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In fast ramping synchrotrons, like the Fermilab Booster, the usual methods for evaluating the betatron tunes from the spectrum of turn-by-turn data may fail due to fast decoherence of particle motion or rapid tune changes, in addition to the BPM noise. We propose a technique based on phasing of the signals from different BPMs. Although the number of the Fermilab Booster BPMs is limited to 48 per plane, this method allows to detect the beam tunes in conditions where the other algorithms were unsuccessful. In this paper we describe the method and its implementation in the Fermilab Booster control system. Results of measurements are also presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Pepper-pot based transverse emittance measurement has the advantage of providing a fast (single shot) measurement with a relatively simple hardware. We report on Pepper-pot based transverse emittance measurements made at the CERN Linac 4 test stand., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

CERN’s Large Hadron Collider (LHC) is equipped with three distinct types of intensity measurement systems: total intensity measurement using DC transformers (DCCTs) with a bandwidth up to a few kHz; total intensity measurements on a turn-by-turn basis for lifetime measurements using AC-coupled fast transformers (fast BCTs); bunch-by-bunch intensity measurements with a bandwidth up to a few hundred MHz also using the fast BCTs. In addition to providing intensity information these devices are part of the machine protection system, indicating whether or not there is beam circulating, transmitting intensity for evaluation of safe beam conditions and capable of triggering a beam dump if fast losses are detected. This paper reports on the commissioning of all these systems and their initial performance., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

LINAC4 is the first step in the upgrade of the injector chain for the LHC and will accelerate H⁻ ions to 160 MeV. The ion source has initially been installed in a laboratory setup where its commissioning started at the end of 2009. A slit-grid system is used to monitor the transverse emittance at the exit of the source. Measurement results have been compared to analytical and numerical predictions of the system performance, addressing the system resolution, accuracy and sensitivity. This information has been used to improve the design of a new slit-grid system required for commissioning the linac at higher energies., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Gas Electron Multipliers (GEM) find their way to more and more applications in beam instrumentation. Gas Electron Multiplication uses a very similar physical phenomenon to that of Multi Wire Proportional Chambers (MWPC) but for small profile monitors they are much more cost efficient both to produce and to maintain. This paper presents the new GEM profile monitors intended to replace the MWPCs currently used at CERN’s low energy Antiproton Decelerator (AD). It will be shown how GEMs overcome the documented problems of profile measurements with MWPCs for low energy beams, where the interaction of the beam with the detector has a large influence on the measured profile. Results will be presented from profile measurements performed at 5 MeV using four different GEM prototypes, with discussion on the possible use of GEMs at even lower energies needed at the AD in 2012., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Beam injections to KEKB and Photon Factory are performed with pulse-to-pulse modulation at 50Hz. Three very different beams are switched every 20ms in order to inject those beams into KEKB HER, LER and Photon Factory (PF) simultaneously. Human operators work on one of those three virtual accelerators, which correspond to three-fold accelerator parameters. Beam charges for PF injection and the primary electron for positron generation are 50-times different, and beam energies for PF and HER injection are 3-times different. Thus, the beam stabilities are sensitive to operational parameters, and if any instability in accelerator equipment occurred, beam parameter adjustments for those virtual accelerators have to be performed. In order to cure such a situation, beam energy and orbit feedback systems are installed that can respond to each of virtual accelerators independently., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

We present the design of a stripline beam position monitor (BPM) signal processor with low latency (c. 10ns) and micron-level spatial resolution in single-pass mode. Such a BPM processor has applications in single-pass beamlines such as those at linear colliders and FELs. The processor was deployed and tested at the Accelerator Test Facility (ATF2) extraction line at KEK, Japan. We report the beam test results and processor performance, including response, linearity, spatial resolution and latency., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

To keep and achieve desired performance of a modern synchrotron light source, it requires continuous efforts including good design of the accelerator, good performed subsystems and sophisticated feedback system. While some wonders happen unexpectedly and could deteriorate performance of the light source. For examples, some strong source occasionally occurred especially after long shut down or malfunction of some corrector power supply and it would result in increased noise level. Non ideal injection element will cause large perturbation as well. This report presents algorithms to spatially locate source and summarize some of our practical experience to identify the source., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The design luminosity of the future linear colliders requires transverse beam size at the nanometre level at the interaction point (IP), as well as stabilisation of the beams at the sub-nanometre level. Different imperfections, for example ground motion, can generate relative vertical offsets of the two colliding beams at the IP which significantly degrade the luminosity. In principle, a beam-based intra-train feedback system in the interaction region can correct the relative beam-beam offset and steer the beams back into collision. In addition, this feedback system might considerably help to relax the required tight stability tolerances of the final doublet magnets. For CLIC, with bunch separations of 0.5 ns and train length of 156 ns intra-train feedback corrections are specially challenging. In this paper we describe the design and simulation of an intra-train feedback system for CLIC. Results of luminosity performance simulation are presented and discussed., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A noninvasive technique to determine a sub-mm length of electron bunches (rms 100 um) based on a measurement of the coherent Cherenkov radiation (CChR) spectrum in THz range is proposed. CChR is generated when electron bunch moves in a vacuum near dielectric target. If the optical properties and geometry of a target are chosen in order to achieve a low absorption with a dispersion allowing expanding the Cherenkov cone, such target may be considered as the «natural Cherenkov prism». We demonstrated a feasibility of using of CsI prism for measurement of a bunch length in the range 50-200 um for Lorentz factor = 100. We also measured CChR power from Teflon target generated by the 6.1 MeV bunched electron beam with bunch rms length 1.2 mm and compared it with coherent diffraction radiation one for identical conditions. CChR seems to be a promising radiation mechanism for a new beam diagnostics technique., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

We have studied a beam orbit tilt monitor for stabilizing the beam orbit in ATF2. Once we can measure a beam orbit tilt with high precision at one point, we can relate this data with the beam position profile at the focal point. A tilt monitor is composed of a single rectangular sensor cavity and a waveguide to extract the signal. In the sensor cavity, there is the most basic resonant mode called monopole mode. This monopole mode is perpendicular to the nominal beam axis, and excited by the beam tilt. We extract this monopole mode. As the result, the amplitude of the extracted signal is proportional to the tilt angle. The tilt monitor is almost indepnedent with beam postion, so we can get the tilt date independently. According to our simulation, the sensitivity is estimated about 35nrad in the vertical direction. The prototype was completed and installed in the test area on the ATF2 beamline. The first beam test will be performed in December 2009. We will report this result and future update plan., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Installation of electron lenses for the purpose of head-on beam-beam compensation is foreseen at RHIC. To optimize the relative alignment of the electron lens beam with the circulating proton (or ion) beam, photon detectors will be installed to measure the bremsstrahlung generated by momentum transfer from protons to electrons. We present the detector layout and simulations of the bremsstrahlung signal as function of beam offset and crossing angle., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

An x-ray beam size monitor based on coded aperture imaging* has been developed at CesrTA, for the purpose of making bunch-by-bunch, turn-by-turn measurements of low emittance beams. Using low-emittance beam (~44 pm, or 16 microns at the x-ray source point) we have been able to make detailed comparisons between the measured mask response and that predicted by theory, validating our simulations of the mask response. In turn, we demonstrate the ability to measure both integrated and single-bunch turn-by-turn beam sizes and positions for monitoring the progress of the low-emittance tuning of the machine, and for electron-cloud instability-related beam dynamics studies., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

With a 7T wiggler in operation any attempts to detect the resonant depolarization of the electron spins were unsuccessful at BESSY II. This was attributed to the severely reduced final degree of spin polarization in the alternating fields of the strong wiggler which on the other hand nearly double the radiation loss per turn. The key to a clear detection of the depolarization were the improvement of the sensitivity of the polarimeter based on the spin dependent Touschek scattering cross section and the more effective and thus full depolarization of the beam. In the paper the steps taken will be presented in detail. With these improvements in place the high precision energy determination of the stored beam can be performed once again in parallel to the normal user operation and without any noticeable perturbations to the beam., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The main facility of the Brazilian Synchrotron Light Laboratory is a 93 meters circumference, 1.37 GeV storage ring. Recently, the first superconducting insertion device was installed in the machine. This 4 T ID produces powerful beams that can damage the non-cooled parts of the accelerator vessel in the case of a miss-steered beam, even with a relatively large vacuum chamber cross section. In this paper we present the design details and the first operational results of the electronic beam position interlock system. Topics about redundancy engineering will be discussed as well., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The shielding design for the NSLS-II will provide adequate protection for the full injected beam loss in two periods of the ring around the injection point, but the remainder of the ring is shielded for lower losses of 10% full beam loss. This will require a system to insure that beam losses don¿t exceed these levels for a period of time that could cause levels outside the shield walls. This beam containment system will measure, provide a level of control and alarm indication of the beam power losses along the beam path from the source (e-gun, linac) thru the injection system and the storage ring. This system will consist of collimators that will provide limits to (an potentially measure) the beam miss-steering and control the loss points of the charge and monitors that will measure the average beam current losses along the beam path and alarm when this beam power loss exceeds the level set by the shielding specifications. This will require some new ideas in beam loss detection capability and collimation. The initial planning and R program will be presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The 40 MeV L-band electron linac at the Institute of Scientific and Industrial Research, Osaka University is extensively used for various applications on advanced beam sciences including radiation chemistry by means of pulse radiolysis and development of the free electron laser in the THz region. It was constructed in 1975-78 and has been remodeled sometimes for improving its performance. The most recent one was made in 2002-2004 for higher operational stability and reproducibility, resulting in significant advances in the studies. We will report the present status of the linac and results of its performance evaluation., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Modbus-TCP is a widely used in industry for a long time and accelerator control system recently. Modbus protocol over Ethernet has advantages for non real-time applications due to its maturity. The TPS (Taiwan Photon Source) project will have many Modbus-TCP enable devices which distributed in utility system and accelerator system. The accelerator control environment of TPS project is an EPICS toolkit based system. Modbus-TCP might adopt for some subsystems. There are several possible Modbus-TCP devices including the prototype power supply for magnet field mapping application equip with Modbus-TCP interface, vacuum system local controller, front-end controller, and some monitoring devices. In this paper, we will summarise preparation efforts to accommodate the Modbus-TCP support in the TPS control system., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Electricity generation from scattered secondary particles has been examined for a kind of energy-recovery by using a beam loss monitor at the SPring-8 storage ring, in which PIN photodiodes are utilized without a reversed bias voltage in similar to a solar cell. The system and results will be reported., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

For successful operation and beam characterization, fourth generation light sources require the observation of sub-picosecond bunches with femtosecond resolution. In this paper, we report on the design and development of a novel technique to achieve sub-femtosecond temporal resolution of high brightness bunches. The technique involves the coupling of the electron beam to a high power laser in an undulator field, which is optimized to maximize the angular deviation of the bunch. The beam angular components are imaged on a distant screen yielding a sweep across angles in one dimension. The addition of an x-band deflecting cavity downstream of the undulator creates another sweep of the beam, in the perpendicular dimension. The temporal resolution of the bunch is dependent on the seed laser wavelength and the spatial resolution of the screen. Initial calculations show that for a CO₂ laser (T~30fs) and a phosphor screen (~50micron spatial resolution), the longitudinal resolution is approximately l/200 of the laser wavelength, or ~150 attoseconds., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The hyperfine transition frequency of hydrogen is known to a very high precision and therefore the measurement of this transition frequency in antihydrogen is offering one of the most accurate tests of CPT symmetry. The ASACUSA collaboration will run an experiment designed to produce ground state antihydrogen atoms in a CUSP trap. These antihydrogen atoms will pass with a low rate in the order of 1 per second through a spin-flip cavity where they get excited depending on their polarization by a 1.42 GHz magnetic field. Due to the small amount of antihydrogen atoms that will be available the requirement of good field homogeneity is imposed in order to obtain an interaction with as many antihydrogen atoms as possible. This leads to a requirement of an RF field deviation of less than ± 10 % transverse to the beam direction over a beam aperture with 100 mm diameter. All design aspects of this new spin-flip cavity, including the required field homogeneity and vacuum aspects, are discussed., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

At Pohang Accelerator Laboratory, a femto-second THz facility was constructed for the experiments using femto-second THz radiation. The fs-THz radiation is generated from 60-MeV electron linac which consists of a photocathode RF gun, two accelerating columns, and two magnetic-chicane bunch compressors. The coherent transition radiation (CTR) is used for THz radiation generation. To generate high intensity THz radiation, the electron bunch length should be smaller than 200 fs. We report THz image obtained using IR-CCD camera and measured beam parameters including bunch length, energy spread, charge, emittance, and transverse beam size., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Electron bunch profile and length measurement from large bandwidth synchrotron radiation with a streak camera can be strongly limited by the chirp introduced by the length of material present in the input refractive optics of streak cameras. Elimination of the chirp can be done either by filtering the bandwidth of the synchrotron radiation pulses, by measuring time resolved spectra with the streak camera, or by replacing the front optics lenses by focussing mirrors. The first solution reduces the power available, thus limiting measurements to minimum bunch current that can be too high to assess the ’zero’ current bunch length. The second elegant solution allows measurement of the bunch length with the whole bandwidth and available power but with loss of the second sweep axis in the camera, so that no beam dynamics can be observed. In order to prevent any pulse chirp, keep all the available power and capability of beam dynamics observation, we designed a new input optics exclusively with mirrors. We present here our design and the results of the system with our streak camera, measuring 2ps bunch in the new Diamond low-alpha lattice., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

ATF2 is the final focus test facility for ILC to realize and demonstrate nanometer focusing. One of the goals of the ATF2 is a demonstration of a compact final focus system based on the local chromaticity correction. A designed beam size at the focal point is to be 37 nm in vertical. To achieve the goal, a beam size monitor capable of nanometer beam size measurement is inevitably needed. Shintake monitor satisfies the demands, and is installed at the virtual interaction point of the ATF2. Shintake monitor is a beam size monitor which uses laser interference fringe pattern to measure beam size. The beam test for the Shintake monitor was successful in measurement of signal modulation with the laser interference fringe pattern in November 2009. In April 2010, beam size of less than 1 micron was achieved. We have studied the error sources, and evaluated the total error to be less than 10% for 1 minute measurement. This paper is about the evaluation of the Shintake monitor performance by analyzing beam tests data. Most systematic error sources are well understood, so that we can estimate accuracy of beam size measurement when the beam size reaches 37nm., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

We present preliminary results of beam diagnostics for the world’s first Non-Scaling FFAG Accelerator ’EMMA’. Amongst other means, a single-shot/turn-by-turn BPM system is used, that was first tested on the ALICE injector. The BPM system utilizes a front-end conversion of button pickup signals into flat-top-envelope 700 MHz bursts, time-domain multiplexing (in each plane, signals are made spaced by 13.8 ns), and the manufacture of both synchronous detector and ADC clocks directly from the beam signal. The system performance is discussed; results of beam-based resolution measurement are given. First turn beam trajectories furthest from the Septum and Kicker are presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

In the J-PARC Main Ring (MR), the bending, quadrupole, sextupole, and steering magnets can be controlled on the operating interfaces (OPI). The optics parameters for all magnets are calculated by using SAD, and are converted to BL tables (ex: 2000 points for a steering magnet) for each power supplies. The BL tables are made from the parameters of optics, pattern timing, and beam energy at flat bottom and flat top. For MR beam studies, the BL tables are adjustable with offset and factor. This system is useful for COD correction, beta function measurement, aperture survey, and slow extraction. In this proceeding, the structure of the magnet control system and OPIs for beam studies will be shown., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The ISAC accelerators presently deliver various stable and radioactive CW heavy ion beams to experiments with energies ranging from 2keV/u up to about 4.5 MeV/u ( for A/q = 6 ). Beam intensities also vary enormously being as low as a few hundred ions per second for certain radioactive ion species and as high as 100 enA for stable and pilot beams. Monitoring of beams with currents of less than ~0.5 epA requires a dedicated diagnostics instrumentation which typically makes use of radiation hard single particle detectors. Several such devices have been built and are under development at TRIUMF. Electron multiplier based SEEM monitors, solid state and scintillator detectors with a count rate capability in excess of 10⁶ pps are employed. Device controls are integrated into the EPICS environment and provide standardized, simple and transparent operation. Details of the design, tests and beam measurements will be present., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

For high intensity beam operation (3mA, 1.8MW) in the PSI cyclotron, a new current monitor for proton beams has been installed during the 2009 maintenance period. This current monitor is an actively cooled re-entrant cavity with its resonance tuned at the 2nd RF harmonic ({101} MHz). Operating this system presents several challenges due to the heavy shower of energetic particles, the resonator being placed 8 m behind a graphite target. The resonator is actively cooled with water, its external surface was blackened to improve the radiation cooling and its mechanical structure was optimized for good heat conduction. The resonance characteristics are extremely sensitive to structural changes of the resonator. Because of non-uniform temperature distribution and dynamical changes the observed gain drift during operation is of the order of 10%. To correct these drifts 2 tests signals 50 kHz off the RF frequency are measured on-line during beam operation. They provide an innovative mean to estimate and to correct on-line the resonator gain. This paper will present the measurement method and the achieved performances., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

DELTA is a 1.5-GeV synchrotron radiation source at the TU Dortmund University with 2 ns bunch spacing. At nominal operating currents, the beam exhibits significant longitudinal centroid motion due to coupled-bunch instabilities. Two techniques were successfully used at DELTA to damp such instabilities: RF phase modulation, which also improves the beam lifetime, and bunch-by-bunch feedback. Using diagnostic data from the bunch-by-bunch feedback system, modal spectra and growth rates of the longitudinal instabilities were characterized. We also present a preliminary characterization of transverse coupled-bunch oscillations observed at the highest beam currents., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The international Muon Ionization Cooling Experiment (MICE) will carry out a systematic investigations of ionization cooling of a muon beam. As the emittance measurement will be done on a particle-by-particle basis, a sophisticated beam instrumentation is needed to measure particle coordinates and timing vs RF. A PID system based on three time-of-flight detectors, two Aerogel Cerenkov counters and a KLOE-like calorimeter has been constructed in order to keep beam contamination (e, π) well below 1 %. The MICE TOF system will measure timing with a resolution better than 60 ps per plane, in a harsh environment due to high particle rates, fringe magnetic fields and RF backgrounds. Performances in beam of all detectors will be shown, as also future upgrades., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A complex Machine Protection System has been designed to protect the LHC machine from an accidental release of the beam energy, with about 20 subsystems providing status information to the Beam Interlock System (BIS). Only if the subsystems are in the correct state for beam operation, the BIS receives a status flag and beam can be injected into LHC. The BIS also relays commands from the connected subsystems in case of failure for emergency extraction of beam to the LHC Beam Dump Block. To maintain the required level of safety of the BIS, the performance of the key components is verified before every fill of the machine and validated after every emergency beam dump before beam operation is allowed to continue. This includes all critical paths, starting from the inputs from connected system triggering a beam dump request, followed by the correct interruption and propagation sequence of the two redundant beam permit loops until the final extraction of the beam via the LHC beam dumping system. In this paper we report about the experience with the BIS that has been deployed for some years in the SPS (as LHC injector), in the transfer lines between SPS and LHC and recently in LHC., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

It is important to match the injection beam emittance to the acceptance of an accelerator for high beam transmission A system to evaluate transverse beam matching has been developed in the JAEA AVF cyclotron facility. In this presentation, concepts of an apparatus for transverse acceptance measurement will be reported. The apparatus consists of a phase-space collimator in the injection beam line and beam current monitor after the cyclotron. The collimator consists of two pairs of position defining slits and angle defining slits to inject an arbitrarily small portion of transverse phase-space into the cyclotron. Measurement of the acceptance is made by testing every portion in the whole phase-space, which should large enough to cover the acceptance. The acceptance can be estimated from the sum of the portions of the beam which passes through the system., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A part of the beam losses at transition crossing of high intensity beams in the CERN PS have been attributed to an excursion of the closed orbit. The orbit jump occurs simultaneously with the jump of the transition energy triggered by pulsed quadrupoles. Investigations showed that the position of the pickups used for the radial loop system was not optimized with respect to the dispersion change caused by the fast change of the transition energy. Thanks to new electronics of the orbit measurement system, turn-by-turn orbit data could be recorded around transition crossing. Their analysis, together with calculations of the transverse optics, allowed determining a new choice of pickup positions for the radial loop. In comparison to the previous pickup configuration, the new configuration improves the mean radial position not only during transition crossing, but all along the acceleration cycle., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Although the pepper-pot method has been used for decades at low energy to measure the transverse emittance of particles sources, it has only been extended to high energy very recently. We report on some of the recent measurements done at high energy (several hundred MeVs) and discuss the practical consideration of such measurements. We show demonstrate that an extended pepper-pot does not significantly affect the phase space of the beam and thus provides a valid transverse emittance measurement., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The beam position monitor (BPM) system at the Cornell Electron Storage Ring (CESR) has been upgraded for use in both CESR Test Accelerator (CesrTA) and Cornell High Energy Synchrotron Source (CHESS) operations. CesrTA operates with electron and positron bunch trains with as little as 4ns bunch spacing. CHESS operates with simultaneous counter-rotating electron and positron trains with 14ns bunch spacing. The upgraded BPM system provides high resolution measurement capability as is needed for the CesrTA ultra low emittance operations, turn-by-turn digitization of multiple bunches for beam dynamics studies, and the capability for real-time dual beam monitoring in CHESS conditions. In addition to standard position measurement capability, the system is also required to measure betatron phase by synchronous detection of a driven beam for optics diagnosis and correction. This paper describes the characteristics of the BPM hardware upgrade, performance figures of the electronics designed for this purpose and the overall status of the upgrade effort. Examples of key measurement types and the analysis of data acquired from the new instruments will also be presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The Muon Ionization Cooling Experiment (MICE) is an accelerator and particle physics experiment aimed at demonstrating the technique of ionization cooling on a beam of muons. The transverse phase space will be measured by two identical trackers comprised of 5 measurement stations of scintillating fibre inside a 4T solenoid. Both trackers have been assembled and tested using cosmic rays and will be installed in the MICE hall at the Rutherford Appleton Laboratory in 2010. The design, construction and results from cosmic ray testing of both trackers are presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Central Japan Synchrotron Radiation Research Facility which provides synchrotron radiation for a large community of users is under construction in the Aichi prefecture, Japan. The light source accelerator complex consists of a linac, a booster synchrotron and a storage ring. We have developed beam monitor systems which play important role especially in the commissioning stage of the accelerators. An RF knockout system to observe betatron tune of the electron beam in the booster synchrotron and the storage ring has been designed. We paid special attention in an RF source fed to a shaker to realize efficient measurement of the tune of electron beam during acceleration. We made a test experiment using electron beam of a booster synchrotron of the UVSOR facility. We have also developed a BPM system which enables a single path beam monitoring. The signal processing is based on a fast digital oscilloscope and a simple preprocessor circuit which was developed to improve position resolution. The performance was evaluated using an injection beam pulse to the storage ring of the UVSOR., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The Advanced Photon Source (APS) is a third-generation synchrotron light source in the United States. The BPM electronics plays an important part in the beam stability control. This paper presents comparative measurements of two BPM electronics: Libera Brilliance and APS FPGA-based BSP100. Some important parameters such as beam current dependence, electronics resolution and fill pattern dependence have been measured. These measurements were carried out in the lab and in the real system. The results will be useful for deciding which BPM electronics to deploy in the APS upgrade project., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

In view of increased processing bandwidth at demanding experiments and the need for rapid compensation of noise spikes and new, yet unknown excitations a fast orbit feedback aiming at noise suppression in the 1Hz-50Hz range has become mandatory for the 3rd generation light source BESSY II. As a first step the fast setpoint transmission plus the replacement of all corrector power supplies is foreseen. Later - in combination with top-up operation - orbit stability can be further improved by replacing today’s multiplexed analog beam position monitors by parallel processing fast digital units. This paper describes how the pilot installation of a small subset of fast corrector power supplies already allows to tune performance and study the benefits for today’s most sensible experiments., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A laser wire system* has been developed in the Spallation Neutron Source (SNS) superconducting linac (SCL). The SNS laser wire system is the world largest of its kind with a capability of measuring profiles of an operational hydrogen ion (H⁻) beam at each of the 23 cryomodule stations along the SCL by using a single light source. Presently 9 laser wire stations have been commissioned that measure profiles of the H⁻ beam at energy levels from 200 MeV to 1 GeV. The laser wire diagnostics has no moving parts inside the beam pipe and can be run parasitically on a neutron production H⁻ beam. This talk reports our recent study of the laser wire profile measurement performance. Parasitic profile measurements have been conducted at multiple locations of SCL on an operational one-megawatt neutron production beam that SNS recently achieved as a new world record. We will describe experimental investigations of the laser wire system performance including the stability and repeatability of the measurement and the influence of the laser parameters. We will also discuss novel beam diagnostics capabilities at the SNS SCL by using the laser wire system., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

To cope with the large variety of different beams for the LHC, the RF beam control in the CERN PS has evolved continuously to improve its flexibility and reliability. Single-bunch beams, several different multi-bunch beams with 25, 50 or 75 ns bunch spacing at ejection for LHC filling, as well as two lead-ion beam variants are now regularly produced in pulse-to-pulse operation. The multi-bunch beam control for protons can be easily re-adjusted from 0.25·10¹¹ to 1.3·10¹¹ particles per ejected bunch. Depending on the number of bunches injected from the PS Booster, the length of the ejected bunch train may vary from 8 to 72 bunches. This paper summarizes recent improvements in the low-level RF systems and gives an outlook on the future consolidation., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The PEFP (Proton Engineering Frontier Project) is constructing a 100-MeV proton accelerator, consisting of a 50-keV proton injector, LEBT (Low Energy Beam Transport), a 3-MeV RFQ (Radio Frequency Quadrupole), a 20-MeV DTL (Drift Tube Linac), 100-MeV DTL, and beam lines. In order to monitor signals measured from RF components and beam current monitors equipped to the 20-MeV proton accelerator, the commercial digital sampling oscilloscopes (DSO) are used. The signals, which are measured from the DSOs, must be calibrated and transmitted promptly to accelerator operators. So LabView as Window PC-based software, which equipped with various VISA (Virtual Instruments Software Architecture) interface as a standard I/O language for instrumentation programming, was chosen to do this data acquisition. The LabView was built with EPICS middleware by using the Window-based shared memory approach. In this paper, the preliminary design and implementation on integrating EPICS and LabView for the RF and beam current monitor are described., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A thermionic RF gun has been developed to generate very short electron bunch for a THz light source at Tohoku University. Bunch compression scheme requires, in general, linear momentum distribution of the particles with respect to the longitudinal position, so that measurement of longitudinal phase space is significant for better bunch compression. However, such measurement for the low energy electrons is difficult because space charge effect is so strong that longer drift space should not be included. Consequently, we have performed deliberation for employing energy dependent angular distribution of Cherenkov radiation. Though the energy dependence of emission angle of Cherenkov radiation is rapidly getting small as increasing the beam energy, it is still 25 deg/MeV at an energy around 2.0 MeV when we use radiator having refractive index of 1.035. Thus the beam energy distribution can be measured if we observe Cherenkov ring with sufficient angular resolution. Since this method needs only thin radiator, the drift space length will be minimized. We will discuss limitation for resolutions of both the time and the energy as well., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The Compact Linear Collider (CLIC) is a proposed multi-TeV linear electron-positron collider being designed by a world-wide collaboration. It is based on a novel two-beam acceleration scheme in which two beams (drive and main beam) are placed in parallel to each other and energy is transferred from the drive beam to the main one. Beam losses on either of them can have catastrophic consequences for the machine because of high intensity (drive beam) or high energy and small emittance (main beam). In the framework of machine protection, a Beam Loss Monitoring system has to be put in place. This paper discusses the requirements for the beam loss system in terms of detector sensitivity, resolution, dynamic range and ability to distinguish losses originating from various sources. A particular attention is given to the two-beam module where the protection from beam losses is particularly challenging and important., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

At the electron stretcher accelerator ELSA of Bonn University, an external beam of either unpolarized or polarized electrons is supplied to hadron physics experiments. In order to correct dynamic effects caused by eddy currents induced during the fast energy ramp, the transversal tunes have to be measured in situ with high precision. These measurements are based on the excitation of coherent betatron oscillations generated by a pulsed kicker magnet. Horizontal oscillations were excited using one of the injection kicker magnets. Since its installation in 2009 a newly designed kicker magnet enables measurements in the vertical plane as well. Betatron oscillation frequencies were derived from a fast Fourier transform of the demodulated BPM signals, showing a well pronounced peak at the tune frequency. Using this technique, tune shifts were measured and corrected successfully on the fast energy ramp. Measurement and correction of coherent synchrotron oscillations are feasible as well, utilizing a quite similar technique. Coherent synchrotron oscillations are excited by a phase jump of the acceleration voltage using an electrical phase shifter in the reference RF signal path., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The signal processing electronics of the SPring-8 Storage Ring BPM were replaced during the summer shutdown of 2006, and put into operation. However, a large filling pattern dependence was observed. The cause was attributed to the nonlinear response of the diodes to large pulse signals. The diode were attached in front of the RF switches for protection from the electrostatic discharge damages on the switch IC. We took a countermeasure for the filling pattern dependence by reducing the pulse height with a band pass filter (BPF) in front of each channel. The BPF were attached and put into the operation from November 2008. The effect of the BPF was evaluated using the beam with changing the filling patterns and repeating the position measurements. The differences of the measured position data across the filling pattern change were found to be within 10μmeters, which was the same amount of the orbit drift during the filling pattern change., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

Optical Transition Radiation (OTR) appearing when a charged particle crosses a boundary between two media with different dielectric properties has widely been used as a tool for transverse profile measurements of charged particle beams in various facilities worldwide. The resolution of the conventional monitors is defined by so-called Point Spread Function (PSF) dimension - the source distribution generated by a single electron and projected by an optical system onto a screen. In our experiment we managed to create a system which can practically measure the PSF distribution. We demonstrated that is it is non-uniform. In this paper we represent the development of a novel sub-micrometer electron beam profile monitor based on the measurements of the PSF structure. The visibility of the structure is sensitive to micrometer electron beam dimensions. In this report we shall represent the recent experimental results. The future plans on the optimization of the monitor will also be presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

The PETRA-III Laser-wire, a Compton scattering beam size measurement system at DESY, uses an automated mirror to scan a Q-switched laser across the electron beam and is developed from the system previously operated at PETRA-II. This paper reports on recent upgrades of the optics, vacuum vessel and data acquisition. First beam profile measurements are also presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A fiber-based beam loss monitors (BLM) is under development for the undulator section of the SPring-8 X-FEL: the system is based on the detection of the Cerenkov light generated by the secondary charged particles hitting an optical fiber set along the vacuum chamber. Various parameters come into account in the final performance of the system, such as the impact angle and energy of the lost electrons, the fiber position (angular and radial) with respect to the point of impact, fiber characteristics (numerical aperture, index, diameter), etc. Thorough numerical studies have been carried out to investigate the performances of the system. Comparison with the experimental results obtained at the SPring-8 Compact SASE Source (SCSS), a 1/16th model of the future X-FEL are also given., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan

A beam profile monitor utilizing the technological advances in fiber optic manufacturing to obtain micron level resolution is under development at RadiaBeam Technologies. This fiber-optic profiling device would provide a lost cost, turn-key solution with nominal operational supervision and requires minimal beamline real estate. We are currently studying and attempting to mitigate the technical challenges faced by a fiber optic based diagnostic system with a focus on radiation damage to the fibers and its effect on signal integrity. Preliminary irradiation studies and conceptual operation of the system are presented., Proceedings of the 1st International Particle Accelerator Conference, IPAC2010, Kyoto, Japan