WorldWideScience

Sample records for beam loss calibration

  1. Beam Loss Calibration Studies for High Energy Proton Accelerators

    CERN Document Server

    Stockner, M

    2007-01-01

    CERN's Large Hadron Collider (LHC) is a proton collider with injection energy of 450 GeV and collision energy of 7 TeV. Superconducting magnets keep the particles circulating in two counter rotating beams, which cross each other at the Interaction Points (IP). Those complex magnets have been designed to contain both beams in one yoke within a cryostat. An unprecedented amount of energy will be stored in the circulating beams and in the magnet system. The LHC outperforms other existing accelerators in its maximum beam energy by a factor of 7 and in its beam intensity by a factor of 23. Even a loss of a small fraction of the beam particles may cause the transition from the superconducting to the normal conducting state of the coil or cause physical damage to machine components. The unique combination of these extreme beam parameters and the highly advanced superconducting technology has the consequence that the LHC needs a more efficient beam cleaning and beam loss measurement system than previous accelerators....

  2. Beam Imaging and Luminosity Calibration

    CERN Document Server

    Klute, Markus; Salfeld-Nebgen, Jakob

    2016-01-01

    We discuss a method to reconstruct two-dimensional proton bunch densities using vertex distributions accumulated during LHC beam-beam scans. The $x$-$y$ correlations in the beam shapes are studied and an alternative luminosity calibration technique is introduced. We demonstrate the method on simulated beam-beam scans and estimate the uncertainty on the luminosity calibration associated to the beam-shape reconstruction to be below 1\\%.

  3. Beam Loss in Linacs

    CERN Document Server

    Plum, M A

    2016-01-01

    Beam loss is a critical issue in high-intensity accelerators, and much effort is expended during both the design and operation phases to minimize the loss and to keep it to manageable levels. As new accelerators become ever more powerful, beam loss becomes even more critical. Linacs for H- ion beams, such as the one at the Oak Ridge Spallation Neutron Source, have many more loss mechanisms compared to H+ (proton) linacs, such as the one being designed for the European Spallation Neutron Source. Interesting H- beam loss mechanisms include residual gas stripping, H+ capture and acceleration, field stripping, black-body radiation and the recently discovered intra-beam stripping mechanism. Beam halo formation, and ion source or RF turn on/off transients, are examples of beam loss mechanisms that are common for both H+ and H- accelerators. Machine protection systems play an important role in limiting the beam loss.

  4. Overview of LHC Beam Loss Measurements

    CERN Document Server

    Dehning, B; Effinger, E; Emery, J; Fadakis, E; Holzer, E B; Jackson, S; Kruk, G; Kurfuerst, C; Marsili, A; Misiowiec, M; Nebot Del Busto, E; Nordt, A; Priebe, A; Roderick, C; Sapinski, M; Zamantzas, C; Grishin, V; Griesmayer, E

    2011-01-01

    The LHC beam loss monitoring system provides measurements with an update rate of 1 Hz and high time resolution data by event triggering. These informations are used for the initiation of beam aborts, fixed displays and the off line analysis. The analysis of fast and localized loss events resulted in the determination of its rate, duration, peak amplitudes, its scaling with intensity, number of bunches and beam energy. The calibration of the secondary shower beam loss signal in respect to the needed beam energy deposition to quench the magnet coil is addressed at 450GeV and 3.5T eV . The adjustment of collimators is checked my measuring the loss pattern and its variation in the collimation regions of the LHC. Loss pattern changes during a fill allow the observation of non typical fill parameters.

  5. Beam Dynamics and Beam Losses - Circular Machines

    CERN Document Server

    Kain, V

    2016-01-01

    A basic introduction to transverse and longitudinal beam dynamics as well as the most relevant beam loss mechanisms in circular machines will be presented in this lecture. This lecture is intended for physicists and engineers with little or no knowledge of this subject.

  6. LHC beam loss pattern recognition

    CERN Document Server

    Marsili, A; Puzo, P

    2011-01-01

    One of the systems protecting CERN’s Large Hadron Collider (LHC) is the Beam Loss Monitoring system (BLM). More than 3600 monitors are installed around the ring. The beam losses are permanently integrated over 12 different time intervals (from 40 microseconds to 84 seconds). When any loss exceeds the thresholds defined for the integration window, the beam is removed from the machine. Understanding the origin of a beam loss is crucial for machine operation, as it can help to avoid a repetition of the same scenario. The signals read from given monitors can be considered as entries of a vector. This article presents how a loss map of unknown cause can be decomposed using vector based analysis derived from well-known loss scenarios. The algorithms achieving this decomposition are described, as well as the accuracy of the results.

  7. Recent DIII-D neutral beam calibration results

    Energy Technology Data Exchange (ETDEWEB)

    Wight, J.; Hong, R.M.; Phillips, J.

    1991-10-01

    Injected DIII-D neutral beam power is estimated based on three principle quantities: the fraction of ion beam that is neutralized in the neutralizer gas cell, the beamline transmission efficiency, and the fraction of beam reionized in the drift duct. System changes in the past few years have included a new gradient grid voltage operating point, ion source arc regulation, routine deuterium operations and new neutralizer gas flow controllers. Additionally, beam diagnostics have been improved and better calibrated. To properly characterize the beams the principle quantities have been re-measured. Two diagnostics are primarily used to measure the quantities. The beamline waterflow calorimetry system measures the neutralization efficiency and the beamline transmission efficiency, and the target tile thermocouples measure the reionization loss. An additional diagnostic, the target tile pyrometer, confirmed the reionization loss measurement. Descriptions and results of these measurements will be presented. 4 refs., 5 figs., 2 tabs.

  8. Beam Calibration of Radio Telescopes with Drones

    Science.gov (United States)

    Chang, Chihway; Monstein, Christian; Refregier, Alexandre; Amara, Adam; Glauser, Adrian; Casura, Sarah

    2015-11-01

    We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern, and the data analysis scheme. This is the first application of this calibration method to a single dish radio telescope in the far-field. The high signal-to-noise data allows us to characterise the beam pattern with high accuracy out to at least the 4th side-lobe. The resulting 2D beam pattern is compared with that derived from a more traditional calibration approach using an astronomical calibration source. We discuss the advantages of this method compared to other beam calibration methods. Our results show that this drone-based technique is very promising for ongoing and future radio experiments, where the knowledge of the beam pattern is key to obtaining high-accuracy cosmological and astronomical measurements.

  9. Beam calibration of radio telescopes with drones

    CERN Document Server

    Chang, Chihway; Refregier, Alexandre; Amara, Adam; Glauser, Adrian; Casura, Sarah

    2015-01-01

    We present a multi-frequency far-field beam map for the 5m dish telescope at the Bleien Observatory measured using a commercially available drone. We describe the hexacopter drone used in this experiment, the design of the flight pattern, and the data analysis scheme. This is the first application of this calibration method to a single dish radio telescope in the far-field. The high signal-to-noise data allows us to characterise the beam pattern with high accuracy out to at least the 4th side-lobe. The resulting 2D beam pattern is compared with that derived from a more traditional calibration approach using an astronomical calibration source. We discuss the advantages of this method compared to other beam calibration methods. Our results show that this drone-based technique is very promising for ongoing and future radio experiments, where the knowledge of the beam pattern is key to obtaining high-accuracy cosmological and astronomical measurements.

  10. Detection of Equipment Faults Before Beam Loss

    CERN Document Server

    Galambos, J

    2016-01-01

    High-power hadron accelerators have strict limits on fractional beam loss. In principle, once a high-quality beam is set up in an acceptable state, beam loss should remain steady. However, in practice, there are many trips in operational machines, owing to excessive beam loss. This paper deals with monitoring equipment health to identify precursor signals that indicate an issue with equipment that will lead to unacceptable beam loss. To this end, a variety of equipment and beam signal measurements are described. In particular, several operational examples from the Spallation Neutron Source (SNS) of deteriorating equipment functionality leading to beam loss are reported.

  11. Application of diamond based beam loss monitors

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); CERN, Geneva (Switzerland); Baer, Tobias [CERN, Geneva (Switzerland); Hamburg Univ. (Germany); Castro Carballo, Elena Maria [DESY, Zeuthen (Germany); Lohmann, Wolfgang [Brandenburgische Technische Univ. Cottbus (Germany); DESY, Zeuthen (Germany); Schmidt, Ruediger [CERN, Geneva (Switzerland)

    2013-07-01

    The LHC has an operational stored energy of 130MJ per beam. Only a small percentage of beam losses in the LHC equipment can damage material or lead to magnet quenches. Therefore, it is important to monitor different types of beam losses, e.g. scattering on residual gas particles, UFOs, collisions and injection losses. A detailed understanding of beam loss mechanisms is necessary to reduce them and ensure save operation. Two different beam loss monitors are installed in the LHC tunnel: ionization chambers and diamond sensors. Ionization chambers trigger a beam dump if beam losses exceed a certain threshold. They have a time resolution of 40um (half LHC turn) which is not sufficient to resolve bunch-by-bunch beam losses. Diamond sensors have a nanosecond time resolution and can therefore detect bunch-by-bunch beam losses. This time resolution allows an analysis of various types of beam losses and an understanding of the mechanisms. For the first time beam loss intensities were measured bunch-by-bunch caused by different origins of losses. Beam loss measurements using diamond sensors will be presented. The results are compared to simulations and good qualitative agreement was found. The potential of diamond sensors for LHC and experiment applications are discussed.

  12. Calibration beams at the SSC (Superconducting Super Collider)

    Energy Technology Data Exchange (ETDEWEB)

    Autin, A.; Edwards, H. (Superconducting Super Collider Lab., Dallas, TX (USA)); Bensinger, J.R. (Superconducting Super Collider Lab., Dallas, TX (USA) Brandeis Univ., Waltham, MA (USA)); Baller, B.; Browning, F.; Coleman, R.; Cooper, J.; Cossairt, D.; Kula, L.; Malensek, A.; Stefanski, R.; Stutte, L. (Fermi National Accelerator Lab., Batavia, IL (USA))

    1989-04-30

    This paper discusses the following topics on the Superconducting Super Collider: beam specification at calibration halls; high energy booster options with tunnels to surface; switchyard; six beams with high and low power options; switchyard optics for both high and low energy transport; secondary beams; wide band beams; radiation shielding; tagging system; and test and calibration halls.

  13. Preservation of beam loss induced quenches, beam lifetime and beam loss measurements with the HERAp beam-loss-monitor system

    Science.gov (United States)

    Wittenburg, Kay

    1994-06-01

    The beam-loss-monitors (BLMs) in the HERA-proton-ring (HERAp) must fulfill the following requirements: They have to measure losses sensitive and fast enough to prevent the superconducting magnets from beam loss induced quenching; the dynamic range of the monitors must exceed several decades in order to measure losses during beam lifetimes of hundreds of hours as well as the much stronger losses that may quench superconducting magnets; they have to be insensitive to the synchrotron radiation of the adjacent electron-ring (HERAe); and their radiation hardness must allow a monitor-lifetime of a few years of HERA operation. These requirements are well satisfied by the HERAp-BLM-System.

  14. Dynamic Beam Based Calibration of Beam Position Monitors

    CERN Document Server

    Dehning, Bernd; Galbraith, Peter; Mugnai, G; Placidi, Massimo; Sonnemann, F; Tecker, F A; Wenninger, J

    1998-01-01

    The degree of spin polarization at LEP is strongly dependent on the knowledge of the vertical orbit. Quadrupole magnet alignment and beam position monitor (BPM) offsets are the main source of the orbi t uncertainty. The error of the orbit monitor readings can be largely reduced by calibrating the monitor relative to the adjacent quadrupole. At LEP, 16 BPM offsets can be determined in parallel durin g 40 minutes. The error of the measure offset is about 30mm. During the LEP run 1997, more than 500 measurements were made and used for the optimisation of polarization. The method of dynamic beam bas ed calibration will be explained and the results will be shown.

  15. Beam Loss Monitors at LHC

    CERN Document Server

    Dehning, B

    2016-01-01

    One of the main functions of the LHC beam loss measurement system is the protection of equipment against damage caused by impacting particles creating secondary showers and their energy dissipation in the matter. Reliability requirements are scaled according to the acceptable consequences and the frequency of particle impact events on equipment. Increasing reliability often leads to more complex systems. The downside of complexity is a reduction of availability; therefore, an optimum has to be found for these conflicting requirements. A detailed review of selected concepts and solutions for the LHC system will be given to show approaches used in various parts of the system from the sensors, signal processing, and software implementations to the requirements for operation and documentation.

  16. Beam Loss and Beam Shape at the LHC Collimators

    CERN Document Server

    Burkart, Florian

    In this master thesis the beam loss and the beam shape at the LHC collimators was measured, analysed, presented and discussed. Beginning with a short introduction of the LHC, the experiments, the supercon- ducting magnet system, the basics on linear beam dynamics and a describtion of the LHC collimation system are given. This is followed by the presentation of the performance of the LHC collimation sys- tem during 2011. A method to convert the Beam Loss Monitor signal in Gy/s to a proton beam loss rate will be introduced. Also the beam lifetime during the proton physics runs in 2011 will be presented and discussed. Finally, the shape of the LHC beams is analysed by using data obtained by scraping the beam at the LHC primary collimators.

  17. Beam Loss Monitors at the ESRF

    CERN Document Server

    Joly, B; Naylor, G A

    2000-01-01

    The European Synchrotron radiation facility is a third generation x-ray source providing x-rays on a continuous basis. As a facility available to external users, the monitoring of radiation caused by the loss of high-energy stored beam is of great concern. A network of beam loss monitors has been installed inside the storage ring tunnel so as to detect and localize the slow loss of electrons during a beam decay. This diagnostic tool allows optimization of beam parameters and physical aperture limits as well as giving useful information on the machine to allow the lifetime to be optimized and defects localized.

  18. Injection Beam Loss and Beam Quality Checks for the LHC

    CERN Document Server

    Kain, Verena; Bartmann, Wolfgang; Bracco, Chiara; Drosdal, Lene; Holzer, Eva; Khasbulatov, Denis; Magnin, Nicolas; Meddahi, Malika; Nordt, Annika; Sapinski, Mariusz; Vogt, Mathias

    2010-01-01

    The quality of the injection into the LHC is monitored by a dedicated software system which acquires and analyses the pulse waveforms from the injection kickers, and measures key beam parameters and compares them with the nominal ones. The beam losses at injection are monitored on many critical devices in the injection regions, together with the longitudinal filling pattern and maximum trajectory offset on the first 100 turns. The paper describes the injection quality check system and the results from LHC beam commissioning, in particular the beam losses measured during injection at the various aperture limits. The results are extrapolated to full intensity and the consequences are discussed

  19. Cryogenic Beam Loss Monitoring for the LHC

    CERN Document Server

    Kurfuerst, C; Sapinski, M

    A Beam Loss Monitoring (BLM) system was installed on the outside surface of the LHC magnet cryostats to protect the accelerator equipment from beam losses. The protection is achieved by extracting the beam from the ring in case thresholds imposed on measured radiation levels are exceeded. Close to the interaction regions of the LHC, the present BLM system is sensitive to particle showers generated in the interaction region of the two beams. In the future, with beams of higher energy and brightness resulting in higher luminosity, distinguishing between these interaction products and possible quench-provoking beam losses from the primary proton beams will be challenging. The particle showers measured by the present BLM configuration are partly shielded by the cryostat and the iron yoke of the magnets. The system can hence be optimised by locating beam loss monitors as close as possible to the protected element, i. e. the superconducting coils, inside the cold mass of the magnets in superfluid helium at 1.9 K. T...

  20. Beam losses in heavy ion drivers

    CERN Document Server

    Mustafin, E R; Hofmann, I; Spiller, P J

    2002-01-01

    While beam loss issues have hardly been considered in detail for heavy ion fusion scenarios, recent heavy ion machine developments in different labs (European Organization for Nuclear Research (CERN), Gesellschaft fur Schwerionenforschung (GSI), Institute for Theoretical and Experimental Physics (ITEP), Relativistic Heavy-Ion Collider (RHIC)) have shown the great importance of beam current limitations due to ion losses. Two aspects of beam losses in heavy ion accelerators are theoretically considered: (1) secondary neutron production due to lost ions, and (2) vacuum pressure instability due to charge exchange losses. Calculations are compared and found to be in good agreement with measured data. The application to a Heavy-Ion Driven Inertial Fusion (HIDIF) scenario is discussed. 12 Refs.

  1. Beam Loss Detection at Radiation Source ELBE

    CERN Document Server

    Michel, P; Schurig, R; Langenhagen, H

    2003-01-01

    The Rossendorf superconducting Electron Linac of high Brilliance and low Emittance (ELBE) delivers an 40 MeV, 1 mA cw-beam for different applications such as bremsstrahlung production, electron channelling, free-electron lasers or secondary particle beam generation. In this energy region in case of collisions of the electron beam with the pipe nearly all beam power will be deposited into the pipe material. Therefore a reliable beam loss monitoring is essential for machine protection at ELBE. Different systems basing on photo multipliers, compton diodes and long ionization chambers were studied. The pros and cons of the different systems will be discussed. Ionization chambers based on air-isolated RF cables installed some cm away parallel to the beam line turned out to be the optimal solution. The beam shut-off threshold was adjusted to 1 μC integral charge loss during a 100 ms time interval. Due to the favourable geometry the monitor sensitivity varies less than ±50% along the beam line (di...

  2. Measurement of small antenna reflector losses for radiometer calibration budget

    DEFF Research Database (Denmark)

    Skou, Niels

    1997-01-01

    Antenna reflector losses play an important role in the calibration budget for a microwave radiometer. If the losses are small, they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brightness temperature as incident radiation...

  3. Spatial calibration of a tokamak neutral beam diagnostic using in situ neutral beam emission

    Energy Technology Data Exchange (ETDEWEB)

    Chrystal, C. [Oak Ridge Associated Universities, Oak Ridge, Tennessee 37831 (United States); Burrell, K. H.; Pace, D. C. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Grierson, B. A. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451 (United States)

    2015-10-15

    Neutral beam injection is used in tokamaks to heat, apply torque, drive non-inductive current, and diagnose plasmas. Neutral beam diagnostics need accurate spatial calibrations to benefit from the measurement localization provided by the neutral beam. A new technique has been developed that uses in situ measurements of neutral beam emission to determine the spatial location of the beam and the associated diagnostic views. This technique was developed to improve the charge exchange recombination (CER) diagnostic at the DIII-D tokamak and uses measurements of the Doppler shift and Stark splitting of neutral beam emission made by that diagnostic. These measurements contain information about the geometric relation between the diagnostic views and the neutral beams when they are injecting power. This information is combined with standard spatial calibration measurements to create an integrated spatial calibration that provides a more complete description of the neutral beam-CER system. The integrated spatial calibration results are very similar to the standard calibration results and derived quantities from CER measurements are unchanged within their measurement errors. The methods developed to perform the integrated spatial calibration could be useful for tokamaks with limited physical access.

  4. Calibration of Laser Beam Direction for Inner Diameter Measuring Device

    Directory of Open Access Journals (Sweden)

    Tongyu Yang

    2017-02-01

    Full Text Available The laser triangulation method is one of the most advanced methods for large inner diameter measurement. Our research group proposed a kind of inner diameter measuring device that is principally composed of three laser displacement sensors known to be fixed in the same plane measurement position. It is necessary to calibrate the direction of the laser beams that are emitted by laser displacement sensors because they do not meet the theoretical model accurately. For the purpose of calibrating the direction of laser beams, a calibration method and mathematical model were proposed. The inner diameter measuring device is equipped with the spindle of the machine tool. The laser beams rotate and translate in the plane and constitute the rotary rays which are driven to scan the inner surface of the ring gauge. The direction calibration of the laser beams can be completed by the sensors’ distance information and corresponding data processing method. The corresponding error sources are analyzed and the validity of the method is verified. After the calibration, the measurement error of the inner diameter measuring device reduced from ± 25 μ m to ± 15 μ m and the relative error was not more than 0.011%.

  5. Beam Loss Diagnostics Based on Pressure Measurements

    CERN Document Server

    Weinrich, U

    2003-01-01

    The GSI is operating a heavy ion synchrotron, which is currently undergoing an upgrade towards higher beam intensities. It was discovered that beam losses induce a significant pressure increase in the vacuum system. In order to detect the time constants of the pressure increase and decrease, fast total pressure measurements were put into operation. With the recently installed partial pressure diagnostics it is also possible to follow up which types of molecules are released. The presentation will focus on the different techniques applied as well as on some measurement results. The potential and difficulties of this diagnostic tool will also be discussed.

  6. How to calibrate Grenz-beams in clinical practice?

    Energy Technology Data Exchange (ETDEWEB)

    Schaeken, B. [Algemeen Ziekenhius Middelheim, Antwerp (Belgium); Bressers, E. [Virga jesse Ziekenhius, Hasselt (Belgium)

    1995-12-01

    In recent years, considerable efforts have been spent improving the precision and consistency in the whole process of calibration of high energy photon and electron beams (national protocols, primary calibration facilities ....). The reading in air of 5 different ionisation chambers (NE2532, NE2536, NE2571, PTWM23342, Markus) in an X-ray beam (RT50, HVL=0.35 mm Al) has been compared. Ali NE chambers were provided with a calibration factor Nk, the PTW chamber was directly calibrated in dose water ND,W. The polarisation and recombination effects were measured. In our reference field (ssd=4cm, field diameter 40 mm), the readings in air for the dedicated plan parallel chambers deviated by not more than 8%. The measurements with the NE2571 chamber did not correspond very well with the other measurements. For the equipment in our hospital, the dose rate in air for the reference field was measured from 1971 on and found to be very stable: 17.36 Gy/min (0.48) (1sd). An attempt was made to measure the BSF for the field defining cones used in clinical practice using a Markus plane parallel chamber, but the resulting BSF did not correspond to those reported in BJR/suppl. 17. Special attention has been be paid to the calibration of beams with field size comparable to the dimension of the chamber window- chamber body.

  7. Measurement of small antenna reflector losses for radiometer calibration budget

    OpenAIRE

    Skou, Niels

    1997-01-01

    Antenna reflector losses play an important role in the calibration budget for a microwave radiometer. If the losses are small, they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brightness temperature as incident radiation. This paper describes how such measurements are carried out as well as a suitable experimental setup. The main reflector of the European Space Agency's MIMR system is used to demonstrate the principle

  8. Accurate antenna reflector loss measurements for radiometer calibration budget

    DEFF Research Database (Denmark)

    Skou, Niels

    1996-01-01

    Antenna reflector losses may play an important role in the calibration budget for a microwave radiometer. If the losses are small they are difficult to measure by traditional means. However, they can be assessed directly by radiometric means using the sky brightness temperature as incident radiat...... radiation. The paper describes how such measurements are carried out as well as a suitable experimental set-up. The main reflector of the European Space Agency's MIMR system is used to demonstrate the principle...

  9. X-ray cone beam CT system calibration

    Science.gov (United States)

    Sire, Pascal; Rizo, Philippe; Martin, M.

    1993-12-01

    Recently x-ray cone beam computed tomography (CT) has become of interest for nondestructive testing (NDT) of advanced materials. Such a technique takes advantage of the cone beam geometry, to reduce the acquisition time and increase the resolution. Performances of CT systems rely mainly on geometric precision and measurement quality. Inaccurate geometry or incorrect data produce artifacts and blurring which limit the spatial resolution. A precise geometric calibration procedure is required and some corrections must be applied to the raw attenuation data in order to obtain accurate measurements. An x-ray cone beam CT system has been developed at the LETI. This machine was designed to control small parts limited to a few centimeters, with a high spatial resolution close to 30 microns. This paper introduces the machine setup and describes the calibration computing resources involved in the system. Then, we discuss the performances on experimental data.

  10. Analysis of beam loss induced abort kicker instability

    Energy Technology Data Exchange (ETDEWEB)

    Zhang W.; Sandberg, J.; Ahrens, L.; Fischer, W.; Hahn, H.; Mi, J.; Pai, C.; Tan, Y.

    2012-05-20

    Through more than a decade of operation, we have noticed the phenomena of beam loss induced kicker instability in the RHIC beam abort systems. In this study, we analyze the short term beam loss before abort kicker pre-fire events and operation conditions before capacitor failures. Beam loss has caused capacitor failures and elevated radiation level concentrated at failed end of capacitor has been observed. We are interested in beam loss induced radiation and heat dissipation in large oil filled capacitors and beam triggered thyratron conduction. We hope the analysis result would lead to better protection of the abort systems and improved stability of the RHIC operation.

  11. Auto calibration of a cone-beam-CT

    Energy Technology Data Exchange (ETDEWEB)

    Gross, Daniel; Heil, Ulrich; Schulze, Ralf; Schoemer, Elmar; Schwanecke, Ulrich [Department of Design, Computer Science and Media, RheinMain University of Applied Sciences, 65195 Wiesbaden, Germany and Institute of Computer Science, Johannes Gutenberg University Mainz, 55128 Mainz (Germany); Department of Oral Surgery (and Oral Radiology), University Medical Center of the Johannes Gutenberg University Mainz, 55131 Mainz (Germany); Institute of Computer Science, Johannes Gutenberg University Mainz, 55128 Mainz (Germany); Department of Design, Computer Science and Media, RheinMain University of Applied Sciences, 65195 Wiesbaden (Germany)

    2012-10-15

    Purpose: This paper introduces a novel autocalibration method for cone-beam-CTs (CBCT) or flat-panel CTs, assuming a perfect rotation. The method is based on ellipse-fitting. Autocalibration refers to accurate recovery of the geometric alignment of a CBCT device from projection images alone, without any manual measurements. Methods: The authors use test objects containing small arbitrarily positioned radio-opaque markers. No information regarding the relative positions of the markers is used. In practice, the authors use three to eight metal ball bearings (diameter of 1 mm), e.g., positioned roughly in a vertical line such that their projection image curves on the detector preferably form large ellipses over the circular orbit. From this ellipse-to-curve mapping and also from its inversion the authors derive an explicit formula. Nonlinear optimization based on this mapping enables them to determine the six relevant parameters of the system up to the device rotation angle, which is sufficient to define the geometry of a CBCT-machine assuming a perfect rotational movement. These parameters also include out-of-plane rotations. The authors evaluate their method by simulation based on data used in two similar approaches [L. Smekal, M. Kachelriess, S. E, and K. Wa, 'Geometric misalignment and calibration in cone-beam tomography,' Med. Phys. 31(12), 3242-3266 (2004); K. Yang, A. L. C. Kwan, D. F. Miller, and J. M. Boone, 'A geometric calibration method for cone beam CT systems,' Med. Phys. 33(6), 1695-1706 (2006)]. This allows a direct comparison of accuracy. Furthermore, the authors present real-world 3D reconstructions of a dry human spine segment and an electronic device. The reconstructions were computed from projections taken with a commercial dental CBCT device having two different focus-to-detector distances that were both calibrated with their method. The authors compare their reconstruction with a reconstruction computed by the manufacturer of

  12. A Layer Correlation Technique for ATLAS Calorimetry Calibration at the 2004 ATLAS Combined Beam Test

    CERN Document Server

    Carli, T; Spanò, F; Speckmayer, P

    2008-01-01

    A method for calibrating the response of a segmented calorimeter to hadrons is developed. The ansatz is that information on longitudinal shower fluctuations gained from a principal component analysis of the layer energy depositions can improve energy resolution by correcting for hadronic invisible energy and dead material losses: projections along the eigenvectors of the correlation matrix are used as input for the calibration. The technique is used to reconstruct the energy of pions impinging on the ATLAS calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. Simulated Monte Carlo events are used to derive corrections for invisible energy lost in nuclear reactions and in dead material in front and in between the calorimeters. For pion beams with energies between 20 and 180 GeV, the particle energy is reconstructed within 3% and the resolution is improved by about 20%.

  13. Beam Loss Studies for the CERN PS Booster Using FLUKA

    CERN Document Server

    Damjanovic, S; Mikulec, B; Sapinski, M

    2013-01-01

    In view of future upgrade plans, the beam loss monitor (BLM) coverage of the four PS Booster (PSB) rings was reviewed. FLUKA studies at Linac4 injection and PSB extraction energies were performed to simulate the loss patterns. The results of these studies, presented in this paper, have led to the proposal to double the number of beam loss monitors in the PSB.

  14. Beam Loss Control for the Fermilab Main Injector

    CERN Document Server

    Brown, Bruce C

    2013-01-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at 400 kW beam power. Losses were at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  15. Fermilab main injector: High intensity operation and beam loss control

    Science.gov (United States)

    Brown, Bruce C.; Adamson, Philip; Capista, David; Chou, Weiren; Kourbanis, Ioanis; Morris, Denton K.; Seiya, Kiyomi; Wu, Guan Hong; Yang, Ming-Jen

    2013-07-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at 400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  16. Characterizing and Controlling Beam Losses at the LANSCE Facility

    Energy Technology Data Exchange (ETDEWEB)

    Rybarcyk, Lawrence J. [Los Alamos National Laboratory

    2012-09-12

    The Los Alamos Neutron Science Center (LANSCE) currently provides 100-MeV H{sup +} and 800-MeV H{sup -} beams to several user facilities that have distinct beam requirements, e.g. intensity, micropulse pattern, duty factor, etc. Minimizing beam loss is critical to achieving good performance and reliable operation, but can be challenging in the context of simultaneous multi-beam delivery. This presentation will discuss various aspects related to the observation, characterization and minimization of beam loss associated with normal production beam operations in the linac.

  17. Luminosity Loss due to Beam Distortion and the Beam-Beam Instability

    CERN Document Server

    Wu, Juhao; Raubenheimer, Tor O; Seryi, Andrei; Sramek, Christopher K

    2005-01-01

    In a linear collider, sources of emittance dilution such as transverse wakefields or dispersive errors will couple the vertical phase space to the longitudinal position within the beam (the so-called ‘banana effect'). When the Intersection Point (IP) disruption parameter is large, these beam distortions will be amplified by a single bunch kink instability which will lead to luminosity loss. We study this phenomena both analytically using linear theory and via numerical simulation. In particular, we examine the dependence of the luminosity loss on the wavelength of the beam distortions and the disruption parameter. This analysis may prove useful when optimizing the vertical disruption parameter for luminosity operation with given beam distortions.

  18. Calibration of Cone Beam Rotational X-Ray Image Sequence

    Institute of Scientific and Technical Information of China (English)

    YUHengyong; MOUXuanqin; CAIYuanlong

    2004-01-01

    The real X-ray projection does not abide by Lambert-Beer Law, since the X-ray is polychromatic and the imaging chains are nonlinear. Based on the generating process of X-ray images, an equivalent nonlinear transform model is firstly proposed which considers all the nonlinear factors as one nonlinear transform. Then the 3D (three-dimensional) X-ray projection of cone beam is defined. The constraints of Radon transform, named H-L (Helgasson-ludwig) consistency conditions, are expanded to fan-beam. After that an algorithm is developed to calibrate Rotational X-ray image sequence (RXIS). The algorithm uses a set of exponential functions to approximate the nonlinear inverse transform. According to expanded H-L consistency conditions, finally a kind of nonlinear measure for RXIS is defined. Experimental results show that the proposed algorithm can decrease the nonlinear measure to below 0.01.

  19. Measurements of Beam Ion Loss from the Compact Helical System

    Energy Technology Data Exchange (ETDEWEB)

    D. S. Darrow, M. Isobe, Takashi Kondo, M. Sasao, and the CHS Group National Institute for Fusion Science, Toki, Gifu, Japan

    2010-02-03

    Beam ion loss from the Compact Helical System (CHS) has been measured with a scintillator-type probe. The total loss to the probe, and the pitch angle and gyroradius distributions of that loss, have been measured as various plasma parameters were scanned. Three classes of beam ion loss were observed at the probe position: passing ions with pitch angles within 10o of those of transition orbits, ions on transition orbits, and ions on trapped orbits, typically 15o or more from transition orbits. Some orbit calculations in this geometry have been performed in order to understand the characteristics of the loss. Simulation of the detector signal based upon the following of orbits from realistic beam deposition profiles is not able to reproduce the pitch angle distribution of the losses measured. Consequently it is inferred that internal plasma processes, whether magnetohydrodynamic modes, radial electric fields, or plasma turbulence, move previously confined beam ions to transition orbits, resulting in their loss.

  20. Cavity loss factors for non-ultrarelativistic beams

    Energy Technology Data Exchange (ETDEWEB)

    Kurennoy, S.S.

    1998-12-31

    Cavity loss factors can be easily computed for ultrarelativistic beams using time-domain codes like MAFIA or ABCI. However, for non-ultrarelativistic beams the problem is more complicated because of difficulties with its numerical formulation in the time domain. The authors calculate the loss factors of a non-relativistic bunch and compare results with the relativistic case.

  1. Cavity Loss Factors For Non-Ultrarelativistic Beams

    CERN Document Server

    Kurennoy, S S

    1998-01-01

    Cavity loss factors can be easily computed for ultrarelativistic beams using time-domain codes like MAFIA or ABCI. However, for non-ultrarelativistic beams the problem is more complicated because of difficulties with its numerical formulation in the time domain. We calculate the loss factors of a non-ultrarelativistic bunch and compare results with the relativistic case.

  2. Beam Loss Patterns at the LHC Collimators Measurements & Simulations

    CERN Document Server

    Böhlen, Till Tobias

    2008-01-01

    The Beam Loss Monitoring (BLM) system of the Large Hadron Collider (LHC) detects particle losses of circulating beams and initiates an emergency extraction of the beam in case that the BLM thresholds are exceeded. This protection is required as energy deposition in the accelerator equipment due to secondary shower particles can reach critical levels; causing damage to the beam-line components and quenches of superconducting magnets. Robust and movable beam line elements, so-called collimators, are the aperture limitations of the LHC. Consequently, they are exposed to the excess of lost beam particles and their showers. Proton loss patterns at LHC collimators have to be determined to interpret the signal of the BLM detectors and to set adequate BLM thresholds for the protection of collimators and other equipment in case of unacceptably increased loss rates. The first part of this work investigates the agreement of BLM detector measurements with simulations for an LHC-like collimation setup. The setup consists ...

  3. Electronics and Calibration system for the CMS Beam Halo Monitor

    CERN Document Server

    Tosi, Nicolo

    2014-01-01

    In the context of increasing luminosity of LHC, it will be important to accurately measure the Machine Induced Background. A new monitoring system will be installed in the CMS cavern for measuring the beam background at high radius. This detector is composed of synthetic quartz Cherenkov radiators, coupled to fast photomultiplier tubes (PMT). The readout chain of this detector will make use of many components developed for the Phase 1 upgrade to the CMS Hadron Calorimeter electronics, with a dedicated firmware and readout adapted to the beam monitoring requirements. The PMT signal will be digitized by a charge integrating ASIC (QIE10), providing both the signal rise time and the charge integrated over one bunch crossing.The backend electronics will record bunch-by-bunch histograms, which will be published to CMS and the LHC using the newly designed CMS beam instrumentation specific DAQ. A calibration monitoring system has been designed to generate triggered pulses of light to monitor the efficiency of the sys...

  4. LHC Beam Loss Monitoring System Verification Applications

    CERN Document Server

    Dehning, B; Zamantzas, C; Jackson, S

    2011-01-01

    The LHC Beam Loss Mon­i­tor­ing (BLM) sys­tem is one of the most com­plex in­stru­men­ta­tion sys­tems de­ployed in the LHC. In ad­di­tion to protecting the col­lid­er, the sys­tem also needs to pro­vide a means of di­ag­nos­ing ma­chine faults and de­liv­er a feed­back of loss­es to the control room as well as to sev­er­al sys­tems for their setup and analysis. It has to trans­mit and pro­cess sig­nals from al­most 4’000 mon­i­tors, and has near­ly 3 mil­lion con­fig­urable pa­ram­e­ters. The system was de­signed with re­li­a­bil­i­ty and avail­abil­i­ty in mind. The spec­i­fied op­er­a­tion and the fail-safe­ty stan­dards must be guar­an­teed for the sys­tem to per­form its func­tion in pre­vent­ing su­per­con­duc­tive mag­net de­struc­tion caused by par­ti­cle flux. Main­tain­ing the ex­pect­ed re­li­a­bil­i­ty re­quires ex­ten­sive test­ing and ver­i­fi­ca­tion. In this paper we re­port our most re­cent ad­di­t...

  5. Beam loss studies at the ANKA storage ring

    Energy Technology Data Exchange (ETDEWEB)

    Hertle, Edmund; Smale, Nigel; Goetsch, Tobias; Mueller, Anke-Susanne; Wegh, Frans; Worms, Kai [Karlsruher Institut fuer Technologie (Germany)

    2013-07-01

    The real time study and the post mortem analysis of beam loss are powerful tools for the optimization of a storage ring's performance. It allows, for example, a fast identification of failing hardware components or can be used to improve the beam lifetime by a reduction of the losses. This needs a sophisticated beam loss monitor system with appropriate spatial and temporal resolution. This presentation gives an overview of the loss monitor system under study at the ANKA synchrotron radiation facility of the Karlsruhe Institute of Technology.

  6. Beam Loss Monitors for NSLS-II Storage Ring

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.L.; Cameron, P.

    2011-03-28

    The shielding for the NSLS-II storage ring will provide adequate protection for the full injected beam losses in two cells of the ring around the injection point, but the remainder of the ring is shielded for lower losses of <10% top-off injection beam current. This will require a system to insure that beam losses do not exceed levels for a period of time that could cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring system will have beam loss monitors that will measure where the beam charge is lost around the ring, to warn operators if losses approach the design limits. To measure the charge loss quantitatively, we propose measuring the electron component of the shower as beam electrons hit the vacuum chamber (VC) wall. This will be done using the Cerenkov light as electrons transit ultra-pure fused silica rods placed close to the inner edge of the VC. The entire length of the rod will collect light from the electrons of the spread out shower resulting from the small glancing angle of the lost beam particles to the VC wall. The design and measurements results of the prototype Cerenkov BLM will be presented.

  7. High-Precision Calibration of Electron Beam Energy from the Hefei Light Source Using Spin Resonant Depolarization

    Science.gov (United States)

    Lan, Jie-Qin; Xu, Hong-Liang

    2014-12-01

    The electron beam energy at the Hefei Light Source (HLS) in the National Synchrotron Radiation Laboratory is highly precisely calibrated by using the method of spin resonant depolarization for the first time. The spin tune and the beam energy are determined by sweeping the frequency of a radial rf stripline oscillating magnetic field to artificially excite a spin resonance and depolarize the beam. The resonance signal is recognized by observing the sudden change of the Touschek loss counting rate of the beam. The possible systematic errors of the experiment are presented and the accuracy of the calibrated energy is shown to be about 10-4. A series of measurements show that the energy stability of the machine is of the order of 9 × 10-3.

  8. Beam loss monitors comparison at the CERN Proton Synchrotron

    CERN Document Server

    Gilardoni, S S; Effinger, E; Gil-Flores, J; Wienands, U

    2011-01-01

    CERN is planning the renovation and upgrade of the beam loss detection system for the Proton Synchrotron (PS). Improved performance in speed–to be able to monitor beam loss on a bunch-by-bunch basis–and in longterm stability–to reduce or avoid the need for periodic calibration–are aimed for. To select the most suitable technology, different detectors were benchmarked in the machine with respect to the same beam loss. The characteristics of the different detectors, the results of the measurement campaign and their suitability as future monitors for the PS are presented.

  9. Monitoring system experiments on beam loss at SSRF injector

    Science.gov (United States)

    Cai, Jun; Xia, XiaoBin; Xu, XunJiang; Liu, Xin; Xu, JiaQiang; Wang, GuangHong; Zeng, Ming

    2011-12-01

    Experiments on beam loss by using beam loss monitoring (BLM) system were carried out at Shanghai Synchrotron Radiation Facility (SSRF) injector. This system used highly sensitive and current-integrated Si-photodiode detectors and an Ethernet data acquisition (DAQ) system. The experimental results demonstrate that the Si-photodiode detectors are a useful tool that provides dynamic information on beam loss and investigates problems of machine operation. It also shows that the Si-photodiode BLM system is suitable for pulse-radiation of high-energy accelerators.

  10. Monitoring system experiments on beam loss at SSRF injector

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Experiments on beam loss by using beam loss monitoring (BLM) system were carried out at Shanghai Synchrotron Radiation Facility (SSRF) injector. This system used highly sensitive and current-integrated Si-photodiode detectors and an Ethernet data acquisition (DAQ) system. The experimental results demonstrate that the Si-photodiode detectors are a useful tool that provides dynamic information on beam loss and investigates problems of machine operation. It also shows that the Si-photodiode BLM system is suitable for pulse-radiation of high-energy accelerators.

  11. Calibration report for Avent 5-beam Demonstrator lidar

    DEFF Research Database (Denmark)

    Borraccino, Antoine; Courtney, Michael

    . Their estimation is the ultimate goal of a calibration: a relation is established between reference measurements from calibrated instruments and corresponding LiDAR indications. Traceability in the calibration is obtained by transferring measurement uncertainties from the reference instrument through...

  12. Beam Loss Estimates and Control for the BNL Neutrino Facility

    CERN Document Server

    Weng, Wu-Tsung; Raparia, Deepak; Tsoupas, Nicholaos; Wei, Jie; Yung Lee, Yong; Zhang, S Y

    2005-01-01

    BNL plans to upgrade the AGS proton beam from the current 0.14 MW to higher than 1.0 MW for a very long baseline neutrino oscillation experiment. This increase in beam power is mainly due to the faster repetition rate of the AGS by a new 1.5 GeV superconductiong linac as injector, replacing the existing booster. The requirement for low beam loss is very important both to protect the beam component, and to make the hands-on maintenance possible. In this report, the design considerations for achieving high intensity and low loss will be presented. We start by specifying the beam loss limit at every physical process followed by the proper design and parameters for realising the required goals. The process considered in this paper include the emittance growth in the linac, the H-

  13. CCD based beam loss monitor for ion accelerators

    Science.gov (United States)

    Belousov, A.; Mustafin, E.; Ensinger, W.

    2014-04-01

    Beam loss monitoring is an important aspect of proper accelerator functioning. There is a variety of existing solutions, but each has its own disadvantages, e.g. unsuitable dynamic range or time resolution, high cost, or short lifetime. Therefore, new options are looked for. This paper shows a method of application of a charge-coupled device (CCD) video camera as a beam loss monitor (BLM) for ion beam accelerators. The system was tested with a 500 MeV/u N+7 ion beam interacting with an aluminum target. The algorithms of camera signal processing with LabView based code and beam loss measurement are explained. Limits of applicability of this monitor system are discussed.

  14. FLUKA simulations for the optimization of the Beam Loss Monitors

    CERN Document Server

    Brugger, M; Ferrari, A; Magistris, M; Santana-Leitner, M; Vlachoudis, V; CERN. Geneva. AB Department

    2006-01-01

    The collimation system in the beam cleaning insertion IR7 of the Large Hadron Collider (LHC) is expected to clean the primary halo and the secondary radiation of a beam with unprecedented energy and intensity. Accidental beam losses can therefore entail severe consequences to the hardware of the machine. Thus, protection mechanisms, e.g. beam abort, must be instantaneously triggered by a set of Beam Loss Monitors (BLM's). The readings in the BLM's couple the losses from various collimators, thus rendering the identification of any faulty unit rather complex. In the present study the detailed geometry of IR7 is upgraded with the insertion of the BLM's, and the Monte Carlo FLUKA transport code is used to estimate the individual contribution of every collimator to the showers detected in each BLM.

  15. Beam loss mechanisms in relativistic heavy-ion colliders

    CERN Document Server

    Bruce, Roderik; Gilardoni, S; Wallén, E

    2009-01-01

    The Large Hadron Collider (LHC), the largest particle accelerator ever built, is presently under commissioning at the European Organization for Nuclear Research (CERN). It will collide beams of protons, and later Pb82+ ions, at ultrarelativistic energies. Because of its unprecedented energy, the operation of the LHC with heavy ions will present beam physics challenges not encountered in previous colliders. Beam loss processes that are harmless in the presently largest operational heavy-ion collider, the Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory, risk to cause quenches of superconducting magnets in the LHC. Interactions between colliding beams of ultrarelativistic heavy ions, or between beam ions and collimators, give rise to nuclear fragmentation. The resulting isotopes could have a charge-to-mass ratio different from the main beam and therefore follow dispersive orbits until they are lost. Depending on the machine conditions and the ion species, these losses could occur in loca...

  16. Dependence of bunch energy loss in cavities on beam velocity

    Science.gov (United States)

    Kurennoy, Sergey S.

    1999-03-01

    Beam energy loss in a cavity can be easily computed for a relativistic bunch using time-domain codes like MAFIA or ABCI. However, for nonrelativistic beams the problem is more complicated because of difficulties with its numerical formulation in the time domain. We calculate the cavity loss factors for a bunch in frequency domain as a function of its velocity and compare results with the relativistic case.

  17. A Versatile Beam Loss Monitoring System for CLIC

    CERN Document Server

    Kastriotou, Maria; Farabolini, Wilfrid; Holzer, Eva Barbara; Nebot Del Busto, Eduardo; Tecker, Frank; Welsch, Carsten

    2016-01-01

    The design of a potential CLIC beam loss monitoring (BLM) system presents multiple challenges. To successfully cover the 48 km of beamline, ionisation chambers and optical fibre BLMs are under investigation. The former fulfils all CLIC requirements but would need more than 40000 monitors to protect the whole facility. For the latter, the capability of reconstructing the original loss position with a multi-bunch beam pulse and multiple loss locations still needs to be quantified. Two main sources of background for beam loss measurements are identified for CLIC. The two-beam accelerator scheme introduces so-called crosstalk, i.e. detection of losses originating in one beam line by the monitors protecting the other. Moreover, electrons emitted from the inner surface of RF cavities and boosted by the high RF gradients may produce signals in neighbouring BLMs, limiting their ability to detect real beam losses. This contribution presents the results of dedicated experiments performed in the CLIC Test Facility to qu...

  18. Calibration free beam hardening correction for cardiac CT perfusion imaging

    Science.gov (United States)

    Levi, Jacob; Fahmi, Rachid; Eck, Brendan L.; Fares, Anas; Wu, Hao; Vembar, Mani; Dhanantwari, Amar; Bezerra, Hiram G.; Wilson, David L.

    2016-03-01

    Myocardial perfusion imaging using CT (MPI-CT) and coronary CTA have the potential to make CT an ideal noninvasive gate-keeper for invasive coronary angiography. However, beam hardening artifacts (BHA) prevent accurate blood flow calculation in MPI-CT. BH Correction (BHC) methods require either energy-sensitive CT, not widely available, or typically a calibration-based method. We developed a calibration-free, automatic BHC (ABHC) method suitable for MPI-CT. The algorithm works with any BHC method and iteratively determines model parameters using proposed BHA-specific cost function. In this work, we use the polynomial BHC extended to three materials. The image is segmented into soft tissue, bone, and iodine images, based on mean HU and temporal enhancement. Forward projections of bone and iodine images are obtained, and in each iteration polynomial correction is applied. Corrections are then back projected and combined to obtain the current iteration's BHC image. This process is iterated until cost is minimized. We evaluate the algorithm on simulated and physical phantom images and on preclinical MPI-CT data. The scans were obtained on a prototype spectral detector CT (SDCT) scanner (Philips Healthcare). Mono-energetic reconstructed images were used as the reference. In the simulated phantom, BH streak artifacts were reduced from 12+/-2HU to 1+/-1HU and cupping was reduced by 81%. Similarly, in physical phantom, BH streak artifacts were reduced from 48+/-6HU to 1+/-5HU and cupping was reduced by 86%. In preclinical MPI-CT images, BHA was reduced from 28+/-6 HU to less than 4+/-4HU at peak enhancement. Results suggest that the algorithm can be used to reduce BHA in conventional CT and improve MPI-CT accuracy.

  19. Beam filling loss adjustments for ASR-9 weather channel reflectivity estimates

    Science.gov (United States)

    Engholm, Cynthia D.; Troxel, Seth W.

    1990-10-01

    The FAA is deploying over 100 new airport surveillance radars (ASR-9) across the country. In contrast to earlier ASRs, the ASR-9 utilizes a separate digital weather processing channel to provide air traffic controllers with timely, calibrated displays of precipitation intensity. The ASR-9 utilizes dual selectable fan shaped elevation beams designed to track aircraft over a large volume. As a consequence, weather echoes received from these fan shaped beams represent vertically averaged quantities. If the precipitation only partially or nonuniformly fills the beam, then the vertically integrated reflectivity may underestimate the actual intensity of the storm. The ASR-9 weather channel corrects for this by adjusting the range dependent six level reflectivity thresholds. The appropriateness of the currently implemented correction has not been carefully examined and may require modification to take into account regional and morphological variability in storm structure. The method used to derive new beam filling loss adjustments is discussed. An extensive database of volumetric pencil beam radar data were used in conjunction with the ASR-9 simulation facility to derive adjustments aimed at calibrating the precipitation intensity reports to the maximum perceived hazard. Results from this calibration indicate that a single correction is appropriate for all sites and intensities. The new corrections yield substantially improved results over the current corrections in producing these reflectivity reports.

  20. Parasitic mode losses versus signal sensitivity in beam position monitors

    Science.gov (United States)

    Denard, J. C.; Bane, K. L.; Bijleveld, J.; Hutton, A. M.; Pellegrin, J. I.; Rivkin, L.; Wang, P.; Weaver, J. N.

    1985-04-01

    A beam position monitor (BPM) for a storage or damping ring may be subject to heating problems due to the parasitic mode (PM) losses, beam interception and synchrotron radiation interception. In addition, high PM losses can cause beam instabilities under some conditions. Recessing and/or masking the BPM may increase the PM losses in the process of solving the latter two problems. Three complementary methods for estimating the PM losses and for improving the design of a stripline directional coupler type of BPM: bench measurements, computer modeling (TBCI), and an equivalent circuit representation are presented. These methods lead to a decrease in PM losses without significant reduction in output signal for the north Stanford Linear Collider (SLC) damping ring BPMs.

  1. Simultaneous Hand-Eye-Workspace and Camera Calibration using Laser Beam Projection

    OpenAIRE

    Jwu-Sheng Hu; Yung-Jung Chang

    2014-01-01

    This work presents a novel calibration technique capable of simultaneously calibrating a camera’s intrinsic parameters and hand-eye-workspace relations. In addition to relaxing the requirement of a precise calibration reference to achieve manipulator accuracy, the proposed method functions when the hand is not in the view field of the eye. The calibration method uses a laser pointer mounted on the hand to project laser beams onto a planar object, which serves as the working plane. Collected l...

  2. Beam loss detection system in the arcs of the LHC

    Science.gov (United States)

    Arauzo, A.; Bovet, C.

    2000-11-01

    Over the whole circumference of the LHC, Beam Loss Monitors (BLM) will be needed for a continuous surveillance of fast and slow beam losses. In this paper, the location of the BLMs set outside the magnet cryostats in the arcs is proposed. In order to know the number of protons lost on the beam screen, the sensitivity of each BLM has been computed using the program GEANT 3.21, which generates the shower inside the cryostat. The material and the magnetic fields have been described thoroughly in 3-D and the simulation results show the best locations for 6 BLMs needed around each quadrupole. The number of minimum ionizing particles received for each lost proton serves to define local thresholds to dump the beam when the losses are menacing to quench a magnet.

  3. Beam Loss Detection System in the Arcs of the LHC

    CERN Document Server

    Arauzo-Garcia, A

    2000-01-01

    Over the whole circumference of the LHC, Beam Loss Monitors (BLM) will be needed for a continuous surveillance of fast and slow beam losses. In this paper, the location of the BLMs set outside the magnet cryostats in the arcs is proposed. In order to know the number of protons lost on the beam screen, the sensitivity of each BLM has been computed using the program GEANT 3.21, which generates the shower inside the cryostat. The material and the magnetic fields have been described thoroughly in 3-D and the simulation results show the best locations for 6 BLMs needed around each quadrupole. The number of minimum ionizing particles received for each lost proton serves to define local thresholds to dump the beam when the losses are menacing to quench a magnet

  4. Beam loss control in the LINAC4 design

    CERN Document Server

    Stovall, J; Crandall, K

    2010-01-01

    The Linac4 DTL reference design has been modified to reduce the power consumption in tank 1 by modifying the accelerating field and phase law. In addition we have adopted an FFDD focusing lattice throughout to minimize expected losses resulting from alignment errors. We have observed, however, that this design suffers from decreasing transverse acceptance and a sensitivity to misalignments that causes any expected beam loss to occcur at the high energy end of the DTL. In this note we investigate two solutions to increase the acceptance, decrease its sensitivity to misalignments and eliminate the potential for a beam-loss “bottleneck” at 50 MeV.

  5. Simulations of Neutral Beam Ion Ripple Loss on EAST

    Institute of Scientific and Technical Information of China (English)

    李吉波; 丁斯晔; 吴斌; 胡纯栋

    2012-01-01

    Predictions on the ripple loss of neutral beam fast ions on EAST are investigated with a guiding center code, including both ripple and collisional effects. A 6% to 16% loss of neutral beam ions is predicted for typical EAST experiments, and a synergistic enhancement of fast ion loss is found for toroidal field (TF) ripples with collisions. The lost ions are strongly localized and will cause a maximum heat load of - 0.05 MW/m^2 on the first wall.

  6. Application of diamond based beam loss monitors at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Hempel, Maria

    2013-04-15

    The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus(ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments to study the questions: ''What is mass?'', ''What is the universe made of?'' and ''Why is there no antimatter?''. The four experiments take data of the collision products and try to answer the fundamental questions of physics. The two larger detectors, CMS and ATLAS, are looking for the Higgs boson to study the electroweak symmetry breaking. Both detectors were built with contrasting concepts to exclude potential error sources and to rea rm the results. The smaller experiment LHCb studies the matter-antimatter asymmetry with a focus of the beauty quark. Another smaller experiment is ALICE that studies the conditions right after the Big Bang by colliding heavy ions. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150 km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due to deviations of the beam parameters. Several systems called beam loss monitors (BLMs) can measure beam losses. This thesis concentrates on two of them, ionization chambers and diamond detectors. Over 3600 ionization chambers are installed in

  7. A calibration concept for passive MW imaging using beam steering by frequency shift and aperture synthesis

    Science.gov (United States)

    Schreiber, Eric; Peichl, Markus; Jirousek, Matthias

    2013-10-01

    Passive microwave (MW) remote sensing is used in Earth observation missions for example to estimate the salinity of oceans or the soil moisture of landscapes. In these cases the absolute brightness temperature numbers are important for sufficient accuracy of the estimated geo-physical parameters. Consequently a suitable system calibration network is required. At DLR a radiometric demonstrator for fully-electronic MW imaging was set up at Ka-band, which is based on a combination of beam steering by frequency shift using a broadband slotted-waveguide antenna for one scanning direction, and the application of aperture synthesis for the other direction. Aperture synthesis is well known from radio astronomy, but it is still a new imaging principle for Earth observation or security applications. Hence as well new calibration techniques have to be developed for this kind of scanning mechanism. In this paper a novel approach for a noise-source based calibration method taking into account the antenna losses will be introduced. When using aperture synthesis techniques to determine the absolute brightness temperature values, it is very important, among other things, to know the exact phase transfer function of the system in order to achieve the desired radiometric resolution. Consequently our approach enables phase calibration as well. The paper outlines a proof of concept for this calibration method using a two-element interferometer called VESAS (Voll Elektronischer Scanner mit AperturSynthese) as a demonstrator. The functionality of the demonstrator and the proof of concept of the imaging principle mentioned before are written in detail in [1].

  8. Beam studies for the Proton Improvement Plan (PIP) -- reducing beam loss at the Fermilab Booster

    CERN Document Server

    Seiya, K; Johnson, D E; Kapin, V V; Pellico, W A; Tan, C Y; Tesarek, R J

    2015-01-01

    The Fermilab Booster is being upgraded under the Proton Improvement Plan (PIP) to be capable of providing a proton flux of $2.25^{17}$ protons per hour. The intensity per cycle will remain at the present operational $4.3^{12}$ protons per pulse, however the Booster beam cycle rate is going to be increased from 7.5 Hz to 15 Hz. One of the biggest challenges is to maintain the present beam loss power while the doubling the beam flux. Under PIP, there has been a large effort in beam studies and simulations to better understand the mechanisms of the beam loss. The goal is to reduce it by half by correcting and controlling the beam dynamics and by improving operational systems through hardware upgrades. This paper is going to present the recent beam study results and status of the Booster operations.

  9. Beam Loss Studies for Rare Isotope Driver Linacs Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Wangler, T P; Kurennoy, S S; Billen, J H; Crandall, K R; Qiang, J; Ryne, R D; Mustapha, B; Ostroumov, P; Zhao, Q; York, and R. C.

    2008-03-26

    The Fortran 90 RIAPMTQ/IMPACT code package is a pair of linked beam-dynamics simulation codes that have been developed for end-to-end computer simulations of multiple-charge-state heavy-ion linacs for future exotic-beam facilities. These codes have multiple charge-state capability, and include space-charge forces. The simulations can extend from the low-energy beam-transport line after an ECR ion source to the end of the linac. The work has been performed by a collaboration including LANL, LBNL, ANL, and MSU. The code RIAPMTQ simulates the linac front-end beam dynamics including the LEBT, RFQ, and MEBT. The code IMPACT simulates the beam dynamics of the main superconducting linac. The codes have been benchmarked for rms beam properties against previously existing codes at ANL and MSU. The codes allow high-statistics runs on parallel supercomputing platforms, particularly at NERSC at LBNL, for studies of beam losses. The codes also run on desktop PC computers for low-statistics work. The code package is described in more detail in a recent publication [1] in the Proceedings of PAC07 (2007 US Particle Accelerator Conference). In this report we describe the main activities for the FY07 beam-loss studies project using this code package.

  10. Monte Carlo Simulations of Beam Losses in the Test Beam Line of CTF3

    CERN Document Server

    Nebot Del Busto, E; Branger, E; Holzer, E B; Doebert, S; Lillestol, R L; Welsch, C P

    2013-01-01

    The Test Beam Line (TBL) of the CLIC Test Facility 3 (CTF3) aims to validate the drive beam deceleration concept of CLIC, in which the RF power requested to boost particles to multi-TeV energies is obtained via deceleration of a high current and low energy drive beam (DB). Despite a TBL beam energy (150-80 MeV) significantly lower than the minimum nominal energy of the CLIC DB (250 MeV), the pulse time structure of the TBL provides the opportunity to measure beam losses with CLIC-like DB timing conditions. In this contribution, a simulation study on the detection of beam losses along the TBL for the commissioning of the recently installed beam loss monitoring system is presented. The most likely loss locations during stable beam conditions are studied by considering the beam envelope defined by the FODO lattice as well as the emittance growth due to the deceleration process. Moreover, the optimization of potential detector locations is discussed. Several factors are considered, namely: the distance to the bea...

  11. Loss management in the beta-beam decay ring

    CERN Document Server

    Chancé, Antoine

    2006-01-01

    The aim of the beta-beams is to produce pure electron neutrino and anti-neutrino highly energetic beams, coming from β-decay of the 18Ne10+ and 6He2+, both at γ = 100, directed towards experimental halls situated in the Fréjus tunnel [1], [2]. The high intensity ion beams are stored in a ring, until the ions decay. Consequently, all the injected particles will be lost anywhere around the ring generating a high level of irradiation. In order to keep a constant neutrino flux, the losses due to the decay of the radioactive ions are compensated with regular injections. The new ion beam is then merged with the stored beam with a specific RF program [3]. We have to consider two sources of losses: – The β-decay products: their magnetic rigidity being different from the reference one, they are bent differently and lost. – The losses during the injection merging process. The first one needs a particular ring design in order to insert appropriate beam stoppers at the right place. The second one needs a specific...

  12. 2014 Joint International Accelerator School: Beam Loss and Accelerator Protection

    CERN Document Server

    JAS - Joint US-CERN-Japan-Russia Accelerator School

    2016-01-01

    Many particle accelerators operate with very high beam power and very high energy stored in particle beams as well as in magnet systems. In the future, the beam power in high intensity accelerators will further increase. The protection of the accelerator equipment from the consequences of uncontrolled release of the energy is essential. This was the motivation for organizing a first school on beam losses and accelerator protection (in general referred to as machine protection). During the school the methods and technologies to identify, mitigate, monitor and manage the technical risks associated with the operation of accelerators with high-power beams or subsystems with large stored energy were presented. At the completion of the school the participants should have been able to understand the physical phenomena that can damage machine subsystems or interrupt operations and to analyze an accelerator facility to produce a register of technical risks and the corresponding risk mitigation and management strategie...

  13. SPS transverse beam scraping and LHC injection losses

    CERN Document Server

    Drosdal, L; Bartmann, W; Bracco, C; Cornelis, K; Goddard, B; Meddahi, M; Veyrunes, E

    2012-01-01

    Machine protection sets strict requirements for the quality of the injected beam, in particular in the transverse plane. Losses at aperture restrictions and protection elements have to be kept at a minimum. Particles in the beam tails are lost at the tight transfer line collimators and can trigger the LHC beam abort system. These particles have to be removed by scrapers in the vertical and horizontal plane in the SPS. Scraping has become vital for high intensity LHC operation. This paper shows the dependence of injection quality on the SPS scraping and discusses an improved scraper setting up strategy for better reproducibility with the current scraper system.

  14. Cherenkov Fibers for Beam Loss Monitoring at the CLIC Two Beam Module

    CERN Document Server

    van Hoorne, Jacobus Willem; Holzer, E B

    The Compact Linear Collider (CLIC) study is a feasibility study aiming at a nominal center of mass energy of 3TeV and is based on normal conducting travelling-wave accelerating structures, operating at very high field gradients of 100 MV/m. Such high fields require high peak power and hence a novel power source, the CLIC two beam system, has been developed, in which a high intensity, low energy drive beam (DB) supplies energy to a high energy, low intensity main beam (MB). At the Two Beam Modules (TBM), which compose the 2x21km long CLIC main linac, a protection against beam losses resulting from badly controlled beams is necessary and particularly challenging, since the beam power of both main beam (14 MW) and drive beam (70 MW) is impressive. To avoid operational downtimes and severe damages to machine components, a general Machine Protection System (MPS) scheme has been developed. The Beam Loss Monitoring (BLM) system is a key element of the CLIC machine protection system. Its main role will be to detect p...

  15. Simulation and Measurements of Beam Losses on LHC Collimators During Beam Abort Failures

    CERN Document Server

    Lari, L; Bruce, R; Goddard, B; Redaelli, S; Salvachua, B; Valentino, G; Faus-Golfe, A

    2013-01-01

    One of the main purposes of tracking simulations for collimation studies is to produce loss maps along the LHC ring, in order to identify the level of local beam losses during nominal and abnormal operation scenarios. The SixTrack program is the standard tracking tool used at CERN to perform these studies. Recently, it was expanded in order to evaluate the proton load on different collimators in case of fast beam failures. Simulations are compared with beam measurements at 4 TeV. Combined failures are assumed which provide worst-case scenarios of the load on tungsten tertiary collimators.

  16. Beam Loss Monitoring for Run 2 of the LHC

    CERN Document Server

    Kalliokoski, Matti; Dehning, Bernd; Domingues Sousa, Fernando; Effinger, Ewald; Emery, Jonathan; Grishin, Viatcheslav; Holzer, Eva Barbara; Jackson, Stephen; Kolad, Blazej; Nebot Del Busto, Eduardo; Picha, Ondrej; Roderick, Chris; Sapinski, Mariusz; Sobieszek, Marcin; Zamantzas, Christos

    2015-01-01

    The Beam Loss Monitoring (BLM) system of the LHC consists of over 3600 ionization chambers. The main task of the system is to prevent the superconducting magnets from quenching and protect the machine components from damage, as a result of critical beam losses. The BLM system therefore requests a beam abort when the measured dose in the chambers exceeds a threshold value. During Long Shutdown 1 (LS1) a series of modifications were made to the system. Based on the experience from Run 1 and from improved simulation models, all the threshold settings were revised, and modified where required. This was done to improve the machine safety at 7 TeV, and to reduce beam abort requests when neither a magnet quench or damage to machine components is expected. In addition to the updates of the threshold values, about 800 monitors were relocated. This improves the response to unforeseen beam losses in the millisecond time scale due to micron size dust particles present in the vacuum chamber. This contribution will discuss...

  17. Update on beam loss monitoring at CTF3 for CLIC

    CERN Document Server

    Devlin, L J; Effinger, E; Holzer, E B; del Busto, E N; Mallows, S; Branger, E

    2013-01-01

    The primary role of the beam loss monitoring (BLM) system for the compact linear collider (CLIC) study is to work within the machine protection system. Due to the size of the CLIC facility, a BLM that covers large distances along the beam line is highly desirable, in particular for the CLIC drive beam decelerators, which would alternatively require some ~40,000 localised monitors. Therefore, an optical fibre BLM system is currently under investigation which can cover large sections of beam line at a time. A multimode fibre has been installed along the Test Beam Line at the CLIC test facility (CTF3) where the detection principle is based on the production of Cherenkov photons within the fibre resulting from beam loss and their subsequent transport along the fibre where they are then detected at the fibre ends using silicon photomultipliers. Several additional monitors including ACEMs, PEP-II and diamond detectors have also been installed. In this contribution the first results from the BLMs are presented, comp...

  18. The LEP RF Trip and Beam Loss Diagnostics System

    CERN Document Server

    Arnaudon, L; Beetham, G; Ciapala, Edmond; Juillard, J C; Olsen, R

    2002-01-01

    During the last years of operation the number of operationally independent RF stations distributed around LEP reached a total of 40. A serious difficulty when running at high energy and high beam intensities was to establish cause and effect in beam loss situations, where the trip of any single RF station would result in beam loss, rapidly producing further multiple RF station trips. For the last year of operation a fast post-mortem diagnostics system was developed to allow precise time-stamping of RF unit trips and beam intensity changes. The system was based on eight local DSP controlled fast acquisition and event recording units, one in each RF sector, connected to critical RF control signals and fast beam intensity monitors and synchronised by GPS. The acquisition units were armed and synchronised at the start of each fill. At the end of the fill the local time-stamped RF trip and beam intensity change history tables were recovered, events ordered and the results stored in a database for subsequent analys...

  19. Tracking Simulation for Beam Loss Studies with Application to FCC

    CERN Document Server

    Boscolo, M

    2015-01-01

    We present first results on FCC-ee beam losses using a tracking simulation tool originally developed and successfully applied to Flav or Factories designs. After a brief description of the tool, we discuss first results obtained for FCC-ee at top energy, both for the Touschek effect and radiative Bhabha scattering.

  20. The LHC beam loss monitoring system's data acquisition card

    CERN Document Server

    Effinger, E; Emery, J; Ferioli, G; Gauglio, G; Zamantzas, C

    2007-01-01

    The beam loss monitoring (BLM) system [1] of the LHC is one of the most critical elements for the protection of the LHC. It must prevent the super conducting magnets from quenches and the machine components from damages, caused by beam losses. Ionization chambers and secondary emission based beam loss detectors are used on several locations around the ring. The sensors are producing a signal current, which is related to the losses. This current will be measured by a tunnel electronic, which acquires, digitizes and transmits the data via an optical link to the surface electronic. The so called threshold comparator (TC) [2] collects, analyzes and compares the data with threshold table. It also gives a dump signal through the combiner card to the beam inter lock system (BIC). The usage of the system, for protection and tuning of the LHC and the scale of the LHC, imposed exceptional specification of the dynamic range and radiation tolerance. The input current dynamic range should allow measurements between 10pA a...

  1. Real-Time Beam Loss Monitor Display Using FPGA Technology

    CERN Document Server

    North, Matt R W

    2005-01-01

    This paper outlines the design of a Real-time Beam Loss Monitor Display for the ISIS Synchrotron based at Rutherford Appleton Laboratory (Oxon, UK). Beam loss is monitored using 39 argon filled ionisation chambers positioned around the synchrotron, the levels of which are sampled four times in each cycle. The new BLM display acquires the signals and displays four histograms, each relating to an individual sample period; the data acquisition and signal processing required to build the display fields are completed within each machine cycle (50 Hz). Attributes of the new system include setting limits for individual monitors; displaying over-limit detection, and freezing the display field when a beam trip has occurred. The design is based around a reconfigurable Field Programmable Gate Array, interfacing to a desktop monitor via the VGA standard. Results gained using simulated monitor signals have proven the system.

  2. RF Cavity Induced Sensitivity Limitations on Beam Loss Monitors

    Science.gov (United States)

    Kastriotou, M.; Degiovanni, A.; Sousa, F. S. Domingues; Effinger, E.; Holzer, E. B.; Quirante, J. L. Navarro; del Busto, E. N.; Tecker, F.; Viganò, W.; Welsch, C. P.; Woolley, B. J.

    Due to the secondary showers generated when a particle hits the vacuum chamber, beam losses at an accelerator may be detected via radiation detectors located near the beam line. Several sources of background can limit the sensitivity and reduce the dynamic range of a Beam Loss Monitor (BLM). This document concentrates on potential sources of background generated near high gradient RF cavities due to dark current and voltage breakdowns. An optical fibre has been installed at an experiment of the Compact Linear Collider (CLIC) Test Facility (CTF3), where a dedicated study of the performance of a loaded and unloaded CLIC accelerating structure is undergoing. An analysis of the collected data and a benchmarking simulation are presented to estimate BLM sensitivity limitations. Moreover, the feasibility for the use of BLMs optimised for the diagnostics of RF cavities is discussed.

  3. Modelling and calibration of the laser beam-scanning triangulation measurement system

    NARCIS (Netherlands)

    Wang, Guoyu; Zheng, Bing; Li, Xin; Houkes, Z.; Regtien, P.P.L.

    2002-01-01

    We present an approach of modelling and calibration of an active laser beam-scanning triangulation measurement system. The system works with the pattern of two-dimensional beam-scanning illumination and one-dimensional slit-scanning detection with a photo-multiplier tube instead of a CCD camera. By

  4. Identification of LHC beam loss mechanism : a deterministic treatment of loss patterns

    CERN Document Server

    Marsili, Aurélien

    CERN's Large Hadron Collider (LHC) is the largest machine ever built, with a total circumference of 26.7 km; and it is the most powerful accelerator ever, both in beam energy and beam intensity. The main magnets are superconducting, keeping the particles into two counter circulating beams, which collide in four interaction points. CERN and the LHC will be described in chap. 1. The superconducting magnets of the LHC have to be protected against particle losses. Depending on the number of lost particles, the coils of the magnets will become normal conducting and/or will be damaged. To avoid these events a beam loss monitoring (BLM) system was installed to measure the particle loss rates. If the predefined safe thresholds of loss rates are exceeded, the beams are directed out of the accelerator ring towards the beam dump. The detectors of the BLM system are mainly ionization chambers located outside of the cryostats. In total, about 3500 ionisation chambers are installed. Further challenges include the high dyna...

  5. H- Beam Stripping Loss at Background Partial Pressure of Ar

    Institute of Scientific and Technical Information of China (English)

    Hu Chundong; Wang Shaohu; Hu Liqun

    2005-01-01

    It has been observed that H- current could be improved by adding Ar to H2 plasma.But due to a slower pumping speed for Ar with the existing pumping scheme, the tank pressure will increase quickly during the length of a beam pulse. Since H- stripping loss depends on the tank pressure and gas species, part of the H- beam can be converted to H0 and then H0 can be converted into H+ with background H2 and Ar gas thickness. Therefore, the H- beam current,measured by a Faraday cup, situated at a distance L from GG (ground grid), will decrease because it will be converted into a H+ current. This gives a ratio of the Faraday cup net current to the H- beam current before stripping at background partial pressure of Ar.

  6. Beam loss reduction by magnetic shielding using beam pipes and bellows of soft magnetic materials

    Science.gov (United States)

    Kamiya, J.; Ogiwara, N.; Hotchi, H.; Hayashi, N.; Kinsho, M.

    2014-11-01

    One of the main sources of beam loss in high power accelerators is unwanted stray magnetic fields from magnets near the beam line, which can distort the beam orbit. The most effective way to shield such magnetic fields is to perfectly surround the beam region without any gaps with a soft magnetic high permeability material. This leads to the manufacture of vacuum chambers (beam pipes and bellows) with soft magnetic materials. A Ni-Fe alloy (permalloy) was selected for the material of the pipe parts and outer bellows parts, while a ferritic stainless steel was selected for the flanges. An austenitic stainless steel, which is non-magnetic material, was used for the inner bellows for vacuum tightness. To achieve good magnetic shielding and vacuum performances, a heat treatment under high vacuum was applied during the manufacturing process of the vacuum chambers. Using this heat treatment, the ratio of the integrated magnetic flux density along the beam orbit between the inside and outside of the beam pipe and bellows became small enough to suppress beam orbit distortion. The outgassing rate of the materials with this heat treatment was reduced by one order magnitude compared to that without heat treatment. By installing the beam pipes and bellows of soft magnetic materials as part of the Japan Proton Accelerator Research Complex 3 GeV rapid cycling synchrotron beam line, the closed orbit distortion (COD) was reduced by more than 80%. In addition, a 95.5% beam survival ratio was achieved by this COD improvement.

  7. Beam loss reduction by magnetic shielding using beam pipes and bellows of soft magnetic materials

    Energy Technology Data Exchange (ETDEWEB)

    Kamiya, J., E-mail: kamiya.junichiro@jaea.go.jp; Ogiwara, N.; Hotchi, H.; Hayashi, N.; Kinsho, M.

    2014-11-01

    One of the main sources of beam loss in high power accelerators is unwanted stray magnetic fields from magnets near the beam line, which can distort the beam orbit. The most effective way to shield such magnetic fields is to perfectly surround the beam region without any gaps with a soft magnetic high permeability material. This leads to the manufacture of vacuum chambers (beam pipes and bellows) with soft magnetic materials. A Ni–Fe alloy (permalloy) was selected for the material of the pipe parts and outer bellows parts, while a ferritic stainless steel was selected for the flanges. An austenitic stainless steel, which is non-magnetic material, was used for the inner bellows for vacuum tightness. To achieve good magnetic shielding and vacuum performances, a heat treatment under high vacuum was applied during the manufacturing process of the vacuum chambers. Using this heat treatment, the ratio of the integrated magnetic flux density along the beam orbit between the inside and outside of the beam pipe and bellows became small enough to suppress beam orbit distortion. The outgassing rate of the materials with this heat treatment was reduced by one order magnitude compared to that without heat treatment. By installing the beam pipes and bellows of soft magnetic materials as part of the Japan Proton Accelerator Research Complex 3 GeV rapid cycling synchrotron beam line, the closed orbit distortion (COD) was reduced by more than 80%. In addition, a 95.5% beam survival ratio was achieved by this COD improvement.

  8. Test of the LHC DIAMOND Beam Loss Monitors

    CERN Document Server

    Dehning, B; Effinger, E; Pernegger, H; Griesmayer, E

    2011-01-01

    Chemical Vapour Deposition(CVD) diamond detectors were installed in the collimation area of the CERN LHC to study their feasibility as Fast Beam Loss Monitors in a high-­radiation environment. Four detectors were configured with fast, radiation-­hard pre-amplifiers with a bandwidth of 2GHz. The readout was via an oscilloscope with a bandwidth of 1GHz and a sampling rate of 5 GSPS. Despite the 250m cable run from the detectors to the oscilloscope, particle losses were resolved with a 2ns rise time, a pulse width of 10ns and a time resolution of 615ps. Two modes of operation were applied. For the analysis of unexpected beam aborts, the loss profile was recorded in a 1ms buffer and, for nominal operation, the histogram of the time structure of the losses was recorded in synchronism with the LHC period of 89.2us. Measurements during the LHC start-­up (February to December 2010) are presented. The Diamond Monitors gave an unprecedented insight into the time structure of the beam losses resolving the LHC RF freq...

  9. LHC Beam Instrumentation: Beam Loss and Tune Measurements (3/3)

    CERN Document Server

    CERN. Geneva

    2014-01-01

    The LHC is equipped with a full suite of sophisticated beam instrumentation which has been essential for rapid commissioning, the safe increase in total stored beam power and the understanding of machine optics and accelerator physics phenomena. These lectures will introduce these systems and comment on their contributions to the various stages of beam operation. They will include details on: the beam position system and its use for real-time global orbit feedback; the beam loss system and its role in machine protection; total and bunch by bunch intensity measurements; tune measurement and feedback; diagnostics for transverse beam size measurements, abort gap monitoring and longitudinal density measurements. Issues and problems encountered along the way will also be discussed together with the prospect for future upgrades.

  10. Absolute calibration of photon-number-resolving detectors with an analog output using twin beams

    Science.gov (United States)

    Peřina, Jan; Haderka, Ondřej; Allevi, Alessia; Bondani, Maria

    2014-01-01

    A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

  11. Absolute calibration of photon-number-resolving detectors with an analog output using twin beams

    Energy Technology Data Exchange (ETDEWEB)

    Peřina, Jan, E-mail: jan.perina.jr@upol.cz [RCPTM, Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 77146 Olomouc (Czech Republic); Haderka, Ondřej [Joint Laboratory of Optics of Palacký University and Institute of Physics AS CR, 17. listopadu 12, 771 46 Olomouc (Czech Republic); Allevi, Alessia [Dipartimento di Scienza e Alta Tecnologia, Università degli Studi dell' Insubria, I-22100 Como (Italy); Bondani, Maria [Istituto di Fotonica e Nanotecnologie, CNR-IFN, I-22100 Como (Italy)

    2014-01-27

    A method for absolute calibration of a photon-number resolving detector producing analog signals as the output is developed using a twin beam. The method gives both analog-to-digital conversion parameters and quantum detection efficiency for the photon fields. Characteristics of the used twin beam are also obtained. A simplified variant of the method applicable to fields with high signal to noise ratios and suitable for more intense twin beams is suggested.

  12. Application of Diamond Based Beam Loss Monitors at LHC

    CERN Document Server

    AUTHOR|(CDS)2080642; Lohmann, W; Rüdiger, S

    2013-05-14

    The Large Hadron Collider (LHC) was conceived in the 1980s and started the operation in 2008. It needed more than 20 years to plan and construct this accelerator and its experiments. Four main experiments are located around the ring, Compact Muon Solenoid (CMS), A Toroidal LHC Apparatus (ATLAS), A Large Ion Collider Experiment (ALICE) and LHC beauty (LHCb). Two beams that traveling in opposite direction in the LHC tunnel, collide in each of the experiments. The navigation of the beams is done by over 10000 magnets and each beam has a stored energy of 362MJ which correspond to the kinetic energy of a train like the TGV travelling of 150km/h. Only a small percentage of that energy can damage the material in the LHC ring or the magnets. This would mean a repair time of months or years, without taking any data. To avoid such a scenario, it is important to monitor the beam condition and measure the amount of losses of the beam. Such losses can for example happen due to dust particles in the vacuum chambers or due...

  13. Ionization Chambers for the LHC Beam Loss Detection

    CERN Document Server

    Assmann, R W; Ferioli, G; Gschwendtner, E; Kain, V

    2003-01-01

    At the Large Hadron Collider (LHC) a beam loss system will be used to prevent and protect superconducting magnets against coil quenches and coil damages. Ionisation chambers will be mounted outside the cryostat to measure the secondary shower particles caused by lost beam particles. Since the stored particle beam intensity is eight orders of magnitude larger than the lowest quench level and the losses should be detected with a relative error of two, the design and the location of the detectors have to be optimised. For that purpose a two-fold simulation was carried out. The longitudinal loss locations of the tertiary halo is investigated by tracking the halo through several magnet elements. These loss distributions are combined with simulations of the particle fluence outside the cryostat, which is induced by lost protons at the vacuum pipe. The base-line ionisation chamber has been tested at the PS Booster in order to determine the detector response at the high end of the dynamic range.

  14. A Fast CVD Diamond Beam Loss Monitor for LHC

    CERN Document Server

    Griesmayer, E; Dobos, D; Effinger, E; Pernegger, H

    2011-01-01

    Chemical Vapour Deposition (CVD) diamond detectors were installed in the collimation area of the CERN LHC to study their feasibility as Fast Beam Loss Monitors in a high-radiation environment. The detectors were configured with a fast, radiation-hard pre-amplifier with a bandwidth of 2 GHz. The readout was via an oscilloscope with a bandwidth of 1 GHz and a sampling rate of 5 GSPS. Despite the 250 m cable run from the detectors to the oscilloscope, single MIPs were resolved with a 2 ns rise time, a pulse width of 10 ns and a time resolution of less than 1 ns. Two modes of operation were applied. For the analysis of unexpected beam aborts, the loss profile was recorded in a 1 ms buffer and, for nominal operation, the histogram of the time structure of the losses was recorded in synchronism with the LHC period of 89.2 μs. Measurements during the LHC start-up (February to December 2010) are presented. The Diamond Monitors gave an unprecedented insight into the time structure of the beam losses resolving the 400...

  15. RFQ Designs and Beam-Loss Distributions for IFMIF

    Energy Technology Data Exchange (ETDEWEB)

    Jameson, Robert A [ORNL

    2007-01-01

    The IFMIF 125 mA cw 40 MeV accelerators will set an intensity record. Minimization of particle loss along the accelerator is a top-level requirement and requires sophisticated design intimately relating the accelerated beam and the accelerator structure. Such design technique, based on the space-charge physics of linear accelerators (linacs), is used in this report in the development of conceptual designs for the Radio-Frequency-Quadrupole (RFQ) section of the IFMIF accelerators. Design comparisons are given for the IFMIF CDR Equipartitioned RFQ, a CDR Alternative RFQ, and new IFMIF Post-CDR Equipartitioned RFQ designs. Design strategies are illustrated for combining several desirable characteristics, prioritized as minimum beam loss at energies above ~ 1 MeV, low rf power, low peak field, short length, high percentage of accelerated particles. The CDR design has ~0.073% losses above 1 MeV, requires ~1.1 MW rf structure power, has KP factor 1.7,is 12.3 m long, and accelerates ~89.6% of the input beam. A new Post-CDR design has ~0.077% losses above 1 MeV, requires ~1.1 MW rf structure power, has KP factor 1.7 and ~8 m length, and accelerates ~97% of the input beam. A complete background for the designs is given, and comparisons are made. Beam-loss distributions are used as input for nuclear physics simulations of radioactivity effects in the IFMIF accelerator hall, to give information for shielding, radiation safety and maintenance design. Beam-loss distributions resulting from a ~1M particle input distribution representative of the IFMIF ECR ion source are presented. The simulations reported were performed with a consistent family of codes. Relevant comparison with other codes has not been possible as their source code is not available. Certain differences have been noted but are not consistent over a broad range of designs and parameter range. The exact transmission found by any of these codes should be treated as indicative, as each has various sensitivities in

  16. Performance and perspectives of the diamond based Beam Condition Monitor for beam loss monitoring at CMS

    CERN Document Server

    AUTHOR|(CDS)2080862

    2015-01-01

    At CMS, a beam loss monitoring system is operated to protect the silicon detectors from high particle rates, arising from intense beam loss events. As detectors, poly-crystalline CVD diamond sensors are placed around the beam pipe at several locations inside CMS. In case of extremely high detector currents, the LHC beams are automatically extracted from the LHC rings.Diamond is the detector material of choice due to its radiation hardness. Predictions of the detector lifetime were made based on FLUKA monte-carlo simulations and irradiation test results from the RD42 collaboration, which attested no significant radiation damage over several years.During the LHC operational Run1 (2010 â?? 2013), the detector efficiencies were monitored. A signal decrease of about 50 times stronger than expectations was observed in the in-situ radiation environment. Electric field deformations due to charge carriers, trapped in radiation induced lattice defects, are responsible for this signal decrease. This so-called polarizat...

  17. Benchmarking of collimation tracking using RHIC beam loss data.

    Energy Technology Data Exchange (ETDEWEB)

    Robert-Demolaize,G.; Drees, A.

    2008-06-23

    State-of-the-art tracking tools were recently developed at CERN to study the cleaning efficiency of the Large Hadron Collider (LHC) collimation system. In order to estimate the prediction accuracy of these tools, benchmarking studies can be performed using actual beam loss measurements from a machine that already uses a similar multistage collimation system. This paper reviews the main results from benchmarking studies performed with specific data collected from operations at the Relativistic Heavy Ion Collider (RHIC).

  18. Reducing Broadband Shortwave Radiometer Calibration-Bias Caused by Longwave Irradiance in the Reference Direct Beam

    Energy Technology Data Exchange (ETDEWEB)

    Reda, Ibrahim; Andreas, Afshin; Dooraghi, Mike; Sengupta, Manajit; Habte, Aron; Kutchenreiter, Mark

    2017-01-01

    Shortwave radiometers such as pyranometers, pyrheliometers, and photovoltaic cells are calibrated with traceability to consensus reference, maintained by Absolute Cavity Radiometers (ACRs). The ACR is an open cavity with no window, and measures the extended broadband spectrum of the terrestrial direct solar beam irradiance, unlike shortwave radiometers that cover a limited range of the spectrum. The difference between the two spectral ranges may lead to calibration bias that can exceed 1%. This article describes a method to reduce the calibration bias resulting from using broadband ACRs to calibrate shortwave radiometers, by using an ACR with Schott glass window to measure the reference broadband shortwave irradiance in the terrestrial direct solar beam from 0.3 um to 3 um.

  19. Beam test calibration of the balloon-borne imaging calorimeter for the CREAM experiment

    CERN Document Server

    Marrocchesi, P S; Bagliesi, M G; Basti, A; Bigongiari, G; Castellina, A; Ciocci, M A; Di Virgilio, A; Lomtatze, T; Ganel, O; Kim, K C; Lee, M H; Ligabue, F; Lutz, L; Maestro, P; Malinine, A; Meucci, M; Millucci, V; Morsani, F; Seo, E S; Sina, R; Wu, J; Wu, J; Yoon, Y S; Zei, R; Zinn, S Y

    2010-01-01

    CREAM (Cosmic Ray Energetics And Mass) is a multi-flight balloon mission designed to collect direct data on the elemental composition and individual energy spectra of cosmic rays. Two instrument suites have been built to be flown alternately on a yearly base. The tungsten/Sci-Fi imaging calorimeter for the second flight, scheduled for December 2005, was calibrated with electron and proton beams at CERN. A calibration procedure based on the study of the longitudinal shower profile is described and preliminary results of the beam test are presented.

  20. Calibration of wavefront distortion in light modulator setup by Fourier analysis of multi-beam interference

    CERN Document Server

    Leszczyński, Adam

    2015-01-01

    We present a method to calibrate wavefront distortion of the spatial light modulator setup by registering far field images of several gaussian beams diffracted off the modulator. The Fourier transform of resulting interference images reveals phase differences between typically 5 movable points on the modulator. Repeating this measurement yields wavefront surface. Next, the amplitude efficiency is calibrated be registering near field image. As a verification we produced a superposition of 7th and 8th Bessel beams with different phase velocities and observed their interference.

  1. Cross-calibration of pencil-beam (DPX-NT) and fan-beam (QDR-4500C) dual-energy X-ray absorptiometry for sarcopenia.

    Science.gov (United States)

    Ito, Kenyu; Tsushita, Kazuyo; Muramoto, Akiko; Kanzaki, Hiroki; Nohara, Takashi; Shimizu, Hitomi; Nakazawa, Tomoko; Harada, Atsushi

    2015-11-01

    Sarcopenia, defined as the loss of muscle mass accompanied by weakness, is an important factor leading to frailty and is a growing concern in the aging Japanese society. Muscle mass can be calculated by dual-energy X-ray absorptiometry (DXA), but results differ between devices produced by different manufactures. Thus, cross-calibration is needed to compare body composition results in multicenter trials or when scanners are replaced. The purpose of this study was to perform an in vivo calibration of total body scans between pencil-beam (DPX-NT, GE Healthcare) and fan-beam (QDR-4500C, Hologic Inc.) DXA units. A total 30 subjects (15 women, 15 men, mean age = 35 years, range 22-49 years) were recruited. The lumbar bone mineral density (BMD), femoral neck BMD, appendicular fat and lean body mass, and the appendicular skeletal muscle mass index (ASMI) were highly correlated (r = 0.979-0.993, r(2) = 0.889-0.977). The conversion formulas were as follows: lumbar BMD, Y = -0.08 + 1.16X (X = QDR-4500C, Y = DPX-NT), femoral neck BMD, Y = -0.015 + 1.11X, and ASMI Y = 0.92 + 0.90X. There is excellent comparability between the DPX-NT and the QDR-4500C DXA units. However, cross-calibration equations are required to assess muscle volume, fat, and ASMI in multicenter studies investigating sarcopenia.

  2. Calibration artefacts in radio interferometry. III. Phase-only calibration and primary beam correction

    CERN Document Server

    Grobler, T G; Wijnholds, S J; Kenyon, J S; Smirnov, O M

    2016-01-01

    This is the third installment in a series of papers in which we investigate calibration artefacts. Calibration artefacts (also known as ghosts or spurious sources) are created when we calibrate with an incomplete model. In the first two papers of this series we developed a mathematical framework which enabled us to study the ghosting mechanism itself. An interesting concomitant of the second paper was that ghosts appear in symmetrical pairs. This could possibly account for spurious symmetrization. Spurious symmetrization refers to the appearance of a spurious source (the anti-ghost) symmetrically opposite an unmodelled source around a modelled source. The analysis in the first two papers indicates that the anti-ghost is usually very faint, in particular when a large number of antennas are used. This suggests that spurious symmetrization will mainly occur at an almost undetectable flux level. In this paper, we show that phase-only calibration produces an anti-ghost that is $N$-times (where $N$ denotes the numb...

  3. Measurement of Beam Loss at the Australian Synchrotron

    CERN Document Server

    Holzer, EB; Kastriotou, M; Boland, MJ; Jackson, PD; Rasool, RP; Schmidt, J; Welsch, CP

    2014-01-01

    The unprecedented requirements that new machines are setting on their diagnostic systems is leading to the development of new generation of devices with large dynamic range, sensitivity and time resolution. Beam loss detection is particularly challenging due to the large extension of new facilities that need to be covered with localized detector. Candidates to mitigate this problem consist of systems in which the sensitive part of the radiation detectors can be extended over long distance of beam lines. In this document we study the feasibility of a BLM system based on optical fiber as an active detector for an electron storage ring. The Australian Synchrotron (AS) comprises a 216m ring that stores electrons up to 3GeV. The Accelerator has recently claimed the world record ultra low transverse emittance (below pm rad) and its surroundings are rich in synchrotron radiation. Therefore, the AS provides beam conditions very similar to those expected in the CLIC/ILC damping rings. A qualitative benchmark of beam l...

  4. The LCLS Undulator Beam Loss Monitor Readout System

    Energy Technology Data Exchange (ETDEWEB)

    Dusatko, John; Browne, M.; Fisher, A.S.; Kotturi, D.; Norum, S.; Olsen, J.; /SLAC

    2012-07-23

    The LCLS Undulator Beam Loss Monitor System is required to detect any loss radiation seen by the FEL undulators. The undulator segments consist of permanent magnets which are very sensitive to radiation damage. The operational goal is to keep demagnetization below 0.01% over the life of the LCLS. The BLM system is designed to help achieve this goal by detecting any loss radiation and indicating a fault condition if the radiation level exceeds a certain threshold. Upon reception of this fault signal, the LCLS Machine Protection System takes appropriate action by either halting or rate limiting the beam. The BLM detector consists of a PMT coupled to a Cherenkov radiator located near the upstream end of each undulator segment. There are 33 BLMs in the system, one per segment. The detectors are read out by a dedicated system that is integrated directly into the LCLS MPS. The BLM readout system provides monitoring of radiation levels, computation of integrated doses, detection of radiation excursions beyond set thresholds, fault reporting and control of BLM system functions. This paper describes the design, construction and operational performance of the BLM readout system.

  5. Single Gain Radiation Tolerant LHC Beam Loss Acquisition Card

    CERN Document Server

    Effinger, E; Emery, J; Ferioli, G; Zamantzas, C

    2008-01-01

    The beam loss monitoring system is one of the most critical elements for the protection of the LHC. It must prevent the super conducting magnets from quenches and the machine components from damages, caused by beam losses. Ionization chambers and secondary emission based detectors are used at several locations around the ring. The sensors are producing a signal current, which is related to the losses. This current will be measured by a tunnel card, which acquires, digitizes and transmits the data via an optical link to the surface electronic. The usage of the system, for protection and tuning of the LHC and the scale of the LHC, imposed exceptional specifications of the dynamic range and radiation tolerance. The input dynamic allows measurements between 10pA and 1mA and its protected to high pulse of 1.5kV and its corresponding current. To cover this range, a current to frequency converter in combination with an ADC is used. The integrator output voltage is measured with an ADC to improve the resolution. The ...

  6. Beam Loss Ion Chamber System Upgrade for Experimental Halls

    CERN Document Server

    Dotson, Danny W

    2005-01-01

    The Beam loss Ion Chamber System (BLICS) was developed to protect Jefferson Labs transport lines, targets and beam dumps from a catastrophic "burn through." Range changes and testing was accomplished manually requiring the experiment to be shut down. The new upgraded system is based around an "off the shelf" Programmable Logic Controller located in a single controll box supporting up to ten individual detectors. All functions that formerly required an entry into the experimental hall and manual adjustment can be accomplished from the Machine Control Center (MCC). A further innovation was the addition of a High Voltage "Brick" at the detector location. A single cable supplies the required voltage for the Brick and a return line for the ion chamber signal. The read back screens display range, trip point, and accumulated dose for each location. The new system is very cost effective and significantly reduces the amount of lost experimental time.

  7. 2014 CERN Accelerator Schools: Beam Loss and Accelerator Protection

    CERN Multimedia

    2014-01-01

    The US-CERN-JAPAN-RUSSIA Joint International Accelerator School is organising a course on Beam Loss and Accelerator Protection to be held in Newport Beach, California, USA from 5-14 November, 2014.    This school is intended for physicists and engineers who are or may be engaged in the design, construction, and/or operation of accelerators with high power photon or particle beams and/or accelerator sub-systems with large stored energy. Application deadlines are 15 August and 4 September. Further information on this Joint School can be found at: http://cas.web.cern.ch/cas/JAS/Newport%20Beach%202014/NPBadvert.html http://indico.cern.ch/event/287647/ http://uspas.fnal.gov/programs/JAS/JAS14.shtml

  8. Prompt loss of beam ions in KSTAR plasmas

    Science.gov (United States)

    Kim, Jun Young; Rhee, T.; Kim, Junghee; Yoon, S. W.; Park, B. H.; Isobe, M.; Ogawa, K.; Ko, W.-H.

    2016-10-01

    For a toroidal plasma facility to realize fusion energy, researching the transport of fast ions is important not only due to its close relation to the heating and current drive efficiencies but also to determine the heat load on the plasma-facing components. We present a theoretical analysis and orbit simulation for the origin of lost fast-ions during neutral beam injection (NBI) heating in Korea Superconducting Tokamak Advanced Research (KSTAR) device. We adopted a two-dimensional phase diagram of the toroidal momentum and magnetic moment and describe detectable momentums at the fast-ion loss detector (FILD) position as a quadratic line. This simple method was used to model birth ions deposited by NBI and drawn as points in the momentum phase space. A Lorentz orbit code was used to calculate the fast-ion orbits and present the prompt loss characteristics of the KSTAR NBI. The scrape-off layer deposition of fast ions produces a significant prompt loss, and the model and experimental results closely agreed on the pitch-angle range of the NBI prompt loss. Our approach can provide wall load information from the fast ion loss.

  9. Prompt loss of beam ions in KSTAR plasmas

    Directory of Open Access Journals (Sweden)

    Jun Young Kim

    2016-10-01

    Full Text Available For a toroidal plasma facility to realize fusion energy, researching the transport of fast ions is important not only due to its close relation to the heating and current drive efficiencies but also to determine the heat load on the plasma-facing components. We present a theoretical analysis and orbit simulation for the origin of lost fast-ions during neutral beam injection (NBI heating in Korea Superconducting Tokamak Advanced Research (KSTAR device. We adopted a two-dimensional phase diagram of the toroidal momentum and magnetic moment and describe detectable momentums at the fast-ion loss detector (FILD position as a quadratic line. This simple method was used to model birth ions deposited by NBI and drawn as points in the momentum phase space. A Lorentz orbit code was used to calculate the fast-ion orbits and present the prompt loss characteristics of the KSTAR NBI. The scrape-off layer deposition of fast ions produces a significant prompt loss, and the model and experimental results closely agreed on the pitch-angle range of the NBI prompt loss. Our approach can provide wall load information from the fast ion loss.

  10. Impedances and power losses for an off-axis beam

    CERN Document Server

    Kurennoy, S S

    1996-01-01

    A method for calculating coupling impedances and power losses for off-axis beams is developed. It is applied to calculate impedances of small localized discontinuities like holes and slots, as well as the impedance due to a finite resistivity of chamber walls, in homogeneous chambers with an arbitrary shape of the chamber cross section. The approach requires to solve a two-dimensional electrostatic problem, which can be easily done numerically in the general case, while for some particular cases analytical solutions are obtained.

  11. Extended Commissioning and Calibration of the Dual-Beam Imaging Polarimeter

    CERN Document Server

    Masiero, Joseph; Harrington, David; Lin, Haosheng

    2008-01-01

    In our previous paper (Masiero et al. 2007) we presented the design and initial calibrations of the Dual-Beam Imaging Polarimeter (DBIP), a new optical instrument for the University of Hawaii's 2.2 m telescope on the summit of Mauna Kea, Hawaii. In this followup work we discuss our full-Stokes mode commissioning including crosstalk determination and our typical observing methodology.

  12. Performance and calibration studies of silicon strip detectors in a test beam

    Energy Technology Data Exchange (ETDEWEB)

    Banzuzi, K.; Haapakorpi, M.; Heikkinen, A.; Heinonen, J.V.; Honkanen, A.; Karimaeki, V. E-mail: veikko.karimaki@hip.fi; Maeenpaeae, T.; Pietarinen, E.; Salomaeki, T.; Tuominiemi, J

    2000-10-21

    Performance of single-sided DC-coupled silicon strip detectors is studied in the CERN H2 test beam. A great emphasis is put on the calibration of the detector response as well as on the geometric alignment of the detector planes. Performance results are presented for different angles of incidence for the particles.

  13. A simple method for energy calibration of heavy-ion beams

    NARCIS (Netherlands)

    Evers, E.J.; Vries, J.W.; Engelbertink, G.A.P.; Leun, C. van der

    1987-01-01

    A method is described for the calibration of analyzing-magnet systems of heavy-ion accelerators. It makes use of resonances in inverse (p, αγ) reactions, i.e. with heavy-ion beams on hydrogen targets. Instead of a gas target we use the very thin hydrogen-containing surface layer on a gold foil, whic

  14. An investigation into factors affecting electron density calibration for a megavoltage cone-beam CT system.

    Science.gov (United States)

    Hughes, Jessica; Holloway, Lois C; Quinn, Alexandra; Fielding, Andrew

    2012-09-06

    There is a growing interest in the use of megavoltage cone-beam computed tomography (MV CBCT) data for radiotherapy treatment planning. To calculate accurate dose distributions, knowledge of the electron density (ED) of the tissues being irradiated is required. In the case of MV CBCT, it is necessary to determine a calibration-relating CT number to ED, utilizing the photon beam produced for MV CBCT. A number of different parameters can affect this calibration. This study was undertaken on the Siemens MV CBCT system, MVision, to evaluate the effect of the following parameters on the reconstructed CT pixel value to ED calibration: the number of monitor units (MUs) used (5, 8, 15 and 60 MUs), the image reconstruction filter (head and neck, and pelvis), reconstruction matrix size (256 by 256 and 512 by 512), and the addition of extra solid water surrounding the ED phantom. A Gammex electron density CT phantom containing EDs from 0.292 to 1.707 was imaged under each of these conditions. The linear relationship between MV CBCT pixel value and ED was demonstrated for all MU settings and over the range of EDs. Changes in MU number did not dramatically alter the MV CBCT ED calibration. The use of different reconstruction filters was found to affect the MV CBCT ED calibration, as was the addition of solid water surrounding the phantom. Dose distributions from treatment plans calculated with simulated image data from a 15 MU head and neck reconstruction filter MV CBCT image and a MV CBCT ED calibration curve from the image data parameters and a 15 MU pelvis reconstruction filter showed small and clinically insignificant differences. Thus, the use of a single MV CBCT ED calibration curve is unlikely to result in any clinical differences. However, to ensure minimal uncertainties in dose reporting, MV CBCT ED calibration measurements could be carried out using parameter-specific calibration measurements.

  15. The LHC beam loss monitoring system commissioning for 2010

    CERN Document Server

    Zamantzas, C; Chery, C; Effinger, E; Emery, J; Grishin, S; Hajdu, C F; Holzer, E B; Jackson, S; Kurfuerst, C; Marsili, A; Nordt, A; Sapinski, M; Tissier, R; Venturini, G G

    2010-01-01

    The LHC Beam Loss Monitoring (BLM) system is one of the most complex instrumentation systems deployed in the LHC. In addition to protecting the collider, the system also needs to provide a means of diagnosing machine faults and deliver feedback of the losses to the control room as well as to several systems for their setup and analysis. It has to transmit and process signals from approximately 4’000 monitors, and has nearly 3 million configurable parameters. This paper will discuss its performance and ability to provide the expected measurements, the problems encountered and necessary improvements, the adequacy of related software and databases, and in general its readiness and suitability for 3.5 TeV operation.

  16. CALIBRATION ERRORS IN THE CAVITY BEAM POSITION MONITOR SYSTEM AT THE ATF2

    CERN Document Server

    Cullinan, F; Joshi, N; Lyapin, A

    2011-01-01

    It has been shown at the Accelerator Test Facility at KEK, that it is possible to run a system of 37 cavity beam position monitors (BPMs) and achieve high working resolution. However, stability of the calibration constants (position scale and radio frequency (RF) phase) over a three/four week running period is yet to be demonstrated. During the calibration procedure, random beam jitter gives rise to a statistical error in the position scale and slow orbit drift in position and tilt causes systematic errors in both the position scale and RF phase. These errors are dominant and have been evaluated for each BPM. The results are compared with the errors expected after a tested method of beam jitter subtraction has been applied.

  17. Apertures in the LHC Beam Dump System and Beam Losses During Beam Abort

    CERN Document Server

    Kramer, T; Gyr, M; Koschik, A; Uythoven, J; Weiler, T

    2008-01-01

    The LHC beam dumping system (LBDS) is used to dispose accelerated protons and ions in a wide energy range from 450 GeV up to 7 TeV. An abort gap of $3 \\mu$s is foreseen to avoid sweeping particles through the LHC ring aperture. This paper gives a brief overview of the critical apertures in the extraction region and the two beam dump lines. MAD-X tracking studies have been made to investigate the impact of particles swept through the aperture due to extraction kicker failures or the presence of particles within the abort gap. The issue of failures during beam abort is a major concern for machine protection as well as a critical factor for safe operation of the experiments and their detectors.

  18. Secondary Electron Emission Beam Loss Monitor for LHC

    CERN Document Server

    Dehning, B; Holzer, E B; Kramer, Daniel

    2008-01-01

    Beam Loss Monitoring (BLM) system is a vital part of the active protection of the LHC accelerators' elements. It should provide the number of particles lost from the primary hadron beam by measuring the radiation field induced by their interaction with matter surrounding the beam pipe. The LHC BLM system will use ionization chambers as standard detectors but in the areas where very high dose rates are expected, the Secondary Emission Monitor (SEM) chambers will be employed because of their high linearity, low sensitivity and fast response. The SEM needs a high vacuum for proper operation and has to be functional for up to 20 years, therefore all the components were designed according to the UHV requirements and a getter pump was included. The SEM electrodes are made of Ti because of its Secondary Emission Yield (SEY) stability. The sensitivity of the SEM was modeled in Geant4 via the Photo-Absorption Ionization module together with custom parameterization of the very low energy secondary electron production. ...

  19. Scenario for Precision Beam Energy Calibration in FCC-ee

    CERN Document Server

    Koop, I A

    2015-01-01

    The resonance depolarization method was very successfully used in the experiments at LEP, where the mass of the Z-boson was determined with the relative uncertainty [1, 2]. In the future FCC-ee circular electron-positron collider the luminosity at Z-peak (beam energy 45.5 GeV) is expected be 4-5 orders of magnitude higher and one goal is to perform the same experiments as at LEP, but with much greater accuracy, approaching the level of [3]. Obviously this can be done only by measuring the spin precession frequency. But there are many problems which still need to be solved on the way towards a complete design. The first one: the self-polarization takes too long a time. The Sokolov-Ternov polarization time is about 250 hours at Z-peak. One approach is to install the special field-asymmetric polarizing wigglers to make the self-polarization time much shorter [4, 5] and to utilize only few percent of the polarization degree to measure the resonance spin precession frequency. But these very strong wigglers substan...

  20. A new beam loss detector for low-energy proton and heavy-ion accelerators

    Science.gov (United States)

    Liu, Zhengzheng; Crisp, Jenna; Russo, Tom; Webber, Robert; Zhang, Yan

    2014-12-01

    The Facility for Rare Isotope Beams (FRIB) to be constructed at Michigan State University shall deliver a continuous, 400 kW heavy ion beam to the isotope production target. This beam is capable of inflicting serious damage on accelerator components, e.g. superconducting RF accelerating cavities. A Beam Loss Monitoring (BLM) System is essential for detecting beam loss with sufficient sensitivity and promptness to inform the machine protection system (MPS) and operations personnel of impending dangerous losses. Radiation transport simulations reveal shortcomings in the use of ionization chambers for the detection of beam losses in low-energy, heavy-ion accelerators. Radiation cross-talk effects due to the folded geometry of the FRIB LINAC pose further complications to locating specific points of beam loss. We propose a newly developed device, named the Loss Monitor Ring (LMR1

  1. Loss of accuracy using smeared properties in composite beam modeling

    Science.gov (United States)

    Liu, Ning

    Advanced composite materials have broad, proven applications in many engineering systems ranging from sports equipment sectors to components on the space shuttle because of their lightweight characteristics and significantly high stiffness. Together with this merit of composite materials is the challenge of improving computational simulation process for composites analysis. Composite structures, particularly composite laminates, usually consist of many layers with different lay-up angles. The anisotropic and heterogeneous features render 3D finite element analysis (FEA) computationally expensive in terms of the computational time and the computing power. At the constituent level, composite materials are heterogeneous. But quite often one homogenizes each layer of composites, i.e. lamina, and uses the homogenized material properties as averaged (smeared) values of those constituent materials for analysis. This is an approach extensively used in design and analysis of composite laminates. Furthermore, many industries tempted to use smeared properties at the laminate level to further reduce the model of composite structures. At this scale, smeared properties are averaged material properties that are weighted by the layer thickness. Although this approach has the advantage of saving computational time and cost of modeling significantly, the prediction of the structural responses may not be accurate, particularly the pointwise stress distribution. Therefore, it is important to quantify the loss of accuracy when one uses smeared properties. In this paper, several different benchmark problems are carefully investigated in order to exemplify the effect of the smeared properties on the global behavior and pointwise stress distribution of the composite beam. In the classical beam theory, both Newtonian method and variational method include several ad hoc assumptions to construct the model, however, these assumptions are avoided if one uses variational asymptotic method. VABS

  2. Self-calibration of cone-beam CT geometry using 3D-2D image registration

    Science.gov (United States)

    Ouadah, S.; Stayman, J. W.; Gang, G. J.; Ehtiati, T.; Siewerdsen, J. H.

    2016-04-01

    Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D projection data to a previously acquired 3D image. It also yields a method by which calibration of simple circular orbits can be improved. The registration uses a normalized gradient information similarity metric and the covariance matrix adaptation-evolution strategy optimizer for robustness against local minima and changes in image content. The resulting transformation provides a ‘self-calibration’ of system geometry. The algorithm was tested in phantom studies using both a cone-beam CT (CBCT) test-bench and a robotic C-arm (Artis Zeego, Siemens Healthcare) for circular and non-circular orbits. Self-calibration performance was evaluated in terms of the full-width at half-maximum (FWHM) of the point spread function in CBCT reconstructions, the reprojection error (RPE) of steel ball bearings placed on each phantom, and the overall quality and presence of artifacts in CBCT images. In all cases, self-calibration improved the FWHM—e.g. on the CBCT bench, FWHM  =  0.86 mm for conventional calibration compared to 0.65 mm for self-calibration (p  <  0.001). Similar improvements were measured in RPE—e.g. on the robotic C-arm, RPE  =  0.73 mm for conventional calibration compared to 0.55 mm for self-calibration (p  <  0.001). Visible improvement was evident in CBCT reconstructions using self-calibration, particularly about high-contrast, high-frequency objects (e.g. temporal bone air cells and a surgical needle). The results indicate that self-calibration can improve even upon systems with presumably accurate geometric calibration and is

  3. Self-calibration of cone-beam CT geometry using 3D–2D image registration

    Science.gov (United States)

    Ouadah, S; Stayman, J W; Gang, G J; Ehtiati, T; Siewerdsen, J H

    2016-01-01

    Robotic C-arms are capable of complex orbits that can increase field of view, reduce artifacts, improve image quality, and/or reduce dose; however, it can be challenging to obtain accurate, reproducible geometric calibration required for image reconstruction for such complex orbits. This work presents a method for geometric calibration for an arbitrary source-detector orbit by registering 2D projection data to a previously acquired 3D image. It also yields a method by which calibration of simple circular orbits can be improved. The registration uses a normalized gradient information similarity metric and the covariance matrix adaptation-evolution strategy optimizer for robustness against local minima and changes in image content. The resulting transformation provides a ‘self-calibration’ of system geometry. The algorithm was tested in phantom studies using both a cone-beam CT (CBCT) test-bench and a robotic C-arm (Artis Zeego, Siemens Healthcare) for circular and non-circular orbits. Self-calibration performance was evaluated in terms of the full-width at half-maximum (FWHM) of the point spread function in CBCT reconstructions, the reprojection error (RPE) of steel ball bearings placed on each phantom, and the overall quality and presence of artifacts in CBCT images. In all cases, self-calibration improved the FWHM—e.g. on the CBCT bench, FWHM = 0.86 mm for conventional calibration compared to 0.65 mm for self-calibration (p < 0.001). Similar improvements were measured in RPE—e.g. on the robotic C-arm, RPE = 0.73 mm for conventional calibration compared to 0.55 mm for self-calibration (p < 0.001). Visible improvement was evident in CBCT reconstructions using self-calibration, particularly about high-contrast, high-frequency objects (e.g. temporal bone air cells and a surgical needle). The results indicate that self-calibration can improve even upon systems with presumably accurate geometric calibration and is applicable to situations where conventional

  4. The beam-based calibration of an X-ray pinhole camera at SSRF

    Institute of Scientific and Technical Information of China (English)

    LENG Yong-Bin; HUANG Guo-Qing; ZHANG Man-Zhou; CHEN Zhi-Chu; CHEN Jie; YE Kai-Rong

    2012-01-01

    A pinhole camera for imaging X-ray synchrotron radiation from a dipole magnet is now in operation at the Shanghai Synchrotron Radiation Facility (SSRF) storage ring.The electron beam size is derived by unfolding the radiation image and the point spread function (PSF) with deconvolution techniques.The performance of the pinhole is determined by the accuracy of the PSF measurement.This article will focus on a beam-based calibration scheme to measure the PSF system by varying the beam images with different quadrupole settings and fitting them with the corresponding theoretical beam sizes.Applying this method at SSRF,the PSF value of the pinhole is revised from 37 to 44 μm.The deviation in beam size between the theoretical value and the measured value is minimized to 4% after calibration.This optimization allows us to observe the horizontal disturbance due to injection down to as small as 0.5 μm.

  5. Absolute calibration and beam reconstruction of MITO (a ground-based instrument in the millimetric region)

    CERN Document Server

    Savini, G; Battistelli, E S; De Petris, M; Lamagna, L; Luzzi, G; Palladino, E

    2003-01-01

    An efficient sky data reconstruction derives from a precise characterization of the observing instrument. Here we describe the reconstruction of performances of a single-pixel 4-band photometer installed at MITO (Millimeter and Infrared Testagrigia Observatory) focal plane. The strategy of differential sky observations at millimeter wavelengths, by scanning the field of view at constant elevation wobbling the subreflector, induces a good knowledge of beam profile and beam-throw amplitude, allowing efficient data recovery. The problems that arise estimating the detectors throughput by drift scanning on planets are shown. Atmospheric transmission, monitored by skydip technique, is considered for deriving final responsivities for the 4 channels using planets as primary calibrators.

  6. The Fermilab Main Injector: high intensity operation and beam loss control

    CERN Document Server

    Brown, Bruce C; Capista, David; Chou, Weiren; Kourbanis, Ioanis; Morris, Denton K; Seiya, Kiyomi; Wu, Guan Hong; Yang, Ming-Jen

    2013-01-01

    From 2005 through 2012, the Fermilab Main Injector provided intense beams of 120 GeV protons to produce neutrino beams and antiprotons. Hardware improvements in conjunction with improved diagnostics allowed the system to reach sustained operation at ~400 kW beam power. Transmission was very high except for beam lost at or near the 8 GeV injection energy where 95% beam transmission results in about 1.5 kW of beam loss. By minimizing and localizing loss, residual radiation levels fell while beam power was doubled. Lost beam was directed to either the collimation system or to the beam abort. Critical apertures were increased while improved instrumentation allowed optimal use of available apertures. We will summarize the improvements required to achieve high intensity, the impact of various loss control tools and the status and trends in residual radiation in the Main Injector.

  7. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Veltri, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Sonato, P. [Consorzio RFX, Euratom-ENEA association, C.so Stati Uniti 4, 35127 Padova (Italy); Dipartimento di Ingegneria Elettrica, Padova University, Via Gradenigo 6/a, 35131 Padova (Italy)

    2014-02-15

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  8. Comparative study of beam losses and heat loads reduction methods in MITICA beam source

    Science.gov (United States)

    Sartori, E.; Agostinetti, P.; Dal Bello, S.; Marcuzzi, D.; Serianni, G.; Sonato, P.; Veltri, P.

    2014-02-01

    In negative ion electrostatic accelerators a considerable fraction of extracted ions is lost by collision processes causing efficiency loss and heat deposition over the components. Stripping is proportional to the local density of gas, which is steadily injected in the plasma source; its pumping from the extraction and acceleration stages is a key functionality for the prototype of the ITER Neutral Beam Injector, and it can be simulated with the 3D code AVOCADO. Different geometric solutions were tested aiming at the reduction of the gas density. The parameter space considered is limited by constraints given by optics, aiming, voltage holding, beam uniformity, and mechanical feasibility. The guidelines of the optimization process are presented together with the proposed solutions and the results of numerical simulations.

  9. A new and simple calibration-independent method for measuring the beam energy of a cyclotron.

    Science.gov (United States)

    Gagnon, Katherine; Jensen, Mikael; Thisgaard, Helge; Publicover, Julia; Lapi, Suzanne; McQuarrie, Steve A; Ruth, Thomas J

    2011-01-01

    This work recommends a new and simple-to-perform method for measuring the beam energy of an accelerator. The proposed method requires the irradiation of two monitor foils interspaced by an energy degrader. The primary advantage of the proposed method, which makes this method unique from previous energy evaluation strategies that employ the use of monitor foils, is that this method is independent of the detector efficiency calibration. This method was evaluated by performing proton activation of (nat)Cu foils using both a cyclotron and a tandem Van de Graaff accelerator. The monitor foil activities were read using a dose calibrator set to an arbitrary calibration setting. Excellent agreement was noted between the nominal and measured proton energies.

  10. A new and simple calibration-independent method for measuring the beam energy of a cyclotron

    Energy Technology Data Exchange (ETDEWEB)

    Gagnon, Katherine, E-mail: kgagnon1@ualberta.c [Cross Cancer Institute, Edmonton PET Centre, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Jensen, Mikael; Thisgaard, Helge [Hevesy Laboratory, Risoe-DTU, Technical University of Denmark, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Publicover, Julia; Lapi, Suzanne [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); McQuarrie, Steve A. [Cross Cancer Institute, Edmonton PET Centre, University of Alberta, Edmonton, AB, T6G 1Z2 (Canada); Ruth, Thomas J. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)

    2011-01-15

    This work recommends a new and simple-to-perform method for measuring the beam energy of an accelerator. The proposed method requires the irradiation of two monitor foils interspaced by an energy degrader. The primary advantage of the proposed method, which makes this method unique from previous energy evaluation strategies that employ the use of monitor foils, is that this method is independent of the detector efficiency calibration. This method was evaluated by performing proton activation of {sup nat}Cu foils using both a cyclotron and a tandem Van de Graaff accelerator. The monitor foil activities were read using a dose calibrator set to an arbitrary calibration setting. Excellent agreement was noted between the nominal and measured proton energies.

  11. Reliability Tests of the LHC Beam Loss Monitoring FPGA Firmware

    CERN Document Server

    Hajdu, C F; Dehning, B; Jackson, S

    2010-01-01

    The LHC Beam Loss Monitoring (BLM) system is one of the most complex instrumentation systems deployed in the LHC. In addition to protecting the collider, the system also needs to provide a means of diagnosing machine faults and deliver a feedback of losses to the control room as well as to several systems for their setup and analysis. It has to transmit and process signals from almost 4’000 monitors, and has nearly 3 million configurable parameters. In a system of such complexity, firmware reliability is a critical issue. The integrity of the signal chain of the LHC BLM system and its ability to correctly detect unwanted scenarios and thus provide the required protection level must be ensured. In order to analyze the reliability and functionality, an advanced verification environment has been developed to evaluate the performance and response of the FPGA-based data analysis firmware. This paper will report on the numerous tests that have been performed and on how the results are used to quantify the reliabi...

  12. Determination of relative ion chamber calibration coefficients from depth-ionization measurements in clinical electron beams

    Science.gov (United States)

    Muir, B. R.; McEwen, M. R.; Rogers, D. W. O.

    2014-10-01

    A method is presented to obtain ion chamber calibration coefficients relative to secondary standard reference chambers in electron beams using depth-ionization measurements. Results are obtained as a function of depth and average electron energy at depth in 4, 8, 12 and 18 MeV electron beams from the NRC Elekta Precise linac. The PTW Roos, Scanditronix NACP-02, PTW Advanced Markus and NE 2571 ion chambers are investigated. The challenges and limitations of the method are discussed. The proposed method produces useful data at shallow depths. At depths past the reference depth, small shifts in positioning or drifts in the incident beam energy affect the results, thereby providing a built-in test of incident electron energy drifts and/or chamber set-up. Polarity corrections for ion chambers as a function of average electron energy at depth agree with literature data. The proposed method produces results consistent with those obtained using the conventional calibration procedure while gaining much more information about the behavior of the ion chamber with similar data acquisition time. Measurement uncertainties in calibration coefficients obtained with this method are estimated to be less than 0.5%. These results open up the possibility of using depth-ionization measurements to yield chamber ratios which may be suitable for primary standards-level dissemination.

  13. Calibration of a multi-beam Laser System by using a TLS-generated Reference

    Science.gov (United States)

    Gordon, M.; Meidow, J.

    2013-10-01

    Rotating multi-beam LIDARs mounted on moving platforms have become very successful for many applications such as autonomous navigation, obstacle avoidance or mobile mapping. To obtain accurate point coordinates, a precise calibration of such a LIDAR system is required. For the determination of the corresponding parameters we propose a calibration scheme which exploits the information of 3D reference point clouds captured by a terrestrial laser scanning (TLS) device. It is assumed that the accuracy of this point clouds is considerably higher than that from the multi-beam LIDAR and that the data represent faces of man-made objects at different distances. After extracting planes in the reference data sets, the point-plane-incidences of the measured points and the reference planes are used to formulate the implicit constraints. We inspect the Velodyne HDL-64E S2 system as the best-known representative for this kind of sensor system. The usability and feasibility of the calibration procedure is demonstrated with real data sets representing building faces (walls, roof planes and ground). Beside the improvement of the point accuracy by considering the calibration results, we test the significance of the parameters related to the sensor model and consider the uncertainty of measurements w.r.t. the measured distances. The Velodyne returns two kinds of measurements - distances and encoder angles. To account for this, we perform a variance component estimation to obtain realistic standard deviations for the observations.

  14. Identification and Classification of Beam Loss Patterns in the Large Hadron Collider

    CERN Document Server

    Panagiotis, Theodoropoulos; Valentino, Gianluca; Redaelli, Stefano; Herbster, Mark

    The Large Hadron Collider, is the largest particle accelerator ever built, achieving record beam energy and beam intensity. Beam losses are unavoidable and can risk the safety of accelerator’s components. Beam loss maps are used to validate the collimation system, designed to protect the accelerator against beam losses. The complexity of this system requires well defined inspection methods and well defined case studies that ensure normal operation and efficient performance evaluation. In this work, enhancements are proposed to the existing validation methods with extensions towards automating the inspection mechanisms, introducing pattern recognition and statistical learning methods.

  15. Calibration and validation of FLFArs -- a new flood loss function for Australian residential structures

    Science.gov (United States)

    Hasanzadeh Nafari, R.; Ngo, T.; Lehman, W.

    2016-01-01

    Rapid urbanisation, climate change and unsustainable developments are increasing the risk of floods. Flood is a frequent natural hazard that has significant financial consequences for Australia. The emergency response system in Australia is very successful and has saved many lives over the years. However, the preparedness for natural disaster impacts in terms of loss reduction and damage mitigation has been less successful. In this paper, a newly derived flood loss function for Australian residential structures (FLFArs) has been presented and calibrated by using historic data collected from an extreme event in Queensland, Australia, that occurred in 2013. Afterwards, the performance of the method developed in this work (contrasted to one Australian model and one model from USA) has been compared with the observed damage data collected from a 2012 flood event in Maranoa, Queensland. Based on this analysis, validation of the selected methodologies has been performed in terms of Australian geographical conditions. Results obtained from the new empirically based function (FLFArs) and the other models indicate that it is apparent that the precision of flood damage models is strongly dependent on selected stage damage curves, and flood damage estimation without model calibration might result in inaccurate predictions of losses. Therefore, it is very important to be aware of the associated uncertainties in flood risk assessment, especially if models have not been calibrated with real damage data.

  16. A Layer Correlation technique for pion energy calibration at the 2004 ATLAS Combined Beam Test

    CERN Document Server

    INSPIRE-00433248; Abdallah, J.M.; Addy, T.N.; Adragna, P.; Aharrouche, M.; Ahmad, A.; Akesson, T.P.A.; Aleksa, M.; Alexa, C.; Anderson, K.; Andreazza, A.; Anghinolfi, F.; Antonaki, A.; Arabidze, G.; Arik, E.; Atkinson, T.; Baines, J.; Baker, O.K.; Banfi, D.; Baron, S.; Barr, A.J.; Beccherle, R.; Beck, H.P.; Belhorma, B.; Bell, P.J.; Benchekroun, D.; Benjamin, D.P.; Benslama, K.; Bergeaas Kuutmann, E.; Bernabeu, J.; Bertelsen, H.; Binet, S.; Biscarat, C.; Boldea, V.; Bondarenko, V.G.; Boonekamp, M.; Bosman, M.; Bourdarios, C.; Broklova, Z.; Burckhart Chromek, D.; Bychkov, V.; Callahan, J.; Calvet, D.; Canneri, M.; Capeans Garrido, M.; Caprini, M.; Cardiel Sas, L.; Carli, T.; Carminati, L.; Carvalho, J.; Cascella, M.; Castillo, M.V.; Catinaccio, A.; Cauz, D.; Cavalli, D.; Cavalli Sforza, M.; Cavasinni, V.; Cetin, S.A.; Chen, H.; Cherkaoui, R.; Chevalier, L.; Chevallier, F.; Chouridou, S.; Ciobotaru, M.; Citterio, M.; Clark, A.; Cleland, B.; Cobal, M.; Cogneras, E.; Conde Muino, P.; Consonni, M.; Constantinescu, S.; Cornelissen, T.; Correard, S.; Corso Radu, A.; Costa, G.; Costa, M.J.; Costanzo, D.; Cuneo, S.; Cwetanski, P.; Da Silva, D.; Dam, M.; Dameri, M.; Danielsson, H.O.; Dannheim, D.; Darbo, G.; Davidek, T.; De, K.; Defay, P.O.; Dekhissi, B.; Del Peso, J.; Del Prete, T.; Delmastro, M.; Derue, F.; Di Ciaccio, L.; Di Girolamo, B.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; Dobos, D.; Dobson, M.; Dolgoshein, B.A.; Dotti, A.; Drake, G.; Drasal, Z.; Dressnandt, N.; Driouchi, C.; Drohan, J.; Ebenstein, W.L.; Eerola, P.; Efthymiopoulos, I.; Egorov, K.; Eifert, T.F.; Einsweiler, K.; El Kacimi, M.; Elsing, M.; Emelyanov, D.; Escobar, C.; Etienvre, A.I.; Fabich, A.; Facius, K.; Fakhr-Edine, A.I.; Fanti, M.; Farbin, A.; Farthouat, P.; Fassouliotis, D.; Fayard, L.; Febbraro, R.; Fedin, O.L.; Fenyuk, A.; Fergusson, D.; Ferrari, P.; Ferrari, R.; Ferreira, B.C.; Ferrer, A.; Ferrere, D.; Filippini, G.; Flick, T.; Fournier, D.; Francavilla, P.; Francis, D.; Froeschl, R.; Froidevaux, D.; Fullana, E.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Gallas, M.; Gallop, B.J.; Gameiro, S.; Gan, K.K.; Garcia, R.; Garcia, C.; Gavrilenko, I.L.; Gemme, C.; Gerlach, P.; Ghodbane, N.; Giakoumopoulou, V.; Giangiobbe, V.; Giokaris, N.; Glonti, G.; Gottfert, T.; Golling, T.; Gollub, N.; Gomes, A.; Gomez, M.D.; Gonzalez-Sevilla, S.; Goodrick, M.J.; Gorfine, G.; Gorini, B.; Goujdami, D.; Grahn, K.J.; Grenier, P.; Grigalashvili, N.; Grishkevich, Y.; Grosse-Knetter, J.; Gruwe, M.; Guicheney, C.; Gupta, A.; Haeberli, C.; Hartel, R.; Hajduk, Z.; Hakobyan, H.; Hance, M.; Hansen, J.D.; Hansen, P.H.; Hara, K.; Harvey, A., Jr; Hawkings, R.J.; Heinemann, F.E.W.; Henriques Correia, A.; Henss, T.; Hervas, L.; Higon, E.; Hill, J.C.; Hoffman, J.; Hostachy, J.Y.; Hruska, I.; Hubaut, F.; Huegging, F.; Hulsbergen, W.; Hurwitz, M.; Iconomidou-Fayard, L.; Jansen, E.; Jen-La Plante, I.; Johansson, P.D.C.; Jon-And, K.; Joos, M.; Jorgensen, S.; Joseph, J.; Kaczmarska, A.; Kado, M.; Karyukhin, A.; Kataoka, M.; Kayumov, F.; Kazarov, A.; Keener, P.T.; Kekelidze, G.D.; Kerschen, N.; Kersten, S.; Khomich, A.; Khoriauli, G.; Khramov, E.; Khristachev, A.; Khubua, J.; Kittelmann, T.H.; Klingenberg, R.; Klinkby, E.B.; Kodys, P.; Koffas, T.; Kolos, S.; Konovalov, S.P.; Konstantinidis, N.; Kopikov, S.; Korolkov, I.; Kostyukhin, V.; Kovalenko, S.; Kowalski, T.Z.; Kruger, K.; Kramarenko, V.; Kudin, L.G.; Kulchitsky, Y.; Lacasta, C.; Lafaye, R.; Laforge, B.; Lampl, W.; Lanni, F.; Laplace, S.; Lari, T.; Le Bihan, A.C.; Lechowski, M.; Ledroit-Guillon, F.; Lehmann, G.; Leitner, R.; Lelas, D.; Lester, C.G.; Liang, Z.; Lichard, P.; Liebig, W.; Lipniacka, A.; Lokajicek, M.; Louchard, L.; Lourerio, K.F.; Lucotte, A.; Luehring, F.; Lund-Jensen, B.; Lundberg, B.; Ma, H.; Mackeprang, R.; Maio, A.; Maleev, V.P.; Malek, F.; Mandelli, L.; Maneira, J.; Mangin-Brinet, M.; Manousakis, A.; Mapelli, L.; Marques, C.; Marti i Garcia, S.; Martin, F.; Mathes, M.; Mazzanti, M.; McFarlane, K.W.; McPherson, R.; Mchedlidze, G.; Mehlhase, S.; Meirosu, C.; Meng, Z.; Meroni, C.; Mialkovski, V.; Mikulec, B.; Milstead, D.; Minashvili, I.; Mindur, B.; Mitsou, V.A.; Moed, S.; Monnier, E.; Moorhead, G.; Morettini, P.; Morozov, S.V.; Mosidze, M.; Mouraviev, S.V.; Moyse, E.W.J.; Munar, A.; Myagkov, A.; Nadtochi, A.V.; Nakamura, K.; Nechaeva, P.; Negri, A.; Nemecek, S.; Nessi, M.; Nesterov, S.Y.; Newcomer, F.M.; Nikitine, I.; Nikolaev, K.; Nikolic-Audit, I.; Ogren, H.; Oh, S.H.; Oleshko, S.B.; Olszowska, J.; Onofre, A.; Padilla Aranda, C.; Paganis, S.; Pallin, D.; Pantea, D.; Paolone, V.; Parodi, F.; Parsons, J.; Parzhitskiy, S.; Pasqualucci, E.; Passmored, S.M.; Pater, J.; Patrichev, S.; Peez, M.; Perez Reale, V.; Perini, L.; Peshekhonov, V.D.; Petersen, J.; Petersen, T.C.; Petti, R.; Phillips, P.W.; Pina, J.; Pinto, B.; Podlyski, F.; Poggioli, L.; Poppleton, A.; Poveda, J.; Pralavorio, P.; Pribyl, L.; Price, M.J.; Prieur, D.; Puigdengoles, C.; Puzo, P.; Rohne, O.; Ragusa, F.; Rajagopalan, S.; Reeves, K.; Reisinger, I.; Rembser, C.; Bruckman de Renstrom, P.A.; Reznicek, P.; Ridel, M.; Risso, P.; Riu, I.; Robinson, D.; Roda, C.; Roe, S.; Rohne, O.; Romaniouk, A.; Rousseau, D.; Rozanov, A.; Ruiz, A.; Rusakovich, N.; Rust, D.; Ryabov, Y.F.; Ryjov, V.; Salto, O.; Salvachua, B.; Salzburger, A.; Sandaker, H.; Santamarina Rios, C.; Santi, L.; Santoni, C.; Saraiva, J.G.; Sarri, F.; Sauvage, G.; Says, L.P.; Schaefer, M.; Schegelsky, V.A.; Schiavi, C.; Schieck, J.; Schlager, G.; Schlereth, J.; Schmitt, C.; Schultes, J.; Schwemling, P.; Schwindling, J.; Seixas, J.M.; Seliverstov, D.M.; Serin, L.; Sfyrla, A.; Shalanda, N.; Shaw, C.; Shin, T.; Shmeleva, A.; Silva, J.; Simion, S.; Simonyan, M.; Sloper, J.E.; Smirnov, S.Yu; Smirnova, L.; Solans, C.; Solodkov, A.; Solovianov, O.; Soloviev, I.; Sosnovtsev, V.V.; Spano, F.; Speckmayer, P.; Stancu, S.; Stanek, R.; Starchenko, E.; Straessner, A.; Suchkov, S.I.; Suk, M.; Szczygiel, R.; Tarrade, F.; Tartarelli, F.; Tas, P.; Tayalati, Y.; Tegenfeldt, F.; Teuscher, R.; Thioye, M.; Tikhomirov, V.O.; Timmermans, C.J.W.P.; Tisserant, S.; Toczek, B.; Tremblet, L.; Troncon, C.; Tsiareshka, P.; Tyndel, M.; Karagoez Unel, M.; Unal, G.; Unel, G.; Usai, G.; Van Berg, R.; Valero, A.; Valkar, S.; Valls, J.A.; Vandelli, W.; Vannucci, F.; Vartapetian, A.; Vassilakopoulos, V.I.; Vasilyeva, L.; Vazeille, F.; Vernocchi, F.; Vetter-Cole, Y.; Vichou, I.; Vinogradov, V.; Virzi, J.; Vivarelli, I.; de Vivie, J.B.; Volpi, M.; Vu Anh, T.; Wang, C.; Warren, M.; Weber, J.; Weber, M.; Weidberg, A.R.; Weingarten, J.; Wells, P.S.; Werner, P.; Wheeler, S.; Wiessmann, M.; Wilkens, H.; Williams, H.H.; Wingerter-Seez, I.; Yasu, Y.; Zaitsev, A.; Zenin, A.; Zenis, T.; Zenonos, Z.; Zhang, H.; Zhelezko, A.; Zhou, N.

    2011-01-01

    A new method for calibrating the hadron response of a segmented calorimeter is developed and successfully applied to beam test data. It is based on a principal component analysis of the calorimeter layer energy deposits, exploiting longitudinal shower development information to improve the measured energy resolution. Corrections for invisible hadronic energy and energy lost in dead material in front of and between the calorimeters of the ATLAS experiment were calculated with simulated Geant4 Monte Carlo events and used to reconstruct the energy of pions impinging on the calorimeters during the 2004 Barrel Combined Beam Test at the CERN H8 area. For pion beams with energies between 20 and 180 GeV, the particle energy is reconstructed within 3% and the energy resolution is improved by 11% to 25% compared to the response at the electromagnetic scale.

  17. Cryogenic Beam Loss Monitors for the Superconducting Magnets of the LHC

    CERN Document Server

    Bartosik, MR; Sapinski, M; Kurfuerst, C; Griesmayer, E; Eremin, V; Verbitskaya, E

    2014-01-01

    The Beam Loss Monitor detectors close to the interaction points of the Large Hadron Collider are currently located outside the cryostat, far from the superconducting coils of the magnets. In addition to their sensitivity to lost beam particles, they also detect particles coming from the experimental collisions, which do not contribute significantly to the heat deposition in the superconducting coils. In the future, with beams of higher energy and brightness resulting in higher luminosity, distinguishing between these interaction products and dangerous quench-provoking beam losses from the primary proton beams will be challenging. The system can be optimised by locating beam loss monitors as close as possible to the superconducting coils, inside the cold mass in a superfluid helium environment, at 1.9 K. The dose then measured by such Cryogenic Beam Loss Monitors would more precisely correspond to the real dose deposited in the coil. The candidates under investigation for such detectors are based on p+-n-n+ si...

  18. Mitigation of Numerical Noise for Beam Loss Simulations Proc. HB2016 Malmo, Sweden

    CERN Document Server

    Kesting, Frederik

    2017-01-01

    Numerical noise emerges in self-consistent simulations of charged particles, and its mitigation is investigated since the first numerical studies in plasma physics. In accelerator physics, recent studies find an artificial diffusion of the particle beam due to numerical noise in particle-in-cell tracking, which is of particular importance for high intensity machines with a long storage time, as the SIS100 at FAIR or in context of the LIU upgrade at CERN. In beam loss simulations for these projects artificial effects must be distinguished from physical beam loss. Therefore, it is important to relate artificial diffusion to artificial beam loss, and to choose simulation parameters such that physical beam loss is well resolved. As a practical tool, we therefore suggest a scaling law to find optimal simulation parameters for a given maximum percentage of acceptable artificial beam loss.

  19. Development, Production and Testing of 4500 Beam Loss Monitors

    CERN Document Server

    Holzer, E B; Dehning, B; Ferioli, G; Grishin, V; Jimenez, T M; Koshelev, A; Kramer, Daniel; Larionov, A; Taborelli, M; Seleznev, V; Sleptsov, M; Sytin, A; Wevers, I

    2008-01-01

    Beam-loss monitoring (BLM) [1] is a key element in the LHC machine protection. 4250 nitrogen filled ionization chambers (IC) and 350 secondary emission monitors (SEM) have been manufactured and tested at the Institute for High Energy Physics (IHEP) in Protvino, Russia, following their development at CERN. Signal speed and robustness against aging were the main design criteria. Each monitor is permanently sealed inside a stainless-steel cylinder. The quality of the welding was a critical aspect during production. The SEMs are requested to hold a vacuum of $10^{-7}$ bar. Impurity levels from thermal and radiationinduced desorption should remain in the range of parts per million in the ICs. To avoid radiation aging (up to $2·10^{8}$ Gy in 20 years) production of the chambers followed strict UHV requirements. IHEP designed and built the UHV production stand. Due to the required dynamic range of $10^{8}$, the leakage current of the monitors has to stay below 2 pA. Several tests during and after production were ...

  20. Simulation and optimization of beam losses during continuous transfer extraction at the CERN Proton Synchrotron

    CERN Document Server

    Garcia, J B

    2011-01-01

    The proton beams used for the fixed target physics at the Super Proton Synchrotron (SPS) are extracted from the Proton Synchrotron ( PS) by a multiturn technique called continuous transfer (CT). During the CT extraction, large losses are observed in locations where the machine aperture should be large enough to accommodate the circulating beam. This limits the maximum intensity deliverable due to the induced stray radiation outside the PS tunnel. Scattered particles from the interaction with the electrostatic septum are identified as the possible source of these losses. This article presents a detailed study aiming to understand the origin of losses and propose possible cures. The simulations could reproduce accurately the beam loss pattern measured in real machine operation and determine the beam shaving, intrinsic to the extraction process, as the cause for the unexpected losses. Since these losses are unavoidable, the proposed solution implies a new optics scheme displacing the losses to a region with bett...

  1. Risk finance for catastrophe losses with Pareto-calibrated Lévy-stable severities.

    Science.gov (United States)

    Powers, Michael R; Powers, Thomas Y; Gao, Siwei

    2012-11-01

    For catastrophe losses, the conventional risk finance paradigm of enterprise risk management identifies transfer, as opposed to pooling or avoidance, as the preferred solution. However, this analysis does not necessarily account for differences between light- and heavy-tailed characteristics of loss portfolios. Of particular concern are the decreasing benefits of diversification (through pooling) as the tails of severity distributions become heavier. In the present article, we study a loss portfolio characterized by nonstochastic frequency and a class of Lévy-stable severity distributions calibrated to match the parameters of the Pareto II distribution. We then propose a conservative risk finance paradigm that can be used to prepare the firm for worst-case scenarios with regard to both (1) the firm's intrinsic sensitivity to risk and (2) the heaviness of the severity's tail.

  2. Heavy ion beams from an Alphatross source for use in calibration and testing of diagnostics

    Science.gov (United States)

    Ward, R. J.; Brown, G. M.; Ho, D.; Stockler, B. F. O. F.; Freeman, C. G.; Padalino, S. J.; Regan, S. P.

    2016-10-01

    Ion beams from the 1.7 MV Pelletron Accelerator at SUNY Geneseo have been used to test and calibrate many inertial confinement fusion (ICF) diagnostics and high energy density physics (HEDP) diagnostics used at the Laboratory for Laser Energetics (LLE). The ion source on this accelerator, a radio-frequency (RF) alkali-metal charge exchange source called an Alphatross, is designed to produce beams of hydrogen and helium isotopes. There is interest in accelerating beams of carbon, oxygen, argon, and other heavy ions for use in testing several diagnostics, including the Time Resolved Tandem Faraday Cup (TRTF). The feasibility of generating these heavy ion beams using the Alphatross source will be reported. Small amounts of various gases are mixed into the helium plasma in the ion source bottle. A velocity selector is used to allow the desired ions to pass into the accelerator. As the heavy ions pass through the stripper canal of the accelerator, they emerge in a variety of charge states. The energy of the ion beam at the high-energy end of the accelerator will vary as a function of the charge state, however the maximum energy deliverable to target is limited by the maximum achievable magnetic field produced by the accelerator's steering magnet. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944.

  3. Self-calibration of a cone-beam micro-CT system

    Energy Technology Data Exchange (ETDEWEB)

    Patel, V.; Chityala, R. N.; Hoffmann, K. R.; Ionita, C. N.; Bednarek, D. R.; Rudin, S. [Toshiba Stroke Research Center, Department of Physics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); The Supercomputing Institute for Advanced Computational Research, University of Minnesota at Twin Cities, Minneapolis, Minnesota 55455 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, Department of Physics, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Computer Science and Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Neurosurgery, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physics, and Department of Physiology and Biophysics, State University of New York at Buffalo, Buffalo, New York 14214 (United States); Toshiba Stroke Research Center, Department of Radiology, Department of Neurosurgery, Department of Physiology and Biophysics, Department of Mechanical and Aerospace Engineering, and Department of Electrical Engineering, State University of New York at Buffalo, Buffalo, New York 14214 (United States)

    2009-01-15

    Use of cone-beam computed tomography (CBCT) is becoming more frequent. For proper reconstruction, the geometry of the CBCT systems must be known. While the system can be designed to reduce errors in the geometry, calibration measurements must still be performed and corrections applied. Investigators have proposed techniques using calibration objects for system calibration. In this study, the authors present methods to calibrate a rotary-stage CB micro-CT (CB{mu}CT) system using only the images acquired of the object to be reconstructed, i.e., without the use of calibration objects. Projection images are acquired using a CB{mu}CT system constructed in the authors' laboratories. Dark- and flat-field corrections are performed. Exposure variations are detected and quantified using analysis of image regions with an unobstructed view of the x-ray source. Translations that occur during the acquisition in the horizontal direction are detected, quantified, and corrected based on sinogram analysis. The axis of rotation is determined using registration of antiposed projection images. These techniques were evaluated using data obtained with calibration objects and phantoms. The physical geometric axis of rotation is determined and aligned with the rotational axis (assumed to be the center of the detector plane) used in the reconstruction process. The parameters describing this axis agree to within 0.1 mm and 0.3 deg with those determined using other techniques. Blurring due to residual calibration errors has a point-spread function in the reconstructed planes with a full-width-at-half-maximum of less than 125 {mu}m in a tangential direction and essentially zero in the radial direction for the rotating object. The authors have used this approach on over 100 acquisitions over the past 2 years and have regularly obtained high-quality reconstructions, i.e., without artifacts and no detectable blurring of the reconstructed objects. This self-calibrating approach not only

  4. A fast beam loss monitor system for the KEK proton synchrotron complex

    Science.gov (United States)

    Holt, J. A.; Kishiro, J.; Arakawa, D.; Hiramatsu, S.

    1991-06-01

    Efforts to increase the intensity of the KEK proton synchrotron have led to the need for a new fast response beam loss monitor system. The design and some prelimitary test results of a new beam loss monitor system are presented.(AIP)

  5. The Long-Term Beam Losses in the CERN Injector Chain

    CERN Document Server

    AUTHOR|(CDS)2067411; Bartosik, Hannes; Benedetto, Elena; Damerau, Heiko; Forte, Vincenzo; Giovannozzi, Massimo; Goddard, Brennan; Hancock, Steven; Hanke, Klaus; Huschauer, Alexander; Kowalska, Magdalena; Mcateer, Meghan Jill; Metral, Elias; Mikulec, Bettina; Papaphilippou, Yannis; Rumolo, Giovanni; Sterbini, Guido; Wasef, Raymond; Arduini, Gianluigi; Meddahi, Malika; Chapochnikova, Elena

    2015-01-01

    For the production of the LHC type beams, but also for the high intensity ones, the budget allocated to losses in the CERN injector chain is maintained as tight as possi- ble, in particular to keep as low as possible the activation of the different machine elements. Various beam dynamics effects, like for example beam interaction with betatronic resonances, beam instabilities, but also reduced efficiency of the RF capture processes or RF noise, can produce losses even on a very long time scale. The main different mecha- nisms producing long term losses observed in the CERN injectors, and their cure or mitigation, will be revised.

  6. Geometric Parameters Estimation and Calibration in Cone-Beam Micro-CT

    Directory of Open Access Journals (Sweden)

    Jintao Zhao

    2015-09-01

    Full Text Available The quality of Computed Tomography (CT images crucially depends on the precise knowledge of the scanner geometry. Therefore, it is necessary to estimate and calibrate the misalignments before image acquisition. In this paper, a Two-Piece-Ball (TPB phantom is used to estimate a set of parameters that describe the geometry of a cone-beam CT system. Only multiple projections of the TPB phantom at one position are required, which can avoid the rotation errors when acquiring multi-angle projections. Also, a corresponding algorithm is derived. The performance of the method is evaluated through simulation and experimental data. The results demonstrated that the proposed method is valid and easy to implement. Furthermore, the experimental results from the Micro-CT system demonstrate the ability to reduce artifacts and improve image quality through geometric parameter calibration.

  7. Extrapolation chamber mounted on perspex for calibration of high energy photon and electron beams from a clinical linear accelerator

    Directory of Open Access Journals (Sweden)

    Ravichandran R

    2009-01-01

    Full Text Available The objective of the present study is to establish radiation standards for absorbed doses, for clinical high energy linear accelerator beams. In the nonavailability of a cobalt-60 beam for arriving at Nd, water values for thimble chambers, we investigated the efficacy of perspex mounted extrapolation chamber (EC used earlier for low energy x-rays and beta dosimetry. Extrapolation chamber with facility for achieving variable electrode separations 10.5mm to 0.5mm using micrometer screw was used for calibrations. Photon beams 6 MV and 15 MV and electron beams 6 MeV and 15 MeV from Varian Clinac linacs were calibrated. Absorbed Dose estimates to Perspex were converted into dose to solid water for comparison with FC 65 ionisation chamber measurements in water. Measurements made during the period December 2006 to June 2008 are considered for evaluation. Uncorrected ionization readings of EC for all the radiation beams over the entire period were within 2% showing the consistency of measurements. Absorbed doses estimated by EC were in good agreement with in-water calibrations within 2% for photons and electron beams. The present results suggest that extrapolation chambers can be considered as an independent measuring system for absorbed dose in addition to Farmer type ion chambers. In the absence of standard beam quality (Co-60 radiations as reference Quality for Nd,water the possibility of keeping EC as Primary Standards for absorbed dose calibrations in high energy radiation beams from linacs should be explored. As there are neither Standard Laboratories nor SSDL available in our country, we look forward to keep EC as Local Standard for hospital chamber calibrations. We are also participating in the IAEA mailed TLD intercomparison programme for quality audit of existing status of radiation dosimetry in high energy linac beams. The performance of EC has to be confirmed with cobalt-60 beams by a separate study, as linacs are susceptible for minor

  8. Tests of Local Hadron Calibration Approaches in ATLAS Combined Beam Tests

    Science.gov (United States)

    Grahn, Karl-Johan; Kiryunin, Andrey; Pospelov, Guennadi; ATLAS Calorimeter Group

    2011-04-01

    Three ATLAS calorimeters in the region of the forward crack at |η| = 3.2 in the nominal ATLAS setup and a typical section of the two barrel calorimeters at |η| = 0.45 of ATLAS have been exposed to combined beam tests with single electrons and pions. Detailed shower shape studies of electrons and pions with comparisons to various Geant4 based simulations utilizing different physics lists are presented for the endcap beam test. The local hadron calibration approach as used in the full Atlas setup has been applied to the endcap beam test data. An extension of it using layer correlations has been tested with the barrel test beam data. Both methods utilize modular correction steps based on shower shape variables to correct for invisible energy inside the reconstructed clusters in the calorimeters (compensation) and for lost energy deposits outside of the reconstructed clusters (dead material and out-of-cluster deposits). Results for both methods and comparisons to Monte Carlo simulations are presented.

  9. Particle Rate and Host Accelerator Beam Loss on the MICE Experiment

    Energy Technology Data Exchange (ETDEWEB)

    Dobbs, Adam James [Imperial College, London (United Kingdom)

    2011-10-01

    A study is presented of particle rates in the MICE Muon Beamline and their relationship to beam loss produced in ISIS. A brief overview of neutrino physics is presented, together with a discussion on the Neutrino Factory as a motivation for MICE. An overview of MICE itself is then presented, highlighting the need for a systematic understanding of the relationship between the MICE target parameters, ISIS beam loss, and MICE particle rate. The variation of beam loss with target depth is examined and observed to be non-linear. The variation of beam loss with respect to the target dip time in the ISIS cycle is examined and observed to be approximately linear for dip times between 11.1 ms and 12.6 ms after ISIS injection, before tailing at earlier dip times. The variation of beam loss with particle rate is also observed to follow an approximately linear relationship from 0.05 V.ms to 4.7 V.ms beam loss, with a further strong indication that this continues up to 7.1 V.ms. Particle identification using time-of-flight data is used to give an insight into the relative abundances of each particle species present in the MICE beam. Estimates of muon rate are then produced as a function of beam loss. At a level of 2 V.ms beam loss ~10.9 muons per spill for a 3.2 ms spill with negative π → μ optics, and ~31.1 muons per 1 ms spill with positive π → μ optics are observed. Simulations using the ORBIT particle tracking code of the beam loss distributions around the ISIS ring, caused by the MICE target, are also presented and the implications for MICE running discussed.

  10. Propagation of Gaussian beams in the presence of gain and loss

    CERN Document Server

    Graefe, Eva-Maria; Schubert, Roman

    2016-01-01

    We consider the propagation of Gaussian beams in a waveguide with gain and loss in the paraxial approximation governed by the Schr\\"odinger equation. We derive equations of motion for the beam in the semiclassical limit that are valid when the waveguide profile is locally well approximated by quadratic functions. For Hermitian systems, without any loss or gain, these dynamics are given by Hamilton's equations for the center of the beam and its conjugate momentum. Adding gain and/or loss to the waveguide introduces a non-Hermitian component, causing the width of the Gaussian beam to play an important role in its propagation. Here we show how the width affects the motion of the beam and how this may be used to filter Gaussian beams located at the same initial position based on their width.

  11. A prototype readout system for the Diamond Beam Loss Monitors at LHC

    CERN Document Server

    Effinger, E; Baer, T; Schmidt, R; Frais-Kölbl, H; Griesmayer, E

    2013-01-01

    Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. In this note, specimen LHC loss measurements with the prototype readout system “ROSY” from CIVIDEC are presented. The readout system is FPGA-based for on-line, real-time, and dead-time-free data processing, including a Linuxbased server for the interconnection to a GUI. The loss analysis makes full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. Two examples are presented: applications of the Time Loss Histogram with 1.6 ns binning and 1.2 ns time jitter for loss measurements that are synchronized with the LHC revolution period and a beam-loss-based tune measurement for all circulating bunches in parallel.

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

    CERN Document Server

    Effinger, E; Baer, T; Schmidt, R; Frais-Kölbl, H; Griesmayer, E; Kavrigin, P; CERN. Geneva. ATS Department

    2013-01-01

    Diamond Beam Loss Monitors are used at the LHC for the measurement of fast beam losses. In this note, specimen LHC loss measurements with the prototype readout system “ROSY” from CIVIDEC are presented. The readout system is FPGA-based for on-line, real-time, and dead-time-free data processing, including a Linux-based server for the interconnection to a GUI. The loss analysis makes full use of the fast signal response of the diamond detectors with 1 ns time resolution and 6.7 ns double pulse resolution. Two examples are presented: applications of the Time Loss Histogram with 1.6 ns binning and 1.2 ns time jitter for loss measurements that are synchronized with the LHC revolution period and a beam-loss-based tune measurement for all circulating bunches in parallel.

  13. Effect of Power Losses on Self-Focusing of High Intensity Laser Beam in Gases

    CERN Document Server

    Semak, V V

    2013-01-01

    A theoretical study of power loss from periphery of an ultrashort pulse laser beam and temporally resolved defocussing produced by laser induced plasma are performed using paraxial approximation. Our analysis incorporate consideration of spatial distribution of the laser beam irradiance and the results show that substantial power losses (10%-80%) occur from the beam periphery limiting length of a filament. It was also shown that generally accepted concept of self-focusing critical power is inconsistent with consideration of self-induced refraction of spatially distributed laser beam. A new criterion for self-focusing and hypothesis for multiple filamentation are proposed.

  14. Beam losses due to the foil scattering for CSNS/RCS

    CERN Document Server

    Huang, Ming-Yang; Wang, Sheng; Xu, Shou-Yan

    2012-01-01

    For the Rapid Cycling Synchrotron of China Spallation Neutron Source (CSNS/RCS), the stripping foil scattering generates the beam halo and gives rise to additional beam losses during the injection process. The interaction between the proton beam and the stripping foil was discussed and the foil scattering was studied. A simple model and the realistic situation of the foil scattering were considered. By using the codes ORBIT and FLUKA, the multi-turn phase space painting injection process with the stripping foil scattering for CSNS/RCS was simulated and the beam losses due to the foil scattering were obtained.

  15. TCDQ-TCT retraction and losses during asynchronous beam dump

    CERN Document Server

    Bracco, Chiara; Quaranta, Elena; CERN. Geneva. ATS Department

    2016-01-01

    The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the The protection provided by the TCDQs in case of asynchronous beam dump depends strongly on their correct setup. They have to respect the strict hierarchy of the full collimation system and shield the tertiary collimators in the experimental regions. This MD aimed at performing asynchronous beam dump tests with different configurations, in order to assess the minimum allowed retraction between TCTs and TCDQs and, as a consequence, on the β* reach.

  16. Tests of Local Hadron Calibration approaches in ATLAS Combined Beam Tests

    CERN Document Server

    Pospelov, G; The ATLAS collaboration

    2010-01-01

    The three Atlas calorimeter systems in the region of the forward crack at |eta| = 3.2 in the nominal Atlas setup and a typical section of the two barrel calorimeters at |eta| = 0.45 of Atlas have been exposed to combined beam tests with single electrons and pions. Detailed shower shape studies of electrons and pions with comparisons to various Geant4 based simulations utilizing different physics lists are presented for the endcap testbeam. The local hadronic calibration approach as used in the full Atlas setup has been applied to the endcap test beam data. An extension of it using layer correlations has been tested on the barrel test beam data. Both methods utilize modular correction steps based on shower shape variables to correct for invisible energy inside the reconstructed clusters in the calorimeters (compensation) and for lost energy deposits outside of the reconstructed clusters (dead material and out-of-cluster deposits). Results for both methods and comparisons to MC simulations are presented.

  17. Electron beam test of key elements of the laser-based calibration system for the muon $g$ $-$ $2$ experiment

    CERN Document Server

    Anastasi, A; Bedeschi, F; Bartolini, M; Cantatore, G; Cauz, D; Corradi, G; Dabagov, S; DI Sciascio, G; Di Stefano, R; Driutti, A; Escalante, O; Ferrari, C; Fienberg, A T; Fioretti, A; Gabbanini, C; Gioiosa, A; Hampai, D; Hertzog, D W; Iacovacci, M; Karuza, M; Kaspar, J; Liedl, A; Luisiani, A; Marignetti, F; Mastroianni, S; Moricciani, D; Pauletta, G; Piacentino, G M; Raha, N; Rossi, E; Santi, L; Venanzoni, G

    2016-01-01

    We report the test of many of the key elements of the laser-based calibration system for muon g - 2 experiment E989 at Fermilab. The test was performed at the Laboratori Nazionali di Frascati's Beam Test Facility using a 450 MeV electron beam impinging on a small subset of the final g - 2 lead-fluoride crystal calorimeter system. The calibration system was configured as planned for the E989 experiment and uses the same type of laser and most of the final optical elements. We show results regarding the calorimeter's response calibration, the maximum equivalent electron energy which can be provided by the laser and the stability of the calibration system components.

  18. Electron beam test of key elements of the laser-based calibration system for the muon g - 2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Anastasi, A.; Basti, A.; Bedeschi, F.; Bartolini, M.; Cantatore, G.; Cauz, D.; Corradi, G.; Dabagov, S.; Di Sciascio, G.; Di Stefano, R.; Driutti, A.; Escalante, O.; Ferrari, C.; Fienberg, A. T.; Fioretti, A.; Gabbanini, C.; Gioiosa, A.; Hampai, D.; Hertzog, D. W.; Iacovacci, M.; Karuza, M.; Kaspar, J.; Liedl, A.; Lusiani, A.; Marignetti, F.; Mastroianni, S.; Moricciani, D.; Pauletta, G.; Piacentino, G. M.; Raha, N.; Rossi, E.; Santi, L.; Venanzoni, G.

    2017-01-01

    We report the test of many of the key elements of the laser-based calibration system for muon g - 2 experiment E989 at Fermilab. The test was performed at the Laboratori Nazionali di Frascati's Beam Test Facility using a 450 MeV electron beam impinging on a small subset of the final g - 2 lead-fluoride crystal calorimeter system. The calibration system was configured as planned for the E989 experiment and uses the same type of laser and most of the final optical elements. We show results regarding the calorimeter's response calibration, the maximum equivalent electron energy which can be provided by the laser and the stability of the calibration system components.

  19. Some specific features of ionization chamber calibrations in linac x-ray beams at the LNE-LNHB.

    Science.gov (United States)

    Delaunay, F; Ostrowsky, A

    2007-05-07

    The purpose of this note is to give some details about the modus operandi employed today to calibrate ionization chambers in radiotherapy linac photon beams at the Laboratoire National Henri Becquerel (LNE-LNHB). Some specific features are described: first the equipment (including the external monitoring ionization chambers), second the calculations of the profile or radial non-uniformity correction factors (up to 0.5% effect for commonly used ionization chambers) and finally the calculations to get the calibration coefficients for customer beam qualities.

  20. Calibration of ionization energy loss at relativistic rise with STAR Time Projection Chamber

    CERN Document Server

    Xu, Yichun; Bichsel, Hans; Dong, Xin; Fachini, Patricia; Fisyak, Yuri; Kocolosky, Adam; Mohanty, Bedanga; Netrakanti, Pawan; Ruan, Lijuan; Suarez, Maria Cristina; Tang, Zebo; van Buren, Gene; Xu, Zhangbu

    2008-01-01

    We derive a method to improve particle identification (PID) at high transverse momentum ($p_T$) using the relativistic rise of the ionization energy loss ($rdE/dx$) when charged particles traverse the Time Projection Chamber (TPC) at STAR. Electrons triggered and identified by the Barrel Electro-Magnetic Calorimeter (BEMC), pure protons and pions from $\\Lambda\\to p+\\pi^{-}$ ($\\bar{\\Lambda}\\to \\bar{p}+\\pi^{+}$), and $K^{0}_{S}\\to\\pi^{+}+\\pi^{-}$ decays are used to obtain the $dE/dx$ value and its width at given $\\beta\\gamma=p/m$. We found that the deviation of the $dE/dx$ from the Bichsel function can be up to $0.4\\sigma$ ($\\sim3%$) in p+p collisions at $\\sqrt{s_{NN}}=200$ GeV taken and subsequently calibrated in year 2005. The deviation is approximately a function of $\\beta\\gamma$ independent of particle species and can be described with a function of $f(x) = A+\\frac{B}{C+x^{2}}$. The deviations obtained with this method are used to re-calibrate the data sample from p+p collision for physics analysis of ident...

  1. A table-top ion and electron beam facility for ionization quenching measurement and gas detector calibration

    Energy Technology Data Exchange (ETDEWEB)

    Muraz, J.F.; Médard, J.; Couturier, C.; Fourrel, C.; Guillaudin, O.; Lamy, T.; Marton, M.; Riffard, Q.; Sortais, P.; Santos, D.; Sauzet, N.

    2016-10-01

    In the frame of the MiMAC project, the LPSC (Laboratoire de Physique Subatomique et de Cosmologie) has developed COMIMAC, a miniaturized and transportable table-top beam line, producing ions or electrons to make measurements of the “quenching” factor in ionization and detector calibration. The energy range of the COMIMAC beam facility starts from a few tens of eV up to 50 keV.

  2. PRELIMINARY DESIGN OF THE BEAM LOSS MONITORING SYSTEM FOR THE SNS.

    Energy Technology Data Exchange (ETDEWEB)

    WITKOVER,R.; GASSNER,D.

    2002-05-06

    The SNS to be built at Oak Ridge National Laboratory will provide a high average intensity 1 GeV beam to produce spallation neutrons. Loss of a even small percentage of this intense beam would result in high radiation. The Beam Loss Monitor (ELM) system must detect such small, long term losses yet be capable of measuring infrequent short high losses. The large dynamic range presents special problems for the system design. Ion chambers will be used as the detectors. A detector originally designed for the FNAL Tevatron, was considered but concerns about ion collection times and low collection efficiency at high loss rates favor a new design. The requirements and design concepts of the proposed approach will be presented. Discussion of the design and testing of the ion chambers and the analog j-Point end electronics will be presented. The overall system design will be described.

  3. Reliability of Beam Loss Monitors System for the Large Hadron Collider

    CERN Document Server

    Guaglio, Gianluca; Santoni, C

    2004-01-01

    The employment of superconducting magnets, in the high energies colliders, opens challenging failure scenarios and brings new criticalities for the whole system protection. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses, while at medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data from the SPS, using temperature and radiation damage experimental data as well as using standar...

  4. Estimation of absorbed dose in clinical radiotherapy linear accelerator beams: Effect of ion chamber calibration and long-term stability.

    Science.gov (United States)

    Ravichandran, Ramamoorthy; Binukumar, Johnson Pichy; Davis, Cheriyathmanjiyil Antony

    2013-10-01

    The measured dose in water at reference point in phantom is a primary parameter for planning the treatment monitor units (MU); both in conventional and intensity modulated/image guided treatments. Traceability of dose accuracy therefore still depends mainly on the calibration factor of the ion chamber/dosimeter provided by the accredited Secondary Standard Dosimetry Laboratories (SSDLs), under International Atomic Energy Agency (IAEA) network of laboratories. The data related to Nd,water calibrations, thermoluminescent dosimetry (TLD) postal dose validation, inter-comparison of different dosimeter/electrometers, and validity of Nd,water calibrations obtained from different calibration laboratories were analyzed to find out the extent of accuracy achievable. Nd,w factors in Gray/Coulomb calibrated at IBA, GmBH, Germany showed a mean variation of about 0.2% increase per year in three Farmer chambers, in three subsequent calibrations. Another ion chamber calibrated in different accredited laboratory (PTW, Germany) showed consistent Nd,w for 9 years period. The Strontium-90 beta check source response indicated long-term stability of the ion chambers within 1% for three chambers. Results of IAEA postal TL "dose intercomparison" for three photon beams, 6 MV (two) and 15 MV (one), agreed well within our reported doses, with mean deviation of 0.03% (SD 0.87%) (n = 9). All the chamber/electrometer calibrated by a single SSDL realized absorbed doses in water within 0.13% standard deviations. However, about 1-2% differences in absorbed dose estimates observed when dosimeters calibrated from different calibration laboratories are compared in solid phantoms. Our data therefore imply that the dosimetry level maintained for clinical use of linear accelerator photon beams are within recommended levels of accuracy, and uncertainties are within reported values.

  5. The geometric calibration of cone-beam imaging and delivery systems in radiation therapy

    CERN Document Server

    Matsinos, E; Kaissl, Wolfgang; Matsinos, Evangelos

    2006-01-01

    We propose a method to achieve the geometric calibration of cone-beam imaging and delivery systems in radiation therapy; our approach applies to devices where an X-ray source and a flat-panel detector, facing each other, move in circular orbits around the irradiated object. In order to extract the parameters of the geometry from the data, we use a light needle phantom which is easy to manufacture. A model with ten free parameters (spatial lengths and distortion angles) has been put forth to describe the geometry and the mechanical imperfections of the units being calibrated; a few additional parameters are introduced to account for residual effects (small effects which lie beyond our model). The values of the model parameters are determined from one complete scan of the needle phantom via a robust optimisation scheme. The application of this method to two sets of five counterclockwise (ccw) and five clockwise (cw) scans yielded consistent and reproducible results. A number of differences have been observed be...

  6. Extended calibration range for prompt photon emission in ion beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Bellini, F. [Dipartimento di Fisica, Sapienza Università di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Boehlen, T.T.; Chin, M.P.W. [CERN, Geneva (Switzerland); Collamati, F. [Dipartimento di Fisica, Sapienza Università di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); De Lucia, E. [Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Faccini, R., E-mail: riccardo.faccini@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Ferrari, A. [CERN, Geneva (Switzerland); Lanza, L. [Dipartimento di Fisica, Sapienza Università di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Mancini-Terracciano, C. [CERN, Geneva (Switzerland); Dipartimento di Fisica, Università Roma Tre, Roma (Italy); Marafini, M. [Museo Storico della Fisica e Centro Studi e Ricerche “E. Fermi”, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Mattei, I. [Dipartimento di Fisica, Università Roma Tre, Roma (Italy); Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Morganti, S. [INFN Sezione di Roma, Roma (Italy); Ortega, P.G. [CERN, Geneva (Switzerland); Patera, V. [Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Piersanti, L. [Dipartimento di Scienze di Base e Applicate per Ingegneria, Sapienza Università di Roma, Roma (Italy); Laboratori Nazionali di Frascati dell' INFN, Frascati (Italy); Russomando, A. [Center for Life Nano Science@Sapienza, Istituto Italiano di Tecnologia, Roma (Italy); INFN Sezione di Roma, Roma (Italy); Sala, P.R. [INFN Sezione di Milano, Milano (Italy); and others

    2014-05-01

    Monitoring the dose delivered during proton and carbon ion therapy is still a matter of research. Among the possible solutions, several exploit the measurement of the single photon emission from nuclear decays induced by the irradiation. To fully characterize such emission the detectors need development, since the energy spectrum spans the range above the MeV that is not traditionally used in medical applications. On the other hand, a deeper understanding of the reactions involving gamma production is needed in order to improve the physic models of Monte Carlo codes, relevant for an accurate prediction of the prompt-gamma energy spectrum. This paper describes a calibration technique tailored for the range of energy of interest and reanalyzes the data of the interaction of a 80 MeV/u fully stripped carbon ion beam with a Poly-methyl methacrylate target. By adopting the FLUKA simulation with the appropriate calibration and resolution a significant improvement in the agreement between data and simulation is reported.

  7. Extended calibration range for prompt photon emission in ion beam irradiation

    CERN Document Server

    Bellini, F.

    2014-01-01

    Monitoring the dose delivered during proton and carbon ion therapy is still a matter of research. Among the possible solutions, several exploit the measurement of the single photon emission from nuclear decays induced by the irradiation. To fully characterize such emission the detectors need development, since the energy spectrum spans the range above the MeV that is not traditionally used in medical applications. On the other hand, a deeper understanding of the reactions involving gamma production is needed in order to improve the physic models of Monte Carlo codes, relevant for an accurate prediction of the prompt-gamma energy spectrum.This paper describes a calibration technique tailored for the range of energy of interest and reanalyzes the data of the interaction of a 80MeV/u fully stripped carbon ion beam with a Poly-methyl methacrylate target. By adopting the FLUKA simulation with the appropriate calibration and resolution a significant improvement in the agreement between data and simulation is report...

  8. Automatic Calibration Method of Voxel Size for Cone-beam 3D-CT Scanning System

    CERN Document Server

    Yang, Min; Liu, Yipeng; Men, Fanyong; Li, Xingdong; Liu, Wenli; Wei, Dongbo

    2013-01-01

    For cone-beam three-dimensional computed tomography (3D-CT) scanning system, voxel size is an important indicator to guarantee the accuracy of data analysis and feature measurement based on 3D-CT images. Meanwhile, the voxel size changes with the movement of the rotary table along X-ray direction. In order to realize the automatic calibration of the voxel size, a new easily-implemented method is proposed. According to this method, several projections of a spherical phantom are captured at different imaging positions and the corresponding voxel size values are calculated by non-linear least square fitting. Through these interpolation values, a linear equation is obtained, which reflects the relationship between the rotary table displacement distance from its nominal zero position and the voxel size. Finally, the linear equation is imported into the calibration module of the 3D-CT scanning system, and when the rotary table is moving along X-ray direction, the accurate value of the voxel size is dynamically expo...

  9. Monte-Carlo investigation of radiation beam quality of the CRNA neutron irradiator for calibration purposes

    Energy Technology Data Exchange (ETDEWEB)

    Mazrou, Hakim, E-mail: mazrou_h@crna.d [Centre de Recherche Nucleaire d' Alger (CRNA), 02 Boulevard Frantz, Fanon, B.P. 399, Alger-RP 16000 (Algeria); Sidahmed, Tassadit [Centre de Recherche Nucleaire d' Alger (CRNA), 02 Boulevard Frantz, Fanon, B.P. 399, Alger-RP 16000 (Algeria); Allab, Malika [Faculte de Physique, Universite des Sciences et de la Technologie de Houari-Boumediene (USTHB), 16111, Alger (Algeria)

    2010-10-15

    An irradiation system has been acquired by the Nuclear Research Center of Algiers (CRNA) to provide neutron references for metrology and dosimetry purposes. It consists of an {sup 241}Am-Be radionuclide source of 185 GBq (5 Ci) activity inside a cylindrical steel-enveloped polyethylene container with radially positioned beam channel. Because of its composition, filled with hydrogenous material, which is not recommended by ISO standards, we expect large changes in the physical quantities of primary importance of the source compared to a free-field situation. Thus, the main goal of the present work is to fully characterize neutron field of such special delivered set-up. This was conducted by both extensive Monte-Carlo calculations and experimental measurements obtained by using BF{sub 3} and {sup 3}He based neutron area dosimeters. Effects of each component present in the bunker facility of the Algerian Secondary Standard Dosimetry Laboratory (SSDL) on the energy neutron spectrum have been investigated by simulating four irradiation configurations and comparison to the ISO spectrum has been performed. The ambient dose equivalent rate was determined based upon a correct estimate of the mean fluence to ambient dose equivalent conversion factors at different irradiations positions by means of a 3-D transport code MCNP5. Finally, according to practical requirements established for calibration purposes an optimal irradiation position has been suggested to the SSDL staff to perform, in appropriate manner, their routine calibrations.

  10. Point Cloud Refinement with a Target-Free Intrinsic Calibration of a Mobile Multi-Beam LIDAR System

    Science.gov (United States)

    Nouiraa, H.; Deschaud, J. E.; Goulettea, F.

    2016-06-01

    LIDAR sensors are widely used in mobile mapping systems. The mobile mapping platforms allow to have fast acquisition in cities for example, which would take much longer with static mapping systems. The LIDAR sensors provide reliable and precise 3D information, which can be used in various applications: mapping of the environment; localization of objects; detection of changes. Also, with the recent developments, multi-beam LIDAR sensors have appeared, and are able to provide a high amount of data with a high level of detail. A mono-beam LIDAR sensor mounted on a mobile platform will have an extrinsic calibration to be done, so the data acquired and registered in the sensor reference frame can be represented in the body reference frame, modeling the mobile system. For a multibeam LIDAR sensor, we can separate its calibration into two distinct parts: on one hand, we have an extrinsic calibration, in common with mono-beam LIDAR sensors, which gives the transformation between the sensor cartesian reference frame and the body reference frame. On the other hand, there is an intrinsic calibration, which gives the relations between the beams of the multi-beam sensor. This calibration depends on a model given by the constructor, but the model can be non optimal, which would bring errors and noise into the acquired point clouds. In the litterature, some optimizations of the calibration parameters are proposed, but need a specific routine or environment, which can be constraining and time-consuming. In this article, we present an automatic method for improving the intrinsic calibration of a multi-beam LIDAR sensor, the Velodyne HDL-32E. The proposed approach does not need any calibration target, and only uses information from the acquired point clouds, which makes it simple and fast to use. Also, a corrected model for the Velodyne sensor is proposed. An energy function which penalizes points far from local planar surfaces is used to optimize the different proposed parameters

  11. Performance characteristics and long-term calibration stability of a beam monitor for a proton scanning gantry

    Energy Technology Data Exchange (ETDEWEB)

    Nichiporov, D.F., E-mail: nichipor@indiana.ed [Indiana University Cyclotron Facility, 2401 Milo B. Sampson Ln., Bloomington, IN 47408 (United States); Klyachko, A.V.; Solberg, K.A. [Indiana University Cyclotron Facility, 2401 Milo B. Sampson Ln., Bloomington, IN 47408 (United States); Zhao, Q. [Midwest Proton Radiotherapy Institute, 2425 Milo B. Sampson Ln., Bloomington, IN 47408 (United States)

    2011-02-15

    A monitor for a uniformly scanned beam was designed and constructed by the Indiana University Cyclotron Facility for use in a clinical proton gantry at the Midwest Proton Radiotherapy Institute. The beam monitor is a thin-walled, wide-aperture ionization chamber, which provides information about dose, beam size, symmetry, flatness, and position. Several characteristics of the monitor's performance were studied, including linearity in dose rate, reproducibility, recombination correction, and dependence on both radiation field size and gantry angle. Additionally, stability of the detector output was analyzed using daily monitor calibrations performed over a period of 21 months. The beam monitor was found to meet design requirements for linearity ({+-}1%), calibration stability ({+-}2%), and stability of response as a function of gantry angle ({+-}1%). Beam monitor calibration statistics also revealed a sine-like yearly trend with a {+-}2% maximum deviation from the average. These and other beam monitor test results are presented and discussed in the context of the detector design. Design changes aimed at further improving the detector's performance characteristics are proposed.

  12. Beam losses due to abrupt crab cavity failures in the LHC

    Energy Technology Data Exchange (ETDEWEB)

    Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B.; Zimmermann, F.

    2011-03-28

    A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting beam impact on LHC collimators and on sensitive components around the ring. Results for the nominal LHC lattice is presented.

  13. Basis for low beam loss in the high-current APT linac

    Energy Technology Data Exchange (ETDEWEB)

    Wangler, T.P.; Gray, E.R.; Krawczyk, F.L.; Kurennoy, S.S.; Lawrence, G.P.; Ryne, R.D. [Los Alamos National Lab., NM (United States); Crandall, K.R. [TECHSOURCE, Santa Fe, NM (United States)

    1998-12-31

    The present evidence that the APT proton linac design will meet its goal of low beam loss operation. The conclusion has three main bases: (1) extrapolation from the understanding of the performance of the 800-MeV LANSCE proton linac at Los Alamos, (2) the theoretical understanding of the dominant halo-forming mechanism in the APT accelerator from physics models and multiparticle simulations, and (3) the conservative approach and key principles underlying the design of the APT linac, which are aimed at minimizing beam halo and providing large apertures to reduce beam loss to a very low value.

  14. Calibration of eddy current carburization measurements in ethylene production tubes using ion beam analysis

    Energy Technology Data Exchange (ETDEWEB)

    Stevens, K J [Materials Performance Technologies, Industrial Research Ltd, PO Box 31-310, Lower Hutt (New Zealand); Trompetter, W J [Rafter Laboratory, Institute of Geological and Nuclear Sciences, PO Box 31-312, Lower Hutt (New Zealand)

    2004-02-07

    Nuclear reaction analysis using a {sup 12}C(d, p{sub 0}){sup 13}C reaction and a {sup 16}O(d, p{sub 1}){sup 17}O reaction, with 1.02 MeV deuterons in an accelerator microprobe, has been used to produce quantitative linescans of the carbon and oxygen levels in ex-service ethylene pyrolysis tubes of HPM, HK40 and Manaurite XM alloy. Particle induced x-ray emission in the ion beam microprobe and energy dispersive analysis of x-rays in a scanning electron microscope were used for linescans of the heavier elements (Cr, Ni, Fe, Si and Ti). The composition linescans were used to calibrate the response and accuracy of an eddy current probe system for measuring carburization near the inner surface of the tubes. The influence of the ferromagnetic outer oxide surface layers has been clarified. A two-dimensional ANSYS finite element model (FEM) was used for interpretation of the eddy current scans. Good correlation was obtained between the ion beam analysis results, the impedance scans and the FEM.

  15. Calibration of eddy current carburization measurements in ethylene production tubes using ion beam analysis

    Science.gov (United States)

    Stevens, K. J.; Trompetter, W. J.

    2004-02-01

    Nuclear reaction analysis using a 12C(d, p0)13C reaction and a 16O(d, p1)17O reaction, with 1.02 MeV deuterons in an accelerator microprobe, has been used to produce quantitative linescans of the carbon and oxygen levels in ex-service ethylene pyrolysis tubes of HPM, HK40 and Manaurite XM alloy. Particle induced x-ray emission in the ion beam microprobe and energy dispersive analysis of x-rays in a scanning electron microscope were used for linescans of the heavier elements (Cr, Ni, Fe, Si and Ti). The composition linescans were used to calibrate the response and accuracy of an eddy current probe system for measuring carburization near the inner surface of the tubes. The influence of the ferromagnetic outer oxide surface layers has been clarified. A two-dimensional ANSYS finite element model (FEM) was used for interpretation of the eddy current scans. Good correlation was obtained between the ion beam analysis results, the impedance scans and the FEM.

  16. Tests of Local Hadron Calibration Approaches in ATLAS Combined Beam Tests

    CERN Document Server

    Grahn, KJ; The ATLAS collaboration; Pospelov, G

    2010-01-01

    Three ATLAS calorimeters in the region of the forward crack at $|eta| = 3.2$ in the nominal ATLAS setup and a typical section of the two barrel calorimeters at $|eta| = 0.45$ of ATLAS have been exposed to combined beam tests with single electrons and pions. Detailed shower shape studies of electrons and pions with comparisons to various Geant4 based simulations utilizing different physics lists are presented for the endcap testbeam. The local hadronic calibration approach as used in the full Atlas setup has been applied to the endcap testbeam data. An extension of it using layer correlations has been tested with the barrel test beam data. Both methods utilize modular correction steps based on shower shape variables to correct for invisible energy inside the reconstructed clusters in the calorimeters (compensation) and for lost energy deposits outside of the reconstructed clusters (dead material and out-of-cluster deposits). Results for both methods and comparisons to Monte-Carlo simulations are presented.

  17. Reliability of Beam Loss Monitor Systems for the Large Hadron Collider

    CERN Document Server

    Guaglio, Gianluca; Santoni, C

    2005-01-01

    The increase of beam energy and beam intensity, together with the use of super conducting magnets, opens new failure scenarios and brings new criticalities for the whole accelerator protection system. For the LHC beam loss protection system, the failure rate and the availability requirements have been evaluated using the Safety Integrity Level (SIL) approach. A downtime cost evaluation is used as input for the SIL approach. The most critical systems, which contribute to the final SIL value, are the dump system, the interlock system, the beam loss monitors system, and the energy monitor system. The Beam Loss Monitors System (BLMS) is critical for short and intense particles losses at 7 TeV and assisted by the Fast Beam Current Decay Monitors at 450 GeV. At medium and higher loss time it is assisted by other systems, such as the quench protection system and the cryogenic system. For BLMS, hardware and software have been evaluated in detail. The reliability input figures have been collected using historical data...

  18. The upgraded data acquisition system for beam loss monitoring at the Fermilab Tevatron and Main Injector

    CERN Document Server

    Baumbaugh, A; Brown, B C; Capista, D; Drennan, C; Fellenz, B; Knickerbocker, K; Lewis, J D; Marchionni, A; Needles, C; Olson, M; Pordes, S; Shi, Z; Still, D; Thurman-Keup, R; Utes, M; Wu, J

    2011-01-01

    A VME-based data acquisition system for beam-loss monitors has been developed and is in use in the Tevatron and Main Injector accelerators at the Fermilab complex. The need for enhanced beam-loss protection when the Tevatron is operating in collider-mode was the main driving force for the new design. Prior to the implementation of the present system, the beam-loss monitor system was disabled during collider operation and protection of the Tevatron magnets relied on the quench protection system. The new Beam-Loss Monitor system allows appropriate abort logic and thresholds to be set over the full set of collider operating conditions. The system also records a history of beam-loss data prior to a beam-abort event for post-abort analysis. Installation of the Main Injector system occurred in the fall of 2006 and the Tevatron system in the summer of 2007. Both systems were fully operation by the summer of 2008. In this paper we report on the overall system design, provide a description of its normal operation, and...

  19. Stochastic Orbit Loss of Neutral Beam Ions From NSTX Due to Toroidal Alfven Eigenmode Avalanches

    Energy Technology Data Exchange (ETDEWEB)

    Darrow, D S; Fredrickson, E D; Gorelenkov, N N; Gorelenkova, M; Kubota, S; Medley, S S; Podesta, M; Shi, L

    2012-07-11

    Short toroidal Alfven eigenmode (TAE) avalanche bursts in the National Spherical Torus Experiment (NSTX) cause a drop in the neutron rate and sometimes a loss of neutral beam ions at or near the full injection energy over an extended range of pitch angles. The simultaneous loss of wide ranges of pitch angle suggests stochastic transport of the beam ions occurs. When beam ion orbits are followed with a guiding center code that incorporates plasma's magnetic equilibrium plus the measured modes, the predicted ranges of lost pitch angle are similar to those seen in the experiment, with distinct populations of trapped and passing orbits lost. These correspond to domains where the stochasticity extends in the orbit phase space from the region of beam ion deposition to the loss boundary.

  20. LHC magnet quench test with beam loss generated by wire scan

    CERN Document Server

    Sapinski, M; Dahlerup-Petersen, K; Dehning, B; Emery, j; Ferrari, A; Guerrero, A; Holzer, E B; Koujili, M; Lechner, A; Nebot, E; Scheubel, M; Steckert, J; Verweij, A; Wenninger, J

    2011-01-01

    Beam losses with millisecond duration have been observed in the LHC in 2010 and 2011. They are thought to be provoked by dust particles falling into the beam. These losses could compromise the LHC availability if they provoke quenches of superconducting magnets. In order to investigate the quench limits for this loss mechanism, a quench test using a wire scanner has been performed, with the wire movement through the beam mimicking a loss with similar spatial and temporal distribution as in the case of dust particles. This paper will show the conclusions reached for millisecond-duration dust-provoked quench limits. It will include details on the maximum energy deposited in the coil as estimated using FLUKA code, showing a reasonable agreement with quench limit estimated from the heat transfer code QP3. In addition, information on the damage limit for carbon wires in proton beamswill be presented, following electronmicroscope analysis which revealed strong wire sublimation.

  1. Incoherent vertical ion losses during multiturn stacking cooling beam injection

    Science.gov (United States)

    Syresin, E. M.

    2014-07-01

    The efficiency of the multiturn ion injection with electron cooling depends on two parameters, namely, cooling efficiency and ion lifetime. The lifetime of freshly injected ions is usually shorter than the lifetime of strongly cooled stacked ions. Freshly injected ions are lost in the vertical direction because the vertical acceptance of the synchrotron is usually a few times smaller than the horizontal acceptance. Incoherent vertical losses of freshly injected ions arise from their multiple scattering by residual gas atoms and transverse diffusion caused by stack noise. Reduced ion lifetime limits the multiturn injection efficiency. Analytical estimations and BETACOOL-based numerical evaluations of the vertical ion losses during multiturn injection are presented in comparison with the experimental data obtained at the HIMAC synchrotron and the S-LSR storage ring.

  2. Demonstration of low-loss electron beam transport and mm-wave experiments of the fusion-FEM

    NARCIS (Netherlands)

    Urbanus, W. H.; Bongers, W. A.; van Dijk, G.; van der Geer, C. A. J.; de Kruif, R.; Manintveld, P.; Pluygers, J.; Poelman, A. J.; Schüller, F. C.; Smeets, P. H. M.; Sterk, A. B.; Verhoeven, A. G. A.; Valentini, M.; van der Wiel, M. J.

    1998-01-01

    In the Fusion-FEM electrostatic Free Electron Maser, an electron beam loss current of less than 0.2% is essential for long-pulse operation. At reduced beam current, 3 A instead of the nominal 12 A, we have demonstrated electron beam acceleration and transport through the undulator at current losses

  3. FNAL Proton Source High Intensity Operations and Beam Loss Control

    CERN Document Server

    Garcia, F G

    2014-01-01

    The 40-year-old Fermilab Proton Source machines, constituted by the Pre-Injector, Linac and the synchrotron Booster, have been the workhorse of the Fermi National Accelerator Laboratory (Fermilab). During this time, the High Energy Physics Program has demanded an increase in proton throughput, especially during the past decade with the beginning of the neutrino program at Fermilab. In order to achieve a successful program, major upgrades and changes were made in Booster. Once again, the Proton Source has been charged to double their beam throughput, while maintain the present residual activation levels, to meet the laboratory Intensity Frontier program goals until new machines are built and operational to replace the Proton Source machines. This paper discusses the present performance of Booster and the plans involved in reaching even higher intensities.

  4. Shielding NSLS-II light source: Importance of geometry for calculating radiation levels from beam losses

    Science.gov (United States)

    Kramer, S. L.; Ghosh, V. J.; Breitfeller, M.; Wahl, W.

    2016-11-01

    Third generation high brightness light sources are designed to have low emittance and high current beams, which contribute to higher beam loss rates that will be compensated by Top-Off injection. Shielding for these higher loss rates will be critical to protect the projected higher occupancy factors for the users. Top-Off injection requires a full energy injector, which will demand greater consideration of the potential abnormal beam miss-steering and localized losses that could occur. The high energy electron injection beam produces significantly higher neutron component dose to the experimental floor than a lower energy beam injection and ramped operations. Minimizing this dose will require adequate knowledge of where the miss-steered beam can occur and sufficient EM shielding close to the loss point, in order to attenuate the energy of the particles in the EM shower below the neutron production threshold (energy on the bulk shield walls and thereby the dose penetrating the shield walls. Designing supplemental shielding near the loss point using the analytic shielding model is shown to be inadequate because of its lack of geometry specification for the EM shower process. To predict the dose rates outside the tunnel requires detailed description of the geometry and materials that the beam losses will encounter inside the tunnel. Modern radiation shielding Monte-Carlo codes, like FLUKA, can handle this geometric description of the radiation transport process in sufficient detail, allowing accurate predictions of the dose rates expected and the ability to show weaknesses in the design before a high radiation incident occurs. The effort required to adequately define the accelerator geometry for these codes has been greatly reduced with the implementation of the graphical interface of FLAIR to FLUKA. This made the effective shielding process for NSLS-II quite accurate and reliable. The principles used to provide supplemental shielding to the NSLS-II accelerators and

  5. Study of Acquisition Electronics with a High Dynamic Range for a Beam Loss Measurement System

    CERN Document Server

    Venturini, G; Dehning, B; Effinger, E

    2010-01-01

    The particles accelerated in CERN accelerator chain reach high energies, topped by the particle energy at collision in the LHC, 7 GeV. During the operation, an amount of particles is inevitably lost from the beam. Depending on the extent of the losses, physical damage to machine components may be caused and the shower of secondary emission particles deposits energy in the surrounding equipment constituting the accelerator. The hadronic cascade also activates their materials, representing a hazard to the workers at CERN. In the LHC, the superconducting magnets that constitute the synchrotron lattice are kept at an operating temperature of 1:9K through a cryogenic facility employing superliquid helium, the increase in their temperature potentially initiates a quench. In the SPS, the damage due to a lost beam is also visible. The Beam Loss Monitoring (BLM) system has been developed to reliably protect the machines composing CERN’s accelerator chain and additionally provide information about the beam status: th...

  6. Study on beam loss system of BEPCII%BEPCII束损系统研究

    Institute of Scientific and Technical Information of China (English)

    何俊; 赵晓岩; 汪林; 杜垚垚; 赵颖; 随艳峰; 岳军会; 曹建社

    2015-01-01

    为更好掌握储存环中的束流状态,在北京正负电子对撞机二期工程的储存环上建立了以二极管为探测器的束流损失探测系统。用蒙特卡罗软件对损失束流产生簇射电子的分布情况进行了模拟,为安装束损探测器位置提供了依据。搭建了包括探头、数据获取系统、数据传输系统在内的束损系统。对束损过程进行了详细的分析与描述。对北京正负电子对撞机多年的束损数据进行了整理分析,对其在丢束诊断、束流寿命研究等多个方面应用情况进行了总结。数据显示建立的束损系统工作状态稳定,是优化机器参数、改善束流寿命、分析丢束过程的有力工具。%Background: A beam loss system that uses the PIN diode as the detector has been set up on Beijing Electron–Positron Collider II (BEPCII) storage after 8-a routine operation. Further study and analysis should been carried out based on the historical data.Purpose: This study aims to learn the beam loss process in depth and further optimize the parameters of the accelerator.Methods: Based on the machine size and beam parameter of BEPCII, the Monte Carlo simulation of the cluster electrons in the storage ring was performed to provide reference for installation position of the beam loss system. Then different methods, including adding all the beam loss monitor (BLM) counts, adding the inner detector, adding the outer detector, have been used for data analysis of the beam life time, beam loss distribution, beam envelope and dispersion,etc., under both the collider mode and synchrotron mode.Results: The results show that the BLM system is useful to study the beam life time and diagnose the beam loss processes. The beam loss system for BEPCII works stablely. The detector counts are much smaller than the dynamic range of the detector.Conclusion: Over the eight years, the response of the beam loss system does not change a lot, which implies that the

  7. Simulation of ion beam losses in LHC magnets

    CERN Document Server

    AUTHOR|(CDS)2068843; Jowett, John M; Riklund, R

    2005-01-01

    At the particle physics laboratory CERN, the largest accelerator ever, the Large Hadron Collider (LHC), is under construction. In the LHC ultra relativistic particles, mainly protons but also lead ions, will be brought into collision. One problem that arises in the operation is that colliding ion beams in the machine have a very large cross section for electromagnetic interactions, in particular Bound Free Pair Production (BFPP). An electron-positron pair is created by the electromagnetic field between two colliding particles and the electron is created in a bound state of one of the ions. Because of this reaction the ion changes its charge and therefore leaves the wanted trajectory and crashes in a superconducting magnet, depositing heat. The impact of the wrongly charged ions on the inside of the vacuum pipe was simulated with the simulation program FLUKA. It was concluded that it is not likely that enough heat is deposited in the coils of the superconducting magnet to induce a quench, although some uncerta...

  8. Beam-loss-induced electrical stress test on CMS Silicon Strip Modules

    CERN Document Server

    Fahrer, M; Hartmann, F; Heier, S; MacPherson, A; Muller, T H; Weiler, T h

    2004-01-01

    Based on simulated LHC beam loss scenarios, fully depleted CMS silicon tracker modules and sensors were exposed to 42 ns-long beam spills of approximately 10**1**1 protons per spill at the PS at CERN. The ionisation dose was sufficient to short circuit the silicon sensors. The dynamic behaviour of bias voltage, leakage currents and voltages over coupling capacitors were monitored during the impact. Results of pre- and post-qualification as well as the dynamic behaviour are shown.

  9. Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

    Science.gov (United States)

    Bruce, R.; Assmann, R. W.; Boccone, V.; Bracco, C.; Brugger, M.; Cauchi, M.; Cerutti, F.; Deboy, D.; Ferrari, A.; Lari, L.; Marsili, A.; Mereghetti, A.; Mirarchi, D.; Quaranta, E.; Redaelli, S.; Robert-Demolaize, G.; Rossi, A.; Salvachua, B.; Skordis, E.; Tambasco, C.; Valentino, G.; Weiler, T.; Vlachoudis, V.; Wollmann, D.

    2014-08-01

    The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010-2013, the LHC was routinely storing protons at 3.5-4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An uncontrolled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multistage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the collimation system. The studies include tracking of protons through the fields of more than 5000 magnets in the 27 km LHC ring over hundreds of revolutions, and Monte Carlo simulations of particle-matter interactions both in collimators and machine elements being hit by escaping particles. The simulation results agree typically within a factor 2 with measurements of beam loss distributions from the previous LHC run. Considering the complex simulation, which must account for a very large number of unknown imperfections, and in view of the total losses around the ring spanning over 7 orders of magnitude, we consider this an excellent agreement. Our results give confidence in the simulation tools, which are used also for the design of future accelerators.

  10. Evaluation of source term induced by beam loss in the superconducting linear accelerator at RAON

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Jin; Kim, Su Na; Nam, Shin Woo; Chung, Yon Sei [Rare Isotope Science Project, Institute for Basic Science, Daejeon (Korea, Republic of)

    2014-11-15

    As a new world-class heavy ion accelerator, RAON is able to accelerate heavy ions from proton to uranium with the energy up to -400 MeV/u and produce rare isotopes. These high purity, high intensity, and high energy beams generate the various secondary radiation which will impact on the shielding aspects of the main linear accelerator tunnels. In the main tunnel the secondary neutrons are produced by uniform beam-loss or accident criteria. In this paper evaluations of several source terms induced by beam-loss will be discussed along with the physics model of the Monte Carlo simulation codes. The beam-loss criteria were tested for the evaluation of source term for the main beam line tunnel of the RAON accelerator. It was found that the amount of the secondary neutrons depends on the incident angle of projectile on the beam pipe and the mass and energy of projectile. The influence of selected physics models and libraries of MCNPX and PHITS has been examined. The secondary neutrons were produced most in the CEM and LAQGSM model.

  11. Simulations and measurements of beam loss patterns at the CERN Large Hadron Collider

    CERN Document Server

    Bruce, R; Boccone, V; Bracco, C; Brugger, M; Cauchi, M; Cerutti, F; Deboy, D; Ferrari, A; Lari, L; Marsili, A; Mereghetti, A; Mirarchi, D; Quaranta, E; Redaelli, S; Robert-Demolaize, G; Rossi, A; Salvachua, B; Skordis, E; Tambasco, C; Valentino, G; Weiler, T; Vlachoudis, V; Wollmann, D

    2014-01-01

    The CERN Large Hadron Collider (LHC) is designed to collide proton beams of unprecedented energy, in order to extend the frontiers of high-energy particle physics. During the first very successful running period in 2010--2013, the LHC was routinely storing protons at 3.5--4 TeV with a total beam energy of up to 146 MJ, and even higher stored energies are foreseen in the future. This puts extraordinary demands on the control of beam losses. An un-controlled loss of even a tiny fraction of the beam could cause a superconducting magnet to undergo a transition into a normal-conducting state, or in the worst case cause material damage. Hence a multi-stage collimation system has been installed in order to safely intercept high-amplitude beam protons before they are lost elsewhere. To guarantee adequate protection from the collimators, a detailed theoretical understanding is needed. This article presents results of numerical simulations of the distribution of beam losses around the LHC that have leaked out of the co...

  12. Beam loss studies on silicon strip detector modules for the CMS experiment

    CERN Document Server

    Fahrer, Manuel

    2006-01-01

    The large beam energy of the LHC demands for a save beam abort system. Nevertheless, failures cannot be excluded with last assurance and are predicted to occur once per year. As the CMS experiment is placed in the neighboured LHC octant, it is affected by such events. The effect of an unsynchronized beam abort on the silicon strip modules of the CMS tracking detector has been investigated in this thesis by performing one accelerator and two lab experiments. The dynamical behaviour of operational parameters of modules and components has been recorded during simulated beam loss events to be able to disentangle the reasons of possible damages. The first study with high intensive proton bunches at the CERN PS ensured the robustness of the module design against beam losses. A further lab experiment with pulsed IR LEDs clarified the physical and electrical processes during such events. The silicon strip sensors on a module are protected against beam losses by a part of the module design that originally has not been...

  13. View-dependent geometric calibration for offset flat-panel cone beam computed tomography systems

    Science.gov (United States)

    Nguyen, Van-Giang

    2016-04-01

    Geometric parameters that define the geometry of imaging systems are crucial for image reconstruction and image quality in x-ray computed tomography (CT). The problem of determining geometric parameters for an offset flat-panel cone beam CT (CBCT) system, a recently introduced modality with a large field of view, with the assumption of an unstable mechanism and geometric parameters that vary in each view, is considered. To accurately and rapidly find the geometric parameters for each projection view, we use the projection matrix method and design a dedicated phantom that is partially visible in all projection views. The phantom consists of balls distributed symmetrically in a cylinder to ensure the inclusion of the phantom in all views, and a large portion of the phantom is covered in the projection image. To efficiently use calibrated geometric information in the reconstruction process and get rid of approximation errors, instead of decomposing the projection matrix into actual geometric parameters that are manually corrected before being used in reconstruction, as in conventional methods, we directly use the projection matrix and its pseudo-inverse in projection and backprojection operations of reconstruction algorithms. The experiments illustrate the efficacy of the proposed method with a real offset flat-panel CBCT system in dental imaging.

  14. Propagation of Gaussian beam in longitudinally inhomogeneous nonlinear graded index waveguides with gain and losses

    CERN Document Server

    Yesayan, G L

    2001-01-01

    The equations for the width and curvature radius of the wave front for a Gaussian beam of light propagating along the axis of the longitudinally inhomogeneous graded index waveguide with gain and losses in the presence of third-order nonlinearity are obtained. By means of numerical calculations it is shown that in such waveguides the mode of stabilization of the beam width is possible, when the absorption of radiation on the edges of the beam compensates its spreading caused by the longitudinal inhomogeneity and nonlinearity of the waveguide

  15. System Architecture for measuring and monitoring Beam Losses in the Injector Complex at CERN

    CERN Document Server

    Zamantzas, C; Dehning, B; Jackson, S; Kwiatkowski, M; Vigano, W

    2012-01-01

    The strategy for beam setup and machine protection of the accelerators at the European Organisation for Nuclear Research (CERN) is mainly based on its Beam Loss Monitoring (BLM) systems. For their upgrade to higher beam energies and intensities, a new BLM system is under development with the aim of providing faster measurement updates with higher dynamic range and the ability to accept more types of detectors as input compared to its predecessors. In this paper, the architecture of the complete system is explored giving an insight to the design choices made to provide a highly reconfigurable system that is able to fulfil the different requirements of each accelerator using reprogrammable devices.

  16. Simulation of Heavy-Ion Beam Losses with the SixTrack-FLUKA Active Coupling

    CERN Document Server

    Hermes, Pascal; Cerutti, Francesco; Ferrari, Alfredo; Jowett, John; Lechner, Anton; Mereghetti, Alessio; Mirarchi, Daniele; Ortega, Pablo; Redaelli, Stefano; Salvachua, Belen; Skordis, Eleftherios; Valentino, Gianluca; Vlachoudis, Vasilis

    2016-01-01

    The LHC heavy-ion program aims to further increase the stored ion beam energy, putting high demands on the LHC collimation system. Accurate simulations of the ion collimation efficiency are crucial to validate the feasibility of new proposed configurations and beam parameters. In this paper we present a generalized framework of the SixTrack-FLUKA coupling to simulate the fragmentation of heavy-ions in the collimators and their motion in the LHC lattice. We compare heavy-ion loss maps simulated on the basis of this framework with the loss distributions measured during heavy-ion operation in 2011 and 2015.

  17. Beam-loss monitoring system with free-air ionization chambers

    Science.gov (United States)

    Nakagawa, H.; Shibata, S.; Hiramatsu, S.; Uchino, K.; Takashima, T.

    1980-08-01

    A monitoring system for proton beam losses was installed in the proton synchrotron at the National Laboratory for High Energy Physics in Japan (KEK). The system consists of 56 air ionization chambers (AIC) for radiation detectors, 56 integrators, 56 variable gain amplifiers, two multiplexers, a computer interface circuit, a manual controller and a high tension power supply. The characteristics of the AIC, time resolution, radiation measurement upper limit saturation, kinetic energy dependence of the sensitivity, chamber activation effect, the beam loss detection system and the results of observations with the monitoring system are described.

  18. Low loss power splitter for antenna beam forming networks using probes in a waveguide

    DEFF Research Database (Denmark)

    Dich, Mikael; Mortensen, Mette Dahl

    1994-01-01

    The design of a low loss one-to-four power splitter suitable for beam forming networks in antenna arrays is presented. The power splitter is constructed of a shorted waveguide in which five coaxial probes are inserted. Methods for the design of the power splitter are presented together with an ex......The design of a low loss one-to-four power splitter suitable for beam forming networks in antenna arrays is presented. The power splitter is constructed of a shorted waveguide in which five coaxial probes are inserted. Methods for the design of the power splitter are presented together...

  19. Special diagnostic methods and beam loss control on high intensity proton synchrotrons and storage rings Circular proton accelerator

    CERN Document Server

    Warsop, C M

    2002-01-01

    Two topics concerning high intensity, medium energy, circular proton accelerators have been studied: specialist diagnostics and beam loss control. The use of specially configured, low intensity diagnostic beams to help measure, understand and control high intensity beams is described. The ideas are developed and demonstrated on the ISIS 800 MeV, high intensity proton synchrotron at the Rutherford Appleton Laboratory in the UK. It is shown that these techniques make much new and valuable information available, which is particularly useful in achieving the precise beam optimisation required for low and controlled losses. Beam loss control in the proposed European Spallation Source (ESS) accumulator rings is studied. The expected losses are summarised, and a design for the beam collimation system presented. A new code for the simulation of loss control is outlined, and then used to test the collimation system under most foreseeable conditions. It is expected that the required loss control levels will be achievab...

  20. Modeling the response of a fast ion loss detector using orbit tracing techniques in a neutral beam prompt-loss study on the DIII-D tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Pace, D. C.; Heidbrink, W. W.; Muscatello, C. M.; Zhu, Y. B. [University of California-Irvine, Irvine, California 92697 (United States); Fisher, R. K.; Van Zeeland, M. A. [General Atomics, P.O. Box 85608, San Diego, California 92186-5608 (United States); Garcia-Munoz, M. [Max-Planck-Institut fuer Plasmaphysik, Garching D-85748 (Germany); Darrow, D. S.; Nazikian, R. [Princeton Plasma Physics Laboratory, Princeton, New Jersey 08543-0451 (United States)

    2010-10-15

    A numerical model describing the expected measurements of neutral beam prompt-losses by a newly commissioned fast ion loss detector (FILD) in DIII-D is presented. This model incorporates the well understood neutral beam deposition profiles from all eight DIII-D beamlines to construct a prompt-loss source distribution. The full range of detectable ion orbit phase space available to the FILD is used to calculate ion trajectories that overlap with neutral beam injection footprints. Weight functions are applied to account for the level of overlap between these detectable orbits and the spatial and velocity (pitch) properties of ionized beam neutrals. An experimental comparison is performed by firing each neutral beam individually in the presence of a ramping plasma current. Fast ion losses determined from the model are in agreement with measured losses.

  1. The Evaluation of the Residual Dose Caused by the Large-Angle Foil Scattering Beam Loss for the High Intensity Beam Operation in the J-PARC RCS

    Science.gov (United States)

    Kato, Shinichi; Yamamoto, Kazami; Harada, Hiroyuki; Hotchi, Hideaki; Saha, Pranab K.; Kinsho, Michikazu

    The Japan Proton Accelerator Research Complex 3-GeV rapid cycling synchrotron (RCS) has adopted the multi-turn charge-exchange injection scheme that uses H- beams. During injection, both the injected and circulating beams scatter from the charge-exchange foil. Therefore, the beam loss caused by the large-angle scattering from the foil occurs downstream of the injection point. For countermeasure against the uncontrolled beam loss, a new collimation system was developed and installed in the summer shutdown period in 2011. During beam commissioning, this uncontrolled beam loss was successfully localized for a 300 kW beam. Since the present target power of the RCS is 1 MW, the accurate simulation model to reproduce experimental results has been constructed in order to evaluate residual dose at higher power operation.

  2. Very Fast Losses of the Circulating LHC Beam, their Mitigation and Machine Protection

    CERN Document Server

    Baer, Tobias; Elsen, Eckhard

    The Large Hadron Collider (LHC) has a nominal energy of 362MJ stored in each of its two counter-rotating beams - over two orders of magnitude more than any previous accelerator and enough to melt 880kg of copper. Therefore, in case of abnormal conditions comprehensive machine protection systems extract the beams safely from the LHC within not more than three turns $\\approx$270$\\mu$s. The first years of LHC operation demonstrated a remarkable reliability of the major machine protection systems. However, they also showed that the LHC is vulnerable to losses of the circulating beams on very fast timescales, which are too fast to ensure an active protection. Very fast equipment failures, in particular of normal-conducting dipole magnets and the transverse damper can lead to such beam losses. Whereas these failures were already studied in the past, other unexpected beam loss mechanisms were observed after the LHC start-up: so-called (un)identified falling objects (UFOs), which are believed to be micrometer-sized m...

  3. Multiple-electron losses in uranium ion beams in heavy ion synchrotrons

    Science.gov (United States)

    Bozyk, L.; Chill, F.; Litsarev, M. S.; Tolstikhina, I. Yu.; Shevelko, V. P.

    2016-04-01

    Charge changing processes as the result of collisions with residual gas particles are the main cause of beam loss in high energy medium charge state heavy ion beams. To investigate the magnitude of this effect for heavy ion synchrotrons like the planned SIS100 at GSI, the multiple-electron and the total electron-loss cross sections are calculated for Uq+ ions, q = 10, 28, 40, 73, colliding with typical gas components H2, He, C, N2, O2, and Ar at ion energies E = 1 MeV/u-10 GeV/u. The total electron-capture cross sections for U28+ and U73+ ions interacting with these gases are also calculated. Most of these cross sections are new and presented for the first time. Calculated charge-changing cross sections are used to determine the ion-beam lifetimes τ for U28+ ions which agree well with the recently measured values at SIS18/GSI in the energy range E = 10-200 MeV/u. Using simulations made by the StrahlSim code with the reference ion U28+, it is found that in SIS100 the beam loss caused by single and multiple electron losses has only little impact on the residual gas density due to the high efficiency of the ion catcher system.

  4. Enhanced relativistic-electron-beam energy loss in warm dense aluminum.

    Science.gov (United States)

    Vaisseau, X; Debayle, A; Honrubia, J J; Hulin, S; Morace, A; Nicolaï, Ph; Sawada, H; Vauzour, B; Batani, D; Beg, F N; Davies, J R; Fedosejevs, R; Gray, R J; Kemp, G E; Kerr, S; Li, K; Link, A; McKenna, P; McLean, H S; Mo, M; Patel, P K; Park, J; Peebles, J; Rhee, Y J; Sorokovikova, A; Tikhonchuk, V T; Volpe, L; Wei, M; Santos, J J

    2015-03-01

    Energy loss in the transport of a beam of relativistic electrons in warm dense aluminum is measured in the regime of ultrahigh electron beam current density over 2×10^{11}  A/cm^{2} (time averaged). The samples are heated by shock compression. Comparing to undriven cold solid targets, the roles of the different initial resistivity and of the transient resistivity (upon target heating during electron transport) are directly observable in the experimental data, and are reproduced by a comprehensive set of simulations describing the hydrodynamics of the shock compression and electron beam generation and transport. We measured a 19% increase in electron resistive energy loss in warm dense compared to cold solid samples of identical areal mass.

  5. Distributed beam loss monitor based on the Cherenkov effect in an optical fiber

    Science.gov (United States)

    Maltseva, Yu; Emanov, F. A.; Petrenko, A. V.; Prisekin, V. G.

    2015-05-01

    This review discusses a distributed beam loss monitor which is based on the Cherenkov effect in an optical fiber and which has been installed at the VEPP-5 Injection Complex at the Budker Institute of Nuclear Physics. The principle of the device operation consists in detecting the Cherenkov radiation generated in an optical fiber by relativistic charged particles that are produced in an electromagnetic shower when highly relativistic beam particles (electrons or positrons) hit the accelerator vacuum chamber wall. Our experiments used a photomultiplier tube (PMT) to detect the Cherenkov light. Knowing when the PMT signal arrives tells us where the beam loss occurs. Using a 20-m-long optical fiber allowed a detector spatial resolution of 3 m. The way to improve the resolution is to optimize the monitor working conditions and optical fiber and PMT parameters, potentially leading to a resolution of as fine as 0.5 m according to our estimates.

  6. Design and Development of a Diagnostics Client for a Beam Loss Measurement System at CERN

    CERN Document Server

    Angelogiannopoulos, Emmanouil; Jackson, Stephen

    The European Organization for Nuclear Research, known as CERN, is one of the biggest research centers in the field of particle physics. Its main function is to provide particle accelerators and other infrastructure needed for high energy physics research. Particles are accelerated through a complex of accelerators and are brought into collision, in order to study the fundamental elements of matter and the forces acting between them. Of course, such complex and expensive machines need control and protection. For that purpose, a variety of different systems -hardware and/or software- is needed. One such system is the Beam Loss Monitoring (BLM) system of an accelerator. This kind of system is designed for measuring beam losses around an accelerator. An appropriate design of the BLM system and an appropriate location of the monitors enable a wide field of very useful beam diagnostics and machine protection possibilities. This thesis focuses on the design and development of a client application, which is realized ...

  7. Recommended Locations of Beam Loss Monitors for the ATLAS Roman Pots

    CERN Document Server

    Hall-Wilton, R J; Talanov, V

    2007-01-01

    This note suggests suitable locations to position beam loss monitors to observe losses on the ATLAS Roman Pot station located close to 240m from IP1. This monitoring is envisaged to help to avoid quenches of the super- conducting magnets downstream of the roman pots and to avert damage to either the LHC machine elements or the roman pot detectors. The results presented in this note indicate the locations where the BLMs should be installed. The recommended locations are determined using previous simulation results on BLM response to losses; therefore these results should be considered in conjunction with the previous results. A more detailed note on the topic will follow later.

  8. Recommended locations of beam-loss monitors for the ATLAS Roman pots

    CERN Document Server

    Hall-Wilton, R J; Talanov, V

    2007-01-01

    This note suggests suitable locations to position beam loss monitors to observe losses on the ATLAS Roman Pot station located close to 240m from IP1. This monitoring is envisaged to help to avoid quenches of the super- conducting magnets downstream of the roman pots and to avert damage to either the LHC machine elements or the roman pot detectors. The results presented in this note indicate the locations where the BLMs should be installed. The recommended locations are determined using previous simulation results on BLM response to losses; therefore these results should be considered in conjunction with the previous results. A more detailed note on the topic will follow later.

  9. Beam Loss Control for the Unstripped Ions from the PS2 Charge Exchange Injection

    CERN Document Server

    Bartmann, W; Benedikt, M; Goddard, B; Kramer, T; Papaphilippou, Y; Vincke, Hel

    2010-01-01

    Control of beam losses is an important aspect of the H-injection system for the PS2, a proposed replacement of the CPS in the CERN injector complex. H- ions may pass the foil unstripped or be partially stripped to excited H0 states which may be stripped in the subsequent strong-field chicane magnet. Depending on the choice of the magnetic field, atoms in the ground and first excited states can be extracted and dumped. The conceptual design of the waste beam handling is presented, including local collimation and the dump line, both of which must take into account the divergence of the beam from stripping in fringe fields. Beam load estimates and activation related requirements of the local collimators and dump are briefly discussed.

  10. Loss of balance during balance beam walking elicits a multifocal theta band electrocortical response.

    Science.gov (United States)

    Sipp, Amy R; Gwin, Joseph T; Makeig, Scott; Ferris, Daniel P

    2013-11-01

    Determining the neural correlates of loss of balance during walking could lead to improved clinical assessment and treatment for individuals predisposed to falls. We used high-density electroencephalography (EEG) combined with independent component analysis (ICA) to study loss of balance during human walking. We examined 26 healthy young subjects performing heel-to-toe walking on a treadmill-mounted balance beam as well as walking on the treadmill belt (both at 0.22 m/s). ICA identified clusters of electrocortical EEG sources located in or near anterior cingulate, anterior parietal, superior dorsolateral-prefrontal, and medial sensorimotor cortex that exhibited significantly larger mean spectral power in the theta band (4-7 Hz) during walking on the balance beam compared with treadmill walking. Left and right sensorimotor cortex clusters produced significantly less power in the beta band (12-30 Hz) during walking on the balance beam compared with treadmill walking. For each source cluster, we also computed a normalized mean time/frequency spectrogram time locked to the gait cycle during loss of balance (i.e., when subjects stepped off the balance beam). All clusters except the medial sensorimotor cluster exhibited a transient increase in theta band power during loss of balance. Cluster spectrograms demonstrated that the first electrocortical indication of impending loss of balance occurred in the left sensorimotor cortex at the transition from single support to double support prior to stepping off the beam. These findings provide new insight into the neural correlates of walking balance control and could aid future studies on elderly individuals and others with balance impairments.

  11. The LHC beam loss monitoring system's real-time data analysis card

    CERN Document Server

    Dehning, B; Ferioli, G; Guaglio, G; Leitner, R; Zamantzas, C

    2005-01-01

    The BLM (Beam Loss Monitoring) system has to prevent the superconducting magnets from being quenched and protect the machine components against damages making it one of the most critical elements for the protection of the LHC. The complete system consists of 3600 detectors, placed at various locations around the ring, tunnel electronics, which are responsible for acquiring, digitizing, and transmitting the data, and surface electronics, which receive the data via 2km optical data links, process, analyze, store, and issue warning and abort triggers. At those surface units, named BLMTCs, the backbone on each of them is an FPGA (field programmable gate array) which treats the loss signals collected from 16 detectors. It takes into account the beam energy and keeps 192 running sums giving loss durations of up to the last 84 seconds before it compares them with thresholds uniquely programmable for each detector. In this paper, the BLMTC's design is explored giving emphasis to the strategies followed in combining t...

  12. Evaluation of Beam Losses and Energy Depositions for a Possible Phase II Design for LHC Collimation

    CERN Document Server

    Lari, L; Bracco, C; Brugger, M; Cerutti, F; Doyle, E; Ferrari, A; Keller, L; Lundgren, S; Keller, L; Mauri, M; Redaelli, S; Sarchiapone, L; Smith, J; Vlachoudis, V; Weiler, T

    2008-01-01

    The LHC beams are designed to have high stability and to be stored for many hours. The nominal beam intensity lifetime is expected to be of the order of 20h. The Phase II collimation system has to be able to handle particle losses in stable physics conditions at 7 TeV in order to avoid beam aborts and to allow correction of parameters and restoration to nominal conditions. Monte Carlo simulations are needed in order to evaluate the behavior of metallic high-Z collimators during operation scenarios using a realistic distribution of losses, which is a mix of the three limiting halo cases. Moreover, the consequences in the IR7 insertion of the worst (case) abnormal beam loss are evaluated. The case refers to a spontaneous trigger of the horizontal extraction kicker at top energy, when Phase II collimators are used. These studies are an important input for engineering design of the collimation Phase II system and for the evaluation of their effect on adjacent components. The goal is to build collimators that can ...

  13. Optimization of electron beam patterned hydrogen silsesquioxane mask edge roughness for low-loss silicon waveguides

    Science.gov (United States)

    Wood, Michael G.; Chen, Li; Burr, Justin R.; Reano, Ronald M.

    2014-01-01

    We carried out a multiparameter fabrication study designed to reduce the line edge roughness (LER) of electron beam (e-beam) patterned hydrogen silsesquioxane resist for the purpose of producing low-loss silicon strip waveguides. Reduced mask roughness was achieved for 50°C pre-exposure baking, 5000 μC/cm2 dose with a beam spot size more than twice as large as the electron beam step size, development in 25% tetramethylammonium hydroxide and postdevelopment baking with rapid thermal annealing in an O2 ambient at 1000°C. The LER caused by pattern fracturing and stage stitches was reduced with multipass writing and per-pass linear and rotational offsets. Si strip waveguides patterned with the optimized mask have root-mean-square sidewall roughness of 2.1 nm with a correlation length of 94 nm, as measured by three-dimensional atomic force microscopy. Measured optical propagation losses of these waveguides across the telecommunications C-band were 2.5 and 2.8 dB/cm for the transverse magnetic and transverse electric modes, respectively. These reduced loss waveguides enable the fabrication of advanced planar lightwave circuit topologies.

  14. Simulation of the ATLAS SCT barrel module response to LHC beam loss scenarios

    CERN Document Server

    Rose, P; The ATLAS collaboration; Fadeyev, V; Spencer, E; Wilder, M; Domingo, M

    2014-01-01

    In the event of beam loss at the LHC, ATLAS Inner Detector components nearest the beam line may be subjected to unusually large amounts of radiation. Understanding their behavior in such an event is important in determining whether they would still function properly. We built a SPICE model of the silicon strip module electrical system to determine the behavior of its elements during a realistic beam loss scenario. We found that the power supply and bias filter characteristics strongly affect the module response in such scenarios. In particular, the following self-limiting phenomena were observed: there is a finite amount of charge initially available on the bias filter capacitors for collection by the strips; the power supply current limit reduces the rate at which the bias filter capacitors' charge can be replenished; the reduced bias voltage leads to a smaller depletion depth in the sensors which results in less collected charge. These effects provide a larger measure of safety during beam loss events than ...

  15. Background gas density and beam losses in NIO1 beam source

    Science.gov (United States)

    Sartori, E.; Veltri, P.; Cavenago, M.; Serianni, G.

    2016-02-01

    NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

  16. Background gas density and beam losses in NIO1 beam source

    Energy Technology Data Exchange (ETDEWEB)

    Sartori, E., E-mail: emanuele.sartori@igi.cnr.it; Veltri, P.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), C.so Stati Uniti 4, 35127 Padova (Italy); Cavenago, M. [INFN-LNL, v.le dell’Università 2, I-35020 Legnaro (PD) (Italy)

    2016-02-15

    NIO1 (Negative Ion Optimization 1) is a versatile ion source designed to study the physics of production and acceleration of H- beams up to 60 keV. In ion sources, the gas is steadily injected in the plasma source to sustain the discharge, while high vacuum is maintained by a dedicated pumping system located in the vessel. In this paper, the three dimensional gas flow in NIO1 is studied in the molecular flow regime by the Avocado code. The analysis of the gas density profile along the accelerator considers the influence of effective gas temperature in the source, of the gas temperature accommodation by collisions at walls, and of the gas particle mass. The calculated source and vessel pressures are compared with experimental measurements in NIO1 during steady gas injection.

  17. Beam-size effect and particle losses at Super$B$ factory developed in Italy

    CERN Document Server

    Kotkin, G L

    2009-01-01

    In the colliders, the macroscopically large impact parameters give a substantial contribution to the standard cross section of the $e^+ e^- \\to e^+ e^- \\gamma$ process. These impact parameters may be much larger than the transverse sizes of the colliding bunches. It means that the standard cross section of this process has to be substantially modified. In the present paper such a beam-size effect is calculated for bremsstrahlung at Super$B$ factory developed in Italy. We find out that this effect reduces beam losses due to bremsstrahlung by about 40%.

  18. Beam-size effect and particle losses at B-factories KEKB and PEP-II

    Energy Technology Data Exchange (ETDEWEB)

    Kotkin, G.L.; Serbo, V.G. E-mail: serbo@math.nsc.ru

    2005-01-01

    In the colliders, the macroscopically large impact parameters give a substantial contribution to the standard cross section of the e{sup +}e{sup -}{yields}e{sup +}e{sup -}{gamma} process. These impact parameters may be much larger than the transverse sizes of the colliding bunches. It means that the standard cross section of this process has to be substantially modified. In the present paper such a beam-size effect is calculated for bremsstrahlung at B-factories KEKB and PEP-II. We find out that this effect reduces beam losses due to bremsstrahlung by about 20%.

  19. Test of Different Beam Loss Detectors at the GSI Heavy Ion Synchrotron

    CERN Document Server

    Forck, P

    2001-01-01

    For the sensitive process of slow extraction from a synchrotron a reliable control of the beam losses is needed. We have tested several types of particle detectors mounted at the extraction path of the SIS: A BF-tube for pure neutron detection, a liquid and a plastic scintillator detecting neutrons, gammas and charged particles and an Argon filled ionization chamber mainly sensitive to charged particles. While the count rate is quite different, the time evolution of all detector signals during the spill are similar, but the plastic scintillator has the highest dynamic range. This type is going to be used for beam alignment.

  20. Controlled Transverse Blow-up of Highenergy Proton Beams for Aperture Measurements and Loss Maps

    CERN Document Server

    Hӧfle, W; Redaelli, S; Schmidt, R; Valuch, D; Wollmann, D; Zerlauth, M

    2012-01-01

    A technique was developed to blow-up transversely in a controlled way high energy proton beams in the LHC. The technique is based on band limited white noise excitation that is injected into the transverse damper feedback loop. The injected signal can be gated to selectively blow-up individual trains of bunches. The speed of transverse blow-up can be precisely controlled. This opens the possibility to perform safely and efficiently aperture measurements and loss maps with high intensity bunch trains well above stored beam energies that are considered to be safe. In particular, lengthy procedures for measurements at top energy, otherwise requiring multiple fills of individual bunches, can be avoided. In this paper, the method is presented and results from beam measurements are discussed and compared with alternative blowup methods.

  1. A Gigabit Ethernet link for an FPGA based Beam Loss Measurement System

    CERN Document Server

    Kwiatkowski, M; Dehning, B; Vigano, W; Zamantzas, C

    2013-01-01

    A new Beam Loss Monitoring (BLM) system is under development at the European Organisation for Nuclear Research (CERN) within the LHC Injector Upgrade (LIU) project. The multi-channel system will have the ability to measure beam losses from various types of detectors with high precision and wide dynamic range. Several modes of data acquisition are supported. The data rate in the singlechannel mode is 16 Mbps and in the multi-channel mode 128 Mbps. The Gigabit Ethernet link is implemented in an FPGA, which allows both a high throughput and a quick validation of the digital data processing algorithms using standard PCs in the initial stages of the development. Both TCP and UDP protocols were explored. The implementation of the Ethernet link is flexible and proved to be highly reliable, leading to its planned use in other measurement systems developed at CERN. The implementation details of the Ethernet link and the results achieved will be described in this paper.

  2. Automatic In Situ Calibration of a Spinning Beam LiDAR System in Static and Kinematic Modes

    Directory of Open Access Journals (Sweden)

    Ting On Chan

    2015-08-01

    Full Text Available The Velodyne LiDAR series is one of the most popular spinning beam LiDAR systems currently available on the market. In this paper, the temporal stability of the range measurements of the Velodyne HDL-32E LiDAR system is first investigated as motivation for the development of a new automatic calibration method that allows quick and frequent recovery of the inherent time-varying errors. The basic principle of the method is that the LiDAR’s internal systematic error parameters are estimated by constraining point clouds of some known and automatically detected cylindrical features such as lamp poles to fit to the 3D cylinder models. This is analogous to the plumb-line calibration method in which the lens distortion parameters are estimated by constraining the image points of straight lines to fit to the 2D line model. The calibration can be performed at every measurement epoch in both static and kinematic modes. Four real datasets were used to verify the method, two of which were captured in static mode and the other two in kinematic mode. The overall results indicate that up to approximately 72% and 41% accuracy improvement were realized as a result of the calibration for the static and kinematic datasets, respectively.

  3. Reducing the extraction loss via laser notching the H- beam at the Booster injection revolution frequency

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xi; Ankenbrandt, Charles M.; /Fermilab

    2005-05-01

    With the requirement for more protons per hour from Booster, the radiation is a limiting factor. Laser notching the H{sup -} beam at the Booster injection revolution frequency and properly aligning those notches on top of each other at the injection and relative to the trigger of firing extraction kickers can remove most of the extraction loss caused by the slow rise time of the kicker field.

  4. Reliability of the Beam Loss Monitors System for the Large Hadron Collider at CERN

    CERN Document Server

    Guaglio, G; Santoni, C

    2005-01-01

    The energy stored in the Large Hadron Collider is unprecedented. The impact of the beam particles can cause severe damage on the superconductive magnets, resulting in significant downtime for repairing. The Beam Loss Monitors System (BLMS) detects the secondary particles shower of the lost beam particles and initiates the extraction of the beam before any serious damage to the equipment can occur. This thesis defines the BLMS specifications in term of reliability. The main goal is the design of a system minimizing both the probability to not detect a dangerous loss and the number of false alarms generated. The reliability theory and techniques utilized are described. The prediction of the hazard rates, the testing procedures, the Failure Modes Effects and Criticalities Analysis and the Fault Tree Analysis have been used to provide an estimation of the probability to damage a magnet, of the number of false alarms and of the number of generated warnings. The weakest components in the BLMS have been pointed out....

  5. Simulation of the ATLAS SCT Barrel Module Response to LHC Beam Loss Scenarios

    CERN Document Server

    Rose, P; The ATLAS collaboration; Fadeyev, V; Spencer, E; Wilder, M; Domingo, M

    2013-01-01

    In the event of beam loss at the LHC, ATLAS Inner Detector components nearest the beamline may be subjected to unusually large amounts of radiation. Understanding their behavior in such an event is important in determining whether they would still function properly. We built a SPICE model of the silicon strip module electrical system to determine the behavior of its elements during a realistic beam loss scenario. We found that the power supply and bias filter characteristics strongly affect the module response in such scenarios. In particular, the following self-limiting phenomena were observed: there is a finite amount of charge initially available on the bias filter capacitors for collection by the strips; the power supply current limit reduces the rate at which the bias filter capacitors' charge can be replenished; the reduced bias voltage leads to a smaller depletion depth which results in less collected charge. These effects provide a larger measure of safety during beam loss events than we have previous...

  6. The applications of in situ electron energy loss spectroscopy to the study of electron beam nanofabrication.

    Science.gov (United States)

    Chen, Shiahn J; Howitt, David G; Gierhart, Brian C; Smith, Rosemary L; Collins, Scott D

    2009-06-01

    An in situ electron energy loss spectroscopy (EELS) technique has been developed to investigate the dynamic processes associated with electron-beam nanofabrication on thin membranes. In this article, practical applications germane to e-beam nanofabrication are illustrated with a case study of the drilling of nanometer-sized pores in silicon nitride membranes. This technique involves successive acquisitions of the plasmon-loss and the core-level ionization-loss spectra in real time, both of which provide the information regarding the hole-drilling kinetics, including two respective rates for total mass loss, individual nitrogen and silicon element depletion, and the change of the atomic bonding environment. In addition, the in situ EELS also provides an alternative method for endpoint detection with a potentially higher time resolution than by imaging. On the basis of the time evolution of in situ EELS spectra, a qualitative working model combining knock-on sputtering, irradiation-induced mass transport, and phase separation can be proposed.

  7. Development of monoenergetic electron beam sources for radiation-instrument calibration

    Science.gov (United States)

    Soares, C. G.; Dick, C. E.; Pruitt, J. S.; Sparrow, J. H.

    1985-05-01

    Accelerator-produced electron beams are being studied for use in obtaining the response of beta-particle dosimetry instrumenta- tion as a function of electron energy. The NBS 4 MV Van de Graaff and 500 kV cascaded rectifier accelerators are being used to generate electron beams from 200 keV to 2.5 MeV. A device capable of scanning the electron beam in two dimensions over an area large enough to cover radiation-survey instruments uniformly is attached to the beam-handling system of each accelerator. The scanned beam exits from vacuum through a 16 cm 2 window consisting of either 25 μm Kapton (for energies below 500 keV) or 100 μm aluminum. The electron beams produced have been characterized in terms of (1) spatial distribution, (2) energy spectrum, and (3) absorbed dose to plastic. Spatial distributions were determined using film, while spectra were measured using a 5 mm-deep Si surface barrier detector. An extrapolation chamber is being used for beam standardization in terms of absorbed dose to plastic.

  8. Development of monoenergetic electron beam sources for radiation-instrument calibration

    Energy Technology Data Exchange (ETDEWEB)

    Soares, C.G.; Dick, C.E.; Pruitt, J.S.; Sparrow, J.H.

    1985-05-15

    Accelerator-produced electron beams are being studied for use in obtaining the response of beta-particle dosimetry instrumentation as a function of electron energy. The NBS 4 MV Van de Graaff and 500 kV cascaded rectifier accelerators are being used to generate electron beams from 200 keV to 2.5 MeV. A device capable of scanning the electron beam in two dimensions over an area large enough to cover radiation-survey instruments uniformly is attached to the beam-handling system of each accelerator. The scanned beam exits from vacuum through a 16 cm/sup 2/ window consisting of either 25 ..mu..m Kapton (for energies below 500 keV) or 100 ..mu..m aluminum. The electron beams produced have been characterized in terms of (1) spatial distribution, (2) energy spectrum, and (3) absorbed dose to plastic. Spatial distributions were determined using film, while spectra were measured using a 5 mm-deep Si surface barrier detector. An extrapolation chamber is being used for beam standardization in terms of absorbed dose to plastic. (orig.).

  9. Quench Tests of LHC Magnets with Beam: Studies on Beam Loss development and determination of Quench levels

    CERN Document Server

    Priebe, A; Sapinski, M

    The application of superconducting materials in the field of high energy accelerator physics not only opens the doors to the generation of the magnetic fields unattainable to normal conductors but also demands facing new challenges. A transition fromthe superconducting state, which is characterized by a resistance-free flow of the electric current, to the normal conducting state is called quenching. This process might be extremely dangerous and even lead to destruction of amagnet superconducting coil if no protecting actions are taken. Therefore, the knowledge of a magnet quench level, i.e. amount of energy which causes the transition to the resistive state, is crucial for the safety and operational efficiency of the accelerator. Regarding that, specific thresholds are incorporated to dedicated quench prevention systems in order to suppress the origin of detected energy perturbation, for example beam losses, or mitigate the consequences of the quenching process by dissipating the energy stored in the magnetic...

  10. Prestress Loss and Bending Capacity of Pre-cracked 40 Year-Old PC Beams Exposed to Marine Environment

    Directory of Open Access Journals (Sweden)

    Dasar Amry

    2016-01-01

    Full Text Available Six prestressed concrete beams (PC beam were used for evaluation, consist of four post-tension beams (PC-O and two pre-tension beams (PC-R. In order to investigate the effect of crack on prestress loss and bending capacity after long-term exposed, prestressed concrete beams were pre-crack and then exposed to marine environment. Experimental work was carried out to evaluate PC beams performance after long-term exposed. In addition, visual observations and load bearing capacity test was carried out. Furthermore, evaluation of prestress loss conducted using three-point loading bending test and the remaining tendon forces in the beam were determined using Crack Re-opening Method. The experimental results revealed that prestress loss was increased due to corrosion of strand/wire which affected by the pre-crack on the prestressed beams. Approximately a prestress loss around 26% and 30% was recorded for post-tension and pre-tension beams respectively.

  11. Improving the Fermilab Booster Notching Efficiency, Beam Losses and Radiation Levels

    CERN Document Server

    Rakhno, I L; Mokhov, N V; Sidorov, V I; Tropin, I S

    2012-01-01

    Currently a fast vertical 1.08-m long kicker (notcher) located in the Fermilab Booster Long-5 straight section is used to remove 3 out of 84 circulating bunches after injection to generate an abort gap. With magnetic field of 72.5 Gauss it removes only 87% of the 3-bunch intensity at 400 MeV, with 75% loss on pole tips of the focusing Booster magnets, 11% on the Long-6 collimators, and 1% in the rest of the ring. We propose to improve the notching efficiency and reduce beam loss in the Booster by using two horizontal kickers in the Long-12 section. The STRUCT calculations show that using such horizontal notchers, one can remove up to 99% of the 3-bunch intensity at 400-700 MeV, directing 96% of it to a new beam dump at the Long-13 section. This fully decouples notching and collimation. The beam dump absorbs most of the impinging proton energy in its jaws. The latter are encapsulated into an appropriate radiation shielding that reduces impact on the machine components, personnel and environment to the tolerabl...

  12. Improved calibration of mass stopping power in low density tissue for a proton pencil beam algorithm.

    Science.gov (United States)

    Warren, Daniel R; Partridge, Mike; Hill, Mark A; Peach, Ken

    2015-06-07

    Dose distributions for proton therapy treatments are almost exclusively calculated using pencil beam algorithms. An essential input to these algorithms is the patient model, derived from x-ray computed tomography (CT), which is used to estimate proton stopping power along the pencil beam paths. This study highlights a potential inaccuracy in the mapping between mass density and proton stopping power used by a clinical pencil beam algorithm in materials less dense than water. It proposes an alternative physically-motivated function (the mass average, or MA, formula) for use in this region. Comparisons are made between dose-depth curves calculated by the pencil beam method and those calculated by the Monte Carlo particle transport code MCNPX in a one-dimensional lung model. Proton range differences of up to 3% are observed between the methods, reduced to  stopping power calculation methodology results in relatively minor differences in dose when plans use three fields, but differences are observed at the 2%-2 mm level when a single field uniform dose technique is adopted. It is therefore suggested that the MA formula is adopted by users of the pencil beam algorithm for optimal dose calculation in lung, and that a similar approach is considered when beams traverse other low density regions such as the paranasal sinuses and mastoid process.

  13. Improved calibration of mass stopping power in low density tissue for a proton pencil beam algorithm

    Science.gov (United States)

    Warren, Daniel R.; Partridge, Mike; Hill, Mark A.; Peach, Ken

    2015-06-01

    Dose distributions for proton therapy treatments are almost exclusively calculated using pencil beam algorithms. An essential input to these algorithms is the patient model, derived from x-ray computed tomography (CT), which is used to estimate proton stopping power along the pencil beam paths. This study highlights a potential inaccuracy in the mapping between mass density and proton stopping power used by a clinical pencil beam algorithm in materials less dense than water. It proposes an alternative physically-motivated function (the mass average, or MA, formula) for use in this region. Comparisons are made between dose-depth curves calculated by the pencil beam method and those calculated by the Monte Carlo particle transport code MCNPX in a one-dimensional lung model. Proton range differences of up to 3% are observed between the methods, reduced to  calculation methodology results in relatively minor differences in dose when plans use three fields, but differences are observed at the 2%-2 mm level when a single field uniform dose technique is adopted. It is therefore suggested that the MA formula is adopted by users of the pencil beam algorithm for optimal dose calculation in lung, and that a similar approach is considered when beams traverse other low density regions such as the paranasal sinuses and mastoid process.

  14. Prediction of dissolved reactive phosphorus losses from small agricultural catchments: calibration and validation of a parsimonious model

    Directory of Open Access Journals (Sweden)

    C. Hahn

    2013-10-01

    Full Text Available Eutrophication of surface waters due to diffuse phosphorus (P losses continues to be a severe water quality problem worldwide, causing the loss of ecosystem functions of the respective water bodies. Phosphorus in runoff often originates from a small fraction of a catchment only. Targeting mitigation measures to these critical source areas (CSAs is expected to be most efficient and cost-effective, but requires suitable tools. Here we investigated the capability of the parsimonious Rainfall-Runoff-Phosphorus (RRP model to identify CSAs in grassland-dominated catchments based on readily available soil and topographic data. After simultaneous calibration on runoff data from four small hilly catchments on the Swiss Plateau, the model was validated on a different catchment in the same region without further calibration. The RRP model adequately simulated the discharge and dissolved reactive P (DRP export from the validation catchment. Sensitivity analysis showed that the model predictions were robust with respect to the classification of soils into "poorly drained" and "well drained", based on the available soil map. Comparing spatial hydrological model predictions with field data from the validation catchment provided further evidence that the assumptions underlying the model are valid and that the model adequately accounts for the dominant P export processes in the target region. Thus, the parsimonious RRP model is a valuable tool that can be used to determine CSAs. Despite the considerable predictive uncertainty regarding the spatial extent of CSAs, the RRP can provide guidance for the implementation of mitigation measures. The model helps to identify those parts of a catchment where high DRP losses are expected or can be excluded with high confidence. Legacy P was predicted to be the dominant source for DRP losses and thus, in combination with hydrologic active areas, a high risk for water quality.

  15. Calibration of solid state nuclear track detectors at high energy ion beams for cosmic radiation measurements: HAMLET results

    Energy Technology Data Exchange (ETDEWEB)

    Szabo, J., E-mail: julianna.szabo@energia.mta.hu [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary); Palfalvi, J.K. [Hungarian Academy of Sciences, Centre for Energy Research, Konkoly Thege Miklos ut 29-33, 1525 Budapest 114, P.O. Box 49 (Hungary)

    2012-12-01

    The MATROSHKA experiments and the related HAMLET project funded by the European Commission aimed to study the dose burden of the crew working on the International Space Station (ISS). During these experiments a human phantom equipped with several thousands of radiation detectors was exposed to cosmic rays inside and outside the ISS. Besides the measurements realized in Earth orbit, the HAMLET project included also a ground-based program of calibration and intercomparison of the different detectors applied by the participating groups using high-energy ion beams. The Space Dosimetry Group of the Centre for Energy Research (formerly Atomic Energy Research Institute) participated in these experiments with passive solid state nuclear track detectors (SSNTDs). The paper presents the results of the calibration experiments performed in the years 2008-2011 at the Heavy Ion Medical Accelerator (HIMAC) of the National Institute of Radiological Sciences (NIRS), Chiba, Japan. The data obtained serve as update and improvement for the previous calibration curves which are necessary for the evaluation of the SSNTDs exposed in unknown space radiation fields.

  16. Stochastic orbit loss of neutral beam ions from NSTX due to toroidal Alfvén eigenmode avalanches

    Energy Technology Data Exchange (ETDEWEB)

    Darrow, D. S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Crocker, N. [Univ. of California, Los Angeles, CA (United States). Dept. of Physics; Fredrickson, E. D. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkov, N. N. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Gorelenkova, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Kubota, S. [Univ. of California, Los Angeles, CA (United States). Dept. of Physics; Medley, S. S. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Podestà, M. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); Shi, L. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States); White, R. B. [Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)

    2012-12-17

    Short toroidal Alfvén eigenmode (TAE) avalanche bursts in the National Spherical Torus Experiment (NSTX) cause a drop in the neutron rate and could also cause a loss of neutral beam ions at or near the full injection energy over an extended range of pitch angles. The simultaneous loss of wide ranges of pitch angle suggests stochastic transport of the beam ions takes place. When beam ion orbits are followed with a guiding centre code that incorporates the plasma's magnetic equilibrium plus the measured modes, the predicted ranges of lost pitch angle are like those seen in the experiment, with distinct populations of trapped and passing orbits lost. These correspond to domains where the stochasticity extends in the orbit phase space from the region of beam ion deposition to the loss boundary and the trajectories along which modes may transport particles extend from the deposition volume to the loss boundary.

  17. Beam-size effect and particle losses at SuperB factory developed in Italy

    Energy Technology Data Exchange (ETDEWEB)

    Kotkin, G L; Serbo, V G [Novosibirsk State University, 630090, Novosibirsk, Pirogova st., 2 (Russian Federation)], E-mail: serbo@math.nsc.ru

    2009-06-15

    In the colliders, the macroscopically large impact parameters give a substantial contribution to the standard cross section of the e{sup +}e{sup -}{yields} e{sup +}e{sup -}{gamma} process. These impact parameters may be much larger than the transverse sizes of the colliding bunches. It means that the standard cross section of this process has to be substantially modified. In the present paper such a beam-size effect is calculated for bremsstrahlung at SuperB factory developed in Italy. We find out that this effect reduces beam losses due to bremsstrahlung by about 40%. We perform a critical comparison of our result with that presented in the Conceptual Design Report of the Italian SuperB factory.

  18. Validation of the Local Hadronic Calibration Scheme of ATLAS with Combined Beam Test Data in the End-Cap and Forward Regions of ATLAS

    CERN Document Server

    Kiryunin, A; The ATLAS collaboration

    2011-01-01

    The three Atlas calorimeter systems in the region of the forward crack at |eta| = 3.2 in the nominal Atlas setup have been exposed to combined beam tests with single electrons and pions. Detailed shower shape studies of electrons and pions with comparisons to various Geant4 based simulations utilizing different physics lists are presented. The Local Hadron Calibration developed for the energy reconstruction and the calibration of jets and missing transverse energy in ATLAS, has been validated using data obtained during these beam tests. The analysis has been carried out by using special sets of calibration weights and corrections obtained with the Geant4 simulation of a detailed beam test set-up. The validation itself has been performed by careful studying specific calorimeter performance parameters such as e.g. energy response, energy resolution, shower shapes, cluster energy density as well as different physics lists of the Geant4 simulation.

  19. A COMPACTRIO-BASED BEAM LOSS MONITOR FOR THE SNS RF TEST CAVE

    Energy Technology Data Exchange (ETDEWEB)

    Blokland, Willem [ORNL; Armstrong, Gary A [ORNL

    2009-01-01

    An RF Test Cave has been built at the Spallation Neutron Source (SNS) to be able to test RF cavities without interfering the SNS accelerator operations. In addition to using thick concrete wall to minimize radiation exposure, a Beam Loss Monitor (BLM) must abort the operation within 100 usec when the integrated radiation within the cave exceeds a threshold. We choose the CompactRIO platform to implement the BLM based on its performance, cost-effectiveness, and rapid development. Each in/output module is connected through an FPGA to provide point-by-point processing. Every 10 usec the data is acquired analyzed and compared to the threshold. Data from the FPGA is transferred using DMA to the real-time controller, which communicates to a gateway PC to talk to the SNS control system. The system includes diagnostics to test the hardware and integrates the losses in real-time. In this paper we describe our design, implementation, and results

  20. Real-Time System Supervision for the LHC Beam Loss Monitoring System at CERN

    CERN Document Server

    Zamantzas, C; Effinger, E; Emery, J; Jackson, S

    2014-01-01

    The strategy for machine protection and quench prevention of the Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is mainly based on the Beam Loss Monitoring (BLM) system. The LHC BLM system is one of the most complex and large instrumentation systems deployed in the LHC. In addition to protecting the collider, the system also needs to provide a means of diagnosing machine faults and deliver feedback of the losses to the control room as well as to several systems for their setup and analysis. In order to augment the dependability of the system several layers of supervision has been implemented internally and externally to the system. This paper describes the different methods employed to achieve the expected availability and system fault detection.

  1. Calibrating IR cameras for in-situ temperature measurement during the electron beam melt processing of Inconel 718 and Ti-Al6-V4

    Science.gov (United States)

    Dinwiddie, R. B.; Kirka, M. M.; Lloyd, P. D.; Dehoff, R. R.; Lowe, L. E.; Marlow, G. S.

    2016-05-01

    High performance mid-wave infrared (IR) cameras are used for in-situ electron beam melt process monitoring and temperature measurements. Since standard factory calibrations are insufficient due to very low transmissions of the leaded glass window required for X-ray absorption, two techniques for temperature calibrations are compared. In-situ measurement of emittance will also be discussed. Ultimately, these imaging systems have the potential for routine use for online quality assurance and feedback control.

  2. Updated analytical solutions of continuity equation for electron beams precipitation - II. Mixed energy losses

    Science.gov (United States)

    Zharkova, V. V.; Dobranskis, R. R.

    2016-06-01

    In this paper we consider simultaneous analytical solutions of continuity equations for electron beam precipitation (a) in collisional losses and (b) in ohmic losses, or mixed energy losses (MEL) by applying the iterative method to calculate the resulting differential densities at given precipitation depth. The differential densities of precipitating electrons derived from the analytical solutions for MELs reveal increased flattening at energies below 10-30 keV compared to a pure collisional case. This flattening becomes stronger with an increasing precipitation depth turning into a positive slope at greater precipitation depths in the chromosphere resulting in a differential density distribution with maximum that shifts towards higher energies with increase in column depth, while the differential densities combining precipitating and returning electrons are higher at lower energies than those for a pure collisional case. The resulting hard X-ray (HXR) emission produced by the beams with different initial energy fluxes and spectral indices is calculated using the MEL approach for different ratios between the differential densities of precipitating and returning electrons. The number of returning electrons can be even further enhanced by a magnetic mirroring, not considered in the present model, while dominating at lower atmospheric depths where the magnetic convergence and magnitude are the highest. The proposed MEL approach provides an opportunity to account simultaneously for both collisional and ohmic losses in flaring events, which can be used for a quick spectral fitting of HXR spectra and evaluation of a fraction of returning electrons versus precipitating ones. The semi-analytical MEL approach is used for spectral fitting to Reuven High Energy Solar Spectroscopic Imager observations of nine C, M and X class flares revealing a close fit to the observations and good resemblance to numerical FP solutions.

  3. Method to obtain absolute impurity density profiles combining charge exchange and beam emission spectroscopy without absolute intensity calibration

    Energy Technology Data Exchange (ETDEWEB)

    Kappatou, A.; Delabie, E. [FOM Institute DIFFER - Dutch Institute for Fundamental Energy Research, Association EURATOM-FOM, 3430 BE Nieuwegein (Netherlands); Jaspers, R. J. E.; Jakobs, M. A. [Science and Technology of Nuclear Fusion, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Marchuk, O.; Biel, W. [Institute for Energy and Climate Research, Forschungszentrum Julich GmbH, Trilateral Euregio Cluster, 52425 Julich (Germany)

    2012-10-15

    Investigation of impurity transport properties in tokamak plasmas is essential and a diagnostic that can provide information on the impurity content is required. Combining charge exchange recombination spectroscopy (CXRS) and beam emission spectroscopy (BES), absolute radial profiles of impurity densities can be obtained from the CXRS and BES intensities, electron density and CXRS and BES emission rates, without requiring any absolute calibration of the spectra. The technique is demonstrated here with absolute impurity density radial profiles obtained in TEXTOR plasmas, using a high efficiency charge exchange spectrometer with high etendue, that measures the CXRS and BES spectra along the same lines-of-sight, offering an additional advantage for the determination of absolute impurity densities.

  4. A Study of Hadronic Calibration Schemes for Pion Test Beam Data in the ATLAS Forward Calorimeter

    CERN Document Server

    McCarthy, Thomas G

    The ATLAS forward calorimeters constitute a small though important fraction of the detector's calorimeter system, designed in part to accurately and precisely measure the energy of particles and jets of particles originating from the collisions of high-energy protons at the detector's centre. The application of hadronic weights, a practice common in high-energy calorimetry, provides a means of compensation for the fraction of energy which is deposited by particles in the detector, but which is invisible to the detector due to the nature of hadronic showers. Explored here are various schemes of extracting hadronic weights, as well as the application of such weights, based on pion data from the 2003 ATLAS forward calorimeter test beam. During the collection of test beam data, beams of both pions and electrons of known energy, ranging from 10 to 200 GeV, were fired at specific points of an isolated detector in order to understand its response. The improvement in noise-subtracted energy resolution with respect to...

  5. Calibrated Heat Flow Model for Determining the Heat Conduction Losses in Laser Cutting of CFRP

    Science.gov (United States)

    Mucha, P.; Weber, R.; Speker, N.; Berger, P.; Sommer, B.; Graf, T.

    Laser machining has great potential regarding automation in fabrication of CFRP (carbon-fiber-reinforced plastics) parts, due to the nearly force and tool-wear free processing at high process speeds. The high vaporization temperatures and the large heat conductivity of the carbon fibers lead to a large heat transport into the sample. This causes the formation of a heat-affected zone and a decrease of the process speed. In the present paper,an analytical heat flow model was adapted in order to understand and investigate the heat conduction losses. Thermal sensors were embedded in samples at different distances from the kerf to fit the calculated to the measured temperatures. Heat conduction losses of up to 30% of the laser power were determined. Furthermore, the energy not absorbed by the sample, the energy for sublimating the composite material in the kerf, the energy for the formation of the HAZ, and the residual heat in the sample are compared in an energy balance.

  6. Improving calibration of two key parameters in Hydrologic Engineering Center hydrologic modelling system, and analysing the influence of initial loss on flood peak flows.

    Science.gov (United States)

    Lin, Musheng; Chen, Xingwei; Chen, Ying; Yao, Huaxia

    2013-01-01

    Parameter calibration is a key and difficult issue for a hydrological model. Taking the Jinjiang Xixi watershed of south-east China as the study area, we proposed methods to improve the calibration of two very sensitive parameters, Muskingum K and initial loss, in the Hydrologic Engineering Center hydrologic modelling system (HEC-HMS) model. Twenty-three rainstorm flood events occurring from 1972 to 1977 were used to calibrate the model using a trial-and-error approach, and a relationship between initial loss and initial discharge for these flood events was established; seven rainstorm events occurring from 1978 to 1979 were used to validate the two parameters. The influence of initial loss change on different return-period floods was evaluated. A fixed Muskingum K value, which was calibrated by assuming a flow wave velocity at 3 m/s, could be used to simulate a flood hydrograph, and the empirical power-function relationship between initial loss and initial discharge made the model more applicable for flood forecasting. The influence of initial loss on peak floods was significant but not identical for different flood levels, and the change rate of peak floods caused by the same initial loss change was more remarkable when the return period increased.

  7. Development of a Beam Loss Measurement System with Gigabit Ethernet Readout at CERN

    CERN Document Server

    Kwiatkowski, M; Angelogiannopoulos, E; Dehning, B; Jackson, S; Vigano, W; Zamantzas, C

    2012-01-01

    The aim of the BLM Dual Polarity module under development at the European Organisation for Nuclear Research (CERN) is to measure and digitise with high precision the current produced by several types of beam loss detectors. In its default configuration, it is expected to provide data to the processing electronics through two point-to-point connections with bidirectional multi-gigabit optical links. For the development phases as well as later serving as a standalone measurement system, its reconfigurable FPGA device is exploited to provide a soft-core CPU with a custom made server. This server, running on the CPU, will expose through the Gigabit Ethernet connection and the TCP/IP protocol different types of data in the network. In this paper the development of the system and of the communication protocol is explored as well as the accompanying client ap- plication that is realised with the purpose of commanding, collecting storing and viewing the different types of data.

  8. 10 Orders of Magnitude Current Measurement Digitisers for the CERN Beam Loss Systems

    CERN Document Server

    Vigano, W; Dehning, B; Kwiatkowski, M; Venturini, G G; Zamantzas, C

    2014-01-01

    A wide range current digitizer card is needed for the acquisition module of the beam loss monitoring systems in the CERN Injector Complex. The fully differential frequency converter allows measuring positive and negative input currents with a resolution of 31nA in an integration window of 2μs. Increasing the integration window, the dynamic range covers 2•1010 were the upper part of the range is converted by measuring directly the voltage drop on a resistor. The key elements of this design are the fully differential integrator and the switches operated by an FPGA. The circuit is designed to avoid any dead time in the acquisition and reliability and failsafe operational considerations are main design goals. The circuit will be discussed in detail and lab and field measurements will be shown.

  9. Improved design and construction of an ionization chamber for the CSNS beam loss monitor (BLM)

    Institute of Scientific and Technical Information of China (English)

    TIAN Jian-Min; XU Mei-Hang; ZHAO Zhong-Liang; CHEN Chang; RUAN Xiang-Dong; CHEN Yuan-Bo; XU Tao-Guang; LU Shuang-Tong

    2012-01-01

    Based on the first ionization chamber (IC) prototype,the structure,working gas component and electrode material of the IC are improved.The test of the improved IC shows that the plateau length is about 2000 V,the plateau slope is less than 0.2%/100 V,the sensitivity is 19.6 pA/rad.h-1,the up-limitation of the linearity can be up to 3.6× 105 rad/h,and the applied voltage can be operated to 3500 V.The test results show that the performance of the improved IC meets the requirements of the beam loss monitor.

  10. Effects of Optical Loss Factors on Heliostat Field Layout for Beam-Down Solar Concentrating Systems

    Science.gov (United States)

    Utamura, Motoaki; Takamatsu, Tadahiko; Yuasa, Minoru; Kajita, Rina; Yamamoto, Takashi

    A methodology to give an optimal layout of a group of heliostats has been developed for beam-down concentrating solar tower systems. Given the maximum solar power together with optical parameters, the method determines an optimal configuration of a heliostat field around a tower. Various optical losses such as cosine factor, shadowing and blocking at heliostats are considered in the calculation. Furthermore, spillage at the receiver is taken into account due to the spread of light caused by the effects of a finite solar disk, flat facet and various stochastic errors in optical hardware and control. It is found the effect of spillage becomes significant at heliostats from the tower at the distance farther than four times of upper focus height of the reflector when receiver diameter is one fifteenth of the height and dominates the configuration of the optimal heliostat layout.

  11. 10 orders of magnitude current measurement digitisers for the CERN beam loss systems

    Science.gov (United States)

    Viganò, W.; Alsdorf, M.; Dehning, B.; Kwiatkowski, M.; Venturini, G. G.; Zamantzas, C.

    2014-02-01

    A wide range current digitizer card is needed for the acquisition module of the beam loss monitoring systems in the CERN Injector Complex. The fully differential frequency converter allows measuring positive and negative input currents with a resolution of 31 nA in an integration window of 2 μs. Increasing the integration window, the dynamic range covers 21010 were the upper part of the range is converted by measuring directly the voltage drop on a resistor. The key elements of this design are the fully differential integrator and the switches operated by an FPGA. The circuit is designed to avoid any dead time in the acquisition and reliability and failsafe operational considerations are main design goals. The circuit will be discussed in detail and lab and field measurements will be shown.

  12. Study on the radiation problem caused by electron beam loss in accelerator tubes

    Institute of Scientific and Technical Information of China (English)

    LI Quan-Feng; GUO Bing-Qi; ZHANG Jie-Xi; CHEN Huai-Bi

    2008-01-01

    The beam dynamic code PARMELA was used to simulate the transportation process of accelerating electrons in S-band SW linacs with different energies of 2.5, 6 and 20 MeV. The results indicated that in the ideal condition, the percentage of electron beam loss was 50% in accelerator tubes. Also we calculated the spectrum, the location and angular distribution of the lost electrons. Calculation performed by Monte Carlo code MCNP demonstrated that the radiation distribution of lost electrons was nearly uniform along the tube axis, the angular distributions of the radiation dose rates of the three tubes were similar, and the highest leaking dose was at the angle of 160° with respect to the axis. The lower the energy of the accelerator, the higher the radiation relative leakage. For the 2.5 MeV accelerator, the maximum dose rate reached 5% of the main dose and the one on the head of the electron gun was 1%, both of which did not meet the eligible protection requirement for accelerators. We adopted different shielding designs for different accelerators. The simulated result showed that the shielded radiation leaking dose rates fulfilled the requirement.

  13. Energy loss of a fast-electron beam due to the excitation of collective oscillation in hot plasma

    Institute of Scientific and Technical Information of China (English)

    Ma Jin-Yi; Qiu Xi-Jun; Zhu Zhi-Yuan

    2004-01-01

    Energy loss due to a fast-electron beam interacting with the hot plasma at a high density is analysed theoretically.By splitting the particle density fluctuations into the individual part due to the random thermal motion of the individual electrons and the collective part due to plasma-wave excitation, we are concerned with the collective interaction of the relativistic plasma electrons resulting from the Coulomb interactions. Consequently, we derive the frequency of the hot plasma and the "Debye length" with the modification of the relativistic effect. And finally we calculate the energy loss of a fast-electron beam due to the excitation of collective oscillation in the hot plasma.

  14. Calibration of the OHREX high-resolution imaging crystal spectrometer at the Livermore electron beam ion traps

    Science.gov (United States)

    Hell, N.; Beiersdorfer, P.; Magee, E. W.; Brown, G. V.

    2016-11-01

    We report the calibration of the Orion High-Resolution X-ray (OHREX) imaging crystal spectrometer at the EBIT-I electron beam ion trap at Livermore. Two such instruments, dubbed OHREX-1 and OHREX-2, are fielded for plasma diagnostics at the Orion laser facility in the United Kingdom. The OHREX spectrometer can simultaneously house two spherically bent crystals with a radius of curvature of r = 67.2 cm. The focusing properties of the spectrometer allow both for larger distance to the source due to the increase in collected light and for observation of extended sources. OHREX is designed to cover a 2.5°-3° spectral range at Bragg angles around 51.3°. The typically high resolving powers at these large Bragg angles are ideally suited for line shape diagnostics. For instance, the nominal resolving power of the instrument (>10 000) is much higher than the effective resolving power associated with the Doppler broadening due to the temperature of the trapped ions in EBIT-I. The effective resolving power is only around 3000 at typical EBIT-I conditions, which nevertheless is sufficient to set up and test the instrument's spectral characteristics. We have calibrated the spectral range for a number of crystals using well known reference lines in the first and second order and derived the ion temperatures from these lines. We have also made use of the 50 μm size of the EBIT-I source width to characterize the spatial focusing of the spectrometer.

  15. Evaluating uncertainties in the cross-calibration of parallel ion chambers used in electron beam radiotherapy; Avaliacao das incertezas no processo de calibracao cruzada de camaras de placas paralelas utilizadas em feixes de eletrons para radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, Ernani; Travassos, Paulo; Ferreira, Max da Silva; Carvalho, Samira Marques de; Silva, Michele Maria da; Peixoto, Jose Guilherme Pereira, E-mail: ernanianderson@hotmail.com [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Salmon Junior, Helio Augusto [Grupo COI - Clinicas Oncologicas, Rio de Janeiro, RJ (Brazil)

    2015-07-01

    This study aims to estimative the combined standard uncertainty for a detector parallel plate used for dosimetry of electron beams in linear accelerators for radiotherapy, which has been calibrated by the cross-calibration method. Keeping the combined standard uncertainty next of the uncertainty informed in the calibration certificate of the reference chamber, become possible establish the calibration factor of the detector. The combined standard uncertainty obtained in this study was 2.5 %. (author)

  16. A Cherenkov-based Beam Loss Scintillator system for beam, background and online luminosity monitoring at the LHCb experiment at CERN

    CERN Document Server

    Alessio, F; Jacobsson, R

    2013-01-01

    The installation of a scintillator-based system in the LHCb cavern was initially proposed in order to observe injection problems around the LHCb interaction region. Thanks to the fact that LHCb had already developed a custom-made electronics board (BPIM) for the LHCb beam pickups and global LHCb timing monitoring, a complete, inexpensive but flexible and robust system was quickly developed and installed few cm from the beam pipe just in front of the LHCb VELO detector in time for the very first beams injected in the LHC. The current and final system – commonly referred to as Beam Loss Scintillator (BLS) system - ultimately played a central role in the fast beam, background and online luminosity monitoring at LHCb. In this paper, the features of the detector – based on quartz radiator and Cherenkov light - are described, including the functionalities that the system acquired during the proton-proton physics programmes in 2009- 2013 thanks to its flexibility, reliability and sensitivity to beam hal...

  17. A versatile facility for the calibration of X-ray polarimeters with polarized and unpolarized controlled beams

    CERN Document Server

    Muleri, Fabio; Bellazzini, Ronaldo; Brez, Alessandro; Costa, Enrico; Frutti, Massimo; Mastropietro, Marcello; Morelli, Ennio; Pinchera, Michele; Rubini, Alda; Spandre, Gloria

    2008-01-01

    We devised and built a versatile facility for the calibration of the next generation X-ray polarimeters with unpolarized and polarized radiation. The former is produced at 5.9 keV by means of a Fe55 radioactive source or by X-ray tubes, while the latter is obtained by Bragg diffraction at nearly 45 degrees. Crystals tuned with the emission lines of X-ray tubes with molybdenum, rhodium, calcium and titanium anodes are employed for the efficient production of highly polarized photons at 2.29, 2.69, 3.69 and 4.51 keV respectively. Moreover the continuum emission is exploited for the production of polarized photons at 1.65 keV and 2.04 keV and at energies corresponding to the higher orders of diffraction. The photons are collimated by means of interchangeable capillary plates and diaphragms, allowing a trade-off between collimation and high fluxes. The direction of the beam is accurately arranged by means of high precision motorized stages, controlled via computer so that long and automatic measurements can be do...

  18. A water calorimeter for on-site absorbed dose to water calibrations in 60Co and MV-photon beams including MRI incorporated treatment equipment

    Science.gov (United States)

    de Prez, Leon; de Pooter, Jacco; Jansen, Bartel; Aalbers, Tony

    2016-07-01

    In reference dosimetry the aim is to establish the absorbed dose to water, D w, under reference conditions. However, existing dosimetry protocols are not always applicable for rapidly emerging new treatment modalities. For primary standard dosimetry laboratories it is generally not feasible to acquire such modalities. Therefore it is strongly desired that D w measurements with primary standards can be performed on-site in clinical beams for the new treatment modalities in order to characterize and calibrate detectors. To serve this need, VSL has developed a new transportable water calorimeter serving as a primary D w standard for 60Co and MV-photons including MRI incorporated treatment equipment. Special attention was paid to its operation in different beam geometries and beam modalities including the application in magnetic fields. The new calorimeter was validated in the VSL 60Co beam and on-site in clinical MV-photon beams. Excellent agreement of 0.1% was achieved with previous 60Co field calibrations, i.e. well within the uncertainty of the previous calorimeter, and with measurements performed in horizontal and vertical MV-photon beams. k Q factors, determined for two PTW 30013 ionization chambers, agreed very well with available literature data. The relative combined standard uncertainty (k  =  1) for D w measurements in 60Co and MV-photons is 0.37%. Calibrations are carried out with a standard uncertainty of 0.42% and k Q -factors are determined with a relative standard uncertainty of 0.40%.

  19. Severe signal loss in diamond beam loss monitors in high particle rate environments by charge trapping in radiation-induced defects

    CERN Document Server

    Kassel, Florian; Dabrowski, Anne; de Boer, Wim

    2016-01-01

    The beam condition monitoring leakage (BCML) system is a beam monitoring device in the compact muon solenoid (CMS) experiment at the large hadron collider (LHC). As detectors 32 poly-crystalline (pCVD) diamond sensors are positioned in rings around the beam pipe. Here, high particle rates occur from the colliding beams scattering particles outside the beam pipe. These particles cause defects, which act as traps for the ionization, thus reducing the charge collection efficiency (CCE). However, the loss in CCE was much more severe than expected from low rate laboratory measurements and simulations, especially in single-crystalline (sCVD) diamonds, which have a low initial concentration of defects. The reason why in real experiments the CCE is much worse than in laboratory experiments is related to the ionization rate. At high particle rates the trapping rate of the ionization is so high compared with the detrapping rate, that space charge builds up. This space charge reduces locally the internal electric field,...

  20. Orbital angular moment of a partially coherent beam propagating through an astigmatic ABCD optical system with loss or gain.

    Science.gov (United States)

    Cai, Yangjian; Zhu, Shijun

    2014-04-01

    We derive the general expression for the orbital angular momentum (OAM) flux of an astigmatic partially coherent beam carrying twist phase [i.e., twisted anisotropic Gaussian-Schell model (TAGSM) beam] propagating through an astigmatic ABCD optical system with loss or gain. The evolution properties of the OAM flux of a TAGSM beam in a Gaussian cavity or propagating through a cylindrical thin lens are illustrated numerically with the help of the derived formula. It is found that we can modulate the OAM of a partially coherent beam by varying the parameters of the cavity or the orientation angle of the cylindrical thin lens, which will be useful in some applications, such as free-space optical communications and particle trapping.

  1. Low-resistance strip sensors for beam-loss event protection

    Energy Technology Data Exchange (ETDEWEB)

    Ullán, M., E-mail: Miguel.Ullan@imb-cnm.csic.es [Centro Nacional de Microelectrónica (IMB-CNM, CSIC), Campus Universitario de Bellaterra, 08193 Barcelona (Spain); Benítez, V.; Quirion, D.; Zabala, M.; Pellegrini, G.; Lozano, M. [Centro Nacional de Microelectrónica (IMB-CNM, CSIC), Campus Universitario de Bellaterra, 08193 Barcelona (Spain); Lacasta, C.; Soldevila, U.; García, C. [Instituto de Fisica Corpuscular (IFIC, CSIC-UV), Valencia (Spain); Fadeyev, V.; Wortman, J.; DeFilippis, J.; Shumko, M.; Grillo, A.A; Sadrozinski, H.F.-W. [Santa Cruz Institute for Particle Physics (SCIPP), University of California Santa Cruz (UCSC), Santa Cruz, CA (United States)

    2014-11-21

    AC-coupled silicon strip sensors can be damaged in case of a beam loss due to the possibility of a large charge accumulation in the bulk, developing very high voltages across the coupling capacitors which can destroy them. Punch-through structures are currently used to avoid this problem helping to evacuate the accumulated charge as large voltages are developing. Nevertheless, previous experiments, performed with laser pulses, have shown that these structures can become ineffective in relatively long strips. The large value of the implant resistance can effectively isolate the “far” end of the strip from the punch-through structure leading to large voltages. We present here our developments to fabricate low-resistance strip sensors to avoid this problem. The deposition of a conducting material in contact with the implants drastically reduces the strip resistance, assuring the effectiveness of the punch-through structures. First devices have been fabricated with this new technology. Initial results with laser tests show the expected reduction in peak voltages on the low resistivity implants. Other aspects of the sensor performance, including the signal formation, are not affected by the new technology.

  2. Localization of the large-angle foil-scattering beam loss caused by the multiturn charge-exchange injection

    Science.gov (United States)

    Kato, Shinichi; Yamamoto, Kazami; Yoshimoto, Masahiro; Harada, Hiroyuki; Kinsho, Michikazu

    2013-07-01

    In the 3 GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, significant losses were observed at the branching of the H0 dump line and the beam position monitor that was inserted downstream of the H0 dump branch duct. These losses were caused by the large-angle scattering of the injection and circulating beams at the charge-exchange foil. To realize high-power operation, these losses must be mitigated. Therefore, a new collimation system was developed and installed in October 2011. To efficiently optimize this system, the behavior of particles scattered by the foil and produced by the absorber were simulated, and the optimal position and angle of the absorber were investigated. During this process, an angle regulation method for the absorber was devised. An outline of this system, the angle regulation method for the absorber, and the performance of this new collimation system are described.

  3. TH-C-BRD-05: Reducing Proton Beam Range Uncertainty with Patient-Specific CT HU to RSP Calibrations Based On Single-Detector Proton Radiography

    Energy Technology Data Exchange (ETDEWEB)

    Doolan, P [University College London, London (United Kingdom); Massachusetts General Hospital, Boston, MA (United States); Sharp, G; Testa, M; Lu, H-M [Massachusetts General Hospital, Boston, MA (United States); Bentefour, E [Ion Beam Applications (IBA), Louvain la Neuve (Belgium); Royle, G [University College London, London (United Kingdom)

    2014-06-15

    Purpose: Beam range uncertainty in proton treatment comes primarily from converting the patient's X-ray CT (xCT) dataset to relative stopping power (RSP). Current practices use a single curve for this conversion, produced by a stoichiometric calibration based on tissue composition data for average, healthy, adult humans, but not for the individual in question. Proton radiographs produce water-equivalent path length (WEPL) maps, dependent on the RSP of tissues within the specific patient. This work investigates the use of such WEPL maps to optimize patient-specific calibration curves for reducing beam range uncertainty. Methods: The optimization procedure works on the principle of minimizing the difference between the known WEPL map, obtained from a proton radiograph, and a digitally-reconstructed WEPL map (DRWM) through an RSP dataset, by altering the calibration curve that is used to convert the xCT into an RSP dataset. DRWMs were produced with Plastimatch, an in-house developed software, and an optimization procedure was implemented in Matlab. Tests were made on a range of systems including simulated datasets with computed WEPL maps and phantoms (anthropomorphic and real biological tissue) with WEPL maps measured by single detector proton radiography. Results: For the simulated datasets, the optimizer showed excellent results. It was able to either completely eradicate or significantly reduce the root-mean-square-error (RMSE) in the WEPL for the homogeneous phantoms (to zero for individual materials or from 1.5% to 0.2% for the simultaneous optimization of multiple materials). For the heterogeneous phantom the RMSE was reduced from 1.9% to 0.3%. Conclusion: An optimization procedure has been designed to produce patient-specific calibration curves. Test results on a range of systems with different complexities and sizes have been promising for accurate beam range control in patients. This project was funded equally by the Engineering and Physical Sciences

  4. Influence of the beam-size effect on particle losses at B-factories PEP-II and KEKB

    Energy Technology Data Exchange (ETDEWEB)

    Kotkin, G.L.; Serbo, V.G. E-mail: serbo@math.nsc.ru

    2004-01-21

    In the colliders, the macroscopically large impact parameters give a substantial contribution to the standard cross-section of the e{sup +}e{sup -}{yields}e{sup +}e{sup -}{gamma} process. These impact parameters may be much larger than the transverse sizes of the colliding bunches. It means that the standard cross-section of this process has to be substantially modified. In the present paper such a beam-size is calculated for bremsstrahlung at B-factories PEP-II and KEKB. We find out that this effect reduces beam losses due to bremsstrahlung by about 20%.

  5. Characteristic parameters analysis on diagnostic X-ray beams for dosemeter calibration; Analise de parametros caracteristicos de feixes de raios-X diagnostico para calibracao de dosimetros

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Paulo Marcio Campos de

    2008-07-01

    Ionizing radiation metrology is the base to achieve reliable dose measurements in ali areas; it is also part of the framework that is established to assure radiation protection procedures in order to avoid or minimize the harmful biological effect that may be caused by ionizing radiation. A well done metrology means the use of reliable instruments that comply with standard performance requirements worldwide accepted. Those instruments are expected to be calibrated by Metrology Laboratories under well defined conditions. The International Electrotechnical Commission (IEC) in Standard 61267 established the reference radiations for medical diagnostic x-ray equipment that are recommended to be used for calibrating dosimetric systems for diagnostic dosimetry. In this work, X-ray beam qualities were established in a Calibration Laboratory and their characteristics were analyzed through the measurement of beam parameters like inherent tube filtration, beam uniformity and field size, energy spectra and peak voltage for additional filtration with 94.425 por cent and 99.999 por cent purity filters. Also, the first half-value layer and the homogeneity coefficient were measured for the three RQR 2, RQR 6 and RQR 10 IEC beam qualities and they were analyzed according to the IEC standard. Air-kerma measurements were carried out with an ionization chamber that had its reliability confirmed through repetition and reproducibility reading tests. In 50 sets of measurements the maximum standard deviation found of 10 successive readings was 0.19 %; the maximum shift of the reading mean value at a fixed geometry condition was 0.80 % with an overall standard deviation of 0.23 %. Results showed that the use of different purity filters did not cause a relevant influence on the beam energy spectra. An ionization chamber was also calibrated against a standard dosimeter in ali implemented reference radiations and the relevant sources of uncertainties were estimated. Calibration could be done

  6. Analysis of the Pipe Heat Loss of the Water Flow Calorimetry System in EAST Neutral Beam Injector

    Science.gov (United States)

    Hu, Chundong; Chen, Yu; Xu, Yongjian; Yu, Ling; Li, Xiang; Zhang, Weitang

    2016-11-01

    Neutral beam injection heating is one of the main auxiliary heating methods in controllable nuclear fusion research. In the EAST neutral beam injector, a water flow calorimetry (WFC) system is applied to measure the heat load on the electrode system of the ion source and the heat loading components of the beamline. Due to the heat loss in the return water pipe, there are some measuring errors for the current WFC system. In this paper, the errors were measured experimentally and analyzed theoretically, which lay a basis for the exact calculation of beam power deposition distribution and neutralization efficiency. supported by the National Magnetic Confinement Fusion Science Program of China (No. 2013GB101001) and the International Science & Technology Cooperation Program of China (No. 2014DFG61950)

  7. Comparison of three different concepts of high dynamic range and dependability optimised current measurement digitisers for beam loss systems

    CERN Document Server

    Viganò, W; Effinger, E; Venturini, G G; Zamantzas, C

    2012-01-01

    Three Different Concepts of High Dynamic Range and Dependability Optimised Current Measurement Digitisers for Beam Loss Systems will be compared on this paper. The first concept is based on Current to Frequency Conversion, enhanced with an ADC for extending the dynamic range and decreasing the response time. A summary of 3 years’ worth of operational experience with such a system for LHC beam loss monitoring will be given. The second principle is based on an Adaptive Current to Frequency Converter implemented in an ASIC. The basic parameters of the circuit are discussed and compared with measurements. Several measures are taken to harden both circuits against single event effects and to make them tolerant for operation in radioactive environments. The third circuit is based on a Fully Differential Integrator for enhanced dynamic range, where laboratory and test installation measurements will be presented. All circuits are designed to avoid any dead time in the acquisition and have reliability and fail safe...

  8. Calculation of abort thresholds for the Beam Loss Monitoring System of the Large Hadron Collider at CERN

    CERN Document Server

    Nemcic, Martin; Dehning, Bernd

    The Beam Loss Monitoring (BLM) System is one of the most critical machine protection systems for the Large Hadron Collider (LHC) at the European Organization for Nuclear Research (CERN), Switzerland. Its main purpose is to protect the superconducting magnets from quenches and other equipment from damage by requesting a beam abort when the measured losses exceed any of the predefined threshold levels. The system consist of circa 4000 ionization chambers which are installed around the 27 kilometres ring (LHC). This study aims to choose a technical platform and produce a system that addresses all of the limitations with the current system that is used for the calculation of the LHC BLM abort threshold values. To achieve this, a comparison and benchmarking of the Java and .NET technical platforms is performed in order to establish the most suitable solution. To establish which technical platform is a successful replacement of the current abort threshold calculator, comparable prototype systems in Java and .NET we...

  9. Design and construction of the first prototype ionization chamber for CSNS and PA beam loss monitor (BLM) system

    Institute of Scientific and Technical Information of China (English)

    XU Mei-Hang; TIAN Jian-Min; CHEN Chang; CHEN Yuan-Bo; XU Tao-Guang; LU Shuang-Tong

    2009-01-01

    Design and construction of the first prototype ionization chamber for CSNS and Proton Accelerator (PA) beam loss monitor (BLM) system is reported. The low leakage current (<0.1 pA), good plateau (≈800 V) and linearity range up to 200 Roentgen/h axe obtained in the first prototype. All of these give us good experience for further improving the ionization chamber construction.

  10. A novel digitization scheme with FPGA-base TDC for beam loss monitors operating at cryogenic temperature

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jinyuan; Warner, Arden; /Fermilab

    2011-11-01

    Recycling integrators are common current-to-frequency converting circuits for measurements of low current such as that produced by Fermilab's cryogenic ionization chambers. In typical digitization/readout schemes, a counter is utilized to accumulate the number of pulses generated by the recycling integrator to adequately digitize the total charge. In order to calculate current with reasonable resolution (e.g., 7-8 bits), hundreds of pulses must be accumulated which corresponds to a long sampling period, i.e., a very low sampling rate. In our new scheme, an FPGA-based Time-to-Digital Convertor (TDC) is utilized to measure the time intervals between the pulses output from the recycling integrator. Using this method, a sample point of the current can be made with good resolution (>10 bits) for each pulse. This effectively increases the sampling rates by hundreds of times for the same recycling integrator front-end electronics. This scheme provides a fast response to the beams loss and is potentially suitable for accelerator protection applications. Moreover, the method is also self-zero-suppressed, i.e., it produces more data when the beam loss is high while it produces significantly less data when the beam loss is low.

  11. Estimation of propagation losses for infrared laser beam in turbulent atmosphere

    Science.gov (United States)

    Zaponov, A. E.; Sakharov, M. V.

    2016-11-01

    In present work, the radiation propagation in atmosphere from laser source to the receiver is considered by taking into account deviations of optical beam due to turbulence. The photon flux density on the receiver has been evaluated.

  12. Energy loss of intergalactic pair beams: Particle-in-Cell simulation

    CERN Document Server

    Kempf, Andreas; Spanier, Felix

    2016-01-01

    The change of the distribution function of electron-positron pair beams determines whether GeV photons can be produced as secondary radiation from TeV photons. We will discuss the instabilities driven by pair beams. The system of a thermal proton-electron plasma and the electron-positron beam is collision free. We have, therefore, used the Particle-in-Cell simulation approach. It was necessary to alter the physical parameters, but the ordering of growth rates has been retained. We were able to show that plasma instabilities can be recovered in particle-in-cell simulations, but their effect on the pair distribution function is negligible for beam-background energy density ratios typically found in blazars.

  13. Micro-nanopores fabricated by high-energy electron beam irradiation: suitable structure for controlling pesticide loss.

    Science.gov (United States)

    Xiang, Yubin; Wang, Ning; Song, Jimei; Cai, Dongqing; Wu, Zhengyan

    2013-06-01

    Pesticide sprayed onto crop leaves tends to be washed off by rainwater and discharge into the environment through leaching and runoff, resulting in severe pollution to both soil and water. Here, to control pesticide loss, we developed a loss-control pesticide (LCP) by adding modified natural nanoclay (diatomite) through high-energy electron beam (HEEB) to traditional pesticide. After HEEB treatment, the originally clogged pores in diatomite opened, resulting in plenty of micro-nanopores in diatomite, which are beneficial for the pesticide molecules to access and be adsorbed. This pesticide-diatomite complex tended to be retained by the rough surface of crop leaves, displaying a high adhesion performance onto the leaves, so that the pesticide loss reduced, sufficient pesticide for crops was supplied, and the pollution risk of the pesticide could be substantially lowered.

  14. SU-E-T-470: Importance of HU-Mass Density Calibration Technique in Proton Pencil Beam Dose Calculation

    Energy Technology Data Exchange (ETDEWEB)

    Penfold, S; Miller, A [University of Adelaide, Adelaide, SA (Australia)

    2015-06-15

    Purpose: Stoichiometric calibration of Hounsfield Units (HUs) for conversion to proton relative stopping powers (RStPs) is vital for accurate dose calculation in proton therapy. However proton dose distributions are not only dependent on RStP, but also on relative scattering power (RScP) of patient tissues. RScP is approximated from material density but a stoichiometric calibration of HU-density tables is commonly neglected. The purpose of this work was to quantify the difference in calculated dose of a commercial TPS when using HU-density tables based on tissue substitute materials and stoichiometric calibrated ICRU tissues. Methods: Two HU-density calibration tables were generated based on scans of the CIRS electron density phantom. The first table was based directly on measured HU and manufacturer quoted density of tissue substitute materials. The second was based on the same CT scan of the CIRS phantom followed by a stoichiometric calibration of ICRU44 tissue materials. The research version of Pinnacle{sup 3} proton therapy was used to compute dose in a patient CT data set utilizing both HU-density tables. Results: The two HU-density tables showed significant differences for bone tissues; the difference increasing with increasing HU. Differences in density calibration table translated to a difference in calculated RScP of −2.5% for ICRU skeletal muscle and 9.2% for ICRU femur. Dose-volume histogram analysis of a parallel opposed proton therapy prostate plan showed that the difference in calculated dose was negligible when using the two different HU-density calibration tables. Conclusion: The impact of HU-density calibration technique on proton therapy dose calculation was assessed. While differences were found in the calculated RScP of bony tissues, the difference in dose distribution for realistic treatment scenarios was found to be insignificant.

  15. Dosimetric Calibration of CT Pencil Chamber in Cobalt Beams%用60Co射线校准CT电离室的研究

    Institute of Scientific and Technical Information of China (English)

    李懿; 王军良; 王运来

    2014-01-01

    目的探讨CT电离室用60Co射线进行剂量长度乘积刻度的方法。方法 PTW TM30009 CT电离室放在T40017头部模体中心插孔中,用20 cm×20 cm 60Co射线照射60 s,用UNIDOS剂量仪测量电荷量。相同条件下TM300130.6 mL电离室测量吸收剂量。CT电离室的刻度因子用剂量长度乘积表示。同时测量CT电离室在MV级辐射场中的剂量线性和剂量响应均匀性。结果 CT电离室的剂量-长度刻度因子可以从测量数据计算得到。电离室的剂量线性和剂量响应的均匀性很好。结论用60Co射线进行吸收剂量刻度后,CT电离室可以用于MVCT设备的CT剂量指数测量。%Objective To explore the dose-length product calibration method for pencil ionization chamber in cobalt beams. Methods The PTW TM30009 ionization chamber was placed into the central hole of T40017 head phantom and irradiated 60 s in 20 cm×20 cm cobalt beam. The charge was col ected with UNIDOS electrometer. Absorbed doses were measured with TM30013 0.6 mL farmer-type chamber under the same condition. The CT chamber calibration factor was expressed in dose-length product. Dose linearity and spatial response were also investigated. Results The calibration factor in dose-length product was derived from measured data. Dose linearity and spatial response were good in cobalt beams. Conclusion It is feasible to calibrate the CT chamber in cobalt beams for patient dose evaluation in MVCT.

  16. In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

    Science.gov (United States)

    Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M. R.; Eisel, T.; Fabjan, C.; Rementeria, C. A.; Griesmayer, E.; Eremin, V.; Verbitskaya, E.; Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I.; Egorov, N.; Härkönen, J.; Luukka, P.; Tuominen, E.

    2015-05-01

    As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×1016 proton/cm2, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×1016 p/cm2 irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage.

  17. An FPGA Based Implementation for Real-Time Processing of the LHC Beam Loss Monitoring System's Data

    CERN Document Server

    Dehning, B; Emery, J; Ferioli, G; Zamantzas, C

    2006-01-01

    The strategy for machine protection and quench prevention of the Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is mainly based on the Beam Loss Monitoring (BLM) system. At each turn, there will be several thousands of data to record and process in order to decide if the beams should be permitted to continue circulating or their safe extraction is necessary to be triggered. The processing involves a proper analysis of the loss pattern in time and for the decision the energy of the beam needs to be accounted. This complexity needs to be minimized by all means to maximize the reliability of the BLM system and allow a feasible implementation. In this paper, a field programmable gate array (FPGA) based implementation is explored for the real-time processing of the LHC BLM data. It gives emphasis on the highly efficient Successive Running Sums (SRS) technique used that allows many and long integration periods to be maintained for each detector's data with relatively small leng...

  18. Multi-mirror imaging optics for low-loss transport of divergent neutron beams and tailored wavelength spectra

    CERN Document Server

    Zimmer, Oliver

    2016-01-01

    A neutron optical transport system is proposed which comprises nested short elliptical mirrors located halfway between two common focal points M and M'. It images cold neutrons from a diverging beam or a source with finite size at M by single reflections onto a spot of similar size at M'. Direct view onto the neutron source is blocked by a central absorber with little impact on the transported solid angle. Geometric neutron losses due to source size can be kept small using modern supermirrors and distances M-M' of a few tens of metres. Very short flat mirrors can be used in practical implementations. Transport with a minimum of reflections remedies losses due to multiple reflections that are common in long elliptical neutron guides. Moreover, well-defined reflection angles lead to new possibilities for enhancing the spectral quality of primary beams, such as clear-cut discrimination of short neutron wavelengths or beam monochromation using bandpass supermirrors. Multi-mirror imaging systems may thus complemen...

  19. A general algorithm for calculation of recombination losses in ionization chambers exposed to ion beams

    CERN Document Server

    Christensen, Jeppe brage; Bassler, Niels

    2016-01-01

    Dosimetry with ionization chambers in clinical ion beams for radiation therapy requires correction for recombination effects. However, common radiation protocols discriminate between initial and general recombination and provide no universal correction method for the presence of both recombination types in ion beams of charged particles heavier than protons. Here, we present the open source code IonTracks, where the combined initial and general recombination effects in principle can be predicted for any ion beam with arbitrary particle-energy spectrum and temporal structure. IonTracks uses track structure theory to distribute the charge carriers in ion tracks. The charge carrier movements are governed by a pair of coupled differential equations, based on fundamental physical properties as charge carrier drift, diffusion, and recombination, which are solved numerically while the initial and general charge carrier recombination is computed. The algorithm is numerically stable and in accordance with experimental...

  20. Determination of internal-target thickness and experimental luminosity from beam energy loss at HIRFL-CSRe

    Science.gov (United States)

    Shao, Cao-Jie; Yu, De-Yang; Lu, Rong-Chun; Zhao, Tie-Cheng; Mao, Rui-Shi; Li, Jie; Xue, Ying-Li; Wang, Wei; Yang, Bian; Zhang, Ming-Wu; Liu, Jun-Liang; Song, Zhang-Yong; Cai, Xiao-Hong; Chen, Xi-Meng; Yin, Da-Yu; Mao, Li-Jun; Yang, Xiao-Dong; Yang, Jian-Cheng; Yuan, You-Jin

    2016-11-01

    The target thickness for nitrogen was determined from the beam energy loss in HIRFL-CSRe during the experimental study of the K-REC process in 197 MeV/u Xe54+-N2 collisions. Furthermore, the corresponding integrated luminosity of (1.15±0.06) × 1030 cm-2 was obtained. As an independent check on the energy-loss method, we have also determined the integrated luminosity by measuring the produced X-rays from the K-REC process with a known differential cross section. The values of (1.12±0.06) × 1030 and (1.09±0.06) × 1030 cm-2 were obtained by using two high-purity germanium (HPGe) detectors which were oriented at 90° and 120° with respect to the beam path, respectively. The consistent results confirmed the feasibility of the energy-loss method, which may have an important impact on future internal target experiments at HIRFL-CSRe. Supported by National Natural Science Foundation of China (11179017, 11105201, U1532130, and U1332206)

  1. Modelling the Loss of Steel-Concrete Bonds in Corroded Reinforced Concrete Beams

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle

    2007-01-01

    The existing stochastic models for deterioration of reinforced concrete structures is extended by adding modelling of "loss of bond" due to corrosion between the reinforcement bars and the surrounding concrete.......The existing stochastic models for deterioration of reinforced concrete structures is extended by adding modelling of "loss of bond" due to corrosion between the reinforcement bars and the surrounding concrete....

  2. Fullerene-assisted electron-beam lithography for pattern improvement and loss reduction in InP membrane waveguide devices.

    Science.gov (United States)

    Jiao, Yuqing; Pello, Josselin; Mejia, Alonso Millan; Shen, Longfei; Smalbrugge, Barry; Geluk, Erik Jan; Smit, Meint; van der Tol, Jos

    2014-03-15

    In this Letter, we present a method to prepare a mixed electron-beam resist composed of a positive resist (ZEP520A) and C60 fullerene. The addition of C60 to the ZEP resist changes the material properties under electron beam exposure significantly. An improvement in the thermal resistance of the mixed material has been demonstrated by fabricating multimode interference couplers and coupling regions of microring resonators. The fabrication of distributed Bragg reflector structures has shown improvement in terms of pattern definition accuracy with respect to the same structures fabricated with normal ZEP resist. Straight InP membrane waveguides with different lengths have been fabricated using this mixed resist. A decrease of the propagation loss from 6.6 to 3.3  dB/cm has been demonstrated.

  3. Characterization of a wide dynamic-range, radiation-tolerant charge-digitizer asic for monitoring of Beam losses

    CERN Document Server

    Guido Venturini, G G; Dehning, B; Kayal, M

    2012-01-01

    An Application Specific Integrated Circuit (ASIC) has been designed and fabricated to provide a compact solution to digitize current signals from ionization chambers and diamond detectors, employed as beam loss monitors at CERN and several other high energy physics facilities. The circuit topology has been devised to accept positive and negative currents, to have a wide dynamic range (above 120 dB), withstand radiation levels over 10 Mrad and offer different modes of operation, covering a broad range of applications. Furthermore, an internal conversion reference is employed in the digitization, to provide an accurate absolute measurement. This paper discusses the detailed characterization of the first prototype: linearity, radiation tolerance and temperature dependence of the conversion, as well as implications and system-level considerations regarding its use for beam instrumentation applications in a high energy physics facility.

  4. Severe signal loss in diamond beam loss monitors in high particle rate environments by charge trapping in radiation-induced defects

    Energy Technology Data Exchange (ETDEWEB)

    Kassel, Florian; Boer, Wim de [Institute for Experimental Nuclear Physics (IEKP), KIT, Karlsruhe (Germany); Guthoff, Moritz; Dabrowski, Anne [CERN, Meyrin (Switzerland)

    2016-10-15

    The beam condition monitoring leakage (BCML) system is a beam monitoring device in the compact muon solenoid (CMS) experiment at the large hadron collider (LHC). As detectors 32 poly-crystalline (pCVD) diamond sensors are positioned in rings around the beam pipe. Here, high particle rates occur from the colliding beams scattering particles outside the beam pipe. These particles cause defects, which act as traps for the ionization, thus reducing the charge collection efficiency (CCE). However, the loss in CCE was much more severe than expected from low rate laboratory measurements and simulations, especially in single-crystalline (sCVD) diamonds, which have a low initial concentration of defects. After an integrated luminosity of a few fb{sup -1} corresponding to a few weeks of LHC operation, the CCE of the sCVD diamonds dropped by a factor of five or more and quickly approached the poor CCE of pCVD diamonds. The reason why in real experiments the CCE is much worse than in laboratory experiments is related to the ionization rate. At high particle rates the trapping rate of the ionization is so high compared with the detrapping rate, that space charge builds up. This space charge reduces locally the internal electric field, which in turn increases the trapping rate and recombination and hence reduces the CCE in a strongly non-linear way. A diamond irradiation campaign was started to investigate the rate-dependent electrical field deformation with respect to the radiation damage. Besides the electrical field measurements via the transient current technique (TCT), the CCE was measured. The experimental results were used to create an effective deep trap model that takes the radiation damage into account. Using this trap model, the rate-dependent electrical field deformation and the CCE were simulated with the software SILVACO TCAD. The simulation, tuned to rate-dependent measurements from a strong radioactive source, was able to predict the non-linear decrease of the

  5. APT Blanket System Loss-of-Coolant Accident (LOCA) Based on Initial Conceptual Design - Case 2: with Beam Shutdown Only

    Energy Technology Data Exchange (ETDEWEB)

    Hamm, L.L.

    1998-10-07

    This report is one of a series of reports that document normal operation and accident simulations for the Accelerator Production of Tritium (APT) blanket heat removal system. These simulations were performed for the Preliminary Safety Analysis Report. This report documents the results of simulations of a Loss-of-Flow Accident (LOFA) where power is lost to all of the pumps that circulate water in the blanket region, the accelerator beam is shut off and neither the residual heat removal nor cavity flood systems operate.

  6. Combined effects of nuclear and electronic energy losses in solids irradiated with a dual-ion beam

    Science.gov (United States)

    Thomé, Lionel; Debelle, Aurélien; Garrido, Frédérico; Trocellier, Patrick; Serruys, Yves; Velisa, Gihan; Miro, Sandrine

    2013-04-01

    Single and dual-beam irradiations of oxide (c-ZrO2, MgO, Gd2Ti2O7) and carbide (SiC) single crystals were performed to study combined effects of nuclear (Sn) and electronic (Se) energy losses. Rutherford backscattering experiments in channeling conditions show that the Sn/Se cooperation induces a strong decrease of the irradiation-induced damage in SiC and MgO and almost no effects in c-ZrO2 and Gd2Ti2O7. The healing process is ascribed to electronic excitations arising from the electronic energy loss of swift ions. These results present a strong interest for both fundamental understanding of the ion-solid interactions and technological applications in the nuclear industry where expected cooperative Sn/Se effects may lead to the preservation of the integrity of nuclear devices.

  7. Beam losses from ultra-peripheral nuclear collisions between Pb ions in the Large Hadron Collider and their alleviation

    Energy Technology Data Exchange (ETDEWEB)

    Bruce, R.; /CERN; Bocian, D.; /Fermilab /CERN; Gilardoni, S.; Jowett, J.M.; /CERN

    2009-08-01

    Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of {sup 208}Pb{sup 82+} ion operation in the LHC, with focus on the alice interaction region, and show that the expected heat load during nominal {sup 208}Pb{sup 82+} operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

  8. Monitoring Dosimetric Impact of Weight Loss With Kilovoltage (KV) Cone Beam CT (CBCT) During Parotid-Sparing IMRT and Concurrent Chemotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Kean Fatt, E-mail: hokeanfatt@hotmail.com [Academic Radiation Oncology, The Christie NHS Foundation Trust, Manchester (United Kingdom); Marchant, Tom; Moore, Chris; Webster, Gareth; Rowbottom, Carl [North Western Medical Physics, The Christie NHS Foundation Trust, Manchester (United Kingdom); Penington, Hazel [Wade Radiotherapy Research Centre, The Christie NHS Foundation Trust, Manchester (United Kingdom); Lee, Lip; Yap, Beng; Sykes, Andrew; Slevin, Nick [Department of Clinical Oncology, The Christie NHS Foundation Trust, Manchester (United Kingdom)

    2012-03-01

    Purpose: Parotid-sparing head-and-neck intensity-modulated radiotherapy (IMRT) can reduce long-term xerostomia. However, patients frequently experience weight loss and tumor shrinkage during treatment. We evaluate the use of kilovoltage (kV) cone beam computed tomography (CBCT) for dose monitoring and examine if the dosimetric impact of such changes on the parotid and critical neural structures warrants replanning during treatment. Methods and materials: Ten patients with locally advanced oropharyngeal cancer were treated with contralateral parotid-sparing IMRT concurrently with platinum-based chemotherapy. Mean doses of 65 Gy and 54 Gy were delivered to clinical target volume (CTV)1 and CTV2, respectively, in 30 daily fractions. CBCT was prospectively acquired weekly. Each CBCT was coregistered with the planned isocenter. The spinal cord, brainstem, parotids, larynx, and oral cavity were outlined on each CBCT. Dose distributions were recalculated on the CBCT after correcting the gray scale to provide accurate Hounsfield calibration, using the original IMRT plan configuration. Results: Planned contralateral parotid mean doses were not significantly different to those delivered during treatment (p > 0.1). Ipsilateral and contralateral parotids showed a mean reduction in volume of 29.7% and 28.4%, respectively. There was no significant difference between planned and delivered maximum dose to the brainstem (p = 0.6) or spinal cord (p = 0.2), mean dose to larynx (p = 0.5) and oral cavity (p = 0.8). End-of-treatment mean weight loss was 7.5 kg (8.8% of baseline weight). Despite a {>=}10% weight loss in 5 patients, there was no significant dosimetric change affecting the contralateral parotid and neural structures. Conclusions: Although patient weight loss and parotid volume shrinkage was observed, overall, there was no significant excess dose to the organs at risk. No replanning was felt necessary for this patient cohort, but a larger patient sample will be investigated

  9. ShakeMap Atlas 2.0: an improved suite of recent historical earthquake ShakeMaps for global hazard analyses and loss model calibration

    Science.gov (United States)

    Garcia, D.; Mah, R.T.; Johnson, K.L.; Hearne, M.G.; Marano, K.D.; Lin, K.-W.; Wald, D.J.

    2012-01-01

    We introduce the second version of the U.S. Geological Survey ShakeMap Atlas, which is an openly-available compilation of nearly 8,000 ShakeMaps of the most significant global earthquakes between 1973 and 2011. This revision of the Atlas includes: (1) a new version of the ShakeMap software that improves data usage and uncertainty estimations; (2) an updated earthquake source catalogue that includes regional locations and finite fault models; (3) a refined strategy to select prediction and conversion equations based on a new seismotectonic regionalization scheme; and (4) vastly more macroseismic intensity and ground-motion data from regional agencies All these changes make the new Atlas a self-consistent, calibrated ShakeMap catalogue that constitutes an invaluable resource for investigating near-source strong ground-motion, as well as for seismic hazard, scenario, risk, and loss-model development. To this end, the Atlas will provide a hazard base layer for PAGER loss calibration and for the Earthquake Consequences Database within the Global Earthquake Model initiative.

  10. In situ radiation test of silicon and diamond detectors operating in superfluid helium and developed for beam loss monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Kurfürst, C.; Dehning, B.; Sapinski, M.; Bartosik, M.R.; Eisel, T.; Fabjan, C.; Rementeria, C.A. [CERN, Geneva (Switzerland); Griesmayer, E. [CIVIDEC Instrumentation, GmbH, Vienna (Austria); Eremin, V. [Ioffe Institute, St. Petersburg (Russian Federation); Verbitskaya, E., E-mail: elena.verbitskaya@cern.ch [Ioffe Institute, St. Petersburg (Russian Federation); Zabrodskii, A.; Fadeeva, N.; Tuboltsev, Y.; Eremin, I. [Ioffe Institute, St. Petersburg (Russian Federation); Egorov, N. [Research Institute of Material Science and Technology, Zelenograd, Moscow (Russian Federation); Härkönen, J.; Luukka, P.; Tuominen, E. [Helsinki Institute of Physics, Helsinki (Finland)

    2015-05-11

    As a result of the foreseen increase in the luminosity of the Large Hadron Collider, the discrimination between the collision products and possible magnet quench-provoking beam losses of the primary proton beams is becoming more critical for safe accelerator operation. We report the results of ongoing research efforts targeting the upgrading of the monitoring system by exploiting Beam Loss Monitor detectors based on semiconductors located as close as possible to the superconducting coils of the triplet magnets. In practice, this means that the detectors will have to be immersed in superfluid helium inside the cold mass and operate at 1.9 K. Additionally, the monitoring system is expected to survive 20 years of LHC operation, resulting in an estimated radiation fluence of 1×10{sup 16} proton/cm{sup 2}, which corresponds to a dose of about 2 MGy. In this study, we monitored the signal degradation during the in situ irradiation when silicon and single-crystal diamond detectors were situated in the liquid/superfluid helium and the dependences of the collected charge on fluence and bias voltage were obtained. It is shown that diamond and silicon detectors can operate at 1.9 K after 1×10{sup 16} p/cm{sup 2} irradiation required for application as BLMs, while the rate of the signal degradation was larger in silicon detectors than in the diamond ones. For Si detectors this rate was controlled mainly by the operational mode, being larger at forward bias voltage. - Highlights: • Silicon and diamond detectors are proposed for beam loss monitoring at LHC. • The first in situ radiation test of Si and diamond detectors at 1.9 K is described. • Both diamond and silicon detectors survived after 1×10{sup 16} p/cm{sup 2} irradiation at 1.9 K. • The rate of Si detectors degradation depends on bias polarity and is larger at V{sub forw}. • Sensitivity of Si detectors irradiated to 1×10{sup 16} p/cm{sup 2} is independent on resistivity.

  11. Beam Losses in the Extraction Line of a TeV E+ E- Linear Collider With a 20-Mrad Crossing Angle

    Energy Technology Data Exchange (ETDEWEB)

    Ferrari, A.; /Uppsala U.; Nosochkov, Y.; /SLAC

    2006-03-29

    In this paper, we perform a detailed study of the power losses along the postcollision extraction line of a TeV e+e- collider with a crossing angle of 20 mrad between the beams at the interaction point. Five cases are considered here: four luminosity configurations for ILC and one for CLIC. For all of them, the strong beam-beam effects at the interaction point lead to an emittance growth for the outgoing beams, as well as to the production of beamstrahlung photons and e+e- pairs. The power losses along the 20 mrad extraction line, which are due to energy deposition by a fraction of the disrupted beam, of the beamstrahlung photons and of the e+e- coherent pairs, were estimated in the case of ideal collisions, as well as with a vertical position or angular o set at the interaction point.

  12. Evolution of beam losses after a power cut of the SR7 AC supply

    CERN Document Server

    GOMEZ ALONSO, A

    2009-01-01

    Magnet failures in the LHC could lead to equipment damage if the energy stored in the accelerator was not discharged properly. The Machine Protection Systems (MPS) ensure this proper discharge and knowledge about the evolution of losses in case of failure is needed to evaluate the adequacy of the protection. A power cut of the AC supply in SR7 would lead to a simultaneous current decay in three normal conducting circuits. The evolution of the losses after such failure is slow, with a loss time constant of more than 100 ms both at 450 GeV and 7 TeV, and in both cases the damage level is not reached before 45 ms. This leaves sufficient time for the MPS to ensure redundant protection. A similar scenario would be expected for a power cut at SR3.

  13. A new standard cylindrical graphite-walled ionization chamber for dosimetry in 60Co beams at calibration laboratories

    Science.gov (United States)

    Neves, Lucio P.; Perini, Ana P.; Caldas, Linda V. E.

    2014-11-01

    60Co sources are used mostly at dosimetry laboratories for calibration of ionization chambers utilized for radiotherapy dosimetry, mainly in those laboratories where there is no linear accelerator available. In this work, a new cylindrical ionization chamber was developed and characterized to be used as a reference dosimeter at the Calibration Laboratory of the IPEN. The characterization tests were performed according to the IEC 60731 standard, and all tests presented results within its recommended limits. Furthermore, the correction factors for the wall, stem, central collecting electrode, nonaxial uniformity and the mass-energy absorption coefficient were determined using the EGSnrc Monte Carlo code. The air kerma rate determined with this new dosimeter was compared to the one obtained with the IPEN standard, presenting a difference of 1.5%. Therefore, the new ionization chamber prototype developed and characterized in this work presents potential use as a primary standard dosimeter at radiation metrology laboratories.

  14. A Bench Measurement of the Energy Loss of a Stored Beam to a Cavity

    Energy Technology Data Exchange (ETDEWEB)

    Sands, M; Rees, J.; /SLAC

    2016-12-19

    A rather simple electronic bench experiment is proposed for obtaining a measure of the impulse energy loss of a stored particle bunch to an rf cavity or other vacuum-chamber structure--the so-called "cavity radiation". The proposed method is analyzed in some detail.

  15. Exercise for laboratory comparison of calibration coefficient in {sup 137}Cs beam, radiation protection - 2013/2014; Exercicio de comparacao laboratorial do coeficiente de calibracao em feixe de Cesio-137, radioprotecao - 2013/2014

    Energy Technology Data Exchange (ETDEWEB)

    Cabral, T.S. [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Potiens, M.P.A., E-mail: tschirn@ird.gov.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Soares, C.M.A. [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil); Silveira, R.R. [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil); Khoury, H. [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil). Departamento de Energia Nuclear; Fernandes, E. [Universidade do Estado do Rio de Janeiro (UERJ), Rio de Janeiro, RJ (Brazil). Laboratorio de Ciencias Radiologicas; Cardoso, W.F. [Eletrobras Termonuclear S.A. (Eletronuclear), Rio de Janeiro, RJ (Brazil); Borges, J.C. [MRA Comercio de Instrumentos Eletronicos Ltda., Ribeirao Preto, SP (Brazil)

    2015-07-01

    This work deals with the preliminary results of the second exercise of comparing the radiation monitors calibration laboratories in Brazil. The exercise involved eight laboratories and the measured quantity is the air kerma in a beam of {sup 137}Cs for radioprotection. The exercise was conducted by the LNMRI/IRD, in a star shaped arrangement from October 2013 to July 2015. The largest deviation was 2% of the calibration coefficient that is acceptable for applications in radioprotection. (author)

  16. Evaluation of the local hadronic calibration with combined beam-test data for the endcap and forward calorimeters of ATLAS in the pseudorapidity region 2.5<|η|<4.0

    Science.gov (United States)

    Pinfold, J.; Soukup, J.; Archambault, J. P.; Cojocaru, C.; Khakzad, M.; Oakham, G.; Schram, M.; Vincter, M. G.; Datskov, V.; Drobin, V.; Fedorov, A.; Golubykh, S.; Javadov, N.; Kalinnikov, V.; Kakurin, S.; Kazarinov, M.; Kukhtin, V.; Ladygin, E.; Lazarev, A.; Neganov, A.; Petrova, L.; Pisarev, I.; Rousakovitch, N.; Serochkin, E.; Shilov, S.; Shalyugin, A.; Usov, Yu.; Pecsy, M.; Stavina, P.; Strizenec, P.; Barreiro, F.; Gabaldon, C.; Labarga, F.; Nebot, E.; Oliver, C.; Rodier, S.; Del Peso, J.; Belkin, A.; Heldmann, M.; Koepke, L.; Othegraven, R.; Schliephake, T.; Schroff, D.; Secker, H.; Thomas, J.; Benchouk, C.; Djama, F.; Hubaut, F.; Monnier, E.; Niess, V.; Pralavorio, P.; Raymond, M.; Resende, B.; Sauvage, D.; Serfon, C.; Tisserant, S.; Toth, J.; Azuelos, G.; Delsart, P.; Leroy, C.; Mehdiyev, R.; Akimov, A.; Blagov, M.; Komar, A.; Snesarev, A.; Speransky, M.; Sulin, V.; Yakimenko, M.; Epshtein, V.; Khovansky, V.; Shatalov, P.; Barillari, T.; Erdmann, J.; Kiryunin, A.; Kurchaninov, L.; Menke, S.; Nagel, M.; Oberlack, H.; Pospelov, G.; Salihagic, D.; Schacht, P.; Chen, T.; Ping, J.; Qi, M.; Maslennikov, A.; Soukharev, A.; Talyshev, A.; Tikhonov, Yu.; Cavalleri, P.; Schwemling, P.; Chekulaev, S.; Denisov, S.; Evdokimov, V.; Levitsky, M.; Minaenko, A.; Mitrofanov, G.; Moiseev, A.; Pleskatch, A.; Stoyanova, D.; Zakamsky, L.; Bieri, M.; Rani, J.; Schouten, D.; Vetterli, M.; Loch, P.; Rutherfoord, J.; Savin, A.; Shaver, L.; Shupe, M.; Galt, C.; Gorbounov, P.; Knecht, N.; Krieger, P.; Ma, L.; Mazini, R.; Orr, R.; Losty, M.; Oram, C. J.; Fincke-Keeler, M.; Hughes, T.; Kanaya, N.; Keeler, R. K.; Langstaff, R.; Lefebvre, M.; McPherson, R.; Shaw, W.; Wielers, M.; Braun, H. M.; Thadome, J.; Zeitnitz, Ch.; Atlas Liquid Argon Endcap Collaboration

    2012-11-01

    The local hadronic calibration scheme developed for the reconstruction and calibration of jets and missing transverse energy in ATLAS has been evaluated using data obtained during combined beam tests of modules of the ATLAS liquid argon endcap and forward calorimeters. These tests covered the pseudorapidity range of 2.5GEANT4 simulation of a detailed beam-test setup. The evaluation itself has been performed through the careful study of specific calorimeter performance parameters such as e.g. energy response and resolution, shower shapes, as well as different physics lists of the GEANT4 simulation.

  17. Numerical study for beam loss occurring for wide-ranging transverse injection painting and its mitigation scenario in the J-PARC 3-GeV RCS

    Science.gov (United States)

    Hotchi, Hideaki; Tani, Norio; Watanabe, Yasuhiro

    2015-04-01

    In the J-PARC 3-GeV Rapid Cycling Synchrotron (RCS), transverse injection painting is utilized to manipulate the transverse beam profile according to the requirements from the downstream facilities as well as to mitigate the space-charge induced beam loss in RCS. Therefore, a flexible control is required for the transverse painting area. But now the available range of transverse painting is limited to small area due to beta function beating caused by the edge focus of injection bump magnets which operate during the beam injection period. This beta function beating additionally excites various random betatron resonances through a distortion of the lattice super-periodicity, causing a shrinkage of the dynamic aperture during the injection period. This decrease of the dynamic aperture leads to extra beam loss at present when applying large transverse painting. For beta function beating caused by the edge focus, we proposed a correction scheme with additional pulse-type quadrupole correctors. In this paper, we will discuss the feasibility and effectiveness of this correction scheme for expanding the transverse injection painting area with no extra beam loss, while considering the beam loss and its mitigation mechanisms, based on numerical simulations.

  18. Synthesis of Pt nanoparticles and their burrowing into Si due to synergistic effects of ion beam energy losses

    Directory of Open Access Journals (Sweden)

    Pravin Kumar

    2014-10-01

    Full Text Available We report the synthesis of Pt nanoparticles and their burrowing into silicon upon irradiation of a Pt–Si thin film with medium-energy neon ions at constant fluence (1.0 × 1017 ions/cm2. Several values of medium-energy neon ions were chosen in order to vary the ratio of the electronic energy loss to the nuclear energy loss (Se/Sn from 1 to 10. The irradiated films were characterized using Rutherford backscattering spectroscopy (RBS, atomic force microscopy (AFM, scanning electron microscopy (SEM, X-ray diffraction (XRD and high resolution transmission electron microscopy (HRTEM. A TEM image of a cross section of the film irradiated with Se/Sn = 1 shows ≈5 nm Pt NPs were buried up to ≈240 nm into the silicon. No silicide phase was detected in the XRD pattern of the film irradiated at the highest value of Se/Sn. The synergistic effect of the energy losses of the ion beam (molten zones are produced by Se, and sputtering and local defects are produced by Sn leading to the synthesis and burrowing of Pt NPs is evidenced. The Pt NP synthesis mechanism and their burrowing into the silicon is discussed in detail.

  19. Calibrating IR Cameras for In-Situ Temperature Measurement During the Electron Beam Melting Process using Inconel 718 and Ti-Al6-V4

    Energy Technology Data Exchange (ETDEWEB)

    Dinwiddie, Ralph Barton [ORNL; Lloyd, Peter D [ORNL; Dehoff, Ryan R [ORNL; Lowe, Larry E [ORNL

    2016-01-01

    The Department of Energy s (DOE) Manufacturing Demonstration Facility (MDF) at Oak Ridge National Laboratory (ORNL) provides world-leading capabilities in advanced manufacturing (AM) facilities which leverage previous, on-going government investments in materials science research and characterization. MDF contains systems for fabricating components with complex geometries using AM techniques (i.e. 3D-Printing). Various metal alloy printers, for example, use electron beam melting (EBM) systems for creating these components which are otherwise extremely difficult- if not impossible- to machine. ORNL has partnered with manufacturers on improving the final part quality of components and developing new materials for further advancing these devices. One method being used to study (AM) processes in more depth relies on the advanced imaging capabilities at ORNL. High performance mid-wave infrared (IR) cameras are used for in-situ process monitoring and temperature measurements. However, standard factory calibrations are insufficient due to very low transmissions of the leaded glass window required for X-ray absorption. Two techniques for temperature calibrations will be presented and compared. In-situ measurement of emittance will also be discussed. Ample information can be learned from in-situ IR process monitoring of the EBM process. Ultimately, these imaging systems have the potential for routine use for online quality assurance and feedback control.

  20. Assessing the long-term weathering of petroleum on shorelines : uses of conserved components for calibrating loss and bioremediation potential

    Energy Technology Data Exchange (ETDEWEB)

    Atlas, R. [Louisville Univ., Louisville, KY (United States); Bragg, J. [Creative Petroleum Solutions, Houston, TX (United States)

    2007-07-01

    Shoreline samples from the Exxon Valdez oil spill were used to study the limitations and strengths of different conserved components as markers based on a 17-year field monitoring program. Approximately 100 oil samples collected from the shoreline in Prince William Sound, Alaska from 1999-2006 had been analyzed for internal markers such as chrysenes, terpanes, steranes and triaromatic steroids and then used to assess the biodegradation of the spilled petroleum. The specific biomarkers used in this study were selected to exclude those that might be generated via biodegradation and were chosen from those having the most significant concentrations in the extracts. Concentrations of the recovered weathered oil compounds were quantified and the concentrations of the polycyclic aromatic hydrocarbons (PAH) components were measured in the aromatic fractions. The extent of PAH weathering was subsequently calculated as a percentage loss of total PAH in order to calculate a bioremediation index to evaluate if an oil at a given shoreline may be amenable to bioremediation (or nutrient addition) to accelerate removal of remaining PAH. In order to compare the extent of weathering over the 17 years since the spill, chemical analyses were performed for samples from 1989-1991 for which no biomarkers were measured. The weathering of the oil has progressed in such a way that most of the remaining oil is now highly weathered. The trend of increasing biodegradation with time indicates that given sufficient time, the oil will continue to degrade naturally until all of the PAH components are consumed. The most stable biomarker compounds to quantify the loss of PAH or other oil components was shown to be C{sub 29}R-stigmastane. 35 refs., 4 tabs., 7 figs.

  1. High purity pion beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Aguilar-Arevalo, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Blecher, M. [Physics Department, Virginia Tech., Blacksburg, VA 24061 (United States); Bryman, D.A. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Comfort, J. [Arizona State University, Tempe, AZ 85287 (United States); Doornbos, J.; Doria, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Hussein, A. [University of Northern British Columbia, Prince George, BC, V2N 4Z9 (Canada); Ito, N. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan); Kettell, S. [Brookhaven National Laboratory, Upton, NY 11973-5000 (United States); Kurchaninov, L. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Malbrunot, C. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Marshall, G.M. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Numao, T. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada)], E-mail: toshio@triumf.ca; Poutissou, R.; Sher, A. [TRIUMF, 4004 Wesbrook Mall, Vancouver, BC, V6T 2A3 (Canada); Walker, B. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Yamada, K. [Physics Department, Osaka University, Toyonaka, Osaka 560-0043 (Japan)

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +}{yields}e{sup +}{nu} is also described.

  2. High Purity Pion Beam at TRIUMF

    Energy Technology Data Exchange (ETDEWEB)

    Kettell, S.; Kettell, S.; Aguilar-Arevalo, A.; Blecher, M.; Bryman, D.A.; Comfort, J.; Doornbos, J.; Doria, L.; Hussein, A.; Ito, N.; et al.

    2009-10-11

    An extension of the TRIUMF M13 low-energy pion channel designed to suppress positrons based on an energy-loss technique is described. A source of beam channel momentum calibration from the decay {pi}{sup +} {yields} e{sup +}{nu} is also described.

  3. Influence of the beam-size or MD-effect on particle losses at B-factories PEP-II and KEKB

    CERN Document Server

    Kotkin, G L

    2004-01-01

    For the $e^+ e^- \\to e^+ e^- \\gamma$ process at colliding beams, macroscopically large impact parameters give an essential contribution to the standard cross section. These impact parameters may be much larger than the transverse sizes of the colliding bunches. It means that the standard calculations have to be essentially modify. In the present paper such a beam-size or MD-effect is calculated for bremsstrahlung at B-factories PEP-II and KEKB using the list of nominal parameters from Review of Particle Physics (2002). We find out that this effect reduces beam losses due to bremsstrahlung by about 20%.

  4. Monte Carlo simulations to estimate the damage potential of electron beam and tests of beam loss detector based on quartz Cherenkov radiator read out by a silicon photomultiplier on CLIC Test Facility 3(CTF3)

    CERN Document Server

    Orfanelli, Styliani; Gazis, E

    The Compact Linear Collider (CLIC) study is a feasibility study aiming at the development of an electron/positron linear collider with a centre of mass energy in the multi-TeV energy range. Each Linac will have a length of 21 km, which means that very high accelerating gradients (>100 MV/m) are required. To achieve the high accelerating gradients, a novel two-beam acceleration scheme, in which RF power is transferred from a high-current, low-energy drive beam to the low-current, high energy main accelerating beam is designed. A Beam Loss Monitoring (BLM) system will be designed for CLIC to meet the requirements of the accelerator complex. Its main role as part of the machine protection scheme will be to detect potentially dangerous beam instabilities and prevent subsequent injection into the main beam or drive beam decelerators. The first part of this work describes the GEANT4 Monte Carlo simulations performed to estimate the damage potential of high energy electron beams impacting a copper target. The second...

  5. Calibrating nacelle lidars

    DEFF Research Database (Denmark)

    Courtney, Michael

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report...... presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated...... a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam...

  6. INVESTIGATION OF DYNAMIC PARAMETRS OF SPLIT SKEWED BRIDGE SPANS IN CASE OF LOSS OF CONTACT BETWEEN END BEAM AND ITS SUPPORT

    Directory of Open Access Journals (Sweden)

    V.S.Safronov

    2015-02-01

    Full Text Available Statement of the problem. In order to get a valid estimate of risks of fracture during the mainten-ance of simply supported skew slab-and-girder reinforced concrete spans of highway bridges the influence of the supporting skew on the natural frequencies spectrum and the corresponding ei-genmodes in case of changing the design model due to loss of contact between beams and support.Results. Possible loss of contact between one of the marginal beams and its support near the sharp angle during the maintenance of transport facility depending on its type and geometrical parameters is substantiated. Modal and frequency spectrum analysis of spans in case of loss of contact between one of the marginal beams and its support is performed.Conclusions. The analysis revealed possible loss of contact between marginal beams and support, which increases as the skew angle grows and the width and length of the span reduce. A signifi-cant influence of support separation on eigenmodes and frequency spectrum of spans is revealed.

  7. Measurement of Absolute Excitation Cross Sections in Highly-Charged Ions Using Electron Energy Loss and Merged Beams

    Science.gov (United States)

    Chutjian, A.; Smith, Steven J.; Lozano, J.

    2002-01-01

    There is increasing emphasis during this decade on understanding energy balance and phenomena observed in high electron temperature plasmas. The UV spectral return from FUSE, the X-ray spectral return from the HETG on Chandra and the LETGS 011 XMM-Newton are just beginning. Line emissions are almost entirely from highly-charged ions (HCIs) of C, N, 0, Ne, Mg, S, Si, Ca, and Fe. The Constellation-X mission will provide X-ray spectroscopy up to photon energies of 0.12 nm (10 keV) where primary line emitters will be HCIs. A variety of atomic parameters are required to model the stellar and solar plasma. These include cross sections for excitation, ionization, charge-exchange, X-ray emission, direct and indirect recombination, lifetimes and branching ratios, and dependences on l, m mixing by external E and B fields. In almost all cases the atomic quantities are calculated, and few comparisons to experiment have been carried out. Collision strengths and Einstein A-values are required to convert the observed spectral intensities to electron temperatures and densities in the stellar plasma. The JPL electron energy-loss and merged beam approach has been used to measure absolute collision strengths in a number of ions, with critical comparison made to the best available theories.

  8. Calibrating nacelle lidars

    Energy Technology Data Exchange (ETDEWEB)

    Courtney, M.

    2013-01-15

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail. The first of these is a line of sight calibration method in which both lines of sight (for a two beam lidar) are individually calibrated by accurately aligning the beam to pass close to a reference wind speed sensor. A testing procedure is presented, reporting requirements outlined and the uncertainty of the method analysed. It is seen that the main limitation of the line of sight calibration method is the time required to obtain a representative distribution of radial wind speeds. An alternative method is to place the nacelle lidar on the ground and incline the beams upwards to bisect a mast equipped with reference instrumentation at a known height and range. This method will be easier and faster to implement and execute but the beam inclination introduces extra uncertainties. A procedure for conducting such a calibration is presented and initial indications of the uncertainties given. A discussion of the merits and weaknesses of the two methods is given together with some proposals for the next important steps to be taken in this work. (Author)

  9. Self-calibration of cone-beam CT geometry using 3D-2D image registration: development and application to tasked-based imaging with a robotic C-arm

    Science.gov (United States)

    Ouadah, S.; Stayman, J. W.; Gang, G.; Uneri, A.; Ehtiati, T.; Siewerdsen, J. H.

    2015-03-01

    Purpose: Robotic C-arm systems are capable of general noncircular orbits whose trajectories can be driven by the particular imaging task. However obtaining accurate calibrations for reconstruction in such geometries can be a challenging problem. This work proposes a method to perform a unique geometric calibration of an arbitrary C-arm orbit by registering 2D projections to a previously acquired 3D image to determine the transformation parameters representing the system geometry. Methods: Experiments involved a cone-beam CT (CBCT) bench system, a robotic C-arm, and three phantoms. A robust 3D-2D registration process was used to compute the 9 degree of freedom (DOF) transformation between each projection and an existing 3D image by maximizing normalized gradient information with a digitally reconstructed radiograph (DRR) of the 3D volume. The quality of the resulting "self-calibration" was evaluated in terms of the agreement with an established calibration method using a BB phantom as well as image quality in the resulting CBCT reconstruction. Results: The self-calibration yielded CBCT images without significant difference in spatial resolution from the standard ("true") calibration methods (p-value >0.05 for all three phantoms), and the differences between CBCT images reconstructed using the "self" and "true" calibration methods were on the order of 10-3 mm-1. Maximum error in magnification was 3.2%, and back-projection ray placement was within 0.5 mm. Conclusion: The proposed geometric "self" calibration provides a means for 3D imaging on general noncircular orbits in CBCT systems for which a geometric calibration is either not available or not reproducible. The method forms the basis of advanced "task-based" 3D imaging methods now in development for robotic C-arms.

  10. Beam-loss induced pressure rise of Large Hadron Collider collimator materials irradiated with 158 GeV/u $In^{49+}$ ions at the CERN Super Proton Synchrotron

    CERN Document Server

    Mahner, Edgar; Hansen, Jan; Page, Eric; Vincke, H

    2004-01-01

    During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 10/sup 4/ to 10/sup 7/ molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for Large Hadron Collider (LHC) ion operation. In 2003, a desorption experiment was installed at the super proton synchrotron to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN (low carbon with nitrogen) stainless steel were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental ...

  11. Beam-Loss Induced Pressure Rise of LHC Collimator Materials Irradiated with 158 GeV/u $In^{49+}$ Ions at the CERN SPS

    CERN Document Server

    Mahner, Edgar; Hansen, Jan; Page, Eric; Vincke, Helmut H

    2004-01-01

    During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 1044 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measure-ment of heavy-ion induced molecular desorption in the GeV/u energy range is important for LHC ion operation. In 2003, a desorption experiment was installed at the SPS to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316 LN stainless steel, were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental set-up, the results of the pressure rise measurements are presented, and the deri...

  12. Beam-loss induced pressure rise of Large Hadron Collider collimator materials irradiated with 158 GeV/u In49+ ions at the CERN Super Proton Synchrotron

    Science.gov (United States)

    Mahner, E.; Efthymiopoulos, I.; Hansen, J.; Page, E.; Vincke, H.

    2004-10-01

    During heavy ion operation, large pressure rises, up to a few orders of magnitude, were observed at CERN, GSI, and BNL. The dynamic pressure rises were triggered by lost beam ions that impacted onto the vacuum chamber walls and desorbed about 104 to 107 molecules per ion. The deterioration of the dynamic vacuum conditions can enhance charge-exchange beam losses and can lead to beam instabilities or even to beam abortion triggered by vacuum interlocks. Consequently, a dedicated measurement of heavy-ion induced molecular desorption in the GeV/u energy range is important for Large Hadron Collider (LHC) ion operation. In 2003, a desorption experiment was installed at the Super Proton Synchrotron to measure the beam-loss induced pressure rise of potential LHC collimator materials. Samples of bare graphite, sputter coated (Cu, TiZrV) graphite, and 316LN (low carbon with nitrogen) stainless steel were irradiated under grazing angle with 158 GeV/u indium ions. After a description of the new experimental setup, the results of the pressure rise measurements are presented, and the derived desorption yields are compared with data from other experiments.

  13. Study of the alignment of X radiation beam for calibration of chambers used in radiotherapy; Estudo do alinhamento do feixe de raios-X para calibracao de camaras utilizadas em radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Cardoso, Ricardo de Souza; Bossio, Francisco; Peixoto, Jose Guilherme Pereira, E-mail: ricardo@ird.gov.br [Instituto de Radioprotecao e Dosimetria, (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)

    2014-07-01

    The activities developed in radiotherapy, diagnostic radiology and radiation safety, require that the metrological parameters involving these activities have on its results a high degree of reliability, to ensure traceability. To meet the existing demand in Brazil, the National Metrology Laboratory of Ionizing Radiation - LNMRI - is deploying a new tube X-ray beams used in the calibration of the standard rooms, which serve to quality control in hospitals, clinics and industry. (author)

  14. A Real-Time FPGA based Algorithm for the combination of Beam Loss Acquisition Methods used for Measurement Dynamic Range expansion

    CERN Document Server

    Kwiatkowski, M; Alsdorf, M; Dehning, B; Vigano, W

    2012-01-01

    The aim of the Beam Loss Monitoring Dual Polarity (BLEDP) module under development at the European Organisation for Nuclear Research (CERN) is to measure and digitise with high precision the current produced by several types of beam loss detectors. The BLEDP module consists of eight analogue channels each with a fully differential integrator and an accompanying 16 bit ADC at the output of each analogue integrator. The on-board FPGA device controls the integral periods, instructs the ADC devices to perform measurements at the end of each period and collects the measurements. In the next stage it combines the number of charge and discharge cycles accounted in the last interval together with the cycle fractions observed using the ADC samples to produce a digitised high precision value of the charges collected. This paper describes briefly the principle of the fully differential integrator and focuses on the algorithm employed to process the digital data.

  15. Comparative study between cold plasma and hot plasma with ion beam and loss-cone distribution function by particle aspect approach

    Science.gov (United States)

    Patel, Soniya; Varma, P.; Tiwari, M. S.

    2011-03-01

    The electromagnetic ion-cyclotron (EMIC) instabilities with isotropic ion beam and general loss-cone distribution of cold and hot core plasmas are discussed. The growth rate, parallel and perpendicular resonance energies of the electromagnetic ion-cyclotron waves in a low β (ratio of plasma pressure to magnetic pressure), homogeneous plasma have been obtained using the dispersion relation for cold and hot plasmas. The wave is assumed to propagate parallel to the static magnetic field. The whole plasma is considered to consist of resonant and non-resonant particles permeated by isotropic ion beam. It is assumed that resonant particles and ion beam participate in energy exchange with the wave whereas non-resonant particles support the oscillatory motion of the wave. We determined the variation in energies and growth rate in cold and hot plasmas by the energy conservation method with a general loss-cone distribution function. The thermal anisotropy of the core plasma acts as a source of free energy for EMIC wave and enhances the growth rate. It is noted that the EMIC wave emissions occur by extracting energy of perpendicularly heated ions in the presence of up flowing ion beam and steep loss-cone distribution in the anisotropic magnetosphere. The effect of the steep loss-cone distribution is to enhance the growth rate of the EMIC wave. The heating of ions perpendicular and parallel to the magnetic field is discussed along with EMIC wave emission in the auroral acceleration region. The results are interpreted for the space plasma parameters appropriate to the auroral acceleration region of the earth's magnetoplasma.

  16. MD#1182: Calibration of diamond particle detectors in IP6

    CERN Document Server

    Valette, Matthieu; Lindstrom, Bjorn Hans Filip; Wiesner, Christoph

    2017-01-01

    In case of an asynchronous beam dump with a fully filled LHC machine it is expected that all standard ionisation chamber Beam Loss Monitors (IC BLM) around the LHC dumping region in IP6 will be saturated. Diamond Beam Loss Monitors (dBLM) were therefore installed next to the movable dump protection absorber (TCDQ) downstream of the extraction kickers. These detectors allow resolving losses at a nanosecond timescale and with an dynamic range of several orders of magnitude; thus, allowing to know the number of nominal bunches impacting the TCDQ. After a first series of calibrations using asynchronous beam dump tests, an experiment was conducted during MD#1182 to demonstrate the possibility of resolving a nominal bunch hitting the TCDQ. The impact parameter of the bunches on the TCDQ was first scanned using probe bunches with lower intensity then tests were done with nominal bunches (1.1e11 p/bunch) at injection energy. High energy calibration of the losses was also attempted unsuccessfully. Due to different beh...

  17. 预应力损失对连续梁桥内力的影响%Impacts of prestress loss on internal force of continuous beam bridge

    Institute of Scientific and Technical Information of China (English)

    曾辉; 杨凡坤

    2012-01-01

    Integrating with three-span continuous beam bridge on the extra large(48+80+48)m bridge,this paper discusses two conditions with and without considering prestress loss,introduces the composition and calculation method of prestress loss,and studies the impacts of prestress loss on internal force of continuous beam bridge,which has provided theoretical guidance for the design and calculation of three-span continuous beam bridge.%结合广东某特大桥(48+80+48)m三跨连续梁,从考虑和不考虑预应力损失两种情况进行了论述,介绍了预应力损失的组成和计算方法,进行了预应力损失对桥梁结构内力影响的研究,为三跨连续梁桥设计计算提供了理论指导。

  18. Beam loss caused by edge focusing of injection bump magnets and its mitigation in the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex

    Science.gov (United States)

    Hotchi, H.; Tani, N.; Watanabe, Y.; Harada, H.; Kato, S.; Okabe, K.; Saha, P. K.; Tamura, F.; Yoshimoto, M.

    2016-01-01

    In the 3-GeV rapid cycling synchrotron of the Japan Proton Accelerator Research Complex, transverse injection painting is utilized not only to suppress space-charge induced beam loss in the low energy region but also to mitigate foil scattering beam loss during charge-exchange injection. The space-charge induced beam loss is well minimized by the combination of modest transverse painting and full longitudinal painting. But, for sufficiently mitigating the foil scattering part of beam loss, the transverse painting area has to be further expanded. However, such a wide-ranging transverse painting had not been realized until recently due to beta function beating caused by edge focusing of pulsed injection bump magnets during injection. This beta function beating additionally excites random betatron resonances through a distortion of the lattice superperiodicity, and its resultant deterioration of the betatron motion stability causes significant extra beam loss when expanding the transverse painting area. To solve this issue, we newly installed pulse-type quadrupole correctors to compensate the beta function beating. This paper presents recent experimental results on this correction scheme for suppressing the extra beam loss, while discussing the beam loss and its mitigation mechanisms with the corresponding numerical simulations.

  19. Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment

    CERN Document Server

    Tatsuno, H; Bennett, D A; Curceanu, C; Fowler, J W; Gard, J; Gustafsson, F P; Hashimoto, T; Hayano, R S; Hays-Wehle, J P; Hilton, G C; Iliescu, M; Ishimoto, S; Itahashi, K; Iwasaki, M; Kuwabara, K; Ma, Y; Marton, J; Noda, H; O'Neil, G C; Okada, S; Outa, H; Reintsema, C D; Sato, M; Schmidt, D R; Shi, H; Suzuki, K; Suzuki, T; Uhlig, J; Ullom, J N; Widmann, E; Yamada, S; Zmeskal, J; Swetz, D S

    2016-01-01

    A performance evaluation of superconducting transition-edge sensors (TESs) in the environment of a pion beam line at a particle accelerator is presented. Averaged across the 209 functioning sensors in the array, the achieved energy resolution is 5.2 eV FWHM at Co $K_{\\alpha}$ (6.9 keV) when the pion beam is off and 7.3 eV at a beam rate of 1.45 MHz. Absolute energy uncertainty of $\\pm$0.04 eV is demonstrated for Fe $K_{\\alpha}$ (6.4 keV) with in-situ energy calibration obtained from other nearby known x-ray lines. To achieve this small uncertainty, it is essential to consider the non-Gaussian energy response of the TESs and thermal cross-talk pile-up effects due to charged-particle hits in the silicon substrate of the TES array.

  20. Absolute Energy Calibration of X-ray TESs with 0.04 eV Uncertainty at 6.4 keV in a Hadron-Beam Environment

    Science.gov (United States)

    Tatsuno, H.; Doriese, W. B.; Bennett, D. A.; Curceanu, C.; Fowler, J. W.; Gard, J.; Gustafsson, F. P.; Hashimoto, T.; Hayano, R. S.; Hays-Wehle, J. P.; Hilton, G. C.; Iliescu, M.; Ishimoto, S.; Itahashi, K.; Iwasaki, M.; Kuwabara, K.; Ma, Y.; Marton, J.; Noda, H.; O'Neil, G. C.; Okada, S.; Outa, H.; Reintsema, C. D.; Sato, M.; Schmidt, D. R.; Shi, H.; Suzuki, K.; Suzuki, T.; Uhlig, J.; Ullom, J. N.; Widmann, E.; Yamada, S.; Zmeskal, J.; Swetz, D. S.

    2016-08-01

    A performance evaluation of superconducting transition-edge sensors (TESs) in the environment of a pion beam line at a particle accelerator is presented. Averaged across the 209 functioning sensors in the array, the achieved energy resolution is 5.2 eV FWHM at Co K_{α } (6.9 keV) when the pion beam is off and 7.3 eV at a beam rate of 1.45 MHz. Absolute energy uncertainty of ± 0.04 eV is demonstrated for Fe K_{α } (6.4 keV) with in-situ energy calibration obtained from other nearby known X-ray lines. To achieve this small uncertainty, it is essential to consider the non-Gaussian energy response of the TESs and thermal cross-talk pile-up effects due to charged particle hits in the silicon substrate of the TES array.

  1. Results of the studies on energy deposition in IR6 superconducting magnets from continuous beam loss on the TCDQ system

    CERN Document Server

    Bracco, C; Presland, A; Redaelli, S; Sarchiapone, L; Weiler, T

    2007-01-01

    A single sided mobile graphite diluter block TCDQ, in combination with a two-sided secondary collimator TCS and an iron shield TCDQM, will be installed in front of the superconducting quadrupole Q4 magnets in IR6, in order to protect it and other downstream LHC machine elements from destruction in the event of a beam dump that is not synchronised with the abort gap. The TCDQ will be positioned close to the beam, and will intercept the particles from the secondary halo during low beam lifetime. Previous studies (1-4) have shown that the energy deposited in the Q4 magnet coils can be close to or above the quench limit. In this note the results of the latest FLUKA energy deposition simulations for Beam 2 are described, including an upgrade possibility for the TCDQ system with an additional shielding device. The results are discussed in the context of the expected performance levels for the different phases of LHC operation.

  2. Absolute calibration of space-resolving soft X-ray spectrograph for plasma diagnostics

    Science.gov (United States)

    Yoshikawa, M.; Okamoto, Y.; Kawamori, E.; Watanabe, Y.; Watabe, C.; Yamaguchi, N.; Tamano, T.

    2001-07-01

    A grazing incidence flat-field soft X-ray (20-350 Å) spectrograph was constructed and applied for impurity diagnostics in the GAMMA 10 fusion plasma. The spectrograph consisted of a limited height entrance slit, an aberration-corrected concave grating, a microchannel-plate intensified detector and an instant camera/a high speed solid state camera. An absolute calibration experiment for the SX spectrograph was performed at the Photon Factory in the High Energy Accelerator Research Organization with monitoring the incident synchrotron beam intensity by using an absolutely calibrated XUV silicon photodiode. From the results of absolute calibration of the spectrograph, the radiation loss from the plasma was obtained.

  3. Absolute calibration of space-resolving soft X-ray spectrograph for plasma diagnostics

    CERN Document Server

    Yoshikawa, M; Kawamori, E; Watanabe, Y; Watabe, C; Yamaguchi, N; Tamano, T

    2001-01-01

    A grazing incidence flat-field soft X-ray (20-350 A) spectrograph was constructed and applied for impurity diagnostics in the GAMMA 10 fusion plasma. The spectrograph consisted of a limited height entrance slit, an aberration-corrected concave grating, a microchannel-plate intensified detector and an instant camera/a high speed solid state camera. An absolute calibration experiment for the SX spectrograph was performed at the Photon Factory in the High Energy Accelerator Research Organization with monitoring the incident synchrotron beam intensity by using an absolutely calibrated XUV silicon photodiode. From the results of absolute calibration of the spectrograph, the radiation loss from the plasma was obtained.

  4. 锥束X-CT系统校准方法的实际应用分析%Analysis on Application of Calibration Method for Cone-beam X-CT

    Institute of Scientific and Technical Information of China (English)

    侯颖; 孙怡

    2011-01-01

    FDK算法是应用在锥束CT系统中最有代表性的重建算法之一,该算法是在假设CT成像系统满足理想成像关系的条件下得到的.然而实际的锥束CT成像系统很难完全满足理想成像关系的要求,系统的几何失配会极大影响重建图像的质量,因此必须在重建之前对成像系统进行校准,获得系统的几何失配参数,并在重建过程中修正几何失配参数造成的影响.本文以之前所提出的锥束CT系统校准方法为基础,分析了在实际应用这种校准方法时需要注意的关键问题,然后利用所搭建的锥束XCT系统得到实际的校准结果和重建结果.结果证明之前所提出的应用于锥束XCT系统的校准方法对于测量系统的几何失配参数是有效可行的.%The FDK algorithm is a classic cone-beam approximate reconstruction algorithm, which has been widely used in practice. Ideal imaging geometry is a basic condition in the application of the FDK algorithm.However, it is difficult to satisfy this condition in a practical cone-beam CT system. Reconstructed images will suffer from artifacts caused by the misaligned geometry of the CT system. Therefore, calibration of the CT system in advance is an important and necessary task. Misaligned parameters of the CT system will be taken into the reconstruction algorithm after calibration to improve image qualities in the case of the misaligned CT system. Key points on application of the proposed calibration method for cone-beam CT are discussed deeply in this paper. And calibration result and reconstructed results of an X-ray cone-beam CT are given which prove the validity of the proposed calibration method.

  5. Testing and calibration through laser radiation and muon beams of the hadron calorimeter in ATLAS detector; Controle et etalonnage par lumiere laser et par faisceaux de muons du calorimetre hadronique a tuiles scintillantes d'ATLAS

    Energy Technology Data Exchange (ETDEWEB)

    Garde, V

    2003-10-15

    This study is dedicated to the calibration of the hadronic calorimeter (Tilecal) of the ATLAS detector. This detector will be installed on the LHC collider at CERN. The first data will be taken in 2007. This thesis is divided in two parts. The first part is dedicated to the study of the LASER system. A prototype of the final system was studied. It was shown that the stability and the linearity of this prototype are conform to the specification. Several studies were devoted to measurements which can be done on the Tilecal: The relative gain can be calculated and gives the stability of the Tilecal with a resolution of 0.35 %. The number of photoelectrons per charge unit has been calculated. The linearity was checked for a normal range of functioning and was corrected for the functioning at high charge. In both cases it was shown that the non-linearity was smaller than 0.5 %. The second study is devoted to muons beams in test beam periods. These results are used to find a calibration constant. Several problems which come from the difference of size cells are not totally solved. But the resolution of the calibration constant found by this method cannot exceed 2.3%. (author)

  6. CSNS/RCS粒子散射束流损失研究%Study of Beam Loss due to Particle Scattering in CSNS/RCS

    Institute of Scientific and Technical Information of China (English)

    黄明阳; 王娜; 邱静; 王生; 黄楠

    2012-01-01

    在中国散裂中子源快循环同步加速器(CSNS/RCS)中,质子束流在加速过程中会与一些器件(如剥离膜、准直器、散射引出膜等)相互作用,产生粒子散射并导致束流损失.本工作首先利用ORBIT模拟RCS束流注入过程,并用FLUKA模拟注入束流穿过剥离膜的粒子散射过程,计算剥离膜散射所造成的束流损失.其次,模拟质子束流与准直器相互作用的粒子散射,计算质子束流与不同尺寸的次级准直器相互作用的吸收效率,作为对次级准直器优化的依据.最后,研究CSNS/RCS膜散射引出方案,利用FLUKA对不同引出方案进行模拟并比较,得到最佳的可行性方案.%In the Rapid Cycling Synchrotron of China Spallation Neutron Source (CSNS/ RCS) , the proton beam will interact with some devices, such as the stripping foil, beam collimator, and foil for scattering extraction. These interactions result in some particle scattering and beam losses. In this paper, firstly, the beam transportation in the injection procedure was simulated by ORBIT and the particle scattering due to the interaction between the beam and stripping foil was simulated by FLUKA, then the beam loss due to the foil scattering was calculated. Secondly, the particle scattering due to the proton beam interacting with the secondary collimator was simulated, and based on which, the secondary collimator was optimized by calculating the absorb efficiency. The optimization was done for the foil scattering extraction scheme by simulating and comparing different schemes with FLUKA.

  7. Calibration and performance analysis on channel mismatch of multi-beam antenna on satellites%星载多波束天线通道误差特性分析及校准

    Institute of Scientific and Technical Information of China (English)

    赵星惟; 龚文斌; 梁旭文

    2012-01-01

    针对星载多波束天线幅相误差对天线性能影响较大的问题,通过对多波束发射天线的射频通道在不同温度下的幅相特性进行试验测定,得到了通道幅相特性与温度的对应关系,发现不同通道的幅相特性与通道温度的关系曲线在给定温度区间内基本呈线性关系,且斜率基本一致,从而确定了对不同通道的幅相特性进行固定值补偿的校准策略.通过固定值补偿后,各通道的幅相特性曲线基本重合,从而消除了通道间幅相误差.进一步给出了提升温度一致性的措施,并设计了多波束发射天线的校准原理框图和校准流程图.结果表明:新的星载多波束天线幅相误差校准方法是有效的.%To solve the mismatch effect of amplitude-and-phase errors on multi-beam antenna performance , the radio frequency channel amplitude and phase errors of multi-beam transmitting antenna on satellite were experimentally measured to obtain the corresponding relations of channel amplitude-and-phase mismatch and temperature, and to compensate the mismatch. The shell temperatures are almost same after temperature stabilization, which effectively results in channel consistency. Some methods were used to improve temperature consistency. Calibration of channel is the key to guarantee the performance indexes of multi-beam antenna on satellites. The calibration principle block diagram and flow chart of multi-beam transmitting antenna were designed. The theoretical analysis and simulation results show that the proposed calibration method is effective for calibration of multi-beam antenna on satellites.

  8. Development and first use of a novel cylindrical ball bearing phantom for 9-DOF geometric calibrations of flat panel imaging devices used in image-guided ion beam therapy

    Science.gov (United States)

    Zechner, A.; Stock, M.; Kellner, D.; Ziegler, I.; Keuschnigg, P.; Huber, P.; Mayer, U.; Sedlmayer, F.; Deutschmann, H.; Steininger, P.

    2016-11-01

    Image guidance during highly conformal radiotherapy requires accurate geometric calibration of the moving components of the imager. Due to limited manufacturing accuracy and gravity-induced flex, an x-ray imager’s deviation from the nominal geometrical definition has to be corrected for. For this purpose a ball bearing phantom applicable for nine degrees of freedom (9-DOF) calibration of a novel cone-beam computed tomography (CBCT) scanner was designed and validated. In order to ensure accurate automated marker detection, as many uniformly distributed markers as possible should be used with a minimum projected inter-marker distance of 10 mm. Three different marker distributions on the phantom cylinder surface were simulated. First, a fixed number of markers are selected and their coordinates are randomly generated. Second, the quasi-random method is represented by setting a constraint on the marker distances in the projections. The third approach generates the ball coordinates helically based on the Golden ratio, ϕ. Projection images of the phantom incorporating the CBCT scanner’s geometry were simulated and analysed with respect to uniform distribution and intra-marker distance. Based on the evaluations a phantom prototype was manufactured and validated by a series of flexmap calibration measurements and analyses. The simulation with randomly distributed markers as well as the quasi-random approach showed an insufficient uniformity of the distribution over the detector area. The best compromise between uniform distribution and a high packing fraction of balls is provided by the Golden section approach. A prototype was manufactured accordingly. The phantom was validated for 9-DOF geometric calibrations of the CBCT scanner with independently moveable source and detector arms. A novel flexmap calibration phantom intended for 9-DOF was developed. The ball bearing distribution based on the Golden section was found to be highly advantageous. The phantom showed

  9. Assessing electron beam sensitivity for SrTiO3 and La0.7Sr0.3MnO3 using electron energy loss spectroscopy.

    Science.gov (United States)

    Nord, Magnus; Vullum, Per Erik; Hallsteinsen, Ingrid; Tybell, Thomas; Holmestad, Randi

    2016-10-01

    Thresholds for beam damage have been assessed for La0.7Sr0.3MnO3 and SrTiO3 as a function of electron probe current and exposure time at 80 and 200kV acceleration voltage. The materials were exposed to an intense electron probe by aberration corrected scanning transmission electron microscopy (STEM) with simultaneous acquisition of electron energy loss spectroscopy (EELS) data. Electron beam damage was identified by changes of the core loss fine structure after quantification by a refined and improved model based approach. At 200kV acceleration voltage, damage in SrTiO3 was identified by changes both in the EEL fine structure and by contrast changes in the STEM images. However, the changes in the STEM image contrast as introduced by minor damage can be difficult to detect under several common experimental conditions. No damage was observed in SrTiO3 at 80kV acceleration voltage, independent of probe current and exposure time. In La0.7Sr0.3MnO3, beam damage was observed at both 80 and 200kV acceleration voltages. This damage was observed by large changes in the EEL fine structure, but not by any detectable changes in the STEM images. The typical method to validate if damage has been introduced during acquisitions is to compare STEM images prior to and after spectroscopy. Quantifications in this work show that this method possibly can result in misinterpretation of beam damage as changes of material properties.

  10. Absolute cascade-free cross-sections for the 2S to 2P transition in Zn(+) using electron-energy-loss and merged-beams methods

    Science.gov (United States)

    Smith, Steven J.; Man, K.-F.; Chutjian, A.; Mawhorter, R. J.; Williams, I. D.

    1991-01-01

    Absolute cascade-free excitation cross-sections in an ion have been measured for the resonance 2S to 2P transition in Zn(+) using electron-energy-loss and merged electron-ion beams methods. Measurements were carried out at electron energies of below threshold to 6 times threshold. Comparisons are made with 2-, 5-, and 15-state close-coupling and distorted-wave theories. There is good agreement between experiment and the 15-state close-coupling cross-sections over the energy range of the calculations.

  11. Calibrating a detector array for in vivo dosimetry beam electron In this work present a set of detectors calibration for measurements in vivo dose at the entrance of the radiation beam in electron beams; Calibracion de un conjunto de detectores para la dosimetria in vivo de haces de electrones

    Energy Technology Data Exchange (ETDEWEB)

    Martinez Jurado, T.; Jornet Sala, N.; Carrasco de Fez, P.; Eudaldo Puell, T.; Latorre Mussoll, A.; Rodriguez Latorre, D.; Ruiz Martinez, A.; Ribas Morales, M.

    2013-07-01

    In particular we have determined the variation in sensitivity of the diode depending on the field size, power, angle of incidence, DFS, temperature and cumulative dose. From these results we provide a methodology for calibrating a diode array for use in routine. The application of correction factors to reading diodes are warranted when the irradiation conditions differ from the reference by the level of tolerance among the expected dose and the dose obtained. (Author)

  12. Beam losses from ultra-peripheral nuclear collisions between $^{208}$Pb$^{82+}$ ions in the Large Hadron Collider and their alleviation

    CERN Document Server

    Bruce, R; Jowett, J; Bocian, D; CERN. Geneva. BE Department

    2009-01-01

    Electromagnetic interactions between colliding heavy ions at the Large Hadron Collider (LHC) at CERN will give rise to localized beam losses that may quench superconducting magnets, apart from contributing significantly to the luminosity decay. To quantify their impact on the operation of the collider, we have used a three-step simulation approach, which consists of optical tracking, a Monte-Carlo shower simulation and a thermal network model of the heat flow inside a magnet. We present simulation results for the case of Pb ion operation in the LHC, with focus on the ALICE interaction region, and show that the expected heat load during nominal Pb operation is 40% above the quench level. This limits the maximum achievable luminosity. Furthermore, we discuss methods of monitoring the losses and possible ways to alleviate their effect.

  13. Calibration uncertainty

    DEFF Research Database (Denmark)

    Heydorn, Kaj; Anglov, Thomas

    2002-01-01

    Methods recommended by the International Standardization Organisation and Eurachem are not satisfactory for the correct estimation of calibration uncertainty. A novel approach is introduced and tested on actual calibration data for the determination of Pb by ICP-AES. The improved calibration unce...

  14. Monte Carlo Studies of the Radiation Fields in the Linac Coherent Light Source Undulators and of the Corresponding Signals in the Cerenkov Beam Loss Monitors

    Energy Technology Data Exchange (ETDEWEB)

    Santana Leitner, Mario; Fasso, Alberto; Fisher, Alan S.; Nuhn, Heinz D.; /SLAC; Dooling, Jeffrey C.; Berg, William; Yang, Bin X.; /Argonne

    2010-09-14

    In 2009 the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Center started free electron laser (FEL) operation. In order to continue to produce the bright and short-pulsed x-ray laser demanded by FEL scientists, this pioneer hard x-ray FEL requires a perfectly tailored magnetic field at the undulators, so that the photons generated at the electron wiggling path interact at the right phase with the electron beam. In such a precise system, small (>0.01%) radiation-induced alterations of the magnetic field in the permanent magnets could affect FEL performance. This paper describes the simulation studies of radiation fields in permanent magnets and the expected signal in the detectors. The transport of particles from the radiation sources (i.e. diagnostic insert) to the undulator magnets and to the beam loss monitors (BLM) was simulated with the intra nuclear cascade codes FLUKA and MARS15. In order to accurately reproduce the optics of LCLS, lattice capabilities and magnetic fields were enabled in FLUKA and betatron oscillations were validated against reference data. All electron events entering the BLMs were printed in data files. The paper also introduces the Radioactive Ion Beam Optimizer (RIBO) Monte Carlo 3-D code, which was used to read from the event files, to compute Cerenkov production and then to simulate the optical coupling of the BLM detectors, accounting for the transmission of light through the quartz.

  15. A phased array antenna with a broadly steerable beam based on a low-loss metasurface lens

    Science.gov (United States)

    Liu, Yahong; Jin, Xueyu; Zhou, Xin; Luo, Yang; Song, Kun; Huang, Lvhongzi; Zhao, Xiaopeng

    2016-10-01

    A new concept for a gradient phase discontinuity metasurface lens integrated with a phased array antenna possessing a broadly steerable beam is presented in this paper. The metasurface lens is composed of a metallic H-shaped pattern and the metallic square split ring can achieve complete 360° transmission phase coverage at 30° phase intervals. The metasurface can refract an incident plane wave to an angle at will by varying the lattice constant. We demonstrate that the beam steering range of the phased array antenna is between 12° and 85° when the metasurface lens with a refracting electromagnetic wave is employed at 45°. Interestingly, the proposed array antenna has a much higher gain than a conventional phased array antenna at low elevation angles. It is expected that the proposed array antenna will have potential applications in wireless and satellite communications. Furthermore, the proposed array antenna is fabricated easily and is also low in cost due to its microstrip technology.

  16. THE METHOD OF DETERMINATION OF ERROR IN THE REFERENCE VALUE OF THE DOSE DURING THE LINEAR ACCELERATOR RADIATION OUTPUT CALIBRATION PROCEDURE. Part 3. The dependence of the radiation beam characteristics

    Directory of Open Access Journals (Sweden)

    E. V. Titovich

    2016-01-01

    Full Text Available To ensure the radiation protection of oncology patients is needed to provide the constancy of functional characteristics of the medical linear accelerators, which affect the accuracy of dose delivery. For this purpose, their quality control procedures are realized including calibration of radiation output of the linac, so the error in determining the dose reference value during this procedure must not exceed 2 %. The aim is to develop a methodology for determining the error in determining this value, depending on the characteristics of the radiation beam. Dosimetric measurements of Trilogy S/N 3567 linac dose distributions have been carried out for achievement of the objectives, on the basis of which dose errors depending on the dose rate value, the accuracy of the beam quality and output factors determination, the symmetry and uniformity of the radiation field, the angular dependence of the linac radiation output were obtained. It was found that the greatest impact on the value of the error has the error in the output factors determination (up to 5.26 % for both photon energy. Dose errors caused by changing dose rate during treatment were different for two photon energies, and reached 1.6 % for 6 MeV and 1.4 % for 18 MeV. Dose errors caused by inaccuracies of the beam quality determination were different for two photon energies, and reached 1.1 % for 18 MeV and –0.3 % for 6 MeV. Errors caused by the remaining of the characteristic do not exceed 1 %. Thus, there is a possibility to express the results of periodic quality control of the linear accelerator in terms of dose and use them to conduct a comprehensive assessment of the possibility of clinical use of a linear accelerator for oncology patients irradiation on the basis of the calibration of radiation output.

  17. BNL alternating gradient synchrotron with four helical magnets to minimize the losses of the polarized proton beam

    Science.gov (United States)

    Tsoupas, N.; Huang, H.; MacKay, W. W.; Meot, F.; Roser, T.; Trbojevic, D.

    2013-04-01

    The principle of using multiple partial helical magnets to preserve the polarization of the proton beam during its acceleration was applied successfully to the alternating gradient synchrotron (AGS) which currently operates with two partial helical magnets. In this paper we further explore this idea by using four partial helical magnets placed symmetrically in the AGS ring. This provides many advantages over the present setup of the AGS, which uses two partial helical magnets. First, the symmetric placement of the four helical magnets and their relatively lower field of operation allows for better control of the AGS optics with reduced values of the beta functions especially near beam injection and allows both the vertical and horizontal tunes to be placed within the “spin tune gap,” therefore eliminating the horizontal and vertical intrinsic spin resonances of the AGS during the acceleration cycle. Second, it provides a wider spin tune gap. Third, the vertical spin direction during beam injection and extraction is closer to vertical. Although the spin tune gap, which is created with four partial helices, can also be created with a single or two partial helices, the high field strength of a single helical magnet which is required to generate such a spin tune gap makes the use of the single helical magnet impractical, and that of the two helical magnets rather difficult. In this paper we will provide results on the spin tune and on the optics of the AGS with four partial helical magnets, and compare them with those from the present setup of the AGS that uses two partial helical magnets. Although in this paper we specifically discuss the effect of the four partial helices on the AGS, this method which can eliminate simultaneously the vertical and horizontal intrinsic spin resonances is a general method and can be applied to any medium energy synchrotron which operates in similar energy range like the AGS and provides the required space to accommodate the four

  18. Calibration and validation of SWAT model for estimating water balance and nitrogen losses in a small agricultural watershed in central Poland

    Directory of Open Access Journals (Sweden)

    Smarzyńska Karolina

    2016-06-01

    Full Text Available Soil and Water Assessment Tool (SWAT ver. 2005 was applied to study water balance and nitrogen load pathways in a small agricultural watershed in the lowlands of central Poland. The natural flow regime of the Zgłowiączka River was strongly modified by human activity (deforestation and installation of a subsurface drainage system to facilitate stable crop production. SWAT was calibrated for daily and monthly discharge and monthly nitrate nitrogen load. Model efficiency was tested using manual techniques (subjective and evaluation statistics (objective. Values of Nash–Sutcliffe efficiency coefficient (NSE, coefficient of determination (R2 and percentage of bias for daily/monthly discharge simulations and monthly load indicated good or very good fit of simulated discharge and nitrate nitrogen load to the observed data set. Model precision and accuracy of fit was proved in validation. The calibrated and validated SWAT was used to assess water balance and nitrogen fluxes in the watershed. According to the results, the share of tile drainage in water yield is equal to 78%. The model analysis indicated the most significant pathway of NO3-N to surface waters in the study area, namely the tile drainage combined with lateral flow. Its share in total NO3-N load amounted to 89%. Identification of nitrogen fluxes in the watershed is crucial for decision makers in order to manage water resources and to implement the most effective measures to limit diffuse pollution from arable land to surface waters.

  19. Final focus test beam

    Energy Technology Data Exchange (ETDEWEB)

    1991-03-01

    This report discusses the following: the Final Focus Test Beam Project; optical design; magnets; instrumentation; magnetic measurement and BPM calibration; mechanical alignment and stabilization; vacuum system; power supplies; control system; radiation shielding and personnel protection; infrastructure; and administration.

  20. Assessing the long-term weathering of petroleum on shorelines : uses of conserved components for calibrating loss and bioremediation potential, Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    Atlas, R. [Louisville Univ., Louisville, KY (United States); Bragg, J. [Creative Petroleum Solutions, Houston, TX (United States)

    2007-07-01

    Shoreline samples from the Exxon Valdez oil spill were used to study the limitations and strengths of different conserved components as markers based on a 17-year field monitoring program. Approximately 100 oil samples collected from the shoreline in Prince William Sound, Alaska from 1999-2006 had been analyzed for internal markers such as chrysenes, terpanes, steranes and triaromatic steroids and then used to assess the biodegradation of the spilled petroleum. The specific biomarkers used in this study were selected to exclude those that might be generated via biodegradation and were chosen from those having the most significant concentrations in the extracts. Concentrations of the recovered weathered oil compounds were quantified and the concentrations of the polycyclic aromatic hydrocarbons (PAH) components were measured in the aromatic fractions. The extent of PAH weathering was subsequently calculated as a percentage loss of total PAH in order to calculate a bioremediation index to evaluate if an oil at a given shoreline may be amenable to bioremediation (or nutrient addition) to accelerate removal of remaining PAH. In order to compare the extent of weathering over the 17 years since the spill, chemical analyses were performed for samples from 1989-1991 for which no biomarkers were measured. The weathering of the oil has progressed in such a way that most of the remaining oil is now highly weathered. The trend of increasing biodegradation with time indicates that given sufficient time, the oil will continue to degrade naturally until all of the PAH components are consumed. The most stable biomarker compounds to quantify the loss of PAH or other oil components was shown to be C{sub 29}R-stigmastane. 35 refs., 4 tabs., 7 figs.

  1. Calibration of pressure gauge for Cherenkov detector

    CERN Document Server

    Saponjic, Nevena

    2013-01-01

    Solartron/Hamilton pressure gauges are used to monitor the gas pressure in the particle beam detectors installed in the experimental areas. Here is description of the test bench for the calibration of these gauges in Labview.

  2. Margin selection to compensate for loss of target dose coverage due to target motion during external-beam radiation therapy of the lung.

    Science.gov (United States)

    Foster, W Kyle; Osei, Ernest; Barnett, Rob

    2015-01-08

    The aim of this study is to provide guidelines for the selection of external-beam radiation therapy target margins to compensate for target motion in the lung during treatment planning. A convolution model was employed to predict the effect of target motion on the delivered dose distribution. The accuracy of the model was confirmed with radiochromic film measurements in both static and dynamic phantom modes. 502 unique patient breathing traces were recorded and used to simulate the effect of target motion on a dose distribution. A 1D probability density function (PDF) representing the position of the target throughout the breathing cycle was generated from each breathing trace obtained during 4D CT. Changes in the target D95 (the minimum dose received by 95% of the treatment target) due to target motion were analyzed and shown to correlate with the standard deviation of the PDF. Furthermore, the amount of target D95 recovered per millimeter of increased field width was also shown to correlate with the standard deviation of the PDF. The sensitivity of changes in dose coverage with respect to target size was also determined. Margin selection recommendations that can be used to compensate for loss of target D95 were generated based on the simulation results. These results are discussed in the context of clinical plans. We conclude that, for PDF standard deviations less than 0.4 cm with target sizes greater than 5 cm, little or no additional margins are required. Targets which are smaller than 5 cm with PDF standard deviations larger than 0.4 cm are most susceptible to loss of coverage. The largest additional required margin in this study was determined to be 8 mm.

  3. LOFAR facet calibration

    CERN Document Server

    van Weeren, R J; Hardcastle, M J; Shimwell, T W; Rafferty, D A; Sabater, J; Heald, G; Sridhar, S S; Dijkema, T J; Brunetti, G; Brüggen, M; Andrade-Santos, F; Ogrean, G A; Röttgering, H J A; Dawson, W A; Forman, W R; de Gasperin, F; Jones, C; Miley, G K; Rudnick, L; Sarazin, C L; Bonafede, A; Best, P N; Bîrzan, L; Cassano, R; Chyży, K T; Croston, J H; Ensslin, T; Ferrari, C; Hoeft, M; Horellou, C; Jarvis, M J; Kraft, R P; Mevius, M; Intema, H T; Murray, S S; Orrú, E; Pizzo, R; Simionescu, A; Stroe, A; van der Tol, S; White, G J

    2016-01-01

    LOFAR, the Low-Frequency Array, is a powerful new radio telescope operating between 10 and 240 MHz. LOFAR allows detailed sensitive high-resolution studies of the low-frequency radio sky. At the same time LOFAR also provides excellent short baseline coverage to map diffuse extended emission. However, producing high-quality deep images is challenging due to the presence of direction dependent calibration errors, caused by imperfect knowledge of the station beam shapes and the ionosphere. Furthermore, the large data volume and presence of station clock errors present additional difficulties. In this paper we present a new calibration scheme, which we name facet calibration, to obtain deep high-resolution LOFAR High Band Antenna images using the Dutch part of the array. This scheme solves and corrects the direction dependent errors in a number of facets that cover the observed field of view. Facet calibration provides close to thermal noise limited images for a typical 8 hr observing run at $\\sim$ 5arcsec resolu...

  4. First results from the MINOS calibration detector

    CERN Document Server

    Vahle, P; Alner, J; Anderson, B; Attree, D; Barker, M; Belias, A; Crone, G; Durkin, T J; Felt, N; Falk, E; Harris, P; Jenner, L; Kordosky, M; Lang, K; Lebedev, A; Lee, R; Longley, N P; Marshak, M; Miyagawa, P; Michael, D G; Morse, R; Musser, J; Nichol, R; Nicholls, T; Oliver, J; Pearce, G; Petyt, D; Proga, M; Rebel, B; Saakyan, R; Smith, C; Sullivan, P; Thomas, J; Weber, A; Wojcicki, S G

    2002-01-01

    The MINOS calibration detector (CalDet) is a small version of the MINOS Near and Far neutrino detectors. A program of exposure to beams of muons, electrons, pions and protons at the CERN PS will provide calibration of the calorimetric and topological response of the Near and Far detectors. In this talk, we briefly discuss the goals and design of the CalDet and present first results from the initial beam exposure. (3 refs).

  5. CALIBRATION OF THE INFRARED OPTOMETER

    Science.gov (United States)

    An infrared optometer for measuring the absolute status of accommodation is subject to a constant error not associated with chromatic aberration or...on optometer accuracy as long as the pupil does not vignette the optometer beam. A modification is described for calibrating the infrared optometer ...for an individual subject without using trial lenses or a subjective optometer . (Author)

  6. Scintillator based energetic ion loss diagnostic for the National Spherical Torus Experiment.

    Science.gov (United States)

    Darrow, D S

    2008-02-01

    A scintillator based energetic ion loss detector has been built and installed on the National Spherical Torus Experiment (NSTX) [Synakowski et al., Nucl. Fusion 43, 1653 (2000)] to measure the loss of neutral beam ions. The detector is able to resolve the pitch angle and gyroradius of the lost energetic ions. It has a wide acceptance range in pitch angle and energy, and is able to resolve the full, one-half, and one-third energy components of the 80 keV D neutral beams up to the maximum toroidal magnetic field of NSTX. Multiple Faraday cups have been embedded behind the scintillator to allow easy absolute calibration of the diagnostic and to measure the energetic ion loss in several ranges of pitch angle with good time resolution. Several small, vacuum compatible lamps allow simple calibration of the scintillator position within the field of view of the diagnostic's video camera.

  7. Simulation and calibration of the specific energy loss of the central jet chambers of the H1 detector and measurement of the inclusive D{sup *{+-}} meson cross section in photoproduction at HERA

    Energy Technology Data Exchange (ETDEWEB)

    Hennekemper, Eva

    2011-12-15

    In this thesis the photoproduction of D{sup *} mesons in ep collisions at HERA is analysed. D{sup *} mesons are detected in the 'golden' decay channel D{sup *} {yields} K{pi}{pi}{sub s} with the H1 detector. Compared to earlier analyses, the systematic uncertainty is reduced due to two main improvements. Firstly, the simulation of the Fast Track Trigger, which is based on tracks measured within the central jet chambers, allows the trigger efficiency dependence of various kinematic variables to be evaluated. Secondly, the use of specific energy loss provides the possibility to suppress the non-resonant background. In order to use particle identification with the specific energy loss in the analysis, the simulation of the specific energy loss in the central jet chambers of the H1 detector is improved and the necessary correction functions and calibrations have been determined. This improved final H1 detector simulation is used to determine the cross section of photoproduction of D{sup *} mesons in the HERA II data sample, which corresponds to an integrated luminosity of 113 pb{sup -1}. The measurement was performed in the kinematic region of Q{sup 2}<2 GeV for the photon virtuality and photon-proton center of mass energies of 100

  8. Calibration strategy of CMS electromagnetic calorimeter

    CERN Document Server

    Paramatti, R

    2004-01-01

    Calibration is one of the main factors that set limits on the ultimate performance of the CMS electromagnetic calorimeter at LHC. Crystals raw intercalibration from lab measurements during assembly and CERN-SPS test beam of Supermodules will represent the precalibration at the start-up. In situ calibration with physics events will be the main tool to reduce the constant term to the design goal of 0.5%. The calibration strategy will be described in detail.

  9. Calibration of Avent Wind IRIS SN 01030167

    DEFF Research Database (Denmark)

    Courtney, Michael

    This report presents the result of the lidar calibration performed for a two-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  10. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a two-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  11. Calibration of Nacelle-based Lidar instrument

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a four-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark.Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements...... with measurement uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  12. Expression of Interest for a Full-Scale Detector Engineering Test and Test Beam Calibration of a Single-Phase LAr TPC

    CERN Document Server

    Leigui de Oliveira, M A

    2014-01-01

    Following the recommendation of the U.S. Particle Physics Project Prioritization Panel[1], Fermilab is working with the world neutrino community, CERN, and others to establish “a new international collaboration to design and execute a highly capable Long-Baseline Neutrino Facility (LBNF) hosted by the U.S.” This new collaboration, which is expected to be formed during the next several months, will combine, among others, groups that have been developing both single-phase and dual-phase LAr TPC detectors for long-baseline physics, mainly from the LBNE and LBNO collaborations respectively. This Expression of Interest regards a proposed full-scale prototype and beam test of the LBNE-design single-phase detector, utilizing the CERN Neutrino Platform[2] that was recently approved as part of the Medium-Term Plan (MTP) [3]. Once the LBNF collaboration is formed, it is expected that development of both single- and dual-phase detectors will come under the umbrella of the new collaboration.

  13. 贝塞尔高斯光束通过硬边光阑的衍射损耗%Losses of Bessel-Gaussian Beams Propagating through a Hard-Edge Aperture

    Institute of Scientific and Technical Information of China (English)

    王莉

    2001-01-01

    The losses Bessel-Gaussian beams, a kind of non-diffracting beam,propagating through a hard aperture are studied, and a general formula is derived. As an example of applications, numerical calculation is performed to calculate the losses of Bessel-Gaussian beams propagating through a circular aperture. The obtained results are analyzed and discussed. The proposed method can also be applied to calculation of the losses of other types of laser beams propagating through a hard-edge aperture.%对无衍射光束——贝塞尔高斯光束通过硬边光阑时的功率损耗作了研究,给出了普适的损耗公式。作为应用举例,对零阶贝塞尔高斯光束通过圆孔硬边光阑时的衍射损耗作了详细的计算。对计算结果进行了分析和讨论。该方法还可用于其它光束通过硬边光阑的衍射损耗计算。

  14. 1% calibration errors in MQY magnets

    CERN Document Server

    Bach, T; Langner, A; Levinsen, Y; McAteer, M; Maclean, E H; Persson, T; Skowronski, P; Tomás, R; Todesco, E; White, S

    2013-01-01

    Errors in the range of 1% have been observed for the MQY magnets in beam-based measurements. Furthermore, inconsistencies have been observed when comparing previous magnetic measurements to the LHC LSA database. After a revision, new calibration data have been extracted and were compared to the optics corrections that have been obtained from beam-based measurements. In 27-11-2012 a MD session has been performed to test these calibration data. This paper reports on the experimental verification of the new calibration data for the MQY quadrupole magnets.

  15. Calibration of Li-glass Detector Efficiency

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Li-glass detector will be used to measure the flux of neutron beam in Gamma-ray Total Absorption Facility(GTAF). We have calibrated the detection efficiency of Li-glass detector in 5SDH-2 accelerator. The beam of neutron was produced by the reaction 7Li

  16. The ATLAS Inner Detector commissioning and calibration

    CERN Document Server

    Aad, Georges; Abdallah, Jalal; Abdelalim, Ahmed Ali; Abdesselam, Abdelouahab; Abdinov, Ovsat; Abi, Babak; Abolins, Maris; Abramowicz, Halina; Abreu, Henso; Acharya, Bobby Samir; Adams, David; Addy, Tetteh; Adelman, Jahred; Adorisio, Cristina; Adragna, Paolo; Adye, Tim; Aefsky, Scott; Aguilar-Saavedra, Juan Antonio; Aharrouche, Mohamed; Ahlen, Steven; Ahles, Florian; Ahmad, Ashfaq; Ahsan, Mahsana; Aielli, Giulio; Akdogan, Taylan; Åkesson, Torsten Paul Ake; Akimoto, Ginga; Akimov , Andrei; Aktas, Adil; Alam, Mohammad; Alam, Muhammad Aftab; Albrand, Solveig; Aleksa, Martin; Aleksandrov, Igor; Alexa, Calin; Alexander, Gideon; Alexandre, Gauthier; Alexopoulos, Theodoros; Alhroob, Muhammad; Aliev, Malik; Alimonti, Gianluca; Alison, John; Aliyev, Magsud; Allport, Phillip; Allwood-Spiers, Sarah; Almond, John; Aloisio, Alberto; Alon, Raz; Alonso, Alejandro; Alviggi, Mariagrazia; Amako, Katsuya; Amelung, Christoph; Amorim, Antonio; Amorós, Gabriel; Amram, Nir; Anastopoulos, Christos; Andeen, Timothy; Anders, Christoph Falk; Anderson, Kelby; Andreazza, Attilio; Andrei, George Victor; Anduaga, Xabier; Angerami, Aaron; Anghinolfi, Francis; Anjos, Nuno; Annovi, Alberto; Antonaki, Ariadni; Antonelli, Mario; Antonelli, Stefano; Antos, Jaroslav; Antunovic, Bijana; Anulli, Fabio; Aoun, Sahar; Arabidze, Giorgi; Aracena, Ignacio; Arai, Yasuo; Arce, Ayana; Archambault, John-Paul; Arfaoui, Samir; Arguin, Jean-Francois; Argyropoulos, Theodoros; Arik, Metin; Armbruster, Aaron James; Arnaez, Olivier; Arnault, Christian; Artamonov, Andrei; Arutinov, David; Asai, Makoto; Asai, Shoji; Silva, José; Asfandiyarov, Ruslan; Ask, Stefan; Åsman, Barbro; Asner, David; Asquith, Lily; Assamagan, Ketevi; Astvatsatourov, Anatoli; Atoian, Grigor; Auerbach, Benjamin; Augsten, Kamil; Aurousseau, Mathieu; Austin, Nicholas; Avolio, Giuseppe; Avramidou, Rachel Maria; Ay, Cano; Azuelos, Georges; Azuma, Yuya; Baak, Max; Bach, Andre; Bachacou, Henri; Bachas, Konstantinos; Backes, Moritz; Badescu, Elisabeta; Bagnaia, Paolo; Bai, Yu; Bain, Travis; Baines, John; Baker, Mark; Baker, Oliver Keith; Baker, Sarah; Baltasar Dos Santos Pedrosa, Fernando; Banas, Elzbieta; Banerjee, Piyali; Banerjee, Swagato; Banfi, Danilo; Bangert, Andrea Michelle; Bansal, Vikas; Baranov, Sergei; Barashkou, Andrei; Barber, Tom; Barberio, Elisabetta Luigia; Barberis, Dario; Barbero, Marlon; Bardin, Dmitri; Barillari, Teresa; Barisonzi, Marcello; Barklow, Timothy; Barlow, Nick; Barnett, Bruce; Barnett, Michael; Baroncelli, Antonio; Barr, Alan; Barreiro, Fernando; Barreiro Guimarães da Costa, João; Barrillon, Pierre; Bartoldus, Rainer; Bartsch, Detlef; Bates, Richard; Batkova, Lucia; Batley, Richard; Battaglia, Andreas; Battistin, Michele; Bauer, Florian; Bawa, Harinder Singh; Bazalova, Magdalena; Beare, Brian; Beau, Tristan; Beauchemin, Pierre-Hugues; Beccherle, Roberto; Bechtle, Philip; Beck, Graham; Beck, Hans Peter; Beckingham, Matthew; Becks, Karl-Heinz; Beddall, Ayda; Beddall, Andrew; Bednyakov, Vadim; Bee, Christopher; Begel, Michael; Behar Harpaz, Silvia; Behera, Prafulla; Beimforde, Michael; Belanger-Champagne, Camille; Bell, Paul; Bell, William; Bella, Gideon; Bellagamba, Lorenzo; Bellina, Francesco; Bellomo, Massimiliano; Belloni, Alberto; Belotskiy, Konstantin; Beltramello, Olga; Ben Ami, Sagi; Benary, Odette; Benchekroun, Driss; Bendel, Markus; Benedict, Brian Hugues; Benekos, Nektarios; Benhammou, Yan; Benjamin, Douglas; Benoit, Mathieu; Bensinger, James; Benslama, Kamal; Bentvelsen, Stan; Beretta, Matteo; Berge, David; Bergeaas Kuutmann, Elin; Berger, Nicolas; Berghaus, Frank; Berglund, Elina; Beringer, Jürg; Bernabéu , José; Bernat, Pauline; Bernhard, Ralf; Bernius, Catrin; Berry, Tracey; Bertin, Antonio; Besana, Maria Ilaria; Besson, Nathalie; Bethke, Siegfried; Bianchi, Riccardo-Maria; Bianco, Michele; Biebel, Otmar; Biesiada, Jed; Biglietti, Michela; Bilokon, Halina; Bindi, Marcello; Bingul, Ahmet; Bini, Cesare; Biscarat, Catherine; Bitenc, Urban; Black, Kevin; Blair, Robert; Blanchard, Jean-Baptiste; Blanchot, Georges; Blocker, Craig; Blondel, Alain; Blum, Walter; Blumenschein, Ulrike; Bobbink, Gerjan; Bocci, Andrea; Boehler, Michael; Boek, Jennifer; Boelaert, Nele; Böser, Sebastian; Bogaerts, Joannes Andreas; Bogouch, Andrei; Bohm, Christian; Bohm, Jan; Boisvert, Veronique; Bold, Tomasz; Boldea, Venera; Bondarenko, Valery; Bondioli, Mario; Boonekamp, Maarten; Bordoni, Stefania; Borer, Claudia; Borisov, Anatoly; Borissov, Guennadi; Borjanovic, Iris; Borroni, Sara; Bos, Kors; Boscherini, Davide; Bosman, Martine; Boterenbrood, Hendrik; Bouchami, Jihene; Boudreau, Joseph; Bouhova-Thacker, Evelina Vassileva; Boulahouache, Chaouki; Bourdarios, Claire; Boveia, Antonio; Boyd, James; Boyko, Igor; Bozovic-Jelisavcic, Ivanka; Bracinik, Juraj; Braem, André; Branchini, Paolo; Brandt, Andrew; Brandt, Gerhard; Brandt, Oleg; Bratzler, Uwe; Brau, Benjamin; Brau, James; Braun, Helmut; Brelier, Bertrand; Bremer, Johan; Brenner, Richard; Bressler, Shikma; Britton, Dave; Brochu, Frederic; Brock, Ian; Brock, Raymond; Brodet, Eyal; Bromberg, Carl; Brooijmans, Gustaaf; Brooks, William; Brown, Gareth; Bruckman de Renstrom, Pawel; Bruncko, Dusan; Bruneliere, Renaud; Brunet, Sylvie; Bruni, Alessia; Bruni, Graziano; Bruschi, Marco; Bucci, Francesca; Buchanan, James; Buchholz, Peter; Buckley, Andrew; Budagov, Ioulian; Budick, Burton; Büscher, Volker; Bugge, Lars; Bulekov, Oleg; Bunse, Moritz; Buran, Torleiv; Burckhart, Helfried; Burdin, Sergey; Burgess, Thomas; Burke, Stephen; Busato, Emmanuel; Bussey, Peter; Buszello, Claus-Peter; Butin, Françcois; Butler, Bart; Butler, John; Buttar, Craig; Butterworth, Jonathan; Byatt, Tom; Caballero, Jose; Cabrera Urbán, Susana; Caforio, Davide; Cakir, Orhan; Calafiura, Paolo; Calderini, Giovanni; Calfayan, Philippe; Calkins, Robert; Caloba, Luiz; Calvet, David; Camarri, Paolo; Cameron, David; Campana, Simone; Campanelli, Mario; Canale, Vincenzo; Canelli, Florencia; Canepa, Anadi; Cantero, Josu; Capasso, Luciano; Capeans Garrido, Maria Del Mar; Caprini, Irinel; Caprini, Mihai; Capua, Marcella; Caputo, Regina; Caramarcu, Costin; Cardarelli, Roberto; Carli, Tancredi; Carlino, Gianpaolo; Carminati, Leonardo; Caron, Bryan; Caron, Sascha; Carrillo Montoya, German D.; Carron Montero, Sebastian; Carter, Antony; Carter, Janet; Carvalho, João; Casadei, Diego; Casado, Maria Pilar; Cascella, Michele; Castaneda Hernandez, Alfredo Martin; Castaneda-Miranda, Elizabeth; Castillo Gimenez, Victoria; Castro, Nuno Filipe; Cataldi, Gabriella; Catinaccio, Andrea; Catmore, James; Cattai, Ariella; Cattani, Giordano; Caughron, Seth; Cavalleri, Pietro; Cavalli, Donatella; Cavalli-Sforza, Matteo; Cavasinni, Vincenzo; Ceradini, Filippo; Cerqueira, Augusto Santiago; Cerri, Alessandro; Cerrito, Lucio; Cerutti, Fabio; Cetin, Serkant Ali; Chafaq, Aziz; Chakraborty, Dhiman; Chan, Kevin; Chapman, John Derek; Chapman, John Wehrley; Chareyre, Eve; Charlton, Dave; Chavda, Vikash; Cheatham, Susan; Chekanov, Sergei; Chekulaev, Sergey; Chelkov, Gueorgui; Chen, Hucheng; Chen, Shenjian; Chen, Xin; Cheplakov, Alexander; Chepurnov, Vladimir; Cherkaoui El Moursli, Rajaa; Tcherniatine, Valeri; Chesneanu, Daniela; Cheu, Elliott; Cheung, Sing-Leung; Chevalier, Laurent; Chevallier, Florent; Chiefari, Giovanni; Chikovani, Leila; Childers, John Taylor; Chilingarov, Alexandre; Chiodini, Gabriele; Chizhov, Mihail; Choudalakis, Georgios; Chouridou, Sofia; Christidi, Illectra-Athanasia; Christov, Asen; Chromek-Burckhart, Doris; Chu, Ming-Lee; Chudoba, Jiri; Ciapetti, Guido; Ciftci, Abbas Kenan; Ciftci, Rena; Cinca, Diane; Cindro, Vladimir; Ciobotaru, Matei Dan; Ciocca, Claudia; Ciocio, Alessandra; Cirilli, Manuela; Clark, Allan G.; Clark, Philip James; Cleland, Bill; Clemens, Jean-Claude; Clement, Benoit; Clement, Christophe; Coadou, Yann; Cobal, Marina; Coccaro, Andrea; Cochran, James H.; Coggeshall, James; Cogneras, Eric; Colijn, Auke-Pieter; Collard, Caroline; Collins, Neil; Collins-Tooth, Christopher; Collot, Johann; Colon, German; Conde Muiño, Patricia; Coniavitis, Elias; Conidi, Maria Chiara; Consonni, Michele; Constantinescu, Serban; Conta, Claudio; Conventi, Francesco; Cooke, Mark; Cooper, Ben; Cooper-Sarkar, Amanda; Cooper-Smith, Neil; Copic, Katherine; Cornelissen, Thijs; Corradi, Massimo; Corriveau, Francois; Corso-Radu, Alina; Cortes-Gonzalez, Arely; Cortiana, Giorgio; Costa, Giuseppe; Costa, María José; Costanzo, Davide; Costin, Tudor; Côté, David; Coura Torres, Rodrigo; Courneyea, Lorraine; Cowan, Glen; Cowden, Christopher; Cox, Brian; Cranmer, Kyle; Cranshaw, Jack; Cristinziani, Markus; Crosetti, Giovanni; Crupi, Roberto; Crépé-Renaudin, Sabine; Cuenca Almenar, Cristóbal; Cuhadar Donszelmann, Tulay; Curatolo, Maria; Curtis, Chris; Cwetanski, Peter; Czyczula, Zofia; D'Auria, Saverio; D'Onofrio, Monica; D'Orazio, Alessia; Da Via, Cinzia; Dabrowski, Wladyslaw; Dai, Tiesheng; Dallapiccola, Carlo; Dallison, Steve; Daly, Colin; Dam, Mogens; Danielsson, Hans Olof; Dannheim, Dominik; Dao, Valerio; Darbo, Giovanni; Darlea, Georgiana Lavinia; Davey, Will; Davidek, Tomas; Davidson, Nadia; Davidson, Ruth; Davies, Merlin; Davison, Adam; Dawson, Ian; Daya, Rozmin; De, Kaushik; de Asmundis, Riccardo; De Castro, Stefano; De Castro Faria Salgado, Pedro; De Cecco, Sandro; de Graat, Julien; De Groot, Nicolo; de Jong, Paul; De Mora, Lee; De Oliveira Branco, Miguel; De Pedis, Daniele; De Salvo, Alessandro; De Sanctis, Umberto; De Santo, Antonella; De Vivie De Regie, Jean-Baptiste; Dean, Simon; Dedovich, Dmitri; Degenhardt, James; Dehchar, Mohamed; Del Papa, Carlo; Del Peso, Jose; Del Prete, Tarcisio; Dell'Acqua, Andrea; Dell'Asta, Lidia; Della Pietra, Massimo; della Volpe, Domenico; Delmastro, Marco; Delsart, Pierre-Antoine; Deluca, Carolina; Demers, Sarah; Demichev, Mikhail; Demirkoz, Bilge; Deng, Jianrong; Deng, Wensheng; Denisov, Sergey; Derkaoui, Jamal Eddine; Derue, Frederic; Dervan, Paul; Desch, Klaus Kurt; Deviveiros, Pier-Olivier; Dewhurst, Alastair; DeWilde, Burton; Dhaliwal, Saminder; Dhullipudi, Ramasudhakar; Di Ciaccio, Anna; Di Ciaccio, Lucia; Di Girolamo, Alessandro; Di Girolamo, Beniamino; Di Luise, Silvestro; Di Mattia, Alessandro; Di Nardo, Roberto; Di Simone, Andrea; Di Sipio, Riccardo; Diaz, Marco Aurelio; Diblen, Faruk; Diehl, Edward; Dietrich, Janet; Dietzsch, Thorsten; Diglio, Sara; Dindar Yagci, Kamile; Dingfelder, Jochen; Dionisi, Carlo; Dita, Petre; Dita, Sanda; Dittus, Fridolin; Djama, Fares; Djilkibaev, Rashid; Djobava, Tamar; do Vale, Maria Aline Barros; Do Valle Wemans, André; Doan, Thi Kieu Oanh; Dobos, Daniel; Dobson, Ellie; Dobson, Marc; Doglioni, Caterina; Doherty, Tom; Dolejsi, Jiri; Dolenc, Irena; Dolezal, Zdenek; Dolgoshein, Boris; Dohmae, Takeshi; Donega, Mauro; Donini, Julien; Dopke, Jens; Doria, Alessandra; Dos Anjos, Andre; Dotti, Andrea; Dova, Maria-Teresa; Doxiadis, Alexander; Doyle, Tony; Drasal, Zbynek; Dris, Manolis; Dubbert, Jörg; Duchovni, Ehud; Duckeck, Guenter; Dudarev, Alexey; Dudziak, Fanny; Dührssen , Michael; Duflot, Laurent; Dufour, Marc-Andre; Dunford, Monica; Duran Yildiz, Hatice; Duxfield, Robert; Dwuznik, Michal; Düren, Michael; Ebenstein, William; Ebke, Johannes; Eckweiler, Sebastian; Edmonds, Keith; Edwards, Clive; Egorov, Kirill; Ehrenfeld, Wolfgang; Ehrich, Thies; Eifert, Till; Eigen, Gerald; Einsweiler, Kevin; Eisenhandler, Eric; Ekelof, Tord; El Kacimi, Mohamed; Ellert, Mattias; Elles, Sabine; Ellinghaus, Frank; Ellis, Katherine; Ellis, Nicolas; Elmsheuser, Johannes; Elsing, Markus; Emeliyanov, Dmitry; Engelmann, Roderich; Engl, Albert; Epp, Brigitte; Eppig, Andrew; Erdmann, Johannes; Ereditato, Antonio; Eriksson, Daniel; Ermoline, Iouri; Ernst, Jesse; Ernst, Michael; Ernwein, Jean; Errede, Deborah; Errede, Steven; Ertel, Eugen; Escalier, Marc; Escobar, Carlos; Espinal Curull, Xavier; Esposito, Bellisario; Etienvre, Anne-Isabelle; Etzion, Erez; Evans, Hal; Fabbri, Laura; Fabre, Caroline; Facius, Katrine; Fakhrutdinov, Rinat; Falciano, Speranza; Fang, Yaquan; Fanti, Marcello; Farbin, Amir; Farilla, Addolorata; Farley, Jason; Farooque, Trisha; Farrington, Sinead; Farthouat, Philippe; Fassnacht, Patrick; Fassouliotis, Dimitrios; Fatholahzadeh, Baharak; Fayard, Louis; Fayette, Florent; Febbraro, Renato; Federic, Pavol; Fedin, Oleg; Fedorko, Woiciech; Feligioni, Lorenzo; Felzmann, Ulrich; Feng, Cunfeng; Feng, Eric; Fenyuk, Alexander; Ferencei, Jozef; Ferland, Jonathan; Fernandes, Bruno; Fernando, Waruna; Ferrag, Samir; Ferrando, James; Ferrara, Valentina; Ferrari, Arnaud; Ferrari, Pamela; Ferrari, Roberto; Ferrer, Antonio; Ferrer, Maria Lorenza; Ferrere, Didier; Ferretti, Claudio; Fiascaris, Maria; Fiedler, Frank; Filipčič, Andrej; Filippas, Anastasios; Filthaut, Frank; Fincke-Keeler, Margret; Fiolhais, Miguel; Fiorini, Luca; Firan, Ana; Fischer, Gordon; Fisher, Matthew; Flechl, Martin; Fleck, Ivor; Fleckner, Johanna; Fleischmann, Philipp; Fleischmann, Sebastian; Flick, Tobias; Flores Castillo, Luis; Flowerdew, Michael; Fonseca Martin, Teresa; Formica, Andrea; Forti, Alessandra; Fortin, Dominique; Fournier, Daniel; Fowler, Andrew; Fowler, Ken; Fox, Harald; Francavilla, Paolo; Franchino, Silvia; Francis, David; Franklin, Melissa; Franz, Sebastien; Fraternali, Marco; Fratina, Sasa; Freestone, Julian; French, Sky; Froeschl, Robert; Froidevaux, Daniel; Frost, James; Fukunaga, Chikara; Fullana Torregrosa, Esteban; Fuster, Juan; Gabaldon, Carolina; Gabizon, Ofir; Gadfort, Thomas; Gadomski, Szymon; Gagliardi, Guido; Gagnon, Pauline; Galea, Cristina; Gallas, Elizabeth; Gallo, Valentina Santina; Gallop, Bruce; Gallus, Petr; Galyaev, Eugene; Gan, K K; Gao, Yongsheng; Gaponenko, Andrei; Garcia-Sciveres, Maurice; García, Carmen; García Navarro, José Enrique; Gardner, Robert; Garelli, Nicoletta; Garitaonandia, Hegoi; Garonne, Vincent; Gatti, Claudio; Gaudio, Gabriella; Gautard, Valerie; Gauzzi, Paolo; Gavrilenko, Igor; Gay, Colin; Gaycken, Goetz; Gazis, Evangelos; Ge, Peng; Gee, Norman; Geich-Gimbel, Christoph; Gellerstedt, Karl; Gemme, Claudia; Genest, Marie-Hélène; Gentile, Simonetta; Georgatos, Fotios; George, Simon; Gershon, Avi; Ghazlane, Hamid; Ghodbane, Nabil; Giacobbe, Benedetto; Giagu, Stefano; Giakoumopoulou, Victoria; Giangiobbe, Vincent; Gianotti, Fabiola; Gibbard, Bruce; Gibson, Adam; Gibson, Stephen; Gilbert, Laura; Gilchriese, Murdock; Gilewsky, Valentin; Gingrich, Douglas; Ginzburg, Jonatan; Giokaris, Nikos; Giordani, MarioPaolo; Giordano, Raffaele; Giorgi, Francesco Michelangelo; Giovannini, Paola; Giraud, Pierre-Francois; Girtler, Peter; Giugni, Danilo; Giusti, Paolo; Gjelsten, Børge Kile; Gladilin, Leonid; Glasman, Claudia; Glazov, Alexandre; Glitza, Karl-Walter; Glonti, George; Godfrey, Jennifer; Godlewski, Jan; Goebel, Martin; Göpfert, Thomas; Goeringer, Christian; Gössling, Claus; Göttfert, Tobias; Goggi, Virginio; Goldfarb, Steven; Goldin, Daniel; Golling, Tobias; Gomes, Agostinho; Gomez Fajardo, Luz Stella; Gonçcalo, Ricardo; Gonella, Laura; Gong, Chenwei; González de la Hoz, Santiago; Gonzalez Silva, Laura; Gonzalez-Sevilla, Sergio; Goodson, Jeremiah Jet; Goossens, Luc; Gordon, Howard; Gorelov, Igor; Gorfine, Grant; Gorini, Benedetto; Gorini, Edoardo; Gorišek, Andrej; Gornicki, Edward; Gosdzik, Bjoern; Gosselink, Martijn; Gostkin, Mikhail Ivanovitch; Gough Eschrich, Ivo; Gouighri, Mohamed; Goujdami, Driss; Goulette, Marc Phillippe; Goussiou, Anna; Goy, Corinne; Grabowska-Bold, Iwona; Grafström, Per; Grahn, Karl-Johan; Grancagnolo, Sergio; Grassi, Valerio; Gratchev, Vadim; Grau, Nathan; Gray, Heather; Gray, Julia Ann; Graziani, Enrico; Green, Barry; Greenshaw, Timothy; Greenwood, Zeno Dixon; Gregor, Ingrid-Maria; Grenier, Philippe; Griesmayer, Erich; Griffiths, Justin; Grigalashvili, Nugzar; Grillo, Alexander; Grimm, Kathryn; Grinstein, Sebastian; Grishkevich, Yaroslav; Groh, Manfred; Groll, Marius; Gross, Eilam; Grosse-Knetter, Joern; Groth-Jensen, Jacob; Grybel, Kai; Guicheney, Christophe; Guida, Angelo; Guillemin, Thibault; Guler, Hulya; Gunther, Jaroslav; Guo, Bin; Gusakov, Yury; Gutierrez, Andrea; Gutierrez, Phillip; Guttman, Nir; Gutzwiller, Olivier; Guyot, Claude; Gwenlan, Claire; Gwilliam, Carl; Haas, Andy; Haas, Stefan; Haber, Carl; Hadavand, Haleh Khani; Hadley, David; Haefner, Petra; Hajduk, Zbigniew; Hakobyan, Hrachya; Haller, Johannes; Hamacher, Klaus; Hamilton, Andrew; Hamilton, Samuel; Han, Liang; Hanagaki, Kazunori; Hance, Michael; Handel, Carsten; Hanke, Paul; Hansen, Jørgen Beck; Hansen, Jorn Dines; Hansen, John Renner; Hansen, Peter Henrik; Hansl-Kozanecka, Traudl; Hansson, Per; Hara, Kazuhiko; Hare, Gabriel; Harenberg, Torsten; Harrington, Robert; Harris, Orin; Harrison, Karl; Hartert, Jochen; Hartjes, Fred; Harvey, Alex; Hasegawa, Satoshi; Hasegawa, Yoji; Hassani, Samira; Haug, Sigve; Hauschild, Michael; Hauser, Reiner; Havranek, Miroslav; Hawkes, Christopher; Hawkings, Richard John; Hayakawa, Takashi; Hayward, Helen; Haywood, Stephen; Head, Simon; Hedberg, Vincent; Heelan, Louise; Heim, Sarah; Heinemann, Beate; Heisterkamp, Simon; Helary, Louis; Heller, Mathieu; Hellman, Sten; Helsens, Clement; Hemperek, Tomasz; Henderson, Robert; Henke, Michael; Henrichs, Anna; Henriques Correia, Ana Maria; Henrot-Versille, Sophie; Hensel, Carsten; Henß, Tobias; Hernández Jiménez, Yesenia; Hershenhorn, Alon David; Herten, Gregor; Hertenberger, Ralf; Hervas, Luis; Hessey, Nigel; Higón-Rodriguez, Emilio; Hill, John; Hiller, Karl Heinz; Hillert, Sonja; Hillier, Stephen; Hinchliffe, Ian; Hines, Elizabeth; Hirose, Minoru; Hirsch, Florian; Hirschbuehl, Dominic; Hobbs, John; Hod, Noam; Hodgkinson, Mark; Hodgson, Paul; Hoecker, Andreas; Hoeferkamp, Martin; Hoffman, Julia; Hoffmann, Dirk; Hohlfeld, Marc; Holy, Tomas; Holzbauer, Jenny; Homma, Yasuhiro; Horazdovsky, Tomas; Hori, Takuya; Horn, Claus; Horner, Stephan; Hostachy, Jean-Yves; Hou, Suen; Hoummada, Abdeslam; Howe, Travis; Hrivnac, Julius; Hryn'ova, Tetiana; Hsu, Pai-hsien Jennifer; Hsu, Shih-Chieh; Huang, Guang Shun; Hubacek, Zdenek; Hubaut, Fabrice; Huegging, Fabian; Huffman, Todd Brian; Hughes, Emlyn; Hughes, Gareth; Hurwitz, Martina; Husemann, Ulrich; Huseynov, Nazim; Huston, Joey; Huth, John; Iacobucci, Giuseppe; Iakovidis, Georgios; Ibragimov, Iskander; Iconomidou-Fayard, Lydia; Idarraga, John; Iengo, Paolo; Igonkina, Olga; Ikegami, Yoichi; Ikeno, Masahiro; Ilchenko, Yuri; Iliadis, Dimitrios; Ince, Tayfun; Ioannou, Pavlos; Iodice, Mauro; Irles Quiles, Adrian; Ishikawa, Akimasa; Ishino, Masaya; Ishmukhametov, Renat; Isobe, Tadaaki; Issever, Cigdem; Istin, Serhat; Itoh, Yuki; Ivashin, Anton; Iwanski, Wieslaw; Iwasaki, Hiroyuki; Izen, Joseph; Izzo, Vincenzo; Jackson, Brett; Jackson, John; Jackson, Paul; Jaekel, Martin; Jain, Vivek; Jakobs, Karl; Jakobsen, Sune; Jakubek, Jan; Jana, Dilip; Jankowski, Ernest; Jansen, Eric; Jantsch, Andreas; Janus, Michel; Jarlskog, Göran; Jeanty, Laura; Jen-La Plante, Imai; Jenni, Peter; Jež, Pavel; Jézéquel, Stéphane; Ji, Weina; Jia, Jiangyong; Jiang, Yi; Jimenez Belenguer, Marcos; Jin, Shan; Jinnouchi, Osamu; Joffe, David; Johansen, Marianne; Johansson, Erik; Johansson, Per; Johnert, Sebastian; Johns, Kenneth; Jon-And, Kerstin; Jones, Graham; Jones, Roger; Jones, Tim; Jorge, Pedro; Joseph, John; Juranek, Vojtech; Jussel, Patrick; Kabachenko, Vasily; Kaci, Mohammed; Kaczmarska, Anna; Kado, Marumi; Kagan, Harris; Kagan, Michael; Kaiser, Steffen; Kajomovitz, Enrique; Kalinin, Sergey; Kalinovskaya, Lidia; Kama, Sami; Kanaya, Naoko; Kaneda, Michiru; Kantserov, Vadim; Kanzaki, Junichi; Kaplan, Benjamin; Kapliy, Anton; Kaplon, Jan; Kar, Deepak; Karagounis, Michael; Karagoz, Muge; Karnevskiy, Mikhail; Kartvelishvili, Vakhtang; Karyukhin, Andrey; Kashif, Lashkar; Kasmi, Azzedine; Kass, Richard; Kastanas, Alex; Kastoryano, Michael; Kataoka, Mayuko; Kataoka, Yousuke; Katsoufis, Elias; Katzy, Judith; Kaushik, Venkatesh; Kawagoe, Kiyotomo; Kawamoto, Tatsuo; Kawamura, Gen; Kayl, Manuel; Kayumov, Fred; Kazanin, Vassili; Kazarinov, Makhail; Keates, James Robert; Keeler, Richard; Keener, Paul; Kehoe, Robert; Keil, Markus; Kekelidze, George; Kelly, Marc; Kenyon, Mike; Kepka, Oldrich; Kerschen, Nicolas; Kerševan, Borut Paul; Kersten, Susanne; Kessoku, Kohei; Khakzad, Mohsen; Khalil-zada, Farkhad; Khandanyan, Hovhannes; Khanov, Alexander; Kharchenko, Dmitri; Khodinov, Alexander; Khomich, Andrei; Khoriauli, Gia; Khovanskiy, Nikolai; Khovanskiy, Valery; Khramov, Evgeniy; Khubua, Jemal; Kim, Hyeon Jin; Kim, Min Suk; Kim, Peter; Kim, Shinhong; Kind, Oliver; Kind, Peter; King, Barry; Kirk, Julie; Kirsch, Guillaume; Kirsch, Lawrence; Kiryunin, Andrey; Kisielewska, Danuta; Kittelmann, Thomas; Kiyamura, Hironori; Kladiva, Eduard; Klein, Max; Klein, Uta; Kleinknecht, Konrad; Klemetti, Miika; Klier, Amit; Klimentov, Alexei; Klingenberg, Reiner; Klinkby, Esben; Klioutchnikova, Tatiana; Klok, Peter; Klous, Sander; Kluge, Eike-Erik; Kluge, Thomas; Kluit, Peter; Klute, Markus; Kluth, Stefan; Knecht, Neil; Kneringer, Emmerich; Ko, Byeong Rok; Kobayashi, Tomio; Kobel, Michael; Koblitz, Birger; Kocian, Martin; Kocnar, Antonin; Kodys, Peter; Köneke, Karsten; König, Adriaan; Koenig, Sebastian; Köpke, Lutz; Koetsveld, Folkert; Koevesarki, Peter; Koffas, Thomas; Koffeman, Els; Kohn, Fabian; Kohout, Zdenek; Kohriki, Takashi; Kolanoski, Hermann; Kolesnikov, Vladimir; Koletsou, Iro; Koll, James; Kollar, Daniel; Kolos, Serguei; Kolya, Scott; Komar, Aston; Komaragiri, Jyothsna Rani; Kondo, Takahiko; Kono, Takanori; Konoplich, Rostislav; Konovalov, Serguei; Konstantinidis, Nikolaos; Koperny, Stefan; Korcyl, Krzysztof; Kordas, Kostantinos; Korn, Andreas; Korolkov, Ilya; Korolkova, Elena; Korotkov, Vladislav; Kortner, Oliver; Kortner, Sandra; Kostka, Peter; Kostyukhin, Vadim; Kotov, Serguei; Kotov, Vladislav; Kotov, Konstantin; Kourkoumelis, Christine; Koutsman, Alex; Kowalewski, Robert Victor; Kowalski, Henri; Kowalski, Tadeusz; Kozanecki, Witold; Kozhin, Anatoly; Kral, Vlastimil; Kramarenko, Viktor; Kramberger, Gregor; Krasny, Mieczyslaw Witold; Krasznahorkay, Attila; Kraus, James; Kreisel, Arik; Krejci, Frantisek; Kretzschmar, Jan; Krieger, Nina; Krieger, Peter; Kroeninger, Kevin; Kroha, Hubert; Kroll, Joe; Kroseberg, Juergen; Krstic, Jelena; Kruchonak, Uladzimir; Krüger, Hans; Krumshteyn, Zinovii; Kubota, Takashi; Kuehn, Susanne; Kugel, Andreas; Kuhl, Thorsten; Kuhn, Dietmar; Kukhtin, Victor; Kulchitsky, Yuri; Kuleshov, Sergey; Kummer, Christian; Kuna, Marine; Kunkle, Joshua; Kupco, Alexander; Kurashige, Hisaya; Kurata, Masakazu; Kurochkin, Yurii; Kus, Vlastimil; Kwee, Regina; La Rosa, Alessandro; La Rotonda, Laura; Labbe, Julien; Lacasta, Carlos; Lacava, Francesco; Lacker, Heiko; Lacour, Didier; Lacuesta, Vicente Ramón; Ladygin, Evgueni; Lafaye, Rémi; Laforge, Bertrand; Lagouri, Theodota; Lai, Stanley; Lamanna, Massimo; Lampen, Caleb; Lampl, Walter; Lancon, Eric; Landgraf, Ulrich; Landon, Murrough; Lane, Jenna; Lankford, Andrew; Lanni, Francesco; Lantzsch, Kerstin; Lanza, Agostino; Laplace, Sandrine; Lapoire, Cecile; Laporte, Jean-Francois; Lari, Tommaso; Larner, Aimee; Lassnig, Mario; Laurelli, Paolo; Lavrijsen, Wim; Laycock, Paul; Lazarev, Alexandre; Lazzaro, Alfio; Le Dortz, Olivier; Le Guirriec, Emmanuel; Le Menedeu, Eve; Lebedev, Alexander; Lebel, Céline; LeCompte, Thomas; Ledroit-Guillon, Fabienne Agnes Marie; Lee, Hurng-Chun; Lee, Jason; Lee, Shih-Chang; Lefebvre, Michel; Legendre, Marie; LeGeyt, Benjamin; Legger, Federica; Leggett, Charles; Lehmacher, Marc; Lehmann Miotto, Giovanna; Lei, Xiaowen; Leitner, Rupert; Lellouch, Daniel; Lellouch, Jeremie; Lendermann, Victor; Leney, Katharine; Lenz, Tatiana; Lenzen, Georg; Lenzi, Bruno; Leonhardt, Kathrin; Leroy, Claude; Lessard, Jean-Raphael; Lester, Christopher; Leung Fook Cheong, Annabelle; Levêque, Jessica; Levin, Daniel; Levinson, Lorne; Leyton, Michael; Li, Haifeng; Li, Xuefei; Liang, Zhihua; Liang, Zhijun; Liberti, Barbara; Lichard, Peter; Lichtnecker, Markus; Lie, Ki; Liebig, Wolfgang; Lilley, Joseph; Limosani, Antonio; Limper, Maaike; Lin, Simon; Linnemann, James; Lipeles, Elliot; Lipinsky, Lukas; Lipniacka, Anna; Liss, Tony; Lissauer, David; Lister, Alison; Litke, Alan; Liu, Chuanlei; Liu, Dong; Liu, Hao; Liu, Jianbei; Liu, Minghui; Liu, Tiankuan; Liu, Yanwen; Livan, Michele; Lleres, Annick; Lloyd, Stephen; Lobodzinska, Ewelina; Loch, Peter; Lockman, William; Lockwitz, Sarah; Loddenkoetter, Thomas; Loebinger, Fred; Loginov, Andrey; Loh, Chang Wei; Lohse, Thomas; Lohwasser, Kristin; Lokajicek, Milos; Long, Robin Eamonn; Lopes, Lourenco; Lopez Mateos, David; Losada, Marta; Loscutoff, Peter; Lou, Xinchou; Lounis, Abdenour; Loureiro, Karina; Lovas, Lubomir; Love, Jeremy; Love, Peter; Lowe, Andrew; Lu, Feng; Lubatti, Henry; Luci, Claudio; Lucotte, Arnaud; Ludwig, Andreas; Ludwig, Dörthe; Ludwig, Inga; Luehring, Frederick; Lumb, Debra; Luminari, Lamberto; Lund, Esben; Lund-Jensen, Bengt; Lundberg, Björn; Lundberg, Johan; Lundquist, Johan; Lynn, David; Lys, Jeremy; Lytken, Else; Ma, Hong; Ma, Lian Liang; Macana Goia, Jorge Andres; Maccarrone, Giovanni; Macchiolo, Anna; Maček, Boštjan; Machado Miguens, Joana; Mackeprang, Rasmus; Madaras, Ronald; Mader, Wolfgang; Maenner, Reinhard; Maeno, Tadashi; Mättig, Peter; Mättig, Stefan; Magalhaes Martins, Paulo Jorge; Magradze, Erekle; Mahalalel, Yair; Mahboubi, Kambiz; Mahmood, A.; Maiani, Camilla; Maidantchik, Carmen; Maio, Amélia; Majewski, Stephanie; Makida, Yasuhiro; Makouski, Mikhail; Makovec, Nikola; Malecki, Piotr; Malecki, Pawel; Maleev, Victor; Malek, Fairouz; Mallik, Usha; Malon, David; Maltezos, Stavros; Malyshev, Vladimir; Malyukov, Sergei; Mambelli, Marco; Mameghani, Raphael; Mamuzic, Judita; Mandelli, Luciano; Mandić, Igor; Mandrysch, Rocco; Maneira, José; Mangeard, Pierre-Simon; Manjavidze, Ioseb; Manning, Peter; Manousakis-Katsikakis, Arkadios; Mansoulie, Bruno; Mapelli, Alessandro; Mapelli, Livio; March , Luis; Marchand, Jean-Francois; Marchese, Fabrizio; Marchiori, Giovanni; Marcisovsky, Michal; Marino, Christopher; Marroquim, Fernando; Marshall, Zach; Marti-Garcia, Salvador; Martin, Alex; Martin, Andrew; Martin, Brian; Martin, Brian; Martin, Franck Francois; Martin, Jean-Pierre; Martin, Tim; Martin dit Latour, Bertrand; Martinez, Mario; Martinez Outschoorn, Verena; Martyniuk, Alex; Marzano, Francesco; Marzin, Antoine; Masetti, Lucia; Mashimo, Tetsuro; Mashinistov, Ruslan; Masik, Jiri; Maslennikov, Alexey; Massa, Ignazio; Massol, Nicolas; Mastroberardino, Anna; Masubuchi, Tatsuya; Matricon, Pierre; Matsunaga, Hiroyuki; Matsushita, Takashi; Mattravers, Carly; Maxfield, Stephen; Mayne, Anna; Mazini, Rachid; Mazur, Michael; Mc Donald, Jeffrey; Mc Kee, Shawn Patrick; McCarn, Allison; McCarthy, Robert; McCubbin, Norman; McFarlane, Kenneth; McGlone, Helen; Mchedlidze, Gvantsa; McMahon, Steve; McPherson, Robert; Meade, Andrew; Mechnich, Joerg; Mechtel, Markus; Medinnis, Mike; Meera-Lebbai, Razzak; Meguro, Tatsuma; Mehlhase, Sascha; Mehta, Andrew; Meier, Karlheinz; Meirose, Bernhard; Melachrinos, Constantinos; Mellado Garcia, Bruce Rafael; Mendoza Navas, Luis; Meng, Zhaoxia; Menke, Sven; Meoni, Evelin; Mermod, Philippe; Merola, Leonardo; Meroni, Chiara; Merritt, Frank; Messina, Andrea; Metcalfe, Jessica; Mete, Alaettin Serhan; Meyer, Jean-Pierre; Meyer, Jochen; Meyer, Joerg; Meyer, Thomas Christian; Meyer, W. Thomas; Miao, Jiayuan; Michal, Sebastien; Micu, Liliana; Middleton, Robin; Migas, Sylwia; Mijović, Liza; Mikenberg, Giora; Mikestikova, Marcela; Mikuž, Marko; Miller, David; Mills, Corrinne; Mills, Bill; Milov, Alexander; Milstead, David; Milstein, Dmitry; Minaenko, Andrey; Miñano, Mercedes; Minashvili, Irakli; Mincer, Allen; Mindur, Bartosz; Mineev, Mikhail; Ming, Yao; Mir, Lluisa-Maria; Mirabelli, Giovanni; Misawa, Shigeki; Misiejuk, Andrzej; Mitrevski, Jovan; Mitsou, Vasiliki A.; Miyagawa, Paul; Mjörnmark, Jan-Ulf; Moa, Torbjoern; Moed, Shulamit; Moeller, Victoria; Mönig, Klaus; Möser, Nicolas; Mohr, Wolfgang; Mohrdieck-Möck, Susanne; Moles-Valls, Regina; Molina-Perez, Jorge; Monk, James; Monnier, Emmanuel; Montesano, Simone; Monticelli, Fernando; Moore, Roger; Mora Herrera, Clemencia; Moraes, Arthur; Morais, Antonio; Morel, Julien; Morello, Gianfranco; Moreno, Deywis; Moreno Llácer, María; Morettini, Paolo; Morii, Masahiro; Morley, Anthony Keith; Mornacchi, Giuseppe; Morozov, Sergey; Morris, John; Moser, Hans-Guenther; Mosidze, Maia; Moss, Josh; Mount, Richard; Mountricha, Eleni; Mouraviev, Sergei; Moyse, Edward; Mudrinic, Mihajlo; Mueller, Felix; Mueller, James; Mueller, Klemens; Müller, Thomas; Muenstermann, Daniel; Muir, Alex; Munwes, Yonathan; Murillo Garcia, Raul; Murray, Bill; Mussche, Ido; Musto, Elisa; Myagkov, Alexey; Myska, Miroslav; Nadal, Jordi; Nagai, Koichi; Nagano, Kunihiro; Nagasaka, Yasushi; Nairz, Armin Michael; Nakamura, Koji; Nakano, Itsuo; Nakatsuka, Hiroki; Nanava, Gizo; Napier, Austin; Nash, Michael; Nation, Nigel; Nattermann, Till; Naumann, Thomas; Navarro, Gabriela; Nderitu, Simon Kirichu; Neal, Homer; Nebot, Eduardo; Nechaeva, Polina; Negri, Andrea; Negri, Guido; Nelson, Andrew; Nelson, Timothy Knight; Nemecek, Stanislav; Nemethy, Peter; Nepomuceno, Andre Asevedo; Nessi, Marzio; Neubauer, Mark; Neusiedl, Andrea; Neves, Ricardo; Nevski, Pavel; Newcomer, Mitchel; Nickerson, Richard; Nicolaidou, Rosy; Nicolas, Ludovic; Nicoletti, Giovanni; Nicquevert, Bertrand; Niedercorn, Francois; Nielsen, Jason; Nikiforov, Andriy; Nikolaev, Kirill; Nikolic-Audit, Irena; Nikolopoulos, Konstantinos; Nilsen, Henrik; Nilsson, Paul; Nisati, Aleandro; Nishiyama, Tomonori; Nisius, Richard; Nodulman, Lawrence; Nomachi, Masaharu; Nomidis, Ioannis; Nordberg, Markus; Nordkvist, Bjoern; Notz, Dieter; Novakova, Jana; Nozaki, Mitsuaki; Nožička, Miroslav; Nugent, Ian Michael; Nuncio-Quiroz, Adriana-Elizabeth; Nunes Hanninger, Guilherme; Nunnemann, Thomas; Nurse, Emily; O'Neil, Dugan; O'Shea, Val; Oakham, Gerald; Oberlack, Horst; Ochi, Atsuhiko; Oda, Susumu; Odaka, Shigeru; Odier, Jerome; Ogren, Harold; Oh, Alexander; Oh, Seog; Ohm, Christian; Ohshima, Takayoshi; Ohshita, Hidetoshi; Ohsugi, Takashi; Okada, Shogo; Okawa, Hideki; Okumura, Yasuyuki; Okuyama, Toyonobu; Olchevski, Alexander; Oliveira, Miguel Alfonso; Oliveira Damazio, Denis; Oliver Garcia, Elena; Olivito, Dominick; Olszewski, Andrzej; Olszowska, Jolanta; Omachi, Chihiro; Onofre, António; Onyisi, Peter; Oram, Christopher; Oreglia, Mark; Oren, Yona; Orestano, Domizia; Orlov, Iliya; Oropeza Barrera, Cristina; Orr, Robert; Ortega, Eduardo; Osculati, Bianca; Ospanov, Rustem; Osuna, Carlos; Ottersbach, John; Ould-Saada, Farid; Ouraou, Ahmimed; Ouyang, Qun; Owen, Mark; Owen, Simon; Oyarzun, Alejandro; Ozcan, Veysi Erkcan; Ozone, Kenji; Ozturk, Nurcan; Pacheco Pages, Andres; Padilla Aranda, Cristobal; Paganis, Efstathios; Pahl, Christoph; Paige, Frank; Pajchel, Katarina; Palestini, Sandro; Pallin, Dominique; Palma, Alberto; Palmer, Jody; Pan, Yibin; Panagiotopoulou, Evgenia; Panes, Boris; Panikashvili, Natalia; Panitkin, Sergey; Pantea, Dan; Panuskova, Monika; Paolone, Vittorio; Papadopoulou, Theodora; Park, Su-Jung; Park, Woochun; Parker, Andy; Parodi, Fabrizio; Parsons, John; Parzefall, Ulrich; Pasqualucci, Enrico; Passeri, Antonio; Pastore, Fernanda; Pastore, Francesca; Pásztor , Gabriella; Pataraia, Sophio; Pater, Joleen; Patricelli, Sergio; Pauly, Thilo; Peak, Lawrence; Pecsy, Martin; Pedraza Morales, Maria Isabel; Peleganchuk, Sergey; Peng, Haiping; Penson, Alexander; Penwell, John; Perantoni, Marcelo; Perez, Kerstin; Perez Codina, Estel; Pérez García-Estañ, María Teresa; Perez Reale, Valeria; Perini, Laura; Pernegger, Heinz; Perrino, Roberto; Persembe, Seda; Perus, Antoine; Peshekhonov, Vladimir; Petersen, Brian; Petersen, Troels; Petit, Elisabeth; Petridou, Chariclia; Petrolo, Emilio; Petrucci, Fabrizio; Petschull, Dennis; Petteni, Michele; Pezoa, Raquel; Phan, Anna; Phillips, Alan; Phillips, Peter William; Piacquadio, Giacinto; Piccinini, Maurizio; Piegaia, Ricardo; Pilcher, James; Pilkington, Andrew; Pina, João Antonio; Pinamonti, Michele; Pinfold, James; Pinto, Belmiro; Pizio, Caterina; Placakyte, Ringaile; Plamondon, Mathieu; Pleier, Marc-Andre; Poblaguev, Andrei; Poddar, Sahill; Podlyski, Fabrice; Poggioli, Luc; Pohl, Martin; Polci, Francesco; Polesello, Giacomo; Policicchio, Antonio; Polini, Alessandro; Poll, James; Polychronakos, Venetios; Pomeroy, Daniel; Pommès, Kathy; Ponsot, Patrick; Pontecorvo, Ludovico; Pope, Bernard; Popeneciu, Gabriel Alexandru; Popovic, Dragan; Poppleton, Alan; Popule, Jiri; Portell Bueso, Xavier; Porter, Robert; Pospelov, Guennady; Pospisil, Stanislav; Potekhin, Maxim; Potrap, Igor; Potter, Christina; Potter, Christopher; Potter, Keith; Poulard, Gilbert; Poveda, Joaquin; Prabhu, Robindra; Pralavorio, Pascal; Prasad, Srivas; Pravahan, Rishiraj; Pribyl, Lukas; Price, Darren; Price, Lawrence; Prichard, Paul; Prieur, Damien; Primavera, Margherita; Prokofiev, Kirill; Prokoshin, Fedor; Protopopescu, Serban; Proudfoot, James; Prudent, Xavier; Przysiezniak, Helenka; Psoroulas, Serena; Ptacek, Elizabeth; Purdham, John; Purohit, Milind; Puzo, Patrick; Pylypchenko, Yuriy; Qi, Ming; Qian, Jianming; Qian, Weiming; Qin, Zhonghua; Quadt, Arnulf; Quarrie, David; Quayle, William; Quinonez, Fernando; Raas, Marcel; Radeka, Veljko; Radescu, Voica; Radics, Balint; Rador, Tonguc; Ragusa, Francesco; Rahal, Ghita; Rahimi, Amir; Rajagopalan, Srinivasan; Rammensee, Michael; Rammes, Marcus; Rauscher, Felix; Rauter, Emanuel; Raymond, Michel; Read, Alexander Lincoln; Rebuzzi, Daniela; Redelbach, Andreas; Redlinger, George; Reece, Ryan; Reeves, Kendall; Reinherz-Aronis, Erez; Reinsch, Andreas; Reisinger, Ingo; Reljic, Dusan; Rembser, Christoph; Ren, Zhongliang; Renkel, Peter; Rescia, Sergio; Rescigno, Marco; Resconi, Silvia; Resende, Bernardo; Reznicek, Pavel; Rezvani, Reyhaneh; Richards, Alexander; Richter, Robert; Richter-Was, Elzbieta; Ridel, Melissa; Rijpstra, Manouk; Rijssenbeek, Michael; Rimoldi, Adele; Rinaldi, Lorenzo; Rios, Ryan Randy; Riu, Imma; Rizatdinova, Flera; Rizvi, Eram; Roa Romero, Diego Alejandro; Robertson, Steven; Robichaud-Veronneau, Andree; Robinson, Dave; Robinson, James; Robinson, Mary; Robson, Aidan; Rocha de Lima, Jose Guilherme; Roda, Chiara; Roda Dos Santos, Denis; Rodriguez, Diego; Rodriguez Garcia, Yohany; Roe, Shaun; Røhne, Ole; Rojo, Victoria; Rolli, Simona; Romaniouk, Anatoli; Romanov, Victor; Romeo, Gaston; Romero Maltrana, Diego; Roos, Lydia; Ros, Eduardo; Rosati, Stefano; Rosenbaum, Gabriel; Rosselet, Laurent; Rossetti, Valerio; Rossi, Leonardo Paolo; Rotaru, Marina; Rothberg, Joseph; Rousseau, David; Royon, Christophe; Rozanov, Alexander; Rozen, Yoram; Ruan, Xifeng; Ruckert, Benjamin; Ruckstuhl, Nicole; Rud, Viacheslav; Rudolph, Gerald; Rühr, Frederik; Ruggieri, Federico; Ruiz-Martinez, Aranzazu; Rumyantsev, Leonid; Rurikova, Zuzana; Rusakovich, Nikolai; Rutherfoord, John; Ruwiedel, Christoph; Ruzicka, Pavel; Ryabov, Yury; Ryan, Patrick; Rybkin, Grigori; Rzaeva, Sevda; Saavedra, Aldo; Sadrozinski, Hartmut; Sadykov, Renat; Safai Tehrani, Francesco; Sakamoto, Hiroshi; Salamanna, Giuseppe; Salamon, Andrea; Saleem, Muhammad; Salihagic, Denis; Salnikov, Andrei; Salt, José; Salvachua Ferrando, Belén; Salvatore, Daniela; Salvatore, Pasquale Fabrizio; Salvucci, Antonio; Salzburger, Andreas; Sampsonidis, Dimitrios; Samset, Björn Hallvard; Sandaker, Heidi; Sander, Heinz Georg; Sanders, Michiel; Sandhoff, Marisa; Sandhu, Pawan; Sandstroem, Rikard; Sandvoss, Stephan; Sankey, Dave; Sanny, Bernd; Sansoni, Andrea; Santamarina Rios, Cibran; Santoni, Claudio; Santonico, Rinaldo; Saraiva, João; Sarangi, Tapas; Sarkisyan-Grinbaum, Edward; Sarri, Francesca; Sasaki, Osamu; Sasao, Noboru; Satsounkevitch, Igor; Sauvage, Gilles; Savard, Pierre; Savine, Alexandre; Savinov, Vladimir; Sawyer, Lee; Saxon, David; Says, Louis-Pierre; Sbarra, Carla; Sbrizzi, Antonio; Scannicchio, Diana; Schaarschmidt, Jana; Schacht, Peter; Schäfer, Uli; Schaetzel, Sebastian; Schaffer, Arthur; Schaile, Dorothee; Schamberger, R.~Dean; Schamov, Andrey; Scharf, Veit; Schegelsky, Valery; Scheirich, Daniel; Schernau, Michael; Scherzer, Max; Schiavi, Carlo; Schieck, Jochen; Schioppa, Marco; Schlenker, Stefan; Schmidt, Evelyn; Schmieden, Kristof; Schmitt, Christian; Schmitz, Martin; Schöning, André; Schott, Matthias; Schouten, Doug; Schovancova, Jaroslava; Schram, Malachi; Schreiner, Alexander; Schroeder, Christian; Schroer, Nicolai; Schroers, Marcel; Schultes, Joachim; Schultz-Coulon, Hans-Christian; Schumacher, Jan; Schumacher, Markus; Schumm, Bruce; Schune, Philippe; Schwanenberger, Christian; Schwartzman, Ariel; Schwemling, Philippe; Schwienhorst, Reinhard; Schwierz, Rainer; Schwindling, Jerome; Scott, Bill; Searcy, Jacob; Sedykh, Evgeny; Segura, Ester; Seidel, Sally; Seiden, Abraham; Seifert, Frank; Seixas, José; Sekhniaidze, Givi; Seliverstov, Dmitry; Sellden, Bjoern; Semprini-Cesari, Nicola; Serfon, Cedric; Serin, Laurent; Seuster, Rolf; Severini, Horst; Sevior, Martin; Sfyrla, Anna; Shabalina, Elizaveta; Shamim, Mansoora; Shan, Lianyou; Shank, James; Shao, Qi Tao; Shapiro, Marjorie; Shatalov, Pavel; Shaw, Kate; Sherman, Daniel; Sherwood, Peter; Shibata, Akira; Shimojima, Makoto; Shin, Taeksu; Shmeleva, Alevtina; Shochet, Mel; Shupe, Michael; Sicho, Petr; Sidoti, Antonio; Siegert, Frank; Siegrist, James; Sijacki, Djordje; Silbert, Ohad; Silver, Yiftah; Silverstein, Daniel; Silverstein, Samuel; Simak, Vladislav; Simic, Ljiljana; Simion, Stefan; Simmons, Brinick; Simonyan, Margar; Sinervo, Pekka; Sinev, Nikolai; Sipica, Valentin; Siragusa, Giovanni; Sisakyan, Alexei; Sivoklokov, Serguei; Sjölin, Jörgen; Sjursen, Therese; Skovpen, Kirill; Skubic, Patrick; Slater, Mark; Slavicek, Tomas; Sliwa, Krzysztof; Sloper, John erik; Smakhtin, Vladimir; Smirnov, Sergei; Smirnov, Yuri; Smirnova, Lidia; Smirnova, Oxana; Smith, Ben Campbell; Smith, Douglas; Smith, Kenway; Smizanska, Maria; Smolek, Karel; Snesarev, Andrei; Snow, Steve; Snow, Joel; Snuverink, Jochem; Snyder, Scott; Soares, Mara; Sobie, Randall; Sodomka, Jaromir; Soffer, Abner; Solans, Carlos; Solar, Michael; Solc, Jaroslav; Solfaroli Camillocci, Elena; Solodkov, Alexander; Solovyanov, Oleg; Sondericker, John; Sopko, Vit; Sopko, Bruno; Sosebee, Mark; Soukharev, Andrey; Spagnolo, Stefania; Spanò, Francesco; Spighi, Roberto; Spigo, Giancarlo; Spila, Federico; Spiwoks, Ralf; Spousta, Martin; Spreitzer, Teresa; Spurlock, Barry; St. Denis, Richard Dante; Stahl, Thorsten; Stahlman, Jonathan; Stamen, Rainer; Stancu, Stefan Nicolae; Stanecka, Ewa; Stanek, Robert; Stanescu, Cristian; Stapnes, Steinar; Starchenko, Evgeny; Stark, Jan; Staroba, Pavel; Starovoitov, Pavel; Stastny, Jan; Stavina, Pavel; Steele, Genevieve; Steinbach, Peter; Steinberg, Peter; Stekl, Ivan; Stelzer, Bernd; Stelzer, Harald Joerg; Stelzer-Chilton, Oliver; Stenzel, Hasko; Stevenson, Kyle; Stewart, Graeme; Stockton, Mark; Stoerig, Kathrin; Stoicea, Gabriel; Stonjek, Stefan; Strachota, Pavel; Stradling, Alden; Straessner, Arno; Strandberg, Jonas; Strandberg, Sara; Strandlie, Are; Strauss, Michael; Strizenec, Pavol; Ströhmer, Raimund; Strom, David; Stroynowski, Ryszard; Strube, Jan; Stugu, Bjarne; Sturm, Philipp; Su, Dong; Soh, Dart-yin; Sugaya, Yorihito; Sugimoto, Takuya; Suhr, Chad; Suk, Michal; Sulin, Vladimir; Sultansoy, Saleh; Sumida, Toshi; Sun, Xiaohu; Sundermann, Jan Erik; Suruliz, Kerim; Sushkov, Serge; Susinno, Giancarlo; Sutton, Mark; Suzuki, Takuya; Suzuki, Yu; Sykora, Ivan; Sykora, Tomas; Szymocha, Tadeusz; Sánchez, Javier; Ta, Duc; Tackmann, Kerstin; Taffard, Anyes; Tafirout, Reda; Taga, Adrian; Takahashi, Yuta; Takai, Helio; Takashima, Ryuichi; Takeda, Hiroshi; Takeshita, Tohru; Talby, Mossadek; Talyshev, Alexey; Tamsett, Matthew; Tanaka, Junichi; Tanaka, Reisaburo; Tanaka, Satoshi; Tanaka, Shuji; Tapprogge, Stefan; Tardif, Dominique; Tarem, Shlomit; Tarrade, Fabien; Tartarelli, Giuseppe Francesco; Tas, Petr; Tasevsky, Marek; Tassi, Enrico; Tatarkhanov, Mous; Taylor, Christopher; Taylor, Frank; Taylor, Geoffrey; Taylor, Ryan P.; Taylor, Wendy; Teixeira-Dias, Pedro; Ten Kate, Herman; Teng, Ping-Kun; Tennenbaum-Katan, Yaniv-David; Terada, Susumu; Terashi, Koji; Terron, Juan; Terwort, Mark; Testa, Marianna; Teuscher, Richard; Therhaag, Jan; Thioye, Moustapha; Thoma, Sascha; Thomas, Juergen; Thompson, Stan; Thompson, Emily; Thompson, Peter; Thompson, Paul; Thompson, Ray; Thomson, Evelyn; Thun, Rudolf; Tic, Tomas; Tikhomirov, Vladimir; Tikhonov, Yury; Tipton, Paul; Tique Aires Viegas, Florbela De Jes; Tisserant, Sylvain; Toczek, Barbara; Todorov, Theodore; Todorova-Nova, Sharka; Toggerson, Brokk; Tojo, Junji; Tokár, Stanislav; Tokushuku, Katsuo; Tollefson, Kirsten; Tomasek, Lukas; Tomasek, Michal; Tomoto, Makoto; Tompkins, Lauren; Toms, Konstantin; Tonoyan, Arshak; Topfel, Cyril; Topilin, Nikolai; Torchiani, Ingo; Torrence, Eric; Torró Pastor, Emma; Toth, Jozsef; Touchard, Francois; Tovey, Daniel; Trefzger, Thomas; Tremblet, Louis; Tricoli, Alesandro; Trigger, Isabel Marian; Trincaz-Duvoid, Sophie; Trinh, Thi Nguyet; Tripiana, Martin; Triplett, Nathan; Trischuk, William; Trivedi, Arjun; Trocmé, Benjamin; Troncon, Clara; Trzupek, Adam; Tsarouchas, Charilaos; Tseng, Jeffrey; Tsiakiris, Menelaos; Tsiareshka, Pavel; Tsionou, Dimitra; Tsipolitis, Georgios; Tsiskaridze, Vakhtang; Tskhadadze, Edisher; Tsukerman, Ilya; Tsulaia, Vakhtang; Tsung, Jieh-Wen; Tsuno, Soshi; Tsybychev, Dmitri; Tuggle, Joseph; Turecek, Daniel; Turk Cakir, Ilkay; Turlay, Emmanuel; Tuts, Michael; Twomey, Matthew Shaun; Tylmad, Maja; Tyndel, Mike; Uchida, Kirika; Ueda, Ikuo; Ueno, Ryuichi; Ugland, Maren; Uhlenbrock, Mathias; Uhrmacher, Michael; Ukegawa, Fumihiko; Unal, Guillaume; Undrus, Alexander; Unel, Gokhan; Unno, Yoshinobu; Urbaniec, Dustin; Urkovsky, Evgeny; Urquijo, Phillip; Urrejola, Pedro; Usai, Giulio; Uslenghi, Massimiliano; Vacavant, Laurent; Vacek, Vaclav; Vachon, Brigitte; Vahsen, Sven; Valente, Paolo; Valentinetti, Sara; Valkar, Stefan; Valladolid Gallego, Eva; Vallecorsa, Sofia; Valls Ferrer, Juan Antonio; Van Berg, Richard; van der Graaf, Harry; van der Kraaij, Erik; van der Poel, Egge; van der Ster, Daniel; van Eldik, Niels; van Gemmeren, Peter; van Kesteren, Zdenko; van Vulpen, Ivo; Vandelli, Wainer; Vaniachine, Alexandre; Vankov, Peter; Vannucci, Francois; Vari, Riccardo; Varnes, Erich; Varouchas, Dimitris; Vartapetian, Armen; Varvell, Kevin; Vasilyeva, Lidia; Vassilakopoulos, Vassilios; Vazeille, Francois; Vellidis, Constantine; Veloso, Filipe; Veneziano, Stefano; Ventura, Andrea; Ventura, Daniel; Venturi, Manuela; Venturi, Nicola; Vercesi, Valerio; Verducci, Monica; Verkerke, Wouter; Vermeulen, Jos; Vetterli, Michel; Vichou, Irene; Vickey, Trevor; Viehhauser, Georg; Villa, Mauro; Villani, Giulio; Villaplana Perez, Miguel; Vilucchi, Elisabetta; Vincter, Manuella; Vinek, Elisabeth; Vinogradov, Vladimir; Viret, Sébastien; Virzi, Joseph; Vitale , Antonio; Vitells, Ofer; Vivarelli, Iacopo; Vives Vaque, Francesc; Vlachos, Sotirios; Vlasak, Michal; Vlasov, Nikolai; Vogel, Adrian; Vokac, Petr; Volpi, Matteo; von der Schmitt, Hans; von Loeben, Joerg; von Radziewski, Holger; von Toerne, Eckhard; Vorobel, Vit; Vorwerk, Volker; Vos, Marcel; Voss, Rudiger; Voss, Thorsten Tobias; Vossebeld, Joost; Vranjes, Nenad; Vranjes Milosavljevic, Marija; Vrba, Vaclav; Vreeswijk, Marcel; Vu Anh, Tuan; Vudragovic, Dusan; Vuillermet, Raphael; Vukotic, Ilija; Wagner, Peter; Walbersloh, Jorg; Walder, James; Walker, Rodney; Walkowiak, Wolfgang; Wall, Richard; Wang, Chiho; Wang, Haichen; Wang, Jin; Wang, Song-Ming; Warburton, Andreas; Ward, Patricia; Warsinsky, Markus; Wastie, Roy; Watkins, Peter; Watson, Alan; Watson, Miriam; Watts, Gordon; Watts, Stephen; Waugh, Anthony; Waugh, Ben; Weber, Marc; Weber, Manuel; Weber, Michele; Weber, Pavel; Weidberg, Anthony; Weingarten, Jens; Weiser, Christian; Wellenstein, Hermann; Wells, Phillippa; Wenaus, Torre; Wendler, Shanti; Wengler, Thorsten; Wenig, Siegfried; Wermes, Norbert; Werner, Matthias; Werner, Per; Werth, Michael; Werthenbach, Ulrich; Wessels, Martin; Whalen, Kathleen; White, Andrew; White, Martin; White, Sebastian; Whitehead, Samuel Robert; Whiteson, Daniel; Whittington, Denver; Wicek, Francois; Wicke, Daniel; Wickens, Fred; Wiedenmann, Werner; Wielers, Monika; Wienemann, Peter; Wiglesworth, Craig; Wiik, Liv Antje Mari; Wildauer, Andreas; Wildt, Martin Andre; Wilkens, Henric George; Williams, Eric; Williams, Hugh; Willocq, Stephane; Wilson, John; Wilson, Michael Galante; Wilson, Alan; Wingerter-Seez, Isabelle; Winklmeier, Frank; Wittgen, Matthias; Wolter, Marcin Wladyslaw; Wolters, Helmut; Wosiek, Barbara; Wotschack, Jorg; Woudstra, Martin; Wraight, Kenneth; Wright, Catherine; Wright, Dennis; Wrona, Bozydar; Wu, Sau Lan; Wu, Xin; Wulf, Evan; Wynne, Benjamin; Xaplanteris, Leonidas; Xella, Stefania; Xie, Song; Xu, Da; Xu, Neng; Yamada, Miho; Yamamoto, Akira; Yamamoto, Kyoko; Yamamoto, Shimpei; Yamamura, Taiki; Yamaoka, Jared; Yamazaki, Takayuki; Yamazaki, Yuji; Yan, Zhen; Yang, Haijun; Yang, Un-Ki; Yang, Zhaoyu; Yao, Weiming; Yao, Yushu; Yasu, Yoshiji; Ye, Jingbo; Ye, Shuwei; Yilmaz, Metin; Yoosoofmiya, Reza; Yorita, Kohei; Yoshida, Riktura; Young, Charles; Youssef, Saul; Yu, Dantong; Yu, Jaehoon; Yuan, Li; Yurkewicz, Adam; Zaidan, Remi; Zaitsev, Alexander; Zajacova, Zuzana; Zambrano, Valentina; Zanello, Lucia; Zaytsev, Alexander; Zeitnitz, Christian; Zeller, Michael; Zemla, Andrzej; Zendler, Carolin; Zenin, Oleg; Zenis, Tibor; Zenonos, Zenonas; Zenz, Seth; Zerwas, Dirk; Zevi della Porta, Giovanni; Zhan, Zhichao; Zhang, Huaqiao; Zhang, Jinlong; Zhang, Qizhi; Zhang, Xueyao; Zhao, Long; Zhao, Tianchi; Zhao, Zhengguo; Zhemchugov, Alexey; Zhong, Jiahang; Zhou, Bing; Zhou, Ning; Zhou, Yue; Zhu, Cheng Guang; Zhu, Hongbo; Zhu, Yingchun; Zhuang, Xuai; Zhuravlov, Vadym; Zimmermann, Robert; Zimmermann, Simone; Zimmermann, Stephanie; Ziolkowski, Michael; Zivkovic, Lidija; Zobernig, Georg; Zoccoli, Antonio; zur Nedden, Martin; Zutshi, Vishnu

    2010-01-01

    The ATLAS Inner Detector is a composite tracking system consisting of silicon pixels, silicon strips and straw tubes in a 2 T magnetic field. Its installation was completed in August 2008 and the detector took part in data- taking with single LHC beams and cosmic rays. The initial detector operation, hardware commissioning and in-situ calibrations are described. Tracking performance has been measured with 7.6 million cosmic-ray events, collected using a tracking trigger and reconstructed with modular pattern-recognition and fitting software. The intrinsic hit efficiency and tracking trigger efficiencies are close to 100%. Lorentz angle measurements for both electrons and holes, specific energy-loss calibration and transition radiation turn-on measurements have been performed. Different alignment techniques have been used to reconstruct the detector geometry. After the initial alignment, a transverse impact parameter resolution of 22.1+/-0.9 {\\mu}m and a relative momentum resolution {\\sigma}p/p = (4.83+/-0.16)...

  17. Propagation Properties of Dark Hollow Beams in Linear Gain and Loss Media%空心光束在损耗和增益介质中的传输特性

    Institute of Scientific and Technical Information of China (English)

    朱焯炜; 赵琳琳; 苏宙平

    2011-01-01

    Based on the definition of complex wave number and the generalized Huygens-Fresnel diffraction integral,the closed-form propagation equation of Dark hollow beams passing through a paraxial optical ABCD system is derived. The beam-width propagation formula of Dark hollow beams through absorption media are obtained on the basis of the second-order moment method. By numerical analysis,the intensity distributions and beams waist width have been studied. The results show that, the dark hollow beams propagation in linear gain or loss media,when the media property is gain (loss) ,it will heighten (lower) the intensity;but it has little effect on the beams waist width.%从复数波数定义和广义惠更斯-菲涅尔积分出发,推导出空心光束在介质中通过旁轴ABCD光学系统后的一般传输公式.在此基础上,结合光强二阶矩方法,给出了相应的一般束宽变换公式.通过数值分析研究了介质传输场中强度分布和均方根束宽的变化特点.研究结果表明,空心光束在增益或者损耗介质中传输时,当其为增益(损耗)介质时,会增强(衰减)光束的强度;但对均方根束宽却没有太大的影响.

  18. Analog Front End Circuit Design of CSNS Beam Loss Monitor System%CSNS 束流损失监测系统前端模拟电路设计

    Institute of Scientific and Technical Information of China (English)

    肖帅; 郭娴; 田建民; 曾磊; 徐韬光; 傅世年

    2013-01-01

    中国散裂中子源(CSNS)束流损失监测系统利用气体电离室来探测束流损失,电离室输出信号需在前端模拟电路中进行信号处理。本工作自主设计开发了束流损失测量系统前端模拟电路,采用跨导放大的方式实现了低重复频率、低占空比、弱电离室信号的电流-电压(I-V )变换测量。同时,电路还实现了对较大束流损失的快速响应,保障加速器设备的安全运行。联机测试结果表明,该电路满足系统要求。%The China Spallation Neutron Source (CSNS) beam loss monitor system uses gas ionization chamber to detect beam losses . The output signals from ionization chamber need to be processed in the analog front end circuit ,which has been designed and developed independently .The way of transimpedance amplifier was used to achieve current-voltage (I-V ) conversion measurement of signal with low repetition rate ,low duty cycle and low amplitude .The analog front end circuit also realized rapid response to the larger beam loss in order to protect the safe operation of the accelerator equipment . The testing results show that the analog front end circuit meets the requirements of beam loss monitor system .

  19. Calibration services for medical applications of radiation

    Energy Technology Data Exchange (ETDEWEB)

    DeWerd, L.A.

    1993-12-31

    Calibration services for the medical community applications of radiation involve measuring radiation precisely and having traceability to the National Institute of Standards and Technology (NIST). Radiation therapy applications involve the use of ionization chambers and electrometers for external beams and well-type ionization chamber systems as well as radioactive sources for brachytherapy. Diagnostic x-ray applications involve ionization chamber systems and devices to measure other parameters of the x-ray machine, such as non-invasive kVp meters. Calibration laboratories have been established to provide radiation calibration services while maintaining traceability to NIST. New radiation applications of the medical community spur investigation to provide the future calibration needs.

  20. Simulations of beam-beam and beam-wire interactions in RHIC

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung J.; Sen, Tanaji; /Fermilab; Abreu, Natalia P.; Fischer, Wolfram; /Brookhaven

    2009-02-01

    The beam-beam interaction is one of the dominant sources of emittance growth and luminosity lifetime deterioration. A current carrying wire has been proposed to compensate long-range beam-beam effects in the LHC and strong localized long-range beam-beam effects are experimentally investigated in the RHIC collider. Tune shift, beam transfer function, and beam loss rate are measured in dedicated experiments. In this paper, they report on simulations to study the effect of beam-wire interactions based on diffusive apertures, beam loss rates, and beam transfer function using a parallelized weak-strong beam simulation code (BBSIMC). The simulation results are compared with measurements performed in RHIC during 2007 and 2008.

  1. 预应力混凝土后张梁孔道摩阻损失试验分析%Research on the Experiment Test of Frictional Resistance Loss in Post-tensioning Pre-stressed Concrete Beam Pipe

    Institute of Scientific and Technical Information of China (English)

    叶恒梅

    2016-01-01

    The loss of frictional resistance in post -tesioning pre-stressed concrete beam pipe is a big problem during the construction of post-tesioning pre-stressed concrete bridge. The test of frictional resistance loss is important to the quality security and persistence of bridge construction. The formula of beam pipe frictional resistance loss co-effi-cient was calculated by least square method. This formula was applied on the xianhu bridge construction ,then the project of frictional resistance loss test of beam pipe was proposed to reduce the loss of pre-stress and analyze the practical data in the xianhu bridge construction.%在后张法预应力混凝土桥梁结构的建设中,预应力孔道摩阻损失问题十分突出。孔道摩阻测试对确保桥梁结构的施工质量、安全性和耐久性有着重要意义。以仙葫大桥为例,在公式分析的基础上结合最小二乘法原理,推导出孔道摩阻参数的计算公式,为减少预应力损失,提出了孔道摩阻试验检测的方案,同时对该桥现场测试数据进行了计算和分析。研究结果可为同类施工提供参考。

  2. A Study on SNR Loss of Beam Forming Resulted from Several Factors%影响波束合成信噪比若干因素的研究

    Institute of Scientific and Technical Information of China (English)

    朱新国; 张凯

    2012-01-01

    Considering the signal noise ration (SNR) loss of beam forming in practice, the SNR gain of digital beam forming is de-rivated under the ideal case in this paper. The factors of channel failure, amplitude weighting and amplitude-phase error, which can cause SNR performance deterioration of beam forming, are respectively studied, and the analytical expression of SNR loss is derivated. The simulation results indicate that it is approximately linear dependency between SNR loss and channel failure when the percent of disabled channel is below 30%; the SNR loss resulted from the simultaneous existence of channel failure, amplitude weighting and amplitude-phase error is approximately the sum of SNR loss resulted from them respetively.%针对实际工作中波束合成性能下降的问题,推导了理想情况下数字波束合成信噪比相对输入信噪比的增益,研究了通道失效、幅度加权和幅相误差分别对波束合成信噪比的影响,并推导了信噪比损失的解析式.理论分析和仿真结果表明:在失效通道比例小于30%的条件下,信噪比损失与失效通道比例近似成线性关系;在同时存在通道失效、幅度加权和幅相误差的条件下,信噪比损失近似等于通道失效、幅度加权和幅相误差各自引入的信噪比损失之和.

  3. Using cone beam computed tomography to detect the relationship between the periodontal bone loss and mucosal thickening of the maxillary sinus

    Directory of Open Access Journals (Sweden)

    Mahnaz Sheikhi

    2014-01-01

    Full Text Available Background: Maxillary sinuses are covered by a 1 mm thick mucous membrane that when this membrane becomes inflamed, the thickness may increase 10-15 times. The common causes of odontogenic sinusitis are dental abscesses and periodontal disease. Computed tomography (CT is considered the gold standard for sinus diagnosis. Recently, cone beam computed tomography (CBCT has been introduced for dental and maxillofacial imaging, which has several advantages over traditional CT, including lower radiation dose and chairside process. This study aims to find the association between mucosal thickening (MT of the sinus and periodontal bone loss (PBL and pulpoperiapical condition. Materials and Methods: A total of 180 CBCT images were reviewed. PBL was assessed in six points under each sinus at the mesial and distal sides of the upper second premolar and first and second molars by measuring the distance from the alveolar crest to the point 2 mm under the cemento-enamel junction (CEJ. The MT was assessed at six points in the floor of the sinus precisely over the mentioned points. To assess the possible role of pulpoperiapical condition on the sinus MT, the existing teeth were classified into five groups due to the probable effect of each condition on the pulp and peri-apex. The statistical association between MT of sinus and PBL and pulpoperiapical condition was assessed using SPSS software (SPSS Inc., version 16.0, Chicago, IL, USA and bivariate correlation and binary linear regression statistical tests (P < 0.05. Results: MT was observed in 39.4% of patients (mean = 4.68 ± 5.25 mm. PBL was seen in 33% of the patients (mean = 1.87 ± 1.63 mm. Linear regression test showed that there is an association between both PBL and pulpoperiapical condition and MT, but the effect of PBL was about 4 times stronger. Conclusion: This study showed that MT of the maxillary sinus was common among patients with PBL and MT of the maxillary sinus was significantly associated

  4. Evaluation of the energy dependence of ionization chambers pencil type calibrated beam tomography standards; Avaliacao da dependencia energetica de camaras de ionizacao do tipo lapis calibradas em feixes padroes de tomografia

    Energy Technology Data Exchange (ETDEWEB)

    Fontes, Ladyjane Pereira; Potiens, Maria da Penha A., E-mail: lpfontes@ipen.br [Instituto de Pesquisas Energeticas e Nucleres (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    The Instrument Calibration Laboratory of IPEN (LCI - IPEN) performs calibrations of pencil-type ionization chambers (IC) used in measures of dosimetric survey on clinical systems of Computed Tomography (CT). Many users make mistakes when using a calibrated ionization chamber in their CT dosimetry systems. In this work a methodology for determination of factors of correction for quality (Kq) through the calibration curve that is specific for each ionization chamber was established. Furthermore, it was possible to demonstrate the energy dependence on an pencil-type Ionization Chamber(IC) calibrated at the LCI - IPEN. (author)

  5. Muon Energy Calibration of the MINOS Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Paul S.

    2004-09-01

    MINOS is a long-baseline neutrino oscillation experiment designed to search for conclusive evidence of neutrino oscillations and to measure the oscillation parameters precisely. MINOS comprises two iron tracking calorimeters located at Fermilab and Soudan. The Calibration Detector at CERN is a third MINOS detector used as part of the detector response calibration programme. A correct energy calibration between these detectors is crucial for the accurate measurement of oscillation parameters. This thesis presents a calibration developed to produce a uniform response within a detector using cosmic muons. Reconstruction of tracks in cosmic ray data is discussed. This data is utilized to calculate calibration constants for each readout channel of the Calibration Detector. These constants have an average statistical error of 1.8%. The consistency of the constants is demonstrated both within a single run and between runs separated by a few days. Results are presented from applying the calibration to test beam particles measured by the Calibration Detector. The responses are calibrated to within 1.8% systematic error. The potential impact of the calibration on the measurement of oscillation parameters by MINOS is also investigated. Applying the calibration reduces the errors in the measured parameters by {approx} 10%, which is equivalent to increasing the amount of data by 20%.

  6. Muon Energy Calibration of the MINOS Detectors

    Energy Technology Data Exchange (ETDEWEB)

    Miyagawa, Paul S. [Somerville College, Oxford (United Kingdom)

    2004-01-01

    MINOS is a long-baseline neutrino oscillation experiment designed to search for conclusive evidence of neutrino oscillations and to measure the oscillation parameters precisely. MINOS comprises two iron tracking calorimeters located at Fermilab and Soudan. The Calibration Detector at CERN is a third MINOS detector used as part of the detector response calibration programme. A correct energy calibration between these detectors is crucial for the accurate measurement of oscillation parameters. This thesis presents a calibration developed to produce a uniform response within a detector using cosmic muons. Reconstruction of tracks in cosmic ray data is discussed. This data is utilized to calculate calibration constants for each readout channel of the Calibration Detector. These constants have an average statistical error of 1.8%. The consistency of the constants is demonstrated both within a single run and between runs separated by a few days. Results are presented from applying the calibration to test beam particles measured by the Calibration Detector. The responses are calibrated to within 1.8% systematic error. The potential impact of the calibration on the measurement of oscillation parameters by MINOS is also investigated. Applying the calibration reduces the errors in the measured parameters by ~ 10%, which is equivalent to increasing the amount of data by 20%.

  7. The accident of overexposure at the University hospital center of Toulouse. Expertise report n.1. Checking of experimental protocols of micro-beams calibration before and after dysfunction correction; L'accident de surexposition au centre hospitalier universitaire de Toulouse. Rapport d'expertise n.1. Verification des protocoles experimentaux d'etalonnage des microfaisceaux avant et apres correction du dysfonctionnement

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    The regional center of stereotaxic radiosurgery of the University hospital center of Toulouse is equipped since april 2006 of a Novalis accelerator (Brainlab) devoted to the intra-skull stereotaxic radiosurgery. In april 2007, during an intercomparison of dosimetry computer files coming from different sites, the Brainlab society finds an anomaly in the files. The analysis made by the society concludes to to the use of an inappropriate detector for the measurement of a dosimetry parameter during the initial calibration of the accelerator. following this error, 145 patients (on the 172 treated by the service in question) suffer the consequences of an overdose whom importance is variable according the cases. The I.R.S.N. in charge of an expertise about the protocols of calibration of micro-beams before and after the correction of the dysfunction, took up with the search of the technical causes of the dysfunction. This report presents successively: the documents base on which is founded the expertise; the material of dosimetry and quality control necessary to the initial calibration of the device and to its follow-up; the formula made at the accelerator commissioning; the calibration of micro-beams in the two configurations that allows the device (micro-multi-knives and conic collimator) and the definition of parameters of the software of treatment planning; the maintenance and quality control implemented in the frame of its clinical use. (N.C.)

  8. Reliability of the beam loss monitors system for the large hadron collider at CERN; Fiabilite du systeme des moniteurs de pertes du faisceau pour le Large Hadron Collider au CERN

    Energy Technology Data Exchange (ETDEWEB)

    Guaglio, G

    2005-12-15

    The energy stored in the Large Hadron Collider is unprecedented. The impact of the beam particles can cause severe damage on the superconductive magnets, resulting in significant downtime for repairing. The Beam Loss Monitors System (BLMS) detects the secondary particles shower of the lost beam particles and initiates the extraction of the beam before any serious damage to the equipment can occur. This thesis defines the BLMS specifications in term of reliability. The main goal is the design of a system minimizing both the probability to not detect a dangerous loss and the number of false alarms generated. The reliability theory and techniques utilized are described. The prediction of the hazard rates, the testing procedures, the Failure Modes Effects and Criticalities Analysis and the Fault Tree Analysis have been used to provide an estimation of the probability to damage a magnet, of the number of false alarms and of the number of generated warnings. The weakest components in the BLMS have been pointed out. The reliability figures of the BLMS have been calculated using a commercial software package (Isograph.). The effect of the variation of the parameters on the obtained results has been evaluated with a sensitivity analysis. The reliability model has been extended by the results of radiation tests. Design improvements, like redundant optical transmission, have been implemented in an iterative process. The proposed system is compliant with the reliability requirements. The model uncertainties are given by the limited knowledge of the thresholds levels of the superconductive magnets and of the locations of the losses along the ring. The implemented model allows modifications of the system, following the measuring of the hazard rates during the LHC life. It can also provide reference numbers to other accelerators which will implement similar technologies. (author)

  9. A new method for cone beam CT measurements of cyst of jaw bone loss%锥体束CT测量颌骨囊肿骨量缺失的新方法

    Institute of Scientific and Technical Information of China (English)

    张冬梅; 李锐; 李晓燕; 常平

    2015-01-01

    目的:探讨利用锥体束CT预测颌骨囊肿骨量缺失的新方法。方法:随机选取我院接诊的颌骨囊肿患者作为研究对象,拍摄锥体束CT,利用eXamVision软件进行测量,采用公式V=X*Y*Z对颌骨骨量缺失进行预测。结果:该方法所得数据能近似得出颌骨囊肿骨量缺失体积。结论:对颌骨囊肿缺失骨量的术前预测有助于术中植骨及手术方案的选择,锥体束CT能较准确的预测骨量的缺失体积,具有较好的临床指导意义。%Objective To study a new method for prediction of cyst of jaw bone loss by cone beam CT. Methods Random selection of jaw cyst patients as the research object, shooting cone beam CT,were measured using the eXamVision software, using the formula V=X*Y*Z to predict bone loss. Results The data from this method can approximate the missing volume of jaw cyst. Conclusion Contribute to bone grafting and operation scheme for the prediction of cyst of jaw bone loss of the preoperative selection. Cone beam CT can predict accurately the loss of bone volume, has better clinical directive significance.

  10. Characterisation of a protection level Am-241 calibration source

    Science.gov (United States)

    Bass, G. A.; Rossiter, M. J.; Williams, T. T.

    1992-11-01

    The various measurements involved in the commissioning process of an Am-241 radioactive source and transport mechanisms to be used for protection level calibration work are detailed. The source and its handling mechanisms are described and measurements to characterize the resultant gamma ray beam are described. For the beam measurements, the inverse square law is investigated and beam uniformity is assessed. A trial calibration of ionization chambers is described. The Am-241 irradiation facility is concluded to be suitable for calibrating secondary standards as part of the calibration service offered for protection level instruments. The umbra part of beam is acceptably uniform for a range of chambers and the measurements obtained were predictable and consistent. This quality will be added to the range of qualities offered as part of the protection level secondary standard calibration service.

  11. Design and Calibration of a Cryogenic Blackbody Calibrator at Centimeter Wavelengths

    CERN Document Server

    Kogut, A J; Fixsen, D J; Limon, M; Mirel, P G A; Levin, S; Seiffert, M; Lubin, P M

    2004-01-01

    We describe the design and calibration of an external cryogenic blackbody calibrator used for the first two flights of the Absolute Radiometer for Cosmology, Astrophysics, and Diffuse Emission (ARCADE) instrument. The calibrator consists of a microwave absorber weakly coupled to a superfluid liquid helium bath. Half-wave corrugations viewed 30 deg off axis reduce the return loss below -35 dB. Ruthenium oxide resistive thermometers embedded within the absorber monitor the temperature across the face of the calibrator. The thermal calibration transfers the calibration of a reference thermometer to the flight thermometers using the flight thermometer readout system. Data taken near the superfluid transition in 8 independent calibrations 4 years apart agree within 0.3 mK, providing an independent verification of the thermometer calibration at temperatures near that of the cosmic microwave background.

  12. Redundancy Calibration of Phased Array Stations

    CERN Document Server

    Noorishad, Parisa; van Ardenne, Arnold; van der Hulst, Thijs

    2012-01-01

    Our aim is to assess the benefits and limitations of using the redundant visibility information in regular phased array systems for improving the calibration. Regular arrays offer the possibility to use redundant visibility information to constrain the calibration of the array independent of a sky model and a beam models of the station elements. It requires a regular arrangement in the configuration of array elements and identical beam patterns. We revised a calibration method for phased array stations using the redundant visibility information in the system and applied it successfully to a LOFAR station. The performance and limitations of the method were demonstrated by comparing its use on real and simulated data. The main limitation is the mutual coupling between the station elements, which leads to non-identical beams and stronger baseline dependent noise. Comparing the variance of the estimated complex gains with the Cramer-Rao Bound (CRB) indicates that redundancy is a stable and optimum method for cali...

  13. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina

    2016-05-02

    This poster presents the development, implementation, and operation of the Broadband Outdoor Radiometer Calibrations (BORCAL) Longwave (LW) system at the Southern Great Plains Radiometric Calibration Facility for the calibration of pyrgeometers that provide traceability to the World Infrared Standard Group.

  14. Calibration of sound calibrators: an overview

    Science.gov (United States)

    Milhomem, T. A. B.; Soares, Z. M. D.

    2016-07-01

    This paper presents an overview of calibration of sound calibrators. Initially, traditional calibration methods are presented. Following, the international standard IEC 60942 is discussed emphasizing parameters, target measurement uncertainty and criteria for conformance to the requirements of the standard. Last, Regional Metrology Organizations comparisons are summarized.

  15. Measurements of the luminosity and normalised beam-induced background using the CMS Fast Beam Condition Monitor

    CERN Document Server

    Odell, Nathaniel Jay

    2012-01-01

    The CMS Beam Conditions and Radiation Monitoring system (BRM) is installed to protect the CMS detector from high beam losses and to provide feedback to the LHC and CMS on the beam conditions. The Fast Beam Condition Monitor (BCM1F), one of the sub-detectors in the BRM system, is installed inside the pixel volume close to the beam pipe and consists of two planes of 4 modules each located 1.8 m away from the IP, on both ends. It uses single-crystal CVD diamond sensors, radiation hard front-end electronics and an optical transmission of the signal. It is designed for single particle rate measurements, detecting both machine induced beam background and collision products on a bunch-by-bunch basis. Presented is the implementation of the normalized online beam-induced background measurement and the online instantaneous luminosity measurement. The method for determining the luminosity from the measured rates, including the absolute calibration using the Van der Meer scan, and the measurement performance will be d...

  16. Combined crossed molecular beam and ab initio investigation of the multichannel reaction of boron monoxide (BO; X2Σ+) with Propylene (CH3CHCH2; X1A'): competing atomic hydrogen and methyl loss pathways.

    Science.gov (United States)

    Maity, Surajit; Dangi, Beni B; Parker, Dorian S N; Kaiser, Ralf I; An, Yi; Sun, Bing-Jian; Chang, A H H

    2014-10-16

    The reaction dynamics of boron monoxide ((11)BO; X(2)Σ(+)) with propylene (CH(3)CHCH(2); X(1)A') were investigated under single collision conditions at a collision energy of 22.5 ± 1.3 kJ mol(-1). The crossed molecular beam investigation combined with ab initio electronic structure and statistical (RRKM) calculations reveals that the reaction follows indirect scattering dynamics and proceeds via the barrierless addition of boron monoxide radical with its radical center located at the boron atom. This addition takes place to either the terminal carbon atom (C1) and/or the central carbon atom (C2) of propylene reactant forming (11)BOC(3)H(6) intermediate(s). The long-lived (11)BOC(3)H(6) doublet intermediate(s) underwent unimolecular decomposition involving at least three competing reaction mechanisms via an atomic hydrogen loss from the vinyl group, an atomic hydrogen loss from the methyl group, and a methyl group elimination to form cis-/trans-1-propenyl-oxo-borane (CH(3)CHCH(11)BO), 3-propenyl-oxo-borane (CH(2)CHCH(2)(11)BO), and ethenyl-oxo-borane (CH(2)CH(11)BO), respectively. Utilizing partially deuterated propylene (CD(3)CHCH(2) and CH(3)CDCD(2)), we reveal that the loss of a vinyl hydrogen atom is the dominant hydrogen elimination pathway (85 ± 10%) forming cis-/trans-1-propenyl-oxo-borane, compared to the loss of a methyl hydrogen atom (15 ± 10%) leading to 3-propenyl-oxo-borane. The branching ratios for an atomic hydrogen loss from the vinyl group, an atomic hydrogen loss from the methyl group, and a methyl group loss are experimentally derived to be 26 ± 8%:5 ± 3%:69 ± 15%, respectively; these data correlate nicely with the branching ratios calculated via RRKM theory of 19%:5%:75%, respectively.

  17. The Calibration Stategy of CMS Electromagnetic Calorimeter

    CERN Document Server

    Meridiani, P

    2004-01-01

    Calibration is one of the main factors that set limits on the ultimate performance of the CMS electromagnetic calorimeter (ECAL) at LHC. Crystals raw intercalibration from laboratory measurements during assembly will be available for all the crystals and has been demonstrated to be a good precalibration value at the start-up; some crystals will be also intercalibrated using an electron beam. In situ calibration with physics events will be the main tool to reduce the constant term of the emergy resolution to the design goal of 0.5%. In the following the calibration strategy will be described in detail.

  18. DECal: A Spectrophotometric Calibration System For DECam

    CERN Document Server

    Marshall, J L; DePoy, D L; Prochaska, Travis; Allen, Richard; Behm, Tyler W; Martin, Emily C; Veal, Brannon; Villanueva,, Steven; Williams, Patrick; Wise, Jason

    2013-01-01

    DECal is a new calibration system for the CTIO 4 m Blanco telescope. It is currently being installed as part of the Dark Energy Survey and will provide both broadband flat fields and narrowband (about 1 nm bandwidth) spectrophotometric calibration for the new Dark Energy Camera (DECam). Both of these systems share a new Lambertian flat field screen. The broadband flat field system uses LEDs to illuminate each photometric filter. The spectrophotometric calibration system consists of a monochromator-based tunable light source that is projected onto the flat field screen using a custom line-to-spot fiber bundle and an engineered diffuser. Several calibrated photodiodes positioned along the beam monitor the telescope throughput as a function of wavelength. This system will measure the wavelength-dependent instrumental response function of the total telescope+instrument system in the range 300 < lambda < 1100nm. The spectrophotometric calibration will be performed regularly (roughly once per month) to determ...

  19. The ATLAS Electromagnetic Calorimeter Calibration Workshop

    CERN Multimedia

    Hong Ma; Isabelle Wingerter

    The ATLAS Electromagnetic Calorimeter Calibration Workshop took place at LAPP-Annecy from the 1st to the 3rd of October; 45 people attended the workshop. A detailed program was setup before the workshop. The agenda was organised around very focused presentations where questions were raised to allow arguments to be exchanged and answers to be proposed. The main topics were: Electronics calibration Handling of problematic channels Cluster level corrections for electrons and photons Absolute energy scale Streams for calibration samples Calibration constants processing Learning from commissioning Forty-five people attended the workshop. The workshop was on the whole lively and fruitful. Based on years of experience with test beam analysis and Monte Carlo simulation, and the recent operation of the detector in the commissioning, the methods to calibrate the electromagnetic calorimeter are well known. Some of the procedures are being exercised in the commisssioning, which have demonstrated the c...

  20. Calibration of the EGRET high-energy gamma-ray telescope in the range 20-10,000 MeV with a tunable beam of quasi-monoenergetic gamma rays at SLAC

    Science.gov (United States)

    Thompson, D. J.; Bertsch, D. L.; Fichtel, C. E.; Hartman, R. C.; Favale, A.

    1987-01-01

    The EGRET telescope, one of the instruments to be carried on NASA's Gamma Ray Observatory, is designed to explore the high-energy portion (20-24,000 MeV) of the electromagnetic spectrum. A calibration source of gamma-rays over this wide energy range has been used together with an appropriate set of intensity-monitoring instruments, to conduct a calibration of the EGRET telescope over this energy range for the full telescope aperture. The calibration method and an overview of the results are described.

  1. 洛阳博物馆新馆大跨度框架梁预应力损失测试研究%Prestressing Loss Test of the Large Span Frame Beam of Luoyang New Museum

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    In Luoyang New Museum, the prestressing loss monitoring and testing play very important role in the process of tensioning, especially for the prestressed control of the construction sequence of a large span prestressed frame beam adopting the post⁃tensioned prestressed technology. The measured values of stress and strain of the beam characteristic cross section are compared with the theoretical design calculation ones, based on the coefficient of friction loss accurately obtained in this paper. Finally, it can achieve the purpose of precise control of the prestressing construction quality.%洛阳博物馆新馆工程大跨度预应力框架梁采用后张有黏结预应力施工工艺,施工过程中应加强其预应力施工控制,特别是张拉过程中的预应力损失监控及测试十分重要。通过精确计算出摩阻损失系数,测定出特征截面的应力和应变值,并与理论设计验算值进行对比分析,可达到精确控制预应力施工质量的目的。

  2. Study of Intensity Proton Accelerator Beam Loss Readout System%强流质子加速器的束流损失读出系统的研究

    Institute of Scientific and Technical Information of China (English)

    马晓媛; 雷革; 徐韬光

    2012-01-01

    It introduces the research on the Beam - Loss - Readout system, which is part of the Beam - Loss -Monitoring system of the intensity proton accelerator. The hardware scheme of BLR system use ADC sampling e-quipment based on VME bus protocol. The software design is built on the Linux platform using EPICS control system. With the device driver, device support and record support program, the system gets control of the device and reads out the data. It turns out to meet the requirements of the project target.%介绍了强流质子加速器束流损失监测系统中束流损失读出系统的研究.束损读出系统硬件使用基于VME总线协议的ADC设备,软件设计采用EPICS控制软件框架.作者编写设备驱动、设备支持、记录支持程序,实现了对硬件的控制和数据的读取,并满足工程要求的性能指标.

  3. Bunch-by-bunch beam loss monitor system in BEPCⅡ storage ring%BEPCⅡ储存环逐束团丢束监测系统及应用

    Institute of Scientific and Technical Information of China (English)

    邓庆勇; 曹建社; 岳军会; 魏源源; 麻惠洲; 杜垚垚

    2014-01-01

    A new prototype system for bunch-by-bunch beam position measurement has been designed and built to monitor and analyse the beam loss in the Beijing Electron-Positron ColliderⅡ(BEPCⅡ)storage ring.The fast ADC is used to sample the analog signals from the beam position monitor,then the digital signal is processed further using programmable gate array (FP-GA).The beam information can be obtained by means of bunch-by-bunch,such as bunch position,bunch current and bunch tune.Based on system monitoring and data analysis for long terms,as well as the dedicated machine experiments,it’s relatively clear for operators to understand some trip events,especially the beam loss caused by the high-frequency cavity trip,tune drift and multiple bunch instability.The study proves that the system is very useful for the operation of accelerator.%针对北京正负电子对撞机二期工程(BEPCⅡ)在高流强下运行经常出现的突然丢束问题,研制了基于逐束团测量的丢束监测系统。束流位置探头(BPM)的四路电极信号作为监测系统的信号源,四路高速模数转换器(ADC)和现场可编程门阵列(FPGA)进行模拟信号的数字化和数字信号的处理。通过获取丢束前每个束团的位置和流强等信息来分析引起丢束的原因。结合加速器硬件情况,长时间对丢束监测系统数据的分析,以及设计的对比实验,深入研究丢束问题。系统对高频系统故障、束流不稳定性和磁铁电源系统不稳定等原因引起的丢束现象可以做出准确的判断,进而为加速器稳定运行提供优化方向。

  4. The External Calibrator for Hydrogen Observatories

    CERN Document Server

    Jacobs, Daniel C; Bowman, Judd; Neben, Abraham R; Stinnett, Benjamin; Turner, Lauren

    2016-01-01

    Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21cm hydrogen line across the redshift spectrum, from nearby to z=25. These instruments, including CHIME in the sub-meter and HERA in the meter bands, are wide-field arrays with multiple-degree beams, typically operating in transit mode. Accurate knowledge of their primary beams is critical for separation of bright foregrounds from the desired cosmological signals, but difficult to achieve through astronomical observations alone. Previous beam calibration work has focused on model verification and does not address the need of 21cm experiments for routine beam mapping, to the horizon, of the as-built array. We describe the design and methodology of a drone-mounted calibrator, the External Calibrator for Hydrogen Observatories (ECHO), that aims to address this need. We report on a first set of trials to calibrate low-frequency dipoles and co...

  5. Calibrating transport lines using LOCO techniques

    Energy Technology Data Exchange (ETDEWEB)

    Yves Roblin

    2011-09-01

    With the 12GeV upgrade underway at CEBAF, there is a need to re-characterize the beamlines after the modifications made to it to accommodate running at higher energies. We present a linear perturbation approach to calibrating the optics model of transport lines. This method is adapted from the LOCO method in use for storage rings. We consider the effect of quadrupole errors, dipole construction errors as well as beam position monitors and correctors calibrations. The ideal model is expanded to first order in Taylor series of the quadrupole errors. A set of difference orbits obtained by exciting the correctors along the beamline is taken, yielding the measured response matrix. An iterative procedure is invoked and the quadrupole errors as well as beam position monitors and corrector calibration factors are obtained. Here we present details of the method and results of first measurements at CEBAF in early 2011.

  6. Brief Discussion on Comparative Analysis of Dr. Bridge and Steel Beam Loss of MIDAS -Simply Supported Beam Computation with 20m Pretension Method%浅谈桥博与MIDAS之钢束损失比较分析—20m先张法简支梁计算

    Institute of Scientific and Technical Information of China (English)

    陈丽丽; 张明奇

    2012-01-01

    通过实际算例介绍了桥博与MIDAS作为桥梁专业通用性较强的软件,在钢束应力损失方面的计算结果的可靠性与差异。%With practical example, Dr. Bridge and MIDAS as software widely used in bridge major are intro- duced and the reliability and differences between them in computed results of steel beam stress loss are introduced as well.

  7. Calibration of Avent Wind IRIS SN. WI01030176

    DEFF Research Database (Denmark)

    Yordanova, Ginka; Courtney, Michael

    This report presents the result of the lidar calibration performed for a two-beam nacelle based lidar at DTU’s test site for large wind turbines at Høvsøre, Denmark. Calibration is here understood as the establishment of a relation between the reference wind speed measurements with measurement...... uncertainties provided by measurement standard and corresponding lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements....

  8. Large Hadron Collider momentum calibration and accuracy

    CERN Document Server

    Wenninger, Jorg

    2017-01-01

    As a result of the excellent quality of the Large Hadron Collider (LHC) experimental detectors and the accurate calibration of the luminosity at the LHC, uncertainties on the LHC beam energy may contribute significantly to the measurement errors on certain observables unless the relative uncertainty is well below 1%. Direct measurements of the beam energy using the revolution frequency difference of proton and lead beams combined with the magnetic model errors are used to provide the energy uncertainty of the LHC beams. Above injection energy the relative uncertainty on the beam energy is determined to be ±0.1%. The energy values as reconstructed and distributed online to the LHC experiments do not require any correction above injection energy. At injection a correction of +0.31 GeV/c must be applied to the online energy values.

  9. Observed Orbit Effects during Long Range Beam-Beam Studies

    CERN Document Server

    Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D

    2012-01-01

    Possible limitations due to long range beam-beam effects at the LHC have been studied and are presented in this note. With a larger number of bunches and collisions in all interaction points, the crossing angles were reduced to enhance long range beam-beam effects. The analysis of the effects on the dynamic aperture and losses are documented in [1]. This note concentrates on the bunch-by-bunch orbit effects observed during the experiment.

  10. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring.

    Science.gov (United States)

    Kumar, Pradeep; Ghodke, A D; Karnewar, A K; Holikatti, A C; Yadav, S; Puntambekar, T A; Singh, G; Singh, P

    2013-12-01

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  11. Measurements of aperture and beam lifetime using movable beam scrapers in Indus-2 electron storage ring

    Science.gov (United States)

    Kumar, Pradeep; Ghodke, A. D.; Karnewar, A. K.; Holikatti, A. C.; Yadav, S.; Puntambekar, T. A.; Singh, G.; Singh, P.

    2013-12-01

    In this paper, the measurements of vertical and horizontal aperture which are available for stable beam motion in Indus-2 at beam energy 2.5 GeV using movable beam scrapers are presented. These beam scrapers are installed in one of the long straight sections in the ring. With the movement of beam scrapers towards the beam centre, the beam lifetime is measured. The beam lifetime data obtained from the movement of vertical and horizontal beam scrapers are analyzed. The contribution of beam loss due to beam-gas scattering (vacuum lifetime) and electron-electron scattering within a beam bunch (Touschek lifetime) is separated from the measured beam lifetime at different positions of the beam scrapers. Vertical and horizontal beam sizes at scrapers location are estimated from the scraper movement towards the beam centre in quantum lifetime limit and their values closely agree with measured value obtained using X-ray diagnostic beamline.

  12. Optimal Calibration Accuracy for Gravitational Wave Detectors

    CERN Document Server

    Lindblom, Lee

    2009-01-01

    Calibration errors in the response function of a gravitational wave detector degrade its ability to detect and then to measure the properties of any detected signals. This paper derives the needed levels of calibration accuracy for each of these data-analysis tasks. The levels derived here are optimal in the sense that lower accuracy would result in missed detections and/or a loss of measurement precision, while higher accuracy would be made irrelevant by the intrinsic noise level of the detector. Calibration errors affect the data-analysis process in much the same way as errors in theoretical waveform templates. The optimal level of calibration accuracy is expressed therefore as a joint limit on modeling and calibration errors: increased accuracy in one reduces the accuracy requirement in the other.

  13. Trinocular Calibration Method Based on Binocular Calibration

    Directory of Open Access Journals (Sweden)

    CAO Dan-Dan

    2012-10-01

    Full Text Available In order to solve the self-occlusion problem in plane-based multi-camera calibration system and expand the measurement range, a tri-camera vision system based on binocular calibration is proposed. The three cameras are grouped into two pairs, while the public camera is taken as the reference to build the global coordinate. By calibration of the measured absolute distance and the true absolute distance, global calibration is realized. The MRE (mean relative error of the global calibration of the two camera pairs in the experiments can be as low as 0.277% and 0.328% respectively. Experiment results show that this method is feasible, simple and effective, and has high precision.

  14. Calibration of Local Area Weather Radar-Identifying significant factors affecting the calibration

    DEFF Research Database (Denmark)

    Pedersen, Lisbeth; Jensen, Niels Einar; Madsen, Henrik

    2010-01-01

    on calibration. The data processing for handling the partial beam filling issue was found to be essential to the calibration. LAWR uses a different calibration process compared to conventional weather radars, which use a power-law relationship between reflectivity and rainfall rate. Instead LAWR uses a linear...... relationship of reflectivity and rainfall rate as result of the log transformation carried out by the logarithmic receiver as opposed to the linear receiver of conventional weather radars. Based on rain gauge data for a five month period from a dense network of nine gauges within a 500 x 500 m area and data...

  15. Energy calibration issues in nuclear resonant vibrational spectroscopy: observing small spectral shifts and making fast calibrations.

    Science.gov (United States)

    Wang, Hongxin; Yoda, Yoshitaka; Dong, Weibing; Huang, Songping D

    2013-09-01

    The conventional energy calibration for nuclear resonant vibrational spectroscopy (NRVS) is usually long. Meanwhile, taking NRVS samples out of the cryostat increases the chance of sample damage, which makes it impossible to carry out an energy calibration during one NRVS measurement. In this study, by manipulating the 14.4 keV beam through the main measurement chamber without moving out the NRVS sample, two alternative calibration procedures have been proposed and established: (i) an in situ calibration procedure, which measures the main NRVS sample at stage A and the calibration sample at stage B simultaneously, and calibrates the energies for observing extremely small spectral shifts; for example, the 0.3 meV energy shift between the 100%-(57)Fe-enriched [Fe4S4Cl4](=) and 10%-(57)Fe and 90%-(54)Fe labeled [Fe4S4Cl4](=) has been well resolved; (ii) a quick-switching energy calibration procedure, which reduces each calibration time from 3-4 h to about 30 min. Although the quick-switching calibration is not in situ, it is suitable for normal NRVS measurements.

  16. KEKB beam instrumentation systems

    Science.gov (United States)

    Arinaga, M.; Flanagan, J.; Hiramatsu, S.; Ieiri, T.; Ikeda, H.; Ishii, H.; Kikutani, E.; Mimashi, T.; Mitsuhashi, T.; Mizuno, H.; Mori, K.; Tejima, M.; Tobiyama, M.

    2003-02-01

    For the stable high-luminosity operation and luminosity increase, the electron and positron storage rings of the KEK B-Factory (KEKB) is equipped with various beam instrumentations, which have been working well since the start of the commissioning in December, 1998. Details and performance of the beam-position monitor system based on the spectrum analysis using DSPs, the turn-by-turn BPM with four-dimensional function available for measurements of the individual bunch position, phase and intensity, the parametric beam-DCCTs designed so as to avoid the magnetic-core-selection problems for the parametric flux modulation, the bunch-by-bunch feedback system indispensable to suppress the strong multibunch instabilities in KEKB, the various optical beam diagnostic systems, such as synchrotron radiation interferometers for precise beam-size measurement, the tune meters, the bunch length monitors and the beam-loss monitors are described. Delicate machine tuning of KEKB is strongly supported by these instrumentations.

  17. A crossed molecular beam and ab initio investigation of the exclusive methyl loss pathway in the gas phase reaction of boron monoxide (BO; X2Σ+) with dimethylacetylene (CH3CCCH3; X1A(1g)).

    Science.gov (United States)

    Kaiser, Ralf I; Maity, Surajit; Dangi, Beni B; Su, Yuan-Siang; Sun, B J; Chang, Agnes H H

    2014-01-21

    The crossed molecular beam reaction of boron monoxide ((11)BO; X(2)Σ(+)) with dimethylacetylene (CH3CCCH3; X(1)A(1g)) was investigated at a collision energy of 23.9 ± 1.5 kJ mol(-1). The scattering dynamics were suggested to be indirect (complex forming reaction) and were initiated by the addition of (11)BO(X(2)Σ(+)) with the radical center located at the boron atom to the π electron density at the acetylenic carbon-carbon triple bond without entrance barrier leading to cis-trans(11)BOC4H6 doublet radical intermediates. cis-(11)BOC4H6 underwent cis-trans isomerization followed by unimolecular decomposition via a methyl group (CH3) loss forming 1-propynyl boron monoxide (CH3CC(11)BO) in an overall exoergic reaction (experimental: -91 ± 22 kJ mol(-1); theoretical: -105 ± 9 kJ mol(-1); NIST: -104 ± 12 kJ mol(-1)) via a tight exit transition state; trans-(11)BOC4H6 was found to lose a methyl group instantaneously. Neither atomic nor molecular hydrogen loss pathways were detectable. The experimental finding of an exclusive methyl loss pathway gains full support from our computational study predicting a methyl group versus atomic hydrogen loss branching ratio of 99.99% to 0.01% forming 1-propynyl boron monoxide (CH3CC(11)BO) and 1-methyl-propadienyl boron monoxide (CH3((11)BO)CCCH2), respectively.

  18. Performance and Calibration of CASTOR Calorimeter at CMS

    CERN Document Server

    Kuznetsova, Ekaterina

    2012-01-01

    CASTOR trigger was developed and activated during beam injections and ramp-ups. The triggered events correspond to an isolated particle penetrating the calorimeter parallel to the beam axis. Analysis of the obtained spectra provides relative response to a muon per individual read-out channel. An absolute CASTOR calibration is not discussed here.

  19. Beam-beam observations in the Relativistic Heavy Ion Collider

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Y. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Fischer, W. [Brookhaven National Laboratory (BNL), Upton, NY (United States); White, S. [Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2015-06-24

    The Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory has been operating since 2000. Over the past decade, thanks to the continuously increased bunch intensity and reduced β*s at the interaction points, the maximum peak luminosity in the polarized proton operation has been increased by more than two orders of magnitude. In this article, we first present the beam-beam observations in the previous RHIC polarized proton runs. Then we analyze the mechanisms for the beam loss and emittance growth in the presence of beam-beam interaction. The operational challenges and limitations imposed by beam-beam interaction and their remedies are also presented. In the end, we briefly introduce head-on beam-beam compensation with electron lenses in RHIC.

  20. Preliminary evaluation of a Neutron Calibration Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Alvarenga, Talysson S.; Neves, Lucio P.; Perini, Ana P.; Sanches, Matias P.; Mitake, Malvina B.; Caldas, Linda V.E., E-mail: talvarenga@ipen.br, E-mail: lpneves@ipen.br, E-mail: aperini@ipen.br, E-mail: msanches@ipen.br, E-mail: mbmitake@ipen.br, E-mail: lcaldas@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Federico, Claudio A., E-mail: claudiofederico@ieav.cta.br [Instituto de Estudos Avancados (IEAv/DCTA), Sao Jose dos Campos, SP (Brazil). Dept. de Ciencia e Tecnologia Aeroespacial

    2013-07-01

    In the past few years, Brazil and several other countries in Latin America have experimented a great demand for the calibration of neutron detectors, mainly due to the increase in oil prospection and extraction. The only laboratory for calibration of neutron detectors in Brazil is localized at the Institute for Radioprotection and Dosimetry (IRD/CNEN), Rio de Janeiro, which is part of the IAEA SSDL network. This laboratory is the national standard laboratory in Brazil. With the increase in the demand for the calibration of neutron detectors, there is a need for another calibration services. In this context, the Calibration Laboratory of IPEN/CNEN, Sao Paulo, which already offers calibration services of radiation detectors with standard X, gamma, beta and alpha beams, has recently projected a new calibration laboratory for neutron detectors. In this work, the ambient equivalent dose rate (H⁎(10)) was evaluated in several positions inside and around this laboratory, using Monte Carlo simulation (MCNP5 code), in order to verify the adequateness of the shielding. The obtained results showed that the shielding is effective, and that this is a low-cost methodology to improve the safety of the workers and evaluate the total staff workload. (author)

  1. Hearing loss

    Science.gov (United States)

    Decreased hearing; Deafness; Loss of hearing; Conductive hearing loss; Sensorineural hearing loss; Presbycusis ... Symptoms of hearing loss may include: Certain sounds seeming too ... conversations when two or more people are talking Difficulty ...

  2. 金刚石探测器用于C-ADS注入器Ⅱ束损探测的模拟研究%Simulation of the Diamond Detector for the C-ADS Injector II Beam Loss Detection

    Institute of Scientific and Technical Information of China (English)

    左伟; 付鑫; 苏有武; 庞成果; 李武元; 徐俊奎; 李宗强; 毛旺; 严维伟; 徐翀

    2016-01-01

    The Chinese Accelerator Driven Subcritical System (C-ADS) injector II consists of super-conduction accelerating section which is half wave resonator (HWR), the designed beam intensity is 10 mA. To avoid the damage to the resonator due to proton beam loss, special Beam Loss Monitor (BLM) system is essential. BLM system could provide alarm signal when high energy deposition occurs which may cause the resonator quenching. Radiation field of 10 MeV proton lost at different point of the HWR are simulated with MCNPX, BLM could be set at proper positions based on the simulation. Considering the structure of HWR and the BLM detector selecting influence factor, radiation energy deposition in the diamond detector are simulated with MCNPX when the proton incidence angle change from 1°∼5°, Possible beam loss point can be deduced from the relationship of energy deposition in detectors at different locations. The results indicate that energy spectra of secondary particles are independent with incidence angle;the number of secondary particles may be influenced slightly.%加速器驱动次临界系统C-ADS注入器Ⅱ采用强流超导质子直线加速器,设计流强达到10 mA。强流质子束产生的束流损失有可能损伤超导腔,需要专用的束流损失监测系统进行监测,束流损失探测器(BLM)需要在高能量沉积导致超导腔失超之前提供警报。通过MCNPX模拟计算10 MeV质子在半波谐振腔(HWR)不同位置损失产生的辐射场,比较选取超导腔管道进出口处4个位置为推荐束损探测器放置的位置,结合HWR腔结构和束损探测器选择的影响因素,计算了次级辐射在金刚石探测器中的能量沉积以及1°∼5°不同质子入射角度对探测的影响。结果表明,根据不同位置处探测器的能量沉积关系可以推断出束损点;不同入射角度不会影响生成粒子的能量分布,只轻微影响生成粒子的数目。

  3. The calibration of PIXIE

    Science.gov (United States)

    Fixsen, D. J.; Chuss, D. T.; Kogut, Alan; Mirel, Paul; Wollack, E. J.

    2016-07-01

    The FIRAS instrument demonstrated the use of an external calibrator to compare the sky to an instrumented blackbody. The PIXIE calibrator is improved from -35 dB to -65 dB. Another significant improvement is the ability to insert the calibrator into either input of the FTS. This allows detection and correction of additional errors, reduces the effective calibration noise by a factor of 2, eliminates an entire class of systematics and allows continuous observations. This paper presents the design and use of the PIXIE calibrator.

  4. Beam Profiling through Wire Chambing Tracking

    CERN Document Server

    Nash, W

    2013-01-01

    This note describes the calibration of the Delay Wire Chambers (DWCs) used during test runs of CALICE’s Tungsten Digital Hadron Calorimeter (W-DHCAL) prototype in CERN’s SPS beam line (10 – 300 GeV).

  5. ADT fast losses MD

    CERN Document Server

    Priebe, A; Dehning, B; Redaelli, S; Salvachua Ferrando, BM; Sapinski, M; Solfaroli Camillocci, M; Valuch, D

    2013-01-01

    The fast beam losses in the order of 1 ms are expected to be a potential major luminosity limitation for higher beam energies after the LHC long shutdown (LS1). Therefore a Quench Test is planned in the winter 2013 to estimate the quench limit in this timescale and revise the current models. This experiment was devoted to determination the LHC Transverse Damper (ADT) as a system for fast losses induction. A non-standard operation of the ADT was used to develop the beam oscillation instead of suppressing them. The sign flip method had allowed us to create the fast losses within several LHC turns at 450 GeV during the previous test (26th March 2012). Thus, the ADT could be potentially used for the studies of the UFO ("Unidentied Falling Object") impact on the cold magnets. Verification of the system capability and investigations of the disturbed beam properties were the main objectives of this MD. During the experiment, the pilot bunches of proton beam were excited independently in the horizontal and vertical ...

  6. BEAM CONTAINMENT SYSTEM FOR NSLS-II

    Energy Technology Data Exchange (ETDEWEB)

    Kramer, S.L.; Casey, W.; Job, P.K.

    2010-05-23

    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 {le} 10% full beam. This will require a system to insure that beam losses don't exceed these levels for a period of time that could cause excessive radiation 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 (and potentially to 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&D program will be presented.

  7. Calibration Standards for Surface Topography Measuring Systems down to Nanometric Range

    DEFF Research Database (Denmark)

    Trumpold, H.; De Chiffre, Leonardo; Andreasen, Jan Lasson

    calibrator has been designed, built and tested. Primary calibration standards have been produced by ion-beam and plasma etching (step height standards), by holographic generation of sinusoidal structures with two-beam interference exposure and by ultra-precision diamond cutting. From primary standards...... to be replicated during all stages of the replication processes. Procedures for cleaning glass, PVC, PC, PMM and Ni-surfaces have been developed and tested. Calibration procedures for calibration standards and for calibrating instruments in X-, Y- and Z-direction have been developed and tested. Proposals...

  8. Geometric calibration for a SPECT system dedicated to breast imaging

    Institute of Scientific and Technical Information of China (English)

    WU Li-Wei; WEI Long; CAO Xue-Xiang; WANG Lu; HUANG Xian-Chao; CHAI Pei; YUN Ming-Kai; ZHANG Yu-Bao; ZHANG Long; SHAN Bao-Ci

    2012-01-01

    Geometric calibration is critical to the accurate SPECT reconstruction.In this paper,a geometric calibration method was developed for a dedicated breast SPECT system with a tilted parallel beam (TPB)orbit.The acquisition geometry of the breast SPECT was firstly characterized.And then its projection model was established based on the acquisition geometry.Finally,the calibration results were obtained using a nonlinear optimization method that fitted the measured projections to the model.Monte Carlo data of the breast SPECT were used to verify the calibration method.Simulation results showed that the geometric parameters with reasonable accuracy could be obtained by the proposed method.

  9. Aquarius L-Band Radiometers Calibration Using Cold Sky Observations

    Science.gov (United States)

    Dinnat, Emmanuel P.; Le Vine, David M.; Piepmeier, Jeffrey R.; Brown, Shannon T.; Hong, Liang

    2015-01-01

    An important element in the calibration plan for the Aquarius radiometers is to look at the cold sky. This involves rotating the satellite 180 degrees from its nominal Earth viewing configuration to point the main beams at the celestial sky. At L-band, the cold sky provides a stable, well-characterized scene to be used as a calibration reference. This paper describes the cold sky calibration for Aquarius and how it is used as part of the absolute calibration. Cold sky observations helped establish the radiometer bias, by correcting for an error in the spillover lobe of the antenna pattern, and monitor the long-term radiometer drift.

  10. First results about on-ground calibration of the Silicon Tracker for the AGILE satellite

    CERN Document Server

    Cattaneo, P W; Boffelli, F; Bulgarelli, A; Buonomo, B; Chen, A W; D'Ammando, F; Froysland, T; Fuschino, F; Galli, M; Gianotti, F; Giuliani, A; Longo, F; Marisaldi, M; Mazzitelli, G; Pellizzoni, A; Prest, M; Pucella, G; Quintieri, L; Rappoldi, A; Tavani, M; Trifoglio, M; Trois, A; Valente, P; Vallazza, E; Vercellone, S; Zambra, A; Barbiellini, G; Caraveo, P; Cocco, V; Costa, E; De Paris, G; Del Monte, E; Di Cocco, G; Donnarumma, I; Evangelista, Y; Feroci, M; Ferrari, A; Fiorini, M; Labanti, C; Lapshov, I; Lazzarotto, F; Lipari, P; Mastropietro, M; Mereghetti, S; Morelli, E; Moretti, E; Morselli, A; Pacciani, L; Perotti, F; Piano, G; Picozza, P; Pilia, M; Porrovecchio, G; Rapisarda, M; Rubini, A; Sabatini, S; Soffitta, P; Striani, E; Vittorini, V; Zanello, D; Colafrancesco, S; Giommi, P; Pittori, C; Santolamazza, P; Verrecchia, F; Salotti, L

    2011-01-01

    The AGILE scientific instrument has been calibrated with a tagged $\\gamma$-ray beam at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali di Frascati (LNF). The goal of the calibration was the measure of the Point Spread Function (PSF) as a function of the photon energy and incident angle and the validation of the Monte Carlo (MC) simulation of the silicon tracker operation. The calibration setup is described and some preliminary results are presented.

  11. 部分相干平顶光束在增益或损耗介质中传输的M~2因子%M~2-factor of partially coherent flat-top beams propagating in gain or loss media

    Institute of Scientific and Technical Information of China (English)

    李高清; 付文羽

    2009-01-01

    根据光束在介质中传输强度二阶矩计算公式,推导出部分相干平顶光束在增益或损耗介质中传输的M~2因子解析表达式,并将高斯-谢尔模型光束在增益或损耗介质中的传输作为特例统一于一般表达式中.研究结果表明:部分相干平顶光束在增益或损耗介质中传输时的M~2因子与光束传输距离、光束相干长度、光束阶数及介质的特性有关.光束在增益或损耗介质中传输的这种特性为应用和控制光束传输提供了理论依据.%According to the second-order moments intensity formula of the beam propagating in the gain or loss media, an analytical expression for M~2-factor of partially coherent flat-top beams propagating in the media is derived, and Gaussian-Schell model beams propagation in gain or loss media, which is taken as a particular case, is integrated into a common expression. The research result shows that the M~2-factor of partially coherent flat-top beams propagating in the gain or loss media is relative to the propagation distance, the coherent length, the order of the beams and the character of media. The propagation characteristic of the beams propagating in the gain or loss media provides a theoretical basis for the application and control of the beam propagation.

  12. Ku波段旋转扫描扇形波束散射计地面扩展目标在轨定标%Calibration of the Ku-band Rotating Fan-beam Scatterometer Using Land Extended-area Targets

    Institute of Scientific and Technical Information of China (English)

    朱金台; 董晓龙; 林文明; 朱迪

    2013-01-01

    Rotating Fan-beam SCATterometer (RFSCAT) is a new radar scatterometer system for ocean surface vector wind measurement. Compared with other available scatterometers, RFSCAT can provide more combination of azimuth and incidence angles for a single surface resolution cell. To achieve the required wind vector accuracy, radar scatterometry measurement of backscattering coefficient ( )s must be calibrated within a few tenths of a 0 decibel. In this paper, the method for external calibration of RFSCAT is proposed, based on the system parameters of the scatterometer onboard the Chinese French Oceanography SATellite (CFOSAT), and is verified by simulations. Then QuikSCAT L2A data and SIR of several large homogenous areas are analyzed to check the stability and azimuthal dependence of thes over these areas. A new calibration mask is generated and will be 0 used as a reference for the calibration of RFSCAT.%  旋转扫描扇形波束散射计(Rotating Fan-beam SCATterometer, RFSCAT)是一种新体制的海洋风场测量雷达散射计。RFSCAT对同一观测面元能够提供更多的方位角和入射角观测组合,改善海面风矢量场的反演精度。为了达到设计的风场反演精度,系统要求定标精度为0.5 dB。该文基于中法海洋卫星(Chinese French Oceanography SATellite, CFOSAT)雷达散射计的系统参数,考虑了在轨测量的主要误差源,分析了地面扩展目标在轨外定标的特点,给出了可行的RFSCAT在轨外定标方法,并利用仿真数据对该方法进行验证。利用QuikSCAT散射计的L2A 数据和图像重构(SIR)数据,针对地球表面归一化雷达后向散射系数0()s稳定的区域,给出了定标地图,为RFSCAT在轨定标提供参考。

  13. Calibração das câmaras de ionização para feixes de tomografia computadorizada no Brasil: a realidade atual Calibration of ionization chambers for computed tomography beams in Brazil: the present reality

    Directory of Open Access Journals (Sweden)

    Ana Figueiredo Maia

    2006-06-01

    Full Text Available OBJETIVO: O objetivo deste trabalho foi estabelecer, no Laboratório de Calibração de Instrumentos do Instituto de Pesquisas Energéticas e Nucleares, uma metodologia de calibração específica para as câmaras de ionização tipo lápis, que são utilizadas em procedimentos dosimétricos em feixes de tomografia computadorizada, seguindo as mais recentes recomendações internacionais. MATERIAIS E MÉTODOS: Foram utilizados, neste estudo, um equipamento de radiação X industrial, várias câmaras de ionização, um sistema de colimação móvel (tipo diafragma e vários filtros de alumínio de alta pureza. RESULTADOS: Foram estabelecidos os campos padrões de radiodiagnóstico descritos na norma internacional IEC 61267, e foi elaborado um procedimento de calibração adequado para as câmaras de ionização tipo lápis. CONCLUSÃO: Atualmente, já é possível calibrar apropriadamente as câmaras de ionização tipo lápis no Brasil. O procedimento de calibração foi definido com base nas recomendações internacionais e em testes feitos com duas metodologias distintas.OBJECTIVE: The aim of this study was to establish a calibration methodology specific for pencil ionization chambers used in computed tomography dosimetric procedures, in compliance with the most recent recommendations. The study was developed at the Calibration Laboratory of the Instituto de Pesquisas Energéticas e Nucleares. MATERIALS AND METHODS: An industrial x-ray equipment, several types of ionization chambers, a mobile collimator (diaphragm type, and several high purity aluminum filters were utilized in this study. RESULTS: Diagnostic radiology standard irradiation fields were established according to IEC 61267 standard, and an adequate calibration procedure for pencil ionization chambers was elaborated. CONCLUSION: The appropriate calibration of pencil ionization chambers is already a reality in Brazil. The calibration procedure was defined on the basis of

  14. Cumulative sum quality control for calibrated breast density measurements

    Energy Technology Data Exchange (ETDEWEB)

    Heine, John J.; Cao Ke; Beam, Craig [Cancer Prevention and Control Division, Moffitt Cancer Center, 12902 Magnolia Drive, Tampa, Florida 33612 (United States); Division of Epidemiology and Biostatistics, School of Public Health, University of Illinois at Chicago, 1603 W. Taylor St., Chicago, Illinois 60612 (United States)

    2009-12-15

    Purpose: Breast density is a significant breast cancer risk factor. Although various methods are used to estimate breast density, there is no standard measurement for this important factor. The authors are developing a breast density standardization method for use in full field digital mammography (FFDM). The approach calibrates for interpatient acquisition technique differences. The calibration produces a normalized breast density pixel value scale. The method relies on first generating a baseline (BL) calibration dataset, which required extensive phantom imaging. Standardizing prospective mammograms with calibration data generated in the past could introduce unanticipated error in the standardized output if the calibration dataset is no longer valid. Methods: Sample points from the BL calibration dataset were imaged approximately biweekly over an extended timeframe. These serial samples were used to evaluate the BL dataset reproducibility and quantify the serial calibration accuracy. The cumulative sum (Cusum) quality control method was used to evaluate the serial sampling. Results: There is considerable drift in the serial sample points from the BL calibration dataset that is x-ray beam dependent. Systematic deviation from the BL dataset caused significant calibration errors. This system drift was not captured with routine system quality control measures. Cusum analysis indicated that the drift is a sign of system wear and eventual x-ray tube failure. Conclusions: The BL calibration dataset must be monitored and periodically updated, when necessary, to account for sustained system variations to maintain the calibration accuracy.

  15. Distributed Radio Interferometric Calibration

    CERN Document Server

    Yatawatta, Sarod

    2015-01-01

    Increasing data volumes delivered by a new generation of radio interferometers require computationally efficient and robust calibration algorithms. In this paper, we propose distributed calibration as a way of improving both computational cost as well as robustness in calibration. We exploit the data parallelism across frequency that is inherent in radio astronomical observations that are recorded as multiple channels at different frequencies. Moreover, we also exploit the smoothness of the variation of calibration parameters across frequency. Data parallelism enables us to distribute the computing load across a network of compute agents. Smoothness in frequency enables us reformulate calibration as a consensus optimization problem. With this formulation, we enable flow of information between compute agents calibrating data at different frequencies, without actually passing the data, and thereby improving robustness. We present simulation results to show the feasibility as well as the advantages of distribute...

  16. A Simulator for Producing of High Flux Atomic Oxygen Beam by Using ECR Plasma Source

    Institute of Scientific and Technical Information of China (English)

    Shuwang DUO; Meishuan LI; Yaming ZHANG

    2004-01-01

    In order to study the atomic oxygen corrosion of spacecraft materials in low earth orbit environment, an atomic oxygen simulator was established. In the simulator, a 2.45 GHz microwave source with maximum power of 600 W was launched into the circular cavity to generate ECR (electron cyclotron resonance) plasma. The oxygen ion beam moved onto a negatively biased Mo plate under the condition of symmetry magnetic mirror field confine, then was neutralized and reflected to form oxygen atom beam. The properties of plasma density, electron temperature, plasma space potential and ion incident energy were characterized. The atomic oxygen beam flux was calibrated by measuring the mass loss rate of Kapton during the atomic 5~30 eV and a cross section of φ80 mm could be obtained under the operating pressure of 10-1~10-3 Pa. Such a high flux source can provide accelerated simulation tests of materials and coatings for space applications.

  17. The Science of Calibration

    Science.gov (United States)

    Kent, S. M.

    2016-05-01

    This paper presents a broad overview of the many issues involved in calibrating astronomical data, covering the full electromagnetic spectrum from radio waves to gamma rays, and considering both ground-based and space-based missions. These issues include the science drivers for absolute and relative calibration, the physics behind calibration and the mechanisms used to transfer it from the laboratory to an astronomical source, the need for networks of calibrated astronomical standards, and some of the challenges faced by large surveys and missions.

  18. Colorimetric calibration of coupled infrared simulation system

    Science.gov (United States)

    Zhang, Ying; Fei, Jindong; Gao, Yang; Du, Jian

    2015-10-01

    In order to test 2-color infrared sensors, a coupled infrared simulation system can generate radiometric outputs with wavelengths that range from less than 3 microns to more than 12 microns. There are two channels in the coupled simulation system, optically combined by a diachronic beam combiner. Each channel has an infrared blackbody, a filter, a diaphragm, and diaphragm-motors. The system is projected to the sensor under testing by a collimator. This makes it difficult to calibrate the system with only one-band thermal imager. Errors will be caused in the radiance levels measured by the narrow band thermal imager. This paper describes colorimetric temperature measurement techniques that have been developed to perform radiometric calibrations of these infrared simulation systems above. The calibration system consists of two infrared thermal imagers; one is operated at the wavelength range of MW-IR, and the other at the range of LW-IR.

  19. Artificial calibration source for ALMA radio interferometer

    Science.gov (United States)

    Kiuchi, Hitoshi; Hills, Richard; Whyborn, Nicholas D.; Asayama, Shinichiro; Sakamoto, Seiichi; Iguchi, Satoru; Corder, Stuartt A.

    2016-07-01

    The ALMA (Atacama Large Millimeter/submillimeter Array) radio interferometer has some different types of antennas which have a variation of gain and leakages across the primary beam of an individual antenna. We have been developing an artificial calibration source which is used for compensation of individual difference of antennas. In a high-frequency antenna, using astronomical sources to do calibration measurement would be extremely time consuming, whereas with the artificial calibration source becomes a realistic possibility. Photonic techniques are considered to be superior to conventional techniques based on electronic devices in terms of wide bandwidth and high-frequency signals. Conversion from an optical signal to a millimeter/sub-millimeter wave signal is done by a photo-mixer.

  20. Results of long range beam-beam studies and observations during operation in the LHC

    CERN Document Server

    Alemany, R; Buffat, X; Calaga, R; Fitterer, M; Giachino, R; Hemelsoet, GH; Herr, W; Papotti, G; Pieloni, T; Poyer, M; Schaumann, M; Trad, G; Wollmann, D

    2011-01-01

    We studied possible limitations due to the long range beam-beam effects in the LHC. With a larger number of bunches and collisions in all interaction points, we have reduced the crossing angles to enhance long range beam-beam effects to evaluate their influence on dynamic aperture and losses. Experience from operation with reduced separation was analysed and provides additional evidence.

  1. Calibration of Local Area Weather Radar—Identifying significant factors affecting the calibration

    Science.gov (United States)

    Pedersen, Lisbeth; Jensen, Niels Einar; Madsen, Henrik

    2010-07-01

    A Local Area Weather Radar (LAWR) is an X-band weather radar developed to meet the needs of high resolution rainfall data for hydrological applications. The LAWR system and data processing methods are reviewed in the first part of this paper, while the second part of the paper focuses on calibration. The data processing for handling the partial beam filling issue was found to be essential to the calibration. LAWR uses a different calibration process compared to conventional weather radars, which use a power-law relationship between reflectivity and rainfall rate. Instead LAWR uses a linear relationship of reflectivity and rainfall rate as result of the log transformation carried out by the logarithmic receiver as opposed to the linear receiver of conventional weather radars. Based on rain gauge data for a five month period from a dense network of nine gauges within a 500 × 500 m area and data from a nearby LAWR, the existing calibration method was tested and two new methods were developed. The three calibration methods were verified with three external gauges placed in different locations. It can be concluded that the LAWR calibration uncertainties can be reduced by 50% in two out of three cases when the calibration is based on a factorized 3 parameter linear model instead of a single parameter linear model.

  2. CSNS束流损失监控(BLM)系统电离室的改进%Improved Design and Construction of the Lonization Chamber for CSNS Beam Loss Monitor (BLM) System

    Institute of Scientific and Technical Information of China (English)

    赵中亮; 陈昌; 徐美杭; 田建民; 阮向东; 韩晨霞; 陈元柏; 徐韬光; 陆双桐

    2011-01-01

    Improved design and construction of the ionization chamber (IC) for CSNS and PA beam loss monitor (BLM) system is reported. The good plateau( ≥2 000 V) and the measurement range up to 3.6 × 105rad/h are obtained in the improved ionization chamber. All of these show us the performances of the improved ionization chamber can be satisfied for CSNS BLM application.%报道了中国散裂中子源工程(CSNS)和强流质子加速器(PA)柬流损失监控(BLM)系统的电离室的改进.对改进后的电离室测量得到,电离室有良好的坪特性(坪长≥2 000 V),测量的辐照剂量范围到3.6×10 5rad/h,高压加到3500 V仍能稳定工作.测量的结果表明电离室探头性能已能满足CSNS和PA对束流损失监控的性能需求.

  3. Using optical feedback to compensate for the reflection loss caused by partially reflecting mirror in laser power beaming%反馈弥补激光能量传输中部分反射镜反射损失

    Institute of Scientific and Technical Information of China (English)

    黄虎; 李滨; 尤政; 王巍

    2013-01-01

    The photocell is usually covered by a layer of partially reflecting mirror in laser power beaming, which is used to reflect partial laser light, control the light power of receiver in real time and adjust the beam pointing from transmitter to receiver. The partially reflecting mirror will decrease the power transmission efficiency. In this paper a method of optical feedback laser power beaming is presented, the theoretical model is established and the laser output power expression is derived. The expression shows that the optical feedback can reduce the laser threshold current and increase the laser output power. The laser threshold currents and output powers in feedback and non feedback conditions were measured in experiments. The experiment results show that in optical feedback condition the threshold current is reduced by 25% and the output power is increased by 10% at the driving current of 60mA compared with those in non feedback condition. In the experiment, the output powers in the conditions with feedback and without reflecting mirror were also measured. The results show that the optical feedback can reduce the reflection loss caused by reflecting mirror from 10% to 3% . The optical feedback laser power transmission method compensates the reflection loss of the reflecting mirror and improves the power transmission efficiency.%激光能量传输中的光电池表面通常覆盖有一层部分反射镜,用于产生反射光信号,实时控制接收端的光功率大小以及调整发射端和接收端的对准度.部分反射镜会降低能量传输效率,提出了一种反馈式能量传输方式,建立了理论模型,推导了激光器输出功率表达式.从表达式中可以发现反馈激光可降低激光器的阈值电流,提高激光器的输出功率.通过实验测量了反馈和无反馈时激光器的阈值电流和输出功率,实验结果表明相比较于无反馈情况,反馈作用使激光器的阈值电流降低了25%,驱动电流为60 m

  4. OLI Radiometric Calibration

    Science.gov (United States)

    Markham, Brian; Morfitt, Ron; Kvaran, Geir; Biggar, Stuart; Leisso, Nathan; Czapla-Myers, Jeff

    2011-01-01

    Goals: (1) Present an overview of the pre-launch radiance, reflectance & uniformity calibration of the Operational Land Imager (OLI) (1a) Transfer to orbit/heliostat (1b) Linearity (2) Discuss on-orbit plans for radiance, reflectance and uniformity calibration of the OLI

  5. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Fernandez Garcia, Sergio; Villanueva, Héctor

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and correspondi...

  6. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    Bonomo, F., E-mail: federica.bonomo@igi.cnr.it [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Istituto Gas Ionizzati - CNR, Corso Stati Uniti 4, 35127 Padova (Italy); Ruf, B.; Schiesko, L.; Fantz, U.; Franzen, P.; Riedl, R.; Wünderlich, D. [Max-Planck-Institut für Plasmaphysik, Boltzmannstr. 2, 85748 Garching (Germany); Barbisan, M.; Pasqualotto, R.; Serianni, G. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Cristofaro, S. [Universitá degli Studi di Padova, Via 8 Febbraio 2, 35122 Padova (Italy)

    2015-04-08

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (< 0.4 °) together with a low source pressure (≤ 0.3 Pa) would permit to reduce the ion losses along the beamline, keeping the stripping particle losses below 30%. However, the attainment of such beam properties is not straightforward. At IPP, the negative ion source testbed BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the H{sub α} light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of H{sub α} spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  7. The Collaborate Calibration and Alignment of Button-type BPM

    OpenAIRE

    Yuan, Jiandong; Ma, Lizhen; Zhang, Bin; Yao, Junjie

    2015-01-01

    Beam position monitor (BPM) can easily reinforce the handling of beam orbits and measure the absolute beam position [1]. Its data can be used to optimize and correct beam in both first turn and closed orbit mode. In order to set the absolute center position of Button-type BPM, and formulate the offset between mechanic and electronic center precisely, we mounted BPM together with solenoid on a vertical rotated test-bench when its calibration takes out, and developed transform software to calcu...

  8. A crossed molecular beam and ab-initio investigation of the reaction of boron monoxide (BO; X2Σ+) with methylacetylene (CH3CCH; X1A1): competing atomic hydrogen and methyl loss pathways.

    Science.gov (United States)

    Maity, Surajit; Parker, Dorian S N; Dangi, Beni B; Kaiser, Ralf I; Fau, Stefan; Perera, Ajith; Bartlett, Rodney J

    2013-11-21

    The gas-phase reaction of boron monoxide ((11)BO; X(2)Σ(+)) with methylacetylene (CH3CCH; X(1)A1) was investigated experimentally using crossed molecular beam technique at a collision energy of 22.7 kJ mol(-1) and theoretically using state of the art electronic structure calculation, for the first time. The scattering dynamics were found to be indirect (complex forming reaction) and the reaction proceeded through the barrier-less formation of a van-der-Waals complex ((11)BOC3H4) followed by isomerization via the addition of (11)BO(X(2)Σ(+)) to the C1 and/or C2 carbon atom of methylacetylene through submerged barriers. The resulting (11)BOC3H4 doublet radical intermediates underwent unimolecular decomposition involving three competing reaction mechanisms via two distinct atomic hydrogen losses and a methyl group elimination. Utilizing partially deuterated methylacetylene reactants (CD3CCH; CH3CCD), we revealed that the initial addition of (11)BO(X(2)Σ(+)) to the C1 carbon atom of methylacetylene was followed by hydrogen loss from the acetylenic carbon atom (C1) and from the methyl group (C3) leading to 1-propynyl boron monoxide (CH3CC(11)BO) and propadienyl boron monoxide (CH2CCH(11)BO), respectively. Addition of (11)BO(X(2)Σ(+)) to the C1 of methylacetylene followed by the migration of the boronyl group to the C2 carbon atom and/or an initial addition of (11)BO(X(2)Σ(+)) to the sterically less accessible C2 carbon atom of methylacetylene was followed by loss of a methyl group leading to the ethynyl boron monoxide product (HCC(11)BO) in an overall exoergic reaction (78 ± 23 kJ mol(-1)). The branching ratios of these channels forming CH2CCH(11)BO, CH3CC(11)BO, and HCC(11)BO were derived to be 4 ± 3%, 40 ± 5%, and 56 ± 15%, respectively; these data are in excellent agreement with the calculated branching ratios using statistical RRKM theory yielding 1%, 38%, and 61%, respectively.

  9. Sandia WIPP calibration traceability

    Energy Technology Data Exchange (ETDEWEB)

    Schuhen, M.D. [Sandia National Labs., Albuquerque, NM (United States); Dean, T.A. [RE/SPEC, Inc., Albuquerque, NM (United States)

    1996-05-01

    This report summarizes the work performed to establish calibration traceability for the instrumentation used by Sandia National Laboratories at the Waste Isolation Pilot Plant (WIPP) during testing from 1980-1985. Identifying the calibration traceability is an important part of establishing a pedigree for the data and is part of the qualification of existing data. In general, the requirement states that the calibration of Measuring and Test equipment must have a valid relationship to nationally recognized standards or the basis for the calibration must be documented. Sandia recognized that just establishing calibration traceability would not necessarily mean that all QA requirements were met during the certification of test instrumentation. To address this concern, the assessment was expanded to include various activities.

  10. WFPC2 Polarization Calibration

    Science.gov (United States)

    Biretta, J.; McMaster, M.

    1997-12-01

    We derive a detailed calibration for WFPC2 polarization data which is accurate to about 1.5%. We begin by computing polarizer flats, and show how they are applied to data. A physical model for the polarization effects of the WFPC2 optics is then created using Mueller matricies. This model includes corrections for the instrumental polarization (diattenuation and phase retardance) of the pick-off mirror, as well as the high cross-polarization transmission of the polarizer filter. We compare this model against the on-orbit observations of polarization calibrators, and show it predicts relative counts in the different polarizer/aperture settings to 1.5% RMS accuracy. We then show how this model can be used to calibrate GO data, and present two WWW tools which allow observers to easily calibrate their data. Detailed examples are given illustrationg the calibration and display of WFPC2 polarization data. In closing we describe future plans and possible improvements.

  11. 二维根尖周片与锥形束CT成像在牙周病理诊断中的运用比较%Detection of periodontal bone loss using cone beam CT and intraoral radiography

    Institute of Scientific and Technical Information of China (English)

    任迅

    2014-01-01

    目的:比较根尖周片与锥形束CT(Cone beam CT,CBCT)成像在牙周骨丧失中的检测与定位作用。方法:图像选自需进行牙周评价的患者牙片,样本共计51个测量位点,包括水平和垂直骨丧失,分别由三名检测者进行评价,主要通过测量骨丧失的线性高度、深度和宽度以及对X射线断层片上的联合骨缺损进行识别鉴定。结果:两种成像方式在定性骨缺损上差异无统计学意义(P>0.05),但在测量釉牙骨质界(CEJ)和牙槽脊顶(AC)间距离时两种成像方式差异有统计学意义(P0.05)。在本研究的39颗牙中,30.8%有联合骨缺损。结论:两种测量方式在测量牙槽脊的高度时有差异,但在测量骨缺失的深度和宽度时结论相似。应用CBCT 成像方式能对颊侧和舌侧/腭侧进行全面分析,并对骨缺失的表面形态进行观察。%To compare periapical radiographs with cone beam CT(CBCT) imaging in detecting and localizing alveolar bone loss by comparing linear measurements of the height, depth and width of the defects and identifying combined bone defects in tomographic images. Methods: The images were selected from a secondary database containing images of patients referred for periodontal evaluation. The sample consisted of 51 sites showing both horizontal and vertical bone loss, assessed by 3 trained examiners. Results: The results showed that there were no statisticaly significant differences between the imaging methods in terms of identification of the patern of bone loss. However, there were differences between the two methods when the distance between the cemento-enamel junction (CEJ) and the alveolar crest (AC) was measured. When the distance between the CEJ and the deepest point and width of the defect were measured, the methods showed no statisticaly significant difference. In this study, 30.8% of the 39 teeth evaluated had combined bone defects. Conclusions: The two methods

  12. Design and Initial Commissioning of Beam Diagnostics for the PEP-II B Factory.

    Science.gov (United States)

    Fisher, A. S.; Alzofon, D.; Arnett, D.; Bong, E. L.; Brugnoletti, B.; Collins, B.; Daly, E.; Gioumousis, A.; Johnson, R.; Kulikov, A.; Kurita, N.; Langton, J.; McCormick, D.; Noriega, R.; Smith, S.; Smith, V.; Stege, R.; Bjork, M.; Chin, M.; Hinkson, J.; McGill, R.; Suwada, T.

    1997-05-01

    PEP-II is a 2.2-km-circumference collider with a 2.1-A, 3.1-GeV positron ring (the Low-Energy Ring) 1 m above a 1-A, 9-GeV electron ring (the High-Energy Ring); both are designed for 3 A maximum. We will describe the beam diagnostics and present initial measurements from HER commissioning, expected to start in March 1997. LER commissioning will follow in 1998. The beam size and pulse duration are measured using near-UV synchrotron light extracted by grazing-incidence mirrors that must withstand up to 200 W/cm. To measure the charge in every bucket at 60 Hz with an accuracy of ≈0.5%, the sum signal from a set of 4 pickup buttons is digitized and averaged over 256 samples per bucket. The sum is normalized to the ring current, measured by a DC current transformer. The 300 beam-position monitors per ring are multiplexed to share 171 processor modules, which use DSPs for recording positions over 1024 turns and for calibration. For diagnostics and machine protection, 100 photomultiplier-based Cherenkov detectors measure beam losses and abort the beam in case of high loss.

  13. Beam Interlocks for LHC and SPS

    CERN Document Server

    Dinius, A; Gimeno-Vicente, J; Nouchi, P; Puccio, B; Schmidt, R; Wenninger, J

    2003-01-01

    The Large Hadron Collider at CERN (LHC) will operate at 7 TeV/c with a luminosity of 10 cms. This requires two beams with about 3^10 protons/beam, corresponding to a stored energy of about 350 MJ, sufficient to heat and melt 500 kg of copper. Protection of equipment from damage in case of uncontrolled beam losses is challenging. Injection of the beam from the SPS to the LHC could already damage equipment and is only permitted when all LHC systems are correctly prepared. In case of an uncontrolled loss of the circulating LHC beams, it is required to extract the beams into a specially designed target as soon as possible. Beam loss monitors and equipment for hardware surveillance are distributed around the 26 km long accelerator. In case of failures or beam losses, the beam interlock system is informed and sends a dump request to the beam dumping system. The beam interlock system also inhibits injection when the LHC is not ready for beam. In this paper the requirements for the beam interlock system are discussed...

  14. BATMAN beam properties characterization by the beam emission spectroscopy diagnostic

    Science.gov (United States)

    Bonomo, F.; Ruf, B.; Barbisan, M.; Cristofaro, S.; Schiesko, L.; Fantz, U.; Franzen, P.; Pasqualotto, R.; Riedl, R.; Serianni, G.; Wünderlich, D.

    2015-04-01

    The ITER neutral beam heating systems are based on the production and acceleration of negative ions (H/D) up to 1 MV. The requirements for the beam properties are strict: a low core beam divergence (BATMAN (BAvarian Test MAchine for Negative ions) allows for deepening the knowledge of the determination of the beam properties. One of the diagnostics routinely used to this purpose is the Beam Emission Spectroscopy (BES): the Hα light emitted in the beam is detected and the corresponding spectra are evaluated to estimate the beam divergence and the stripping losses. The BES number of lines of sight in BATMAN has been recently increased: five horizontal lines of sight providing a vertical profile of the beam permit to characterize the negative ion beam properties in relation to the source parameters. Different methods of Hα spectra analysis are here taken into account and compared for the estimation of the beam divergence and the amount of stripping. In particular, to thoroughly study the effect of the space charge compensation on the beam divergence, an additional hydrogen injection line has been added in the tank, which allows for setting different background pressure values (one order of magnitude, from about 0.04 Pa up to the source pressure) in the beam drift region.

  15. Joint Gain/Phase and Mutual Coupling Array Calibration Technique with Single Calibrating Source

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2012-01-01

    Full Text Available An iterative-based method for joint gain/phase and mutual coupling array calibration is proposed in this paper. It estimates the array gain/phase and mutual coupling coefficients with a set of simultaneous equations formed by using the beam pattern property of the array. Only one calibrating source with known direction is requiblue to obtain the unique estimate. The effectiveness of this approach is illustrated by simulation results and by experimental data collected with an antenna array operating in high-frequency radio band.

  16. Ground-Based Calibration Of A Microwave Landing System

    Science.gov (United States)

    Kiriazes, John J.; Scott, Marshall M., Jr.; Willis, Alfred D.; Erdogan, Temel; Reyes, Rolando

    1996-01-01

    System of microwave instrumentation and data-processing equipment developed to enable ground-based calibration of microwave scanning-beam landing system (MSBLS) at distances of about 500 to 1,000 ft from MSBLS transmitting antenna. Ensures accuracy of MSBLS near touchdown point, without having to resort to expense and complex logistics of aircraft-based testing. Modified versions prove useful in calibrating aircraft instrument landing systems.

  17. Segment Based Camera Calibration

    Institute of Scientific and Technical Information of China (English)

    马颂德; 魏国庆; 等

    1993-01-01

    The basic idea of calibrating a camera system in previous approaches is to determine camera parmeters by using a set of known 3D points as calibration reference.In this paper,we present a method of camera calibration in whih camera parameters are determined by a set of 3D lines.A set of constraints is derived on camea parameters in terms of perspective line mapping.Form these constraints,the same perspective transformation matrix as that for point mapping can be computed linearly.The minimum number of calibration lines is 6.This result generalizes that of Liu,Huang and Faugeras[12] for camera location determination in which at least 8 line correspondences are required for linear computation of camera location.Since line segments in an image can be located easily and more accurately than points,the use of lines as calibration reference tends to ease the computation in inage preprocessing and to improve calibration accuracy.Experimental results on the calibration along with stereo reconstruction are reported.

  18. The first experience with LHC beam gas ionization monitor

    CERN Document Server

    Sapinski, M; Dehning, B; Guerrero, A; Patecki, M; Versteegen, R

    2012-01-01

    The Beam Gas Ionization Monitors (BGI) are used to measure beam emittance on LHC. This paper describes the detectors and their operation and discusses the issues met during the commissioning. It also discusses the various calibration procedures used to correct for non-uniformity of Multi-Channel plates and to correct the beam size for effects affecting the electron trajectory after ionization.

  19. Field calibration studies for ionisation chambers in mixed high-energy radiation fields.

    Science.gov (United States)

    Theis, C; Forkel-Wirth, D; Fuerstner, M; Mayer, S; Otto, Th; Roesler, S; Vincke, H

    2007-01-01

    The monitoring of ambient doses at work places around high-energy accelerators is a challenging task due the complexity of the mixed stray radiation fields encountered. At CERN, mainly Centronics IG5 high-pressure ionisation chambers are used to monitor radiation exposure in mixed fields. The monitors are calibrated in the operational quantity ambient dose equivalent H*(10) using standard, source-generated photon- and neutron fields. However, the relationship between ionisation chamber reading and ambient dose equivalent in a mixed high-energy radiation field can only be assessed if the spectral response to every component and the field composition is known. Therefore, comprehensive studies were performed at the CERN-EU high-energy reference field facility where the spectral fluence for each particle type has been assessed with Monte Carlo simulations. Moreover, studies have been performed in an accessible controlled radiation area in the vicinity of a beam loss point of CERN's proton synchrotron. The comparison of measurements and calculations has shown reasonable agreement for most exposure conditions. The results indicate that conventionally calibrated ionisation chambers can give satisfactory response in terms of ambient dose equivalent in stray radiation fields at high-energy accelerators in many cases. These studies are one step towards establishing a method of 'field calibration' of radiation protection instruments in which Monte Carlo simulations will be used to establish a correct correlation between the response of specific detectors to a given high-energy radiation field.

  20. Beam Diagnostics for the J-PARC Main Ring Synchrotron

    CERN Document Server

    Toyama, Takeshi; Hashimoto, Yoshinori; Hayashi, Naoki; Kishiro, Junichi; Lee, Seishu; Miura, Takako; Muto, Suguru; Toyokawa, Ryoji

    2005-01-01

    Beam diagnostics: beam intensity monitors (DCCT, SCT, FCT, WCM), beam position monitors (ESM), beam loss monitors (proportional chamber, air ion chamber), beam profile monitors (secondary electron emission, gas-sheet) have been designed, tested, and will be installed for the Main Ring synchrotron of J-PARC (Japan Proton Accelerator Research Complex). This paper describes the basic design principle and specification of each monitor, with a stress on how to cope with high power beam (average circulation current of ~12 A) and low beam loss operation (less than 1 W/m except a collimator region). Some results of preliminary performance test using present beams and a radiation source will be reported.

  1. Lidar to lidar calibration

    DEFF Research Database (Denmark)

    Georgieva Yankova, Ginka; Courtney, Michael

    This report presents the result of the lidar to lidar calibration performed for ground-based lidar. Calibration is here understood as the establishment of a relation between the reference lidar wind speed measurements with measurement uncertainties provided by measurement standard and corresponding...... lidar wind speed indications with associated measurement uncertainties. The lidar calibration concerns the 10 minute mean wind speed measurements. The comparison of the lidar measurements of the wind direction with that from the reference lidar measurements are given for information only....

  2. Site Calibration report

    DEFF Research Database (Denmark)

    Gómez Arranz, Paula; Vesth, Allan

    This report describes the site calibration carried out at Østerild, during a given period. The site calibration was performed with two Windcube WLS7 (v1) lidars at ten measurements heights. The lidar is not a sensor approved by the current version of the IEC 61400-12-1 [1] and therefore the site...... calibration with lidars does not comply with the standard. However, the measurements are carried out following the guidelines of IEC 61400-12-1 where possible, but with some deviations presented in the following chapters....

  3. Calibration Fixture For Anemometer Probes

    Science.gov (United States)

    Lewis, Charles R.; Nagel, Robert T.

    1993-01-01

    Fixture facilitates calibration of three-dimensional sideflow thermal anemometer probes. With fixture, probe oriented at number of angles throughout its design range. Readings calibrated as function of orientation in airflow. Calibration repeatable and verifiable.

  4. Design, Performance, and Calibration of CMS Hadron Endcap Calorimeters

    CERN Document Server

    Baiatian, G; Emeliantchik, Igor; Massolov, V; Shumeiko, Nikolai; Stefanovich, R; Damgov, Jordan; Dimitrov, Lubomir; Genchev, Vladimir; Piperov, Stefan; Vankov, Ivan; Litov, Leander; Bencze, Gyorgy; Laszlo, Andras; Pal, Andras; Vesztergombi, Gyorgy; Zálán, Peter; Fenyvesi, Andras; Bawa, Harinder Singh; Beri, Suman Bala; Bhatnagar, Vipin; Kaur, Manjit; Kohli, Jatinder Mohan; Kumar, Arun; Singh, Jas Bir; Acharya, Bannaje Sripathi; Banerjee, Sunanda; Banerjee, Sudeshna; Chendvankar, Sanjay; Dugad, Shashikant; Kalmani, Suresh Devendrappa; Katta, S; Mazumdar, Kajari; Mondal, Naba Kumar; Nagaraj, P; Patil, Mandakini Ravindra; Reddy, L; Satyanarayana, B; Sharma, Seema; Sudhakar, Katta; Verma, Piyush; Hashemi, Majid; Mohammadi-Najafabadi, M; Paktinat, S; Babich, Kanstantsin; Golutvin, Igor; Kalagin, Vladimir; Kamenev, Alexey; Konoplianikov, V; Kosarev, Ivan; Moissenz, K; Moissenz, P; Oleynik, Danila; Petrosian, A; Rogalev, Evgueni; Semenov, Roman; Sergeyev, S; Shmatov, Sergey; Smirnov, Vitaly; Vishnevskiy, Alexander; Volodko, Anton; Zarubin, Anatoli; Druzhkin, Dmitry; Ivanov, Alexander; Kudinov, Vladimir; Orlov, Alexandre; Smetannikov, Vladimir; Gavrilov, Vladimir; Gershtein, Yuri; Ilyina, N; Kaftanov, Vitali; Kisselevich, I; Kolossov, V; Krokhotin, Andrey; Kuleshov, Sergey; Litvintsev, Dmitri; Ulyanov, A; Safronov, Grigory; Semenov, Sergey; Stolin, Viatcheslav; Demianov, A; Gribushin, Andrey; Kodolova, Olga; Petrushanko, Sergey; Sarycheva, Ludmila; Teplov, V; Vardanyan, Irina; Yershov, A; Abramov, Victor; Goncharov, Petr; Kalinin, Alexey; Khmelnikov, Alexander; Korablev, Andrey; Korneev, Yury; Krinitsyn, Alexander; Kryshkin, V; Lukanin, Vladimir; Pikalov, Vladimir; Ryazanov, Anton; Talov, Vladimir; Turchanovich, L; Volkov, Alexey; Camporesi, Tiziano; de Visser, Theo; Vlassov, E; Aydin, Sezgin; Bakirci, Mustafa Numan; Cerci, Salim; Dumanoglu, Isa; Eskut, Eda; Kayis-Topaksu, A; Koylu, S; Kurt, Pelin; Onengüt, G; Ozkurt, Halil; Polatoz, A; Sogut, Kenan; Topakli, Huseyin; Vergili, Mehmet; Yetkin, Taylan; Cankoc, K; Esendemir, Akif; Gamsizkan, Halil; Güler, M; Ozkan, Cigdem; Sekmen, Sezen; Serin-Zeyrek, M; Sever, Ramazan; Yazgan, Efe; Zeyrek, Mehmet; Deliomeroglu, Mehmet; Gülmez, Erhan; Isiksal, Engin; Kaya, Mithat; Ozkorucuklu, Suat; Levchuk, Leonid; Sorokin, Pavel; Grynev, B; Lyubynskiy, Vadym; Senchyshyn, Vitaliy; Hauptman, John M; Abdullin, Salavat; Elias, John E; Elvira, D; Freeman, Jim; Green, Dan; Los, Serguei; ODell, V; Ronzhin, Anatoly; Suzuki, Ichiro; Vidal, Richard; Whitmore, Juliana; Arcidy, M; Hazen, Eric; Heering, Arjan Hendrix; Lawlor, C; Lazic, Dragoslav; Machado, Emanuel; Rohlf, James; Varela, F; Wu, Shouxiang; Baden, Drew; Bard, Robert; Eno, Sarah Catherine; Grassi, Tullio; Jarvis, Chad; Kellogg, Richard G; Kunori, Shuichi; Mans, Jeremy; Skuja, Andris; Podrasky, V; Sanzeni, Christopher; Winn, Dave; Akgun, Ugur; Ayan, S; Duru, Firdevs; Merlo, Jean-Pierre; Mestvirishvili, Alexi; Miller, Michael; Norbeck, Edwin; Olson, Jonathan; Onel, Yasar; Schmidt, Ianos; Akchurin, Nural; Carrell, Kenneth Wayne; Gusum, K; Kim, Heejong; Spezziga, Mario; Thomas, Ray; Wigmans, Richard; Baarmand, Marc M; Mermerkaya, Hamit; Ralich, Robert; Vodopiyanov, Igor; Kramer, Laird; Linn, Stephan; Markowitz, Pete; Cushman, Priscilla; Ma, Yousi; Sherwood, Brian; Cremaldi, Lucien Marcus; Reidy, Jim; Sanders, David A; Karmgard, Daniel John; Ruchti, Randy; Fisher, Wade Cameron; Tully, Christopher; Bodek, Arie; De Barbaro, Pawel; Budd, Howard; Chung, Yeon Sei; Haelen, T; Hagopian, Sharon; Hagopian, Vasken; Johnson, Kurtis F; Barnes, Virgil E; Laasanen, Alvin T

    2008-01-01

    Detailed measurements have been made with the CMS hadron calorimeter endcaps (HE) in response to beams of muons, electrons, and pions. Readout of HE with custom electronics and hybrid photodiodes (HPDs) shows no change of performance compared to readout with commercial electronics and photomultipliers. When combined with lead-tungstenate crystals, an energy resolution of 8\\% is achieved with 300 GeV/c pions. A laser calibration system is used to set the timing and monitor operation of the complete electronics chain. Data taken with radioactive sources in comparison with test beam pions provides an absolute initial calibration of HE to approximately 4\\% to 5\\%.

  5. Test Beam Coordination: 2003 ATLAS Combined Test Beam

    CERN Multimedia

    Di Girolamo, B.

    The 2003 Test Beam Period The 2003 Test Beam period has been very fruitful for ATLAS. In spite of several days lost because of the accelerator problems, ATLAS has been able to achieve many results: FCAL has completed the calibration program in H6 Tilecal has completed the calibration program in H8 Pixel has performed extensive studies with normal and high intensity beams (up to 1.4*108 hadrons/spill) SCT has completed a variety of studies with quite a high number of modules operated concurrently TRT has performed several studies at high, low and very low energy (first use of the new H8 beam in the range 1 to 9 GeV) Muons (MDT,RPC and TGC) have been operating a large setup for about 5 months. The almost final MDT ROD (MROD) has been integrated in the readout and the final trigger electronics for TGC and RPC has been tested and certified with normal beam and during dedicated 40 MHz beam periods. The TDAQ has exploited a new generation prototype successfully and the new Event Filter infrastructure f...

  6. Evaluation of an optical beam-position-monitor system with closed-loop steering capabilities

    Science.gov (United States)

    Bissen, Mark; Rogers, Greg; Wood, William; Eisert, Dave; Kleman, K. J.; Winter, William; Höchst, Hartmut

    1994-08-01

    Imaging the synchrotron source profile onto the entrance slit of a monochromator provides a stable and reproducible energy calibration which is independent of the absolute position and drift of the electron beam. Potential electron-beam motions occurring during a fill result in a loss of flux through the beamline. We have implemented two independent beam position monitors which can be used as sensors to steer the vertical entrance mirror in order to maintain a maximum flux through a spherical grating varied line-spacing monochromator beamline. The system consists of a slotted plate photodiode which intercepts 2 mrad of synchrotron radiation next to the entrance mirror and a detector utilizing the photocurrents generated at the jaws of the entrance-slit assembly. Both monitors have a wide linear response range with a vertical position resolution of beam position monitors allows an easy check on the mechanical and thermal stability of the entrance optical system as well as on the reproducibility and long-term fluctuations of the electron-beam source during user shifts. We will discuss the performance of the optical beam-position-monitor system and its implementation as a sensor in a closed-loop feedback system to maintain maximum flux through the beamline.

  7. Beam simulation studies of ECR beam extraction and low energy beam transport for FRIB.

    Science.gov (United States)

    Ren, Haitao; Pozdeyev, Eduard; Lund, Steven M; Machicoane, Guillaume; Wu, Xiaoyu; Morgan, Glenn

    2016-02-01

    To meet the beam power requirements of 400 kW at the fragmentation target for facility for Rare Isotope Beams (FRIB), simultaneous acceleration of two-charge states should be used for heavier ions. These intense multi-charged ion beams will be produced by a 28 GHz electron cyclotron resonance (ECR) ion source at a high voltage of 35 kV. After extraction, the ion beam will be pre-accelerated to 12 keV/u with a 50 kV platform, transported down to an achromatic charge state selection (CSS) system followed by a vertical transport line, and then injected into a radio frequency quadrupole accelerator. The TRACK code developed at ANL is used to perform the simulations of the ECR beam extraction and low energy beam transport for FRIB. In this study, we include the magnetic field of ECR ion source into simulations. Different initial beam conditions as well as different space charge neutralization levels are tested for the ECR beamline. The beam loss in CSS system and the corresponding protective measures are discussed. The detailed results about the beam dynamic simulation and beam loss in CSS system will be presented in this paper.

  8. SPOTS Calibration Example

    Directory of Open Access Journals (Sweden)

    Patterson E.

    2010-06-01

    Full Text Available The results are presented using the procedure outlined by the Standardisation Project for Optical Techniques of Strain measurement to calibrate a digital image correlation system. The process involves comparing the experimental data obtained with the optical measurement system to the theoretical values for a specially designed specimen. The standard states the criteria which must be met in order to achieve successful calibration, in addition to quantifying the measurement uncertainty in the system. The system was evaluated at three different displacement load levels, generating strain ranges from 289 µstrain to 2110 µstrain. At the 289 µstrain range, the calibration uncertainty was found to be 14.1 µstrain, and at the 2110 µstrain range it was found to be 28.9 µstrain. This calibration procedure was performed without painting a speckle pattern on the surface of the metal. Instead, the specimen surface was prepared using different grades of grit paper to produce the desired texture.

  9. Air Data Calibration Facility

    Data.gov (United States)

    Federal Laboratory Consortium — This facility is for low altitude subsonic altimeter system calibrations of air vehicles. Mission is a direct support of the AFFTC mission. Postflight data merge is...

  10. Traceable Pyrgeometer Calibrations

    Energy Technology Data Exchange (ETDEWEB)

    Dooraghi, Mike; Kutchenreiter, Mark; Reda, Ibrahim; Habte, Aron; Sengupta, Manajit; Andreas, Afshin; Newman, Martina; Webb, Craig

    2016-05-02

    This presentation provides a high-level overview of the progress on the Broadband Outdoor Radiometer Calibrations for all shortwave and longwave radiometers that are deployed by the Atmospheric Radiation Measurement program.

  11. SRHA calibration curve

    Data.gov (United States)

    U.S. Environmental Protection Agency — an UV calibration curve for SRHA quantitation This dataset is associated with the following publication: Chang, X., and D. Bouchard. Surfactant-Wrapped Multiwalled...

  12. Beam dynamics issues for linear colliders

    Energy Technology Data Exchange (ETDEWEB)

    Ruth, R.D.

    1987-09-01

    In this paper we discuss various beam dynamics issues for linear colliders. The emphasis is to explore beam dynamics effects which lead to an effective dilution of the emittance of the beam and thus to a loss of luminosity. These considerations lead to various tolerances which are evaluated for a particular parameter set.

  13. Generic calibration procedures for nacelle-based profiling lidars

    DEFF Research Database (Denmark)

    Borraccino, Antoine; Courtney, Michael; Wagner, Rozenn

    In power performance testing, it has been demonstrated that the effects of wind speed and direction variations over the rotor disk can no longer be neglected for large wind turbines [1]. A new generation of commercial nacelle-based lidars is now available, offering wind profiling capabilities...... to calibrate profiling nacelle lidars........ Developing standard procedures for power curves using lidars requires assessing lidars measurement uncertainty that is provided by a calibration. Based on the calibration results from two lidars, the Avent 5-beam Demonstrator and the Zephir Dual Mode (ZDM), we present in this paper a generic methodology...

  14. Calibrating nacelle lidars

    OpenAIRE

    Courtney, Michael

    2013-01-01

    Nacelle mounted, forward looking wind lidars are beginning to be used to provide reference wind speed measurements for the power performance testing of wind turbines. In such applications, a formal calibration procedure with a corresponding uncertainty assessment will be necessary. This report presents four concepts for performing such a nacelle lidar calibration. Of the four methods, two are found to be immediately relevant and are pursued in some detail.The first of these is a line of sight...

  15. TWSTFT Link Calibration Report

    Science.gov (United States)

    2015-09-01

    box calibrator with unknown but constant total delay during a calibration tour Total Delay: The total electrical delay from the antenna phase center...to the UTCp including all the devices/cables that the satellite and clock signals pass through. It numerically equals the sum of all the sub-delays...PTB. To average out the dimnal effects and measurement noise , 5-7 days of continuous measurements is required. 3 Setups at the Lab(k) The setup

  16. Hair Loss

    Science.gov (United States)

    ... loss at the scarred areas. These conditions include lichen planus, some types of lupus and sarcoidosis. Hair- ... increase your risk of hair loss, including: Family history Age Poor nutrition Certain medical conditions, such as ...

  17. Hearing Loss

    Science.gov (United States)

    ... effects on your hearing — ringing in the ear (tinnitus) or hearing loss — can occur if you take ... adults with hearing loss, commonly reported problems include: Depression Anxiety An often false sense that others are ...

  18. Calibration of PIXE yields using binary thin films on Si

    Energy Technology Data Exchange (ETDEWEB)

    Meersschaut, J., E-mail: Johan.Meersschaut@imec.be [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Carbonel, J.; Popovici, M. [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); Zhao, Q.; Vantomme, A. [IKS, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium); Vandervorst, W. [Imec, Kapeldreef 75, B-3001 Leuven (Belgium); IKS, KU Leuven, Celestijnenlaan 200D, B-3001 Leuven (Belgium)

    2014-07-15

    We describe the use of binary thin films on Si to calibrate the yields in proton-induced X-ray emission (PIXE) measurements. Besides of the element to be calibrated, the standards also contain a common reference element. The incorporation of a common reference element allows one to eliminate errors in the accumulated beam charge during the calibration of the PIXE set-up. The binary calibration standards allow us to determine the response function with an accuracy close to 1%. As an example, we will perform the calibration for Fe and Co, and we will determine the Co concentration in Fe{sub 1−x}Co{sub x} thin films.

  19. Energy calibration via correlation

    CERN Document Server

    Maier, Daniel

    2015-01-01

    The main task of an energy calibration is to find a relation between pulse-height values and the corresponding energies. Doing this for each pulse-height channel individually requires an elaborated input spectrum with an excellent counting statistics and a sophisticated data analysis. This work presents an easy to handle energy calibration process which can operate reliably on calibration measurements with low counting statistics. The method uses a parameter based model for the energy calibration and concludes on the optimal parameters of the model by finding the best correlation between the measured pulse-height spectrum and multiple synthetic pulse-height spectra which are constructed with different sets of calibration parameters. A CdTe-based semiconductor detector and the line emissions of an 241 Am source were used to test the performance of the correlation method in terms of systematic calibration errors for different counting statistics. Up to energies of 60 keV systematic errors were measured to be le...

  20. Beam-beam simulation code BBSIM for particle accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyung J.; Sen, Tanaji; /Fermilab

    2011-01-01

    A highly efficient, fully parallelized, six-dimensional tracking model for simulating interactions of colliding hadron beams in high energy ring colliders and simulating schemes for mitigating their effects is described. The model uses the weak-strong approximation for calculating the head-on interactions when the test beam has lower intensity than the other beam, a look-up table for the efficient calculation of long-range beam-beam forces, and a self-consistent Poisson solver when both beams have comparable intensities. A performance test of the model in a parallel environment is presented. The code is used to calculate beam emittance and beam loss in the Tevatron at Fermilab and compared with measurements. They also present results from the studies of stwo schemes proposed to compensate the beam-beam interactions: (a) the compensation of long-range interactions in the Relativistic Heavy Ion Collider (RHIC) at Brookhaven and the Large Hadron Collider (LHC) at CERN with a current carrying wire, (b) the use of a low energy electron beam to compensate the head-on interactions in RHIC.

  1. Design and Construction of the First Prototype of Liquid Scintillator Detector for Fast Beam Loss Monitor(FBLM) System%快响应束流损失监控(FBLM)系统液闪探测器初样的研制

    Institute of Scientific and Technical Information of China (English)

    韩晨霞; 陈昌; 田建民; 赵中亮; 徐美杭; 李公平; 陈元柏; 徐韬光; 赵海泉

    2011-01-01

    给出快响应束流损失监控(Fast Beam Lost Monitor,FBLM)系统的液体闪烁体探测器初样的研制.在高频四极加速器(Radio Frequency Quadrupole,RFQ)实验装置上的测试表明,液闪探测器能给出宽度为500 μs 束流宏脉冲结构,能逐个显示出宏脉冲内490 ns的束流切束脉冲.液闪输出信号脉冲较490 ns束流切束脉冲延迟约70 ns.液闪型FBLM输出的信号幅度大于塑闪型.液闪探测器初样的成功研制,为其性能进一步改进提高,打下了良好的基础.%Design and constmction of the first prototype of liquid scintillator detector for fast beam loss monitor ( FBLM ) system are given. A beam chopping device can remove a 490 ns section of beam at approximately 1 MHz repetition rate within a 500 μs macro beam pulse - width. The liquid scintillator displays the measured beam - pulse structure after the beam chopper. Through RFQ special beam structure, the response time of FBLM is measured. The response time of FBLM is about nano second. The signal amplitude from liquid scintillator is larger than plastic scintillator. All of these give us good experiences for the futher improvement of liquid seintillator detector design and construction. According to the measurement data. liquid seintillator is suggested as the detector of FBLM system.

  2. Exposure of Plastic Track Detectors to Relativistic Pb Beam for the Purpose of Providing Calibration for the DUBLIN-ESTEC Ultra Heavy Cosmic Ray Experiment Which was Exposed for Sixty-Nine Months in Earth Orbit

    CERN Multimedia

    2002-01-01

    % WA100 \\\\ \\\\ Solid state nuclear track detectors which formed part of the Dublin-ESTEC ultra heavy~cosmic~ray experiment aboard LDEF (Long Duration Exposure Facility) and which was deployed in Earth orbit for sixty-nine months, will be exposed to relativistic Pb ions. The experiment was the largest of its kind ever undertaken in space and has successfully accumulated more than fifteen times the world sample of cosmic ray nuclei in the region above Z~=~70. The data include the first significant sample of cosmic ray actinide elements and is of major astrophysical importance. The total number of ultra heavy nuclei (Z~$>$~70) in the Dublin-ESTEC sample is $\\sim$~2800. \\\\ \\\\The exposure will be very simple. A stack of detectors (20.5~cm~x~26~cm x~3~cm in size) will be irradiated with a low density beam of Pb ions (a few hundred per cm$^2$ would be ideal, but a wide range of densities and areas could be tolerated). The response of the detectors to these ions of known charge and velocity will be measured and the da...

  3. Calibration of CR-39 with monoenergetic protons

    Science.gov (United States)

    Xiaojiao, Duan; Xiaofei, Lan; Zhixin, Tan; Yongsheng, Huang; Shilun, Guo; Dawei, Yang; Naiyan, Wang

    2009-10-01

    Calibration of solid state nuclear track detector CR-39 was carried out with very low-energy monoenergetic protons of 20-100 keV from a Cockcroft Walton accelerator. To reduce the beam of the proton from the accelerator, a novel method was adopted by means of a high voltage pulse generator. The irradiation time of the proton beam on each CR-39 sheet was shortened to one pulse with duration of 100 ns, so that very separated proton tracks around 104 cm-2 can be irradiated and observed and measured on the surface of the CR-39 detector after etching. The variations of track diameter with etching time as well as with proton energy response curve has been carefully calibrated for the first time in this very low energy region. The calibration shows that the optical limit for the observation of etched tracks of protons in CR-39 is about or a little lower that 20 keV, above which the proton tracks can be seen clearly and the response curve can be used to distinguish protons from the other ions and determine the energy of the protons. The extension of response curve of protons from traditionally 20 to 100 keV in CR-39 is significant in retrieving information of protons produced in the studies of nuclear physics, plasma physics, ultrahigh intensity laser physics and laser acceleration.

  4. LHC Beam Instrumentation: Beam Profile Measurements (2/3)

    CERN Document Server

    CERN. Geneva

    2014-01-01

    The LHC is equipped with a full suite of sophisticated beam instrumentation which has been essential for rapid commissioning, the safe increase in total stored beam power and the understanding of machine optics and accelerator physics phenomena. These lectures will introduce these systems and comment on their contributions to the various stages of beam operation. They will include details on: the beam position system and its use for real-time global orbit feedback; the beam loss system and its role in machine protection; total and bunch by bunch intensity measurements; tune measurement and feedback; diagnostics for transverse beam size measurements, abort gap monitoring and longitudinal density measurements. Issues and problems encountered along the way will also be discussed together with the prospect for future upgrades.

  5. Beam Instrumentation for the Single Electron DAFNE Beam Test Facility

    CERN Document Server

    Mazzitelli, G; Valente, P; Vescovi, M

    2003-01-01

    The DAΦNE Beam Test Facility (BTF) has been successfully commissioned in February 2002, and started operation in November of the same year. Although the BTF is a beam transfer line optimized for single particle production, mainly for high energy detectors calibration, it can provide electrons and positrons in a wide range of multiplicity: between 1-1010, with energies from a few tens of MeV up to 800 MeV. The large multiplicity range requires many different diagnostic devices, from high-energy calorimeters and ionization/fluorescence chambers in the few particles range, to standard beam diagnostics systems. The schemes of operation, the commissioning results, as well as the beam diagnostics are presented.

  6. Critical halo loss locations in the LHC

    CERN Document Server

    Robert-Démolaize, Guillaume; Bracco, Chiara; Redaelli, Stefano; Weiler, Thomas

    2006-01-01

    Results of simulations with all movable elements of the LHC collimation system [1] are discussed for various operation modes. Compared to previous results, the placing of additional collimators reduced the beam losses by a factor 10 in the ideal machine case, i.e. nominal collimators settings for both 450 GeV and 7 TeV beam energies. First results for Beam 2 are also reviewed. The sensitivity of the system to free orbit oscillations is addressed. These results show that it is sufficient to use a limited number of beam loss monitors (BLMs) for the setup and optimization of the LHC Collimation System.

  7. Advanced Beam-Dynamics Simulation Tools for RIA

    CERN Document Server

    Garnett, Robert; Crandall, Kenneth; Ostroumov, Peter; Qiang, Ji; Ryne, Robert D; Wangler, Thomas; York, Richard; Zhao, Qiang

    2005-01-01

    Understanding beam losses is important for the high-intensity RIA driver linac. Small fractional beam losses can produce radioactivation of the beamline components that can prevent or hinder hands-on maintenance, reducing facility availability. Operational and alignment errors in the RIA driver linac can lead to beam losses caused by irreversible beam-emittance growth and halo formation. We are developing multiparticle beam-dynamics simulation codes for RIA driver-linac simulations extending from the low-energy beam transport (LEBT) line to the end of the linac. These codes run on the NERSC parallel supercomputing platforms at LBNL, which allow us to run simulations with large numbers of macroparticles for the beam-loss calculations. The codes have the physics capabilities needed for RIA, including transport and acceleration of multiple-charge-state beams, and beam-line elements such as high-voltage platforms within the linac, interdigital accelerating structures, charge-stripper foils, and capabilities for h...

  8. Calibration Under Uncertainty.

    Energy Technology Data Exchange (ETDEWEB)

    Swiler, Laura Painton; Trucano, Timothy Guy

    2005-03-01

    This report is a white paper summarizing the literature and different approaches to the problem of calibrating computer model parameters in the face of model uncertainty. Model calibration is often formulated as finding the parameters that minimize the squared difference between the model-computed data (the predicted data) and the actual experimental data. This approach does not allow for explicit treatment of uncertainty or error in the model itself: the model is considered the %22true%22 deterministic representation of reality. While this approach does have utility, it is far from an accurate mathematical treatment of the true model calibration problem in which both the computed data and experimental data have error bars. This year, we examined methods to perform calibration accounting for the error in both the computer model and the data, as well as improving our understanding of its meaning for model predictability. We call this approach Calibration under Uncertainty (CUU). This talk presents our current thinking on CUU. We outline some current approaches in the literature, and discuss the Bayesian approach to CUU in detail.

  9. HAWC Timing Calibration

    CERN Document Server

    Huentemeyer, Petra; Dingus, Brenda

    2009-01-01

    The High-Altitude Water Cherenkov (HAWC) Experiment is a second-generation highsensitivity gamma-ray and cosmic-ray detector that builds on the experience and technology of the Milagro observatory. Like Milagro, HAWC utilizes the water Cherenkov technique to measure extensive air showers. Instead of a pond filled with water (as in Milagro) an array of closely packed water tanks is used. The event direction will be reconstructed using the times when the PMTs in each tank are triggered. Therefore, the timing calibration will be crucial for reaching an angular resolution as low as 0.25 degrees.We propose to use a laser calibration system, patterned after the calibration system in Milagro. Like Milagro, the HAWC optical calibration system will use ~1 ns laser light pulses. Unlike Milagro, the PMTs are optically isolated and require their own optical fiber calibration. For HAWC the laser light pulses will be directed through a series of optical fan-outs and fibers to illuminate the PMTs in approximately one half o...

  10. Active Beam Spectroscopy

    Science.gov (United States)

    von Hellermann, M. G.; Delabie, E.; Jaspers, R. J. E.; Biel, W.; Marchuk, O.; Summers, H. P.; Whiteford, A.; Giroud, C.; Hawkes, N. C.; Zastrow, K. D.

    2008-03-01

    Charge eXchange Recombination Spectroscopy (CXRS) plays a pivotal role in the diagnostics of hot fusion plasmas and is implemented currently in most of the operating devices. In the present report the main features of CXRS are summarized and supporting software packages encompassing "Spectral Analysis Code CXSFIT", "Charge Exchange Analysis Package CHEAP", and finally "Forward Prediction of Spectral Features" are described. Beam Emission Spectroscopy (BES) is proposed as indispensable cross-calibration tool for absolute local impurity density measurements and also for the continuous monitoring of the neutral beam power deposition profile. Finally, a full exploitation of the `Motional Stark Effect' pattern is proposed to deduce local pitch angles, total magnetic fields and possibly radial electric fields. For the proposed active beam spectroscopy diagnostic on ITER comprehensive performance studies have been carried out. Estimates of expected spectral signal-to-noise ratios are based on atomic modelling of neutral beam stopping and emissivities for CXRS, BES and background continuum radiation as well as extrapolations from present CXRS diagnostic systems on JET, Tore Supra, TEXTOR and ASDEX-UG. Supplementary to thermal features a further promising application of CXRS has been proposed recently for ITER, that is a study of slowing-down alpha particles in the energy range up to 2 MeV making use of the 100 keV/amu DNB (Diagnostic Neutral Beam) and the 500 keV/amu HNB (Heating Neutral Beam). Synthetic Fast Ion Slowing-Down spectra are evaluated in terms of source rates and slowing-down parameters

  11. Square shaped flat-top beam in refractive beam shapers

    Science.gov (United States)

    Laskin, Alexander; Laskin, Vadim; Ostrun, Aleksei

    2015-08-01

    Lossless transformation of round Gaussian to square shaped flat-top collimated beam is important in building highpower solid state laser systems to improve optical pumping or amplification. There are industrial micromachining applications like scribing, display repair, which performance is improved when a square shaped spot with uniform intensity is created. Proved beam shaping solutions to these techniques are refractive field mapping beam shapers having some important features: flatness of output phase front, small output divergence, high transmittance, extended depth of field, operation with TEM00 and multimode lasers. Usual approach to design refractive beam shapers implies that input and output beams have round cross-section, therefore the only way to create a square shaped output beam is using a square mask, which leads to essential losses. When an input laser beam is linearly polarized it is suggested to generate square shaped flat-top output by applying beam shaper lenses from birefringent materials or by using additional birefringent components. Due to birefringence there is introduced phase retardation in beam parts and is realized a square shaped interference pattern at the beam shaper output. Realization of this approach requires small phase retardation, therefore weak birefringence effect is enough and birefringent optical components, operating in convergent or divergent beams, can be made from refractive materials, which crystal optical axis is parallel to optical axis of entire beam shaper optical system. There will be considered design features of beam shapers creating square shaped flat-top beams. Examples of real implementations and experimental results will be presented as well.

  12. Analysis of radiometer calibration effects with TOUCHSTONE

    Science.gov (United States)

    Stanley, William D.

    1990-01-01

    The microwave circuit analysis program TOUCHSTONE is used to study two effects of importance in radiometer calibration. The two effects are impedance mismatches at the antenna-air and cold load-air interfaces and dissipatives losses, which radiate thermal noise into the system. The results predicted by TOUCHSTONE are shown to be in very close agreement with earlier results obtained by purely analytical methods. The techniques used in establishing the circuit models and in processing the resulting data are described in detail.

  13. The LOFAR long baseline snapshot calibrator survey

    CERN Document Server

    Moldón, J; Wucknitz, O; Jackson, N; Drabent, A; Carozzi, T; Conway, J; Kapińska, A D; McKean, P; Morabito, L; Varenius, E; Zarka, P; Anderson, J; Asgekar, A; Avruch, I M; Bell, M E; Bentum, M J; Bernardi, G; Best, P; Bîrzan, L; Bregman, J; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Carbone, D; Ciardi, B; de Gasperin, F; de Geus, E; Duscha, S; Eislöffel, J; Engels, D; Falcke, H; Fallows, R A; Fender, R; Ferrari, C; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Hamaker, J P; Hassall, T E; Heald, G; Hoeft, M; Juette, E; Karastergiou, A; Kondratiev, V I; Kramer, M; Kuniyoshi, M; Kuper, G; Maat, P; Mann, G; Markoff, S; McFadden, R; McKay-Bukowski, D; Morganti, R; Munk, H; Norden, M J; Offringa, A R; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Rowlinson, A; Scaife, A M M; Schwarz, D; Sluman, J; Smirnov, O; Stappers, B W; Steinmetz, M; Tagger, M; Tang, Y; Tasse, C; Thoudam, S; Toribio, M C; Vermeulen, R; Vocks, C; van Weeren, R J; White, S; Wise, M W; Yatawatta, S; Zensus, A

    2014-01-01

    Aims. An efficient means of locating calibrator sources for International LOFAR is developed and used to determine the average density of usable calibrator sources on the sky for subarcsecond observations at 140 MHz. Methods. We used the multi-beaming capability of LOFAR to conduct a fast and computationally inexpensive survey with the full International LOFAR array. Sources were pre-selected on the basis of 325 MHz arcminute-scale flux density using existing catalogues. By observing 30 different sources in each of the 12 sets of pointings per hour, we were able to inspect 630 sources in two hours to determine if they possess a sufficiently bright compact component to be usable as LOFAR delay calibrators. Results. Over 40% of the observed sources are detected on multiple baselines between international stations and 86 are classified as satisfactory calibrators. We show that a flat low-frequency spectrum (from 74 to 325 MHz) is the best predictor of compactness at 140 MHz. We extrapolate from our sample to sho...

  14. NIST Calibration of a Neutron Spectrometer ROSPEC.

    Science.gov (United States)

    Heimbach, Craig

    2006-01-01

    A neutron spectrometer was acquired for use in the measurement of National Institute of Standards and Technology neutron fields. The spectrometer included options for the measurement of low and high energy neutrons, for a total measurement range from 0.01 eV up to 17 MeV. The spectrometer was evaluated in calibration fields and was used to determine the neutron spectrum of an Americium-Beryllium neutron source. The calibration fields used included bare and moderated (252)Cf, monoenergetic neutron fields of 2.5 MeV and 14 MeV, and a thermal-neutron beam. Using the calibration values determined in this exercise, the spectrometer gives a good approximation of the neutron spectrum, and excellent values for neutron fluence, for all NIST calibration fields. The spectrometer also measured an Americium-Beryllium neutron field in a NIST exposure facility and determined the field quite well. The spectrometer measured scattering effects in neutron spectra which previously could be determined only by calculation or integral measurements.

  15. Relative pointing offset analysis of calibration targets with repeated observations with Herschel-SPIRE Fourier-Transform Spectrometer

    CERN Document Server

    Valtchanov, Ivan; Polehampton, Edward; Benielli, Dominique; Fulton, Trevor; Imhof, Peter; Konopczynski, Tomasz; Lim, Tanya; Lu, Nanyao; Marchili, Nicola; Naylor, David; Swinyard, Bruce

    2014-01-01

    We present a method to derive the relative pointing offsets for SPIRE Fourier-Transform Spectrometer (FTS) solar system object (SSO) calibration targets, which were observed regularly throughout the Herschel mission. We construct ratios of the spectra for all observations of a given source with respect to a reference. The reference observation is selected iteratively to be the one with the highest observed continuum. Assuming that any pointing offset leads to an overall shift of the continuum level, then these ratios represent the relative flux loss due to mispointing. The mispointing effects are more pronounced for a smaller beam, so we consider only the FTS short wavelength array (SSW, 958-1546 GHz) to derive a pointing correction. We obtain the relative pointing offset by comparing the ratio to a grid of expected losses for a model source at different distances from the centre of the beam, under the assumption that the SSW FTS beam can be well approximated by a Gaussian. In order to avoid dependency on the...

  16. Calibration Systems Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Myers, Tanya L.; Broocks, Bryan T.; Phillips, Mark C.

    2006-02-01

    The Calibration Systems project at Pacific Northwest National Laboratory (PNNL) is aimed towards developing and demonstrating compact Quantum Cascade (QC) laser-based calibration systems for infrared imaging systems. These on-board systems will improve the calibration technology for passive sensors, which enable stand-off detection for the proliferation or use of weapons of mass destruction, by replacing on-board blackbodies with QC laser-based systems. This alternative technology can minimize the impact on instrument size and weight while improving the quality of instruments for a variety of missions. The potential of replacing flight blackbodies is made feasible by the high output, stability, and repeatability of the QC laser spectral radiance.

  17. Ibis ground calibration

    Energy Technology Data Exchange (ETDEWEB)

    Bird, A.J.; Barlow, E.J.; Tikkanen, T. [Southampton Univ., School of Physics and Astronomy (United Kingdom); Bazzano, A.; Del Santo, M.; Ubertini, P. [Istituto di Astrofisica Spaziale e Fisica Cosmica - IASF/CNR, Roma (Italy); Blondel, C.; Laurent, P.; Lebrun, F. [CEA Saclay - Sap, 91 - Gif sur Yvette (France); Di Cocco, G.; Malaguti, E. [Istituto di Astrofisica Spaziale e Fisica-Bologna - IASF/CNR (Italy); Gabriele, M.; La Rosa, G.; Segreto, A. [Istituto di Astrofisica Spaziale e Fisica- IASF/CNR, Palermo (Italy); Quadrini, E. [Istituto di Astrofisica Spaziale e Fisica-Cosmica, EASF/CNR, Milano (Italy); Volkmer, R. [Institut fur Astronomie und Astrophysik, Tubingen (Germany)

    2003-11-01

    We present an overview of results obtained from IBIS