reliable charge measurement down to 20 pC, a low noise design of the signal chain from the monitor head to the digitizing ADC is necessary. This paper describes the steps taken in order to increase the sensitivity and dynamic range of the monitors currently used in the FLASH accelerator, and the basic theoretical background will be explained. Finally, first results are presented.
	Poster MOPD65 [0.768 MB]

MOPD91	Pulse-By-Pulse X-ray Beam Monitor Equipped with Microstripline Structure	electron, high-voltage, diagnostics, impedance	260
	H. Aoyagi, S. Takahashi JASRI/SPring-8, Hyogo-ken, Japan H. Kitamura RIKEN/SPring-8, Hyogo, Japan
	Pulse-by-pulse measurement of X-ray beam is import issue for the 3rd generation light sources in order not only to stabilize X-ray beam in an experimental hutch but also to diagnose electron beam in a storage ring. A new pulse-by-pulse X-ray beam monitor equipped with microstripline structure has been developed. The detector head has the microstripline structure. The impedance of the detector head is matched to 50 ohm. Thermodynamics of the detector head is also well considered against severe heat load. The advantage of this monitor is that output signal is short and unipolar pulse, so front-end electronics can be simplified. The feasibility tests have been demonstrated at the X-ray beamline of SPring-8 in the term of (1) pulse intensity monitor, (2) pulse-by-pulse X-ray beam position monitor, and (3) the pulse-timing monitor. Then, we have improved the structure of the detector head in order to sophisticate the function as the pulse timing monitor. As a result, we successfully removed the ringing parts of output signal, and demonstrated that this monitor can be used as the timing monitor. We also describe a new scheme for beam diagnostics using this monitor.
	Poster MOPD91 [1.309 MB]

MOPD97	Beam Position Monitor System for the CERN Linac4	linac, simulation, DTL, resonance	272
	J. Tan, L. Søby, M. Sordet CERN, Geneva, Switzerland
	The new LINAC4 will provide 160 MeV H¯ ion beams for charge-exchange and proton injection into the CERN accelerator complex. Among a wide variety of beam diagnostics devices, shorted stripline pick-ups will measure the absolute beam position, the relative and absolute beam current, and the average beam energy via the time-of-flight between two monitors. This paper describes the beam position monitor (BPM) with its electronic acquisition chain to be implemented on the movable test bench for beam characterization up to 12 MeV.

TUPD05	Diagnostic Scheme for the HITRAP Decelerator	ion, rfq, diagnostics, dipole	311
	G. Vorobjev, C.A. Andre, W.A. Barth, E. Berdermann, M.I. Ciobanu, G. Clemente, L.A. Dahl, P. Forck, P. Gerhard, R. Haseitl, F. Herfurth, M. Kaiser, W. Kaufmann, H.J. Kluge, N. Kotovski, C. Kozhuharov, M.T. Maier, W. Quint, A. Reiter, A. Sokolov, T. Stöhlker GSI, Darmstadt, Germany O.K. Kester, J. Pfister, U. Ratzinger, A. Schempp IAP, Frankfurt am Main, Germany
	The HITRAP linear decelerator currently being set up at GSI will provide slow, few keV/u highly charged ions for atomic physics experiments. The expected beam intensity is up to 10⁵ ions per shot. To optimize phase and amplitude of the RF systems intensity, bunch length and kinetic energy of the particles need to be monitored. The bunch length that we need to fit is about 2 ns, which is typically measured by capacitive pickups. However, they do not work for the low beam intensities that we face. We investigated the bunch length with a fast CVD diamond detector working in single particle counting mode. Averaging over 8 shots yields a clear, regular picture of the bunched beam. Energy measurements by capacitive pickups are limited by the presence of intense primary and partially decelerated beam and hence make tuning of the IH-structure impossible. The energy of the decelerated fraction of the beam behind the first deceleration cavity was determined to about 10 % accuracy with a permanent dipole magnet combined with a MCP. Better detector calibration should help reaching the required 1%. Design of the detectors as well as the results of the measurements will be presented.

TUPD11	Developments for IFMIF/EVEDA LIPAc Beam Position Monitors: The Sensors at the MEBT and the Wire Test Bench	controls, linac, quadrupole, simulation	320
	I. Podadera, J.M. Carmona, A. Guirao, A. Ibarra, L.M. Martinez Fresno, E. Mirones, R. Unamuno, J.G.S. de la Gama CIEMAT, Madrid, Spain
	Funding: This work has been partially supported by the Spanish Ministry of Science and Innovation under Project ENE2009-11230 The IFMIF-EVEDA 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. In the Medium Energy Beam Transport line (MEBT) connecting the RFQ and the MEBT, non-interceptive Beam Position Monitors pickups (MBPMs) will measure the transverse position and phase in order to maximize the transport efficiency of the beamline. The response of the MBPMs must be optimized for a beam current for 5 MeV, and a peak beam current of 125 mA. Due to the lack of space in the MEBT, the MBPMs will be located inside the magnets. The MBPMs will have to fit inside the magnets without perturbing the magnetic field. In this contribution, the electromagnetic and mechanical design of the MBPM will be presented. In addition, in order to validate and characterize all the BPMs type of IFMIF/EVEDA once they are manufactured, a wire test bench has been constructed and verified at CIEMAT. The design and validation results of the test bench will be discussed.

TUPD12	The LHC Beam Position System: Performance during 2010 and Outlook for 2011	feedback, closed-orbit, injection, vacuum	323
	E. Calvo Giraldo, J.L. Gonzalez, L.K. Jensen, O.R. Jones, T. Lefèvre, J.-J. Savioz, R.J. Steinhagen, J. Wenninger CERN, Geneva, Switzerland
	This paper presents the performance of the LHC Beam Position System during 2010. The system proved to meet most specifications, was highly reliable and continuously provided 25Hz real-time orbit data with micron level resolution to the automatic global orbit feedback system. However, several issues were observed and they will be discussed in detail, such as the dependence on bunch intensity and the effect of surface electronics temperature variations on the measured position.

TUPD16	High Frequency Measurements of the Beam Position Monitors for the TBL Line of the CTF3 at CERN	impedance, bunching, monitoring, simulation	335
	J.J. García-Garrigós, C. Blanch Gutierrez, J.V. Civera-Navarrete, A. Faus-Golfe IFIC, Valencia, Spain B. Gimeno UVEG, Burjasot (Valencia), Spain
	Funding: Funding Agency: FPA2010-21456-C02-00 A series of Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and tested at IFIC. A full set of 16 BPMs, so called BPS units, were successfully installed in the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN. Two different characterization tests, at low and high frequencies, were carried out on the BPS units: The low frequency test, in the beam pulse time scale (until 10ns/100MHz), determined the BPSs parameters directly related to the beam position monitoring and the high frequency test, reaching the microwave X-Ku bands around the beam bunching time scale (83ps/12GHz). In this paper we describe the results and methods used to obtain the longitudinal impedance in the frequency range of interest. This test is based on the S-parameters measurements of the propagating TEM mode in a matched coaxial waveguide, specifically designed for the BPS, which is able to emulate an ultra-relativistic electron beam.
	Poster TUPD16 [1.069 MB]

TUPD28	Benchmarking the Performance of the Present Bunch Arrival Time Monitors at FLASH	FEL, feedback, laser, electron	365
	M.K. Bock, M. Bousonville, M. Felber, P. Gessler, T. Lamb, S. Ruzin, H. Schlarb, B. Schmidt, S. Schulz DESY, Hamburg, Germany
	Funding: This work is partly supported by IRUVX-PP, an EU co-funded project under FP7 (Grant Agreement 211285) Presently, at FLASH four bunch arrival time monitors (BAM) are installed and in permanent operation. Moreover, they are incorporated in a longitudinal intra-bunch train feedback. In this paper, we present a review of the performance and the limitations of the current BAM design, based on the most recent machine studies. The detection principle of the monitor implements the electro-optical modulation of synchronised laser pulses. The RF and electro-optical front-ends are designed to be operated in a frequency band from DC up to 10 GHz. This allows for measuring the arrival time of each individual electron bunch at femtosecond resolution. The current design of the BAMs has been tested under the influence of disturbances on the arrival time measurement, such as variation of the bunch charge as well as deviation from the reference transverse bunch position. Those results will be incorporated in an upcoming design revision to upgrade the application and robustness of the BAMs.

TUPD53	A Low-Power Laser Wire with Fiber Optic Distribution	laser, diagnostics, electron, scattering	425
	R.B. Wilcox, J.M. Byrd, M.S. Zolotorev LBNL, Berkeley, California, USA V.E. Scarpine Fermilab, Batavia, USA
	Funding: This work was supported by the US Department of Energy under contract DE-AC02-05CH11231. Laser-based position diagnostics for hydrogen ion (H⁻) beams typically use high power optical pulses that must be transported via free space to the diagnostic point. It is difficult to maintain stable alignment through such systems, especially when multiple channels are required. We describe a method for distributing low power, amplitude modulated pulse trains via fiber optic, and detecting interaction with the H⁻ beam by synchronous detection of the stripped electrons. Trains of 10 ps, 10⁶⁴ nm pulses at 400 MHz repetition rate are modulated by a 1 MHz signal that is the reference for a lockin amplifier. The average beam power is below one Watt. Synchronous detection at RF frequencies allows for efficient noise rejection when using optical powers below the nonlinear (Raman scattering) threshold of an optical fiber. The laser is synchronized with the bunch repetition rate, so the diagnostic can be used for bunch length measurements as well. We present results of tests of the optical system with 10⁰ m, single-mode fiber and realistic detected signal levels, demonstrating detection of the modulation signal with high signal-to-noise ratio and low nonlinearity.

TUPD66	Sensor Optimizations for a Cryogenic Current Comparator	cryogenics, ion, antiproton, storage-ring	458
	R. Geithner, W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany P. Kowina, F. Kurian, M. Schwickert GSI, Darmstadt, Germany R. von Hahn MPI-K, Heidelberg, Germany
	We present a non-destructive superconducting monitoring system for charged particles beams. The system uses the Cryogenic Current Comparator (CCC) principle with a low temperature DC-SQUID. The Cryogenic Current Comparator has shown its capability in the Horizontal Bi-Cavity Test Facility at the Helmholtz-Zentrum Berlin under noisy conditions. In this test facility for superconducting cavities the CCC setup was able to detect dark currents in the nA range. The suitability of the Cryogenic Current Comparator as a beam monitor for the Facility of Antiproton and Ion Research at GSI Darmstadt as well as for the Cryogenic Storage Ring at MPI Heidelberg will be pointed out and discussed. Special attention will be given to the ferromagnetic core materials embedded in the pickup coil.

TUPD92	SPIRAL2 Beam Energy Measurement	simulation, linac, rfq, instrumentation	524
	W. Le Coz, T.A. André, C. Doutresssoulles, C. Jamet, S. Loret GANIL, Caen, France
	In order to produce high intensity exotic beams in the existing experimental rooms of the GANIL facility, the SPIRAL2 project is under development and under construction at GANIL. The first phase of the SPIRAL2 project consists to build a new accelerator composed of two sources, an ion source and a proton/neutron source, a RFQ and a superconducting Linac. The linac is designed to accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. A new electronic device has been developed at GANIL to measure phase and amplitude of pick-up signals and calculate the beam energy. The principle consists of directly digitizing the pick-up pulses by under-sampling. The Phase and amplitude of different harmonics are then calculated with a FPGA by an I/Q method before the beam energy calculation. This paper gives results of the peak-up tests in laboratory and the comparisons with simulations. The tests in laboratory and on the GANIL accelerator of an electronic prototype are shown and presented.

WEOC01	Beam Charge Measurements	vacuum, coupling, impedance, linac	564
	D. Belohrad CERN, Geneva, Switzerland
	The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.
	Slides WEOC01 [5.738 MB]

WEOC02	News About the Cryogenic Current Comparator for Beam Diagnostics	ion, cryogenics, antiproton, simulation	569
	W. Vodel HIJ, Jena, Germany R. Geithner, R. Neubert, P. Seidel FSU Jena, Jena, Germany K.K. Knaack, K. Wittenburg DESY, Hamburg, Germany A. Peters HIT, Heidelberg, Germany H. Reeg, M. Schwickert GSI, Darmstadt, Germany
	An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnostics. Also the measurement of so-called dark currents, generated by superconductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems. This contribution gives an overview on the development of SQUID-based CCC for nuclear physics from the first successful demonstration of the performance at GSI Darmstadt through the recently tested CCC for the XFEL at DESY to the latest improved version for FAIR.
	Slides WEOC02 [2.596 MB]

Paper

Title

Other Keywords

Page

MOOC01

Overview of Recent Trends and Developments for BPM Systems

cavity, coupling, monitoring, linac

18

M. Wendt
Fermilab, Batavia, USA

Beam position monitoring (BPM) systems are the workhorse beam diagnostics for almost any kind of charged particle accelerator; linear, circular or transport-lines, operating with leptons, hadrons or heavy ions. The BPMs are essential for beam commissioning, accelerator fault analysis and trouble shooting, machine optics and lattice measurements, and finally for the accelerator optimization to achieve the ultimate beam quality. This presentation summarizes the efforts of the beam instrumentation community on recent developments and advances on BPM technologies, i.e. BPM pickup monitors and front-end electronics (analog and digital). Principles, examples, and state-of-the-art status on various BPM techniques are outlined, serving hadron and heavy ion machines, sync light synchrotron's, as well as electron linacs for FEL or HEP applications.

Slides MOOC01 [4.123 MB]

MOOC03

The Fermi@Elettra Cavity BPM System: Description and Commissioning Results

cavity, controls, FEL, undulator

26

M. Ferianis, A.O. Borga, P. Craievich, R. De Monte, G. Gaio, M. Predonzani
ELETTRA, Basovizza, Italy
M. Dal Forno
DIEIT, Trieste, Italy

The Fermi@elettra cavity BPM (C-BPM) system is based on an original implementation of the C-BPM scheme as the pick-up, operating at 6.5GHz, is coupled to a dedicated, self-calibrating electronics based on a novel concept. The system has been developed in-house; both the E-M and the mechanical design of the pick-up have been carried out, including an original frequency tuning scheme. The detector electronics directly obtains the envelope of the sum and difference signals by means of an RF 180° hybrid; no mixer for the RF signal down conversion is used. The detector is based on 3 blocks: an RF front-end, a baseband analogue transmission module and a digital back-end unit, based on a micro-TCA platform. The digital back-end is equipped with a powerful Virtex 5 FPGA and several real-time tasks have been implemented on it, including intra-pulse calibration. Ten C-BPM stations have been installed so far, fully integrated in the FERMI control System, enabling a real-time control of this key FEL diagnostics. Results on performances with beam are also presented; the scale factor of C-BPMs is obtained with beam, as two-axis micrometer translation stages have been installed.

Slides MOOC03 [2.733 MB]

MOPD01

Beam Diagnostics for the NSLS-II Booster

booster, betatron, vacuum, controls

29

V.V. Smaluk
BINP, Novosibirsk, Russia
E.A. Bekhtenev, V.P. Cherepanov, G.V. Karpov, V. Kuzminykh, O.I. Meshkov
BINP SB RAS, Novosibirsk, Russia
I. Pinayev, O. Singh, K. Vetter
BNL, Upton, Long Island, New York, USA

For successful commissioning and effective operation of the projected NSLS-II Booster, a set of beam diagnostic instruments has been designed. Fluorescent screens are used for the Booster commissioning and troubleshooting. Closed orbit is measured using electrostatic BPMs with turn-by-turn capability. The circulating current and beam lifetime are measured using a DC current transformer. The fill pattern is monitored by a fast current transformer. Visible synchrotron radiation is registered for observation of the beam image. Betatron tunes are measured using two pairs of striplines, the first pair is for beam excitation and the second one – for beam response measurement. Design and performance of the Booster beam instrumentation are described.

MOPD05

Beam Diagnostic Layout for SIS100 at FAIR

ion, diagnostics, proton, beam-losses

41

M. Schwickert, P. Forck, T. Hoffmann, P. Kowina, H. Reeg
GSI, Darmstadt, Germany

The SIS100 heavy ion synchrotron will be the central machine of the FAIR (Facility for Antiprotons and Ions Research) project currently designed at GSI. The unique features of SIS100, like e.g. the acceleration of high intensity beams of 2.5·10¹³ protons and 5·10¹¹ Uranium ions near the space charge limit, the anticipated large tune spread, extreme UHV conditions of the cryogenic system for superconducting magnets and fast ramp rates of 4 T/s, make challenging demands on the beam diagnostic components. This contribution describes the conceptual design for SIS100 beam diagnostics and reports on the present status of prototype studies. Exemplarily the progress concerning beam position monitors, beam current transformers and beam-loss monitors is presented.

MOPD06

Capabilities and Performance of the LHC Schottky Monitors

injection, emittance, impedance, proton

44

M. Favier, T.B. Bogey, F. Caspers, O.R. Jones
CERN, Geneva, Switzerland
J. Cai, E.S.M. McCrory, R.J. Pasquinelli
Fermilab, Batavia, USA
A. Jansson
ESS, Lund, Sweden

The LHC Schottky system has been under commissioning since summer 2010. This non destructive observation relies on a slotted waveguide structure resonating at 4.8GHz. Four monitors, one for each plane of the two counter-rotating LHC beams, are used to measure the transverse Schottky sidebands Electronic gating allows selective bunch-by-bunch measurements, while a triple down-mixing scheme combined with heavy filtering gives an instantaneous dynamic range of over 100dB within a 20kHz bandwidth. Observations of both proton and lead ion Schottky spectra will be discussed along with a comparison of predicted and measured performance.

Poster MOPD06 [3.484 MB]

MOPD08

Beam Diagnostics in the J-PARC Linac for ACS Upgrade

linac, diagnostics, acceleration, simulation

50

A. Miura, S. Sato
JAEA/J-PARC, Tokai-mura, Japan
Z. Igarashi, M. Ikegami, T. Miyao, T. Toyama
KEK, Ibaraki, Japan
T. Tomisawa
JAEA/LINAC, Ibaraki-ken, Japan

J-PARC had developed the beam diagnostic devices for the current J-PARC linac and has used them since the operation start. J-PARC linac began the energy upgrade project since 2009 and 21 ACS cavities will be installed. In this project, many cavities and related devices are newly installed in the ACS section and its downstream part. Because the beam parameters are updated, new beam diagnostic devices are fabricated and current diagnostic devices are developed. Beam position monitors (BPM) are newly designed and fabricated, based on the computer simulation and bench test. Because the gas proportional BLMs as the current BLM are sensitive to background noise of X-ray emitted from RF cavities, it is difficult to recognize real beam loss. We need to subtract an X-ray noise from the signal from BLM, another candidate BLMs have been tried to measure the beam loss. In addition, the bunch shape monitor for the longitudinal tuning has been developed in the corroboration with the institute for nuclear research, Russia. In this paper, we describe the new developed devices and their development process, especially for beam loss monitor and the developing bunch shape monitor.

MOPD10

A Calibration Method for the RF Front-end Asymmetry of the DBPM Processor

target, controls, instrumentation, factory

56

X. Yi, L.W. Lai, Y.B. Leng, Y.B. Yan, N. Zhang
SSRF, Shanghai, People's Republic of China
Z.C. Chen
SINAP, Shanghai, People's Republic of China

Digital Beam Position Monitor (DBPM) processor, designed to measure the beam positions in the LINAC, booster and the storage ring of a particle accelerator, has been used in many synchrotron radiation facilities. Channels asymmetry, which deteriorates the performance of the DBPM, is inevitable since the RF front-end needs four exactly same blocks. Recently, an RF front-end board for DBPM has been made with calibration circuit which clears the switching noise. The calibration method will be described in detail, including an overview of the RF board. The beam current dependence, which is sensitive to channels asymmetry, decreases from 160μm to 25μm after the calibration in the lab test.

Poster MOPD10 [1.682 MB]

MOPD13

Mode Selective Waveguide BPM

coupling, cavity, simulation, impedance

65

A. Lyapin
JAI, Egham, Surrey, United Kingdom

I propose a mode-selective waveguide Beam Position Monitor (BPM). It uses waveguide couplers arranged at the beampipe to create boundary conditions similar to those in slot-coupled cavity BPMs. This structure allows to couple to the differential waveguide mode co-propagating with the beam, and reject the usually much stronger monopole component of the field. As the full dynamic range of the processing electronics can be used for position measurements, and a waveguide is a native high-pass filter, such a BPM is expected to outperform stripline and button BPMs in terms of both spacial and time resolution. In this paper I give some details on the basic principle and the first simulation results and discuss possible ways of signal processing.

Poster MOPD13 [3.052 MB]

MOPD14

Calibration of the Electrostatic Beam Position Monitors for VEPP-2000

vacuum, electron, optics, positron

68

Yu. A. Rogovsky, I. Nesterenko
BINP SB RAS, Novosibirsk, Russia

The basic requirement for the VEPP-2000 Beam Position Monitor (BPM) is the measurement of the beam orbit with 0.1 mm precision. To improve the measurement accuracy, the response of the electrostatic BPMs (pickups) were mapped in the laboratory before they were installed in the VEPP-2000 ring. The wire method for the sensitivity calibration and position-to-signal mapping is used. The test stand consists of high frequency coaxial switches to select each pickup electrode, movable antenna to simulate the beam, signal source, spectrum analyzer to measure the pickup signals, and analysis software. This calibration showed possibility of required accuracy. During calibration the electrical center of the different BPMs was measured with respect to the mechanical center. Conversion between the BPM signal and the actual beam position is done by using polynomial expansions fit to the mapping data within ± 6 mm square. Results for these portions of the calibration are presented.

Poster MOPD14 [0.393 MB]

MOPD15

Electromagnetic Simulations of an Embedded BPM in Collimator Jaws

simulation, collimation, alignment, proton

71

A.A. Nosych, C.B. Boccard, M. Gasior
CERN, Geneva, Switzerland

Next generation of the LHC collimators will be equipped with button beam position monitors (BPMs) embedded into the collimator jaws. Such a solution will improve the accuracy of the jaw alignment with respect to the beam and reduce the beam time necessary for the collimator setup. This paper describes results of electromagnetic simulations of the jaw BPMs performed with the CST Particle Studio suite, aimed at characterisation of the BPMs as well as the simulation software itself. The results are compared to the measurements obtained with beam on a prototype system installed in the CERN SPS.

Poster MOPD15 [6.439 MB]

MOPD20

Applicability of the AM-PM Conversion Method to Beam Position Monitoring of Electron Beams accelerated in S-Band Frequency Range

electron, insertion, controls, monitoring

86

M. Ruf, P. Quednau, L. Schmidt
U. Erlangen-Nurnberg LHFT, Erlangen, Germany
S. Setzer
Siemens Med, Erlangen, Germany

Funding: Work supported by Bayerische Forschungsstiftung in the project "MEDieMAS - Effiziente Bestrahlungsgeräte für Krebstherapie (Efficient radiation systems for cancer therapy)", file number AZ-735-07
In this paper, the applicability of the amplitude-to-phase-conversion (AM-PM) method to beam position monitoring (BPM) purposes in S-Band frequency range is investigated. The proof-of-principle experiment is done by AM-PM-processing of capacitive pickup signals generated by a 6 MeV S-Band electron beam. It is demonstrated that the AM-PM-output pulsed DC signal is proportional to transverse beam offsets. Furthermore, design considerations and selection criteria of appropriate RF devices are described. Additionally, results of cold measurements of a planar 2-channel AM-PM-receiver module are presented indicating that the applicability will also be given for even higher frequency ranges.

MOPD22

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

simulation, ion, synchrotron

92

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

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

MOPD24

A High-resolution Diode-based Orbit Measurement System – Prototype Results from the LHC

feedback, vacuum, injection, coupling

98

M. Gasior, J. Olexa, R.J. Steinhagen
CERN, Geneva, Switzerland

The prototype of a high resolution beam position monitor (BPM) electronics based on diode peak detectors was tested with LHC beams. In this technique developed at CERN the short beam pulses from each BPM electrode are converted into slowly varying signals by compensated diode peak detectors. The slow signals can be digitised with a laboratory voltmeter or high resolution ADC. As presented in the paper, this technique allows resolutions in the order of 1 ppm of the BPM aperture to be achieved with a measurement rate in the Hz range. Ongoing developments and future prospects for the technique are also discussed.

Poster MOPD24 [2.055 MB]

MOPD26

Testing of New Hadron Beam Phase and Position Monitor at CIEMAT Laboratory

instrumentation, controls, monitoring, feedback

104

M. Znidarcic, B.B. Baricevic, R. Hrovatin
I-Tech, Solkan, Slovenia
J.M. Carmona, A. Ibarra, I. Podadera
CIEMAT, Madrid, Spain

The Libera Single Pass H is the new instrumentation intended for phase, position and charge monitoring in hadron and heavy ion LINACs and transfer lines. Initial measurements and verification of the instrumentation performance were conducted in the laboratory at Instrumentation Technologies. Characterization measurements of the same electronics were later carried out at CIEMAT laboratory. The measurements were performed on a CIEMAT wire test bench with the 175 MHz pulsed signal connected to the wire. Different measurements were performed on the test bench; First, by moving the wire over larger displacements and checking the position and, later, by changing the signal phase and performing the phase shift measurement. This article discusses the new Libera Single Pass H electronics, the tests carried out in the test bench and the performance obtained.

MOPD27

A Sensitive Resonant Schottky Pick-Up for the ESR Storage Ring at GSI

ion, electron, vacuum, impedance

107

F. Nolden, P. Hülsmann, P. Moritz, C. Peschke, P. Petri, M. Steck, H. Weick
GSI, Darmstadt, Germany
Yu.A. Litvinov
MPI-K, Heidelberg, Germany
M.S. Sanjari
IKF, Frankfurt am Main, Germany
J.X. Wu, Y.D. Zang, S.H. Zhang, T.C. Zhao
IMP, Lanzhou, People's Republic of China

A cavity-like Schottky detector for the heavy ion storage ring ESR at GSI is presented. It works at resonant frequencies around 245 MHz, its loaded Q value is 511, and its loaded R/Q value is roughly 55 Ohms. It features both a very good sensitivity even for beams with single circulating ions and the possibility to take valuable spectra in short time. A few experiments with the new device are presented which show clearly that the device offers new experimental opportunities, both for accelerator diagnostics and nuclear physics experiments. A similar device will be built into the CSRe storage ring at IMP.

MOPD33

Pickup Design for a High Resolution Bunch Arrival Time Monitor for FLASH and XFEL

simulation, electron, vacuum, laser

122

A. Angelovski, R. Jakoby, A. Kuhl, A. Penirschke, S. Schnepp
TU Darmstadt, Darmstadt, Germany
M.K. Bock, M. Bousonville, P. Gessler, H. Schlarb
DESY, Hamburg, Germany
J. Rönsch-Schulenburg, J. Roßbach
Uni HH, Hamburg, Germany
T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Funded by the Federal Ministry of Education and Research (BMBF): 05K10RDA "Weiterentwickung eines Ankunftszeitmonitors"
The Free Electron Laser in Hamburg (FLASH) is currently equipped with four Bunch Arrival time Monitors (BAM’s) which are part of the optical synchronization system [1-2]. FLASH usually works with bunch charges of 0.2 to 1 nC, but for a variety of future experiments, the system needs to operate with bunch charges in the range of 10 to 20 pC. Below 0.2 nC the sensitivity of such a BAM scales approximately linearly with the bunch charge and therefore the system no longer fulfills the time resolution requirements for these low charges. For the low bunch charge regime operation, the bandwidth has to be increased substantially. This paper shows a new design of a high frequency button pickup that can operate in a frequency band from DC up to 40 GHz. The design criteria of the pickup are the voltage slope steepness at the zero-crossing, the maximum amplitude and the ringing of the picked-up voltage. The performance of the designed model is analyzed for fabrication tolerances and orbit variations. Some manufacturing and practical issues are discussed and solutions are offered for improving the results. A full wave simulation with CST PARTICLE STUDIO is performed in order to prove the concept.
[1] F. Loehl et. al.,“A Sub 100 fs Electron Bunch Arrival-time Monitor System for FLASH”, THOBFI01, EPAC 2006
[2] F. Loehl et. al.,“A Sub-50 Femtosecond bunch arrival time monitor system for FLASH”, WEPB15, DIPAC 2007

Poster MOPD33 [27.661 MB]

MOPD34

Analysis of New Pickup Designs for the FLASH and XFEL Bunch Arrival Time Monitor System

simulation, laser, electron, vacuum

125

A. Kuhl, A. Angelovski, R. Jakoby, A. Penirschke, S. Schnepp
TU Darmstadt, Darmstadt, Germany
M.K. Bock, M. Bousonville, P. Gessler, H. Schlarb
DESY, Hamburg, Germany
J. Rönsch-Schulenburg, J. Roßbach
Uni HH, Hamburg, Germany
T. Weiland
TEMF, TU Darmstadt, Darmstadt, Germany

Funding: Funded by the Federal Ministry of Education and Research (BMBF): 05K10RDA "Weiterentwickung eines Ankunftszeitmonitors"
The Free Electron Laser in Hamburg (FLASH) is equipped with Bunch Arrival time Monitors (BAM)[1], which provide for a time resolution of less than 10 fs for bunch charges higher than 0.2 nC. Future experiments, however, will aim at generating FEL light pulses from bunch charges of 10-20 pC. The sensitivity of the measurement system is defined by the slope of the pickup signal at the zero crossing and scales close to linear with the bunch charge. The requirements on the time resolution will no longer be fulfilled when operating at decreased bunch charges. Several designs have been developed in CST PARTICLE STUDIO®, each having an increased bandwidth larger than 40 GHz for meeting the requirements when operating at low bunch charges. Furthermore, new post-processing functions for the automatic evaluation of the signal slope and the ringing in the detected voltage signal have been developed and implemented within the CST software for defining optimization goals of the built-in optimizer for determining free design parameters. Results of the new designs are presented and compared with the current BAM pickup.
[1] M.K. Bock et.al., "Recent Developments of the Beam Arrival Time Monitor with Femtosecond Resolution at FLASH", WEOCMH02, IPAC 2010

Poster MOPD34 [3.112 MB]

MOPD35

Improved Signal Treatment for Capacitive Linac Pick-Ups

DTL, rfq, linac, radio-frequency

128

A. Reiter, C.M. Kleffner, B. Schlitt
GSI, Darmstadt, Germany

Phase probes are a crucial diagnostic tool for pulsed particle beams of linear accelerators. In this contribution we present a simple, but very effective analysis procedure which has been established in various applications during commissioning campaigns of injector linacs for medical facilities. These injectors consist of a 400 keV/u radio-frequency quadrupole followed by a 7 MeV/u inter-digital drift tube linac, both operating at 216.8 MHz. At GSI, the new analysis was recently applied at the HITRAP decelerator, also with promising results. The data analysis exploits the periodic nature of sampling process and bunch signal improving the detector sensitivity and achieving an effective resolution of < 10 ps. If the macro-pulse is sufficiently long, the quality of the data can be improved further by a statistical average of subsequent data blocks acquired within one single macro-pulse. The latter is important for experiments with low beam intensity and low repetition rate like HITRAP where averaging over many macro-pulses is cumbersome.

MOPD65

Sensitivity Optimization of the Standard Beam Current Monitors for XFEL and FLASH II

monitoring, impedance, diagnostics, ion

197

M. Werner, J. Lund-Nielsen, Re. Neumann, N. Wentowski
DESY, Hamburg, Germany

There is a tendency to operate 4th generation SASE driven light sources at very low charge in order to further shorten the pulse length. Therefore the operation range of XFEL and FLASH II was extended to a charge range of as low as 20 pC to 1 nC. For a reliable charge measurement down to 20 pC, a low noise design of the signal chain from the monitor head to the digitizing ADC is necessary. This paper describes the steps taken in order to increase the sensitivity and dynamic range of the monitors currently used in the FLASH accelerator, and the basic theoretical background will be explained. Finally, first results are presented.

Poster MOPD65 [0.768 MB]

MOPD91

Pulse-By-Pulse X-ray Beam Monitor Equipped with Microstripline Structure

electron, high-voltage, diagnostics, impedance

260

H. Aoyagi, S. Takahashi
JASRI/SPring-8, Hyogo-ken, Japan
H. Kitamura
RIKEN/SPring-8, Hyogo, Japan

Pulse-by-pulse measurement of X-ray beam is import issue for the 3rd generation light sources in order not only to stabilize X-ray beam in an experimental hutch but also to diagnose electron beam in a storage ring. A new pulse-by-pulse X-ray beam monitor equipped with microstripline structure has been developed. The detector head has the microstripline structure. The impedance of the detector head is matched to 50 ohm. Thermodynamics of the detector head is also well considered against severe heat load. The advantage of this monitor is that output signal is short and unipolar pulse, so front-end electronics can be simplified. The feasibility tests have been demonstrated at the X-ray beamline of SPring-8 in the term of (1) pulse intensity monitor, (2) pulse-by-pulse X-ray beam position monitor, and (3) the pulse-timing monitor. Then, we have improved the structure of the detector head in order to sophisticate the function as the pulse timing monitor. As a result, we successfully removed the ringing parts of output signal, and demonstrated that this monitor can be used as the timing monitor. We also describe a new scheme for beam diagnostics using this monitor.

Poster MOPD91 [1.309 MB]

MOPD97

Beam Position Monitor System for the CERN Linac4

linac, simulation, DTL, resonance

272

J. Tan, L. Søby, M. Sordet
CERN, Geneva, Switzerland

The new LINAC4 will provide 160 MeV H¯ ion beams for charge-exchange and proton injection into the CERN accelerator complex. Among a wide variety of beam diagnostics devices, shorted stripline pick-ups will measure the absolute beam position, the relative and absolute beam current, and the average beam energy via the time-of-flight between two monitors. This paper describes the beam position monitor (BPM) with its electronic acquisition chain to be implemented on the movable test bench for beam characterization up to 12 MeV.

TUPD05

Diagnostic Scheme for the HITRAP Decelerator

ion, rfq, diagnostics, dipole

311

G. Vorobjev, C.A. Andre, W.A. Barth, E. Berdermann, M.I. Ciobanu, G. Clemente, L.A. Dahl, P. Forck, P. Gerhard, R. Haseitl, F. Herfurth, M. Kaiser, W. Kaufmann, H.J. Kluge, N. Kotovski, C. Kozhuharov, M.T. Maier, W. Quint, A. Reiter, A. Sokolov, T. Stöhlker
GSI, Darmstadt, Germany
O.K. Kester, J. Pfister, U. Ratzinger, A. Schempp
IAP, Frankfurt am Main, Germany

The HITRAP linear decelerator currently being set up at GSI will provide slow, few keV/u highly charged ions for atomic physics experiments. The expected beam intensity is up to 10⁵ ions per shot. To optimize phase and amplitude of the RF systems intensity, bunch length and kinetic energy of the particles need to be monitored. The bunch length that we need to fit is about 2 ns, which is typically measured by capacitive pickups. However, they do not work for the low beam intensities that we face. We investigated the bunch length with a fast CVD diamond detector working in single particle counting mode. Averaging over 8 shots yields a clear, regular picture of the bunched beam. Energy measurements by capacitive pickups are limited by the presence of intense primary and partially decelerated beam and hence make tuning of the IH-structure impossible. The energy of the decelerated fraction of the beam behind the first deceleration cavity was determined to about 10 % accuracy with a permanent dipole magnet combined with a MCP. Better detector calibration should help reaching the required 1%. Design of the detectors as well as the results of the measurements will be presented.

TUPD11

Developments for IFMIF/EVEDA LIPAc Beam Position Monitors: The Sensors at the MEBT and the Wire Test Bench

controls, linac, quadrupole, simulation

320

I. Podadera, J.M. Carmona, A. Guirao, A. Ibarra, L.M. Martinez Fresno, E. Mirones, R. Unamuno, J.G.S. de la Gama
CIEMAT, Madrid, Spain

Funding: This work has been partially supported by the Spanish Ministry of Science and Innovation under Project ENE2009-11230
The IFMIF-EVEDA 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. In the Medium Energy Beam Transport line (MEBT) connecting the RFQ and the MEBT, non-interceptive Beam Position Monitors pickups (MBPMs) will measure the transverse position and phase in order to maximize the transport efficiency of the beamline. The response of the MBPMs must be optimized for a beam current for 5 MeV, and a peak beam current of 125 mA. Due to the lack of space in the MEBT, the MBPMs will be located inside the magnets. The MBPMs will have to fit inside the magnets without perturbing the magnetic field. In this contribution, the electromagnetic and mechanical design of the MBPM will be presented. In addition, in order to validate and characterize all the BPMs type of IFMIF/EVEDA once they are manufactured, a wire test bench has been constructed and verified at CIEMAT. The design and validation results of the test bench will be discussed.

TUPD12

The LHC Beam Position System: Performance during 2010 and Outlook for 2011

feedback, closed-orbit, injection, vacuum

323

E. Calvo Giraldo, J.L. Gonzalez, L.K. Jensen, O.R. Jones, T. Lefèvre, J.-J. Savioz, R.J. Steinhagen, J. Wenninger
CERN, Geneva, Switzerland

This paper presents the performance of the LHC Beam Position System during 2010. The system proved to meet most specifications, was highly reliable and continuously provided 25Hz real-time orbit data with micron level resolution to the automatic global orbit feedback system. However, several issues were observed and they will be discussed in detail, such as the dependence on bunch intensity and the effect of surface electronics temperature variations on the measured position.

TUPD16

High Frequency Measurements of the Beam Position Monitors for the TBL Line of the CTF3 at CERN

impedance, bunching, monitoring, simulation

335

J.J. García-Garrigós, C. Blanch Gutierrez, J.V. Civera-Navarrete, A. Faus-Golfe
IFIC, Valencia, Spain
B. Gimeno
UVEG, Burjasot (Valencia), Spain

Funding: Funding Agency: FPA2010-21456-C02-00
A series of Inductive Pick-Ups (IPU) for Beam Position Monitoring (BPM) with its associated electronics were designed, constructed and tested at IFIC. A full set of 16 BPMs, so called BPS units, were successfully installed in the Test Beam Line (TBL) of the 3rd CLIC Test Facility (CTF3) at CERN. Two different characterization tests, at low and high frequencies, were carried out on the BPS units: The low frequency test, in the beam pulse time scale (until 10ns/100MHz), determined the BPSs parameters directly related to the beam position monitoring and the high frequency test, reaching the microwave X-Ku bands around the beam bunching time scale (83ps/12GHz). In this paper we describe the results and methods used to obtain the longitudinal impedance in the frequency range of interest. This test is based on the S-parameters measurements of the propagating TEM mode in a matched coaxial waveguide, specifically designed for the BPS, which is able to emulate an ultra-relativistic electron beam.

Poster TUPD16 [1.069 MB]

TUPD28

Benchmarking the Performance of the Present Bunch Arrival Time Monitors at FLASH

FEL, feedback, laser, electron

365

M.K. Bock, M. Bousonville, M. Felber, P. Gessler, T. Lamb, S. Ruzin, H. Schlarb, B. Schmidt, S. Schulz
DESY, Hamburg, Germany

Funding: This work is partly supported by IRUVX-PP, an EU co-funded project under FP7 (Grant Agreement 211285)
Presently, at FLASH four bunch arrival time monitors (BAM) are installed and in permanent operation. Moreover, they are incorporated in a longitudinal intra-bunch train feedback. In this paper, we present a review of the performance and the limitations of the current BAM design, based on the most recent machine studies. The detection principle of the monitor implements the electro-optical modulation of synchronised laser pulses. The RF and electro-optical front-ends are designed to be operated in a frequency band from DC up to 10 GHz. This allows for measuring the arrival time of each individual electron bunch at femtosecond resolution. The current design of the BAMs has been tested under the influence of disturbances on the arrival time measurement, such as variation of the bunch charge as well as deviation from the reference transverse bunch position. Those results will be incorporated in an upcoming design revision to upgrade the application and robustness of the BAMs.

TUPD53

A Low-Power Laser Wire with Fiber Optic Distribution

laser, diagnostics, electron, scattering

425

R.B. Wilcox, J.M. Byrd, M.S. Zolotorev
LBNL, Berkeley, California, USA
V.E. Scarpine
Fermilab, Batavia, USA

Funding: This work was supported by the US Department of Energy under contract DE-AC02-05CH11231.
Laser-based position diagnostics for hydrogen ion (H⁻) beams typically use high power optical pulses that must be transported via free space to the diagnostic point. It is difficult to maintain stable alignment through such systems, especially when multiple channels are required. We describe a method for distributing low power, amplitude modulated pulse trains via fiber optic, and detecting interaction with the H⁻ beam by synchronous detection of the stripped electrons. Trains of 10 ps, 10⁶⁴ nm pulses at 400 MHz repetition rate are modulated by a 1 MHz signal that is the reference for a lockin amplifier. The average beam power is below one Watt. Synchronous detection at RF frequencies allows for efficient noise rejection when using optical powers below the nonlinear (Raman scattering) threshold of an optical fiber. The laser is synchronized with the bunch repetition rate, so the diagnostic can be used for bunch length measurements as well. We present results of tests of the optical system with 10⁰ m, single-mode fiber and realistic detected signal levels, demonstrating detection of the modulation signal with high signal-to-noise ratio and low nonlinearity.

TUPD66

Sensor Optimizations for a Cryogenic Current Comparator

cryogenics, ion, antiproton, storage-ring

458

R. Geithner, W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
P. Kowina, F. Kurian, M. Schwickert
GSI, Darmstadt, Germany
R. von Hahn
MPI-K, Heidelberg, Germany

We present a non-destructive superconducting monitoring system for charged particles beams. The system uses the Cryogenic Current Comparator (CCC) principle with a low temperature DC-SQUID. The Cryogenic Current Comparator has shown its capability in the Horizontal Bi-Cavity Test Facility at the Helmholtz-Zentrum Berlin under noisy conditions. In this test facility for superconducting cavities the CCC setup was able to detect dark currents in the nA range. The suitability of the Cryogenic Current Comparator as a beam monitor for the Facility of Antiproton and Ion Research at GSI Darmstadt as well as for the Cryogenic Storage Ring at MPI Heidelberg will be pointed out and discussed. Special attention will be given to the ferromagnetic core materials embedded in the pickup coil.

TUPD92

SPIRAL2 Beam Energy Measurement

simulation, linac, rfq, instrumentation

524

W. Le Coz, T.A. André, C. Doutresssoulles, C. Jamet, S. Loret
GANIL, Caen, France

In order to produce high intensity exotic beams in the existing experimental rooms of the GANIL facility, the SPIRAL2 project is under development and under construction at GANIL. The first phase of the SPIRAL2 project consists to build a new accelerator composed of two sources, an ion source and a proton/neutron source, a RFQ and a superconducting Linac. The linac is designed to accelerate 5 mA deuterons up to 40 MeV and 1 mA heavy ions up to 14.5 MeV/u. A new electronic device has been developed at GANIL to measure phase and amplitude of pick-up signals and calculate the beam energy. The principle consists of directly digitizing the pick-up pulses by under-sampling. The Phase and amplitude of different harmonics are then calculated with a FPGA by an I/Q method before the beam energy calculation. This paper gives results of the peak-up tests in laboratory and the comparisons with simulations. The tests in laboratory and on the GANIL accelerator of an electronic prototype are shown and presented.

WEOC01

Beam Charge Measurements

vacuum, coupling, impedance, linac

564

D. Belohrad
CERN, Geneva, Switzerland

The measurement of beam charge is fundamental to all particle accelerators. There exist many methods to achieve this, which can broadly be classified into two categories: intercepting measurements, which are destructive for the beam and result in absorption of a significant amount of energy; non-intercepting measurements using electric or magnetic field coupling. In both categories one can find instruments that process the beam signals with high dynamic range, both in amplitude and time. The aim of this article is to present the current state of beam charge measurement technology. Various measurement methods will be described with their uses, advantages, and achievable resolution and accuracy discussed. The technological problems related to their fabrication will also be addressed.

Slides WEOC01 [5.738 MB]

WEOC02

News About the Cryogenic Current Comparator for Beam Diagnostics

ion, cryogenics, antiproton, simulation

569

W. Vodel
HIJ, Jena, Germany
R. Geithner, R. Neubert, P. Seidel
FSU Jena, Jena, Germany
K.K. Knaack, K. Wittenburg
DESY, Hamburg, Germany
A. Peters
HIT, Heidelberg, Germany
H. Reeg, M. Schwickert
GSI, Darmstadt, Germany

An absolute and exact measurement of the intensity of charged particle beams - extracted from an accelerator or circulating in a Storage Ring - is one of the major problems of beam diagnostics. Also the measurement of so-called dark currents, generated by superconductive RF accelerator cavities at high voltage gradients to characterize the quality of these components becomes more and more important for the commissioning of new accelerators (XFEL). The Cryogenic Current Comparator (CCC) based on high precision LTS SQUIDs is an excellent tool to solve these problems. This contribution gives an overview on the development of SQUID-based CCC for nuclear physics from the first successful demonstration of the performance at GSI Darmstadt through the recently tested CCC for the XFEL at DESY to the latest improved version for FAIR.

Slides WEOC02 [2.596 MB]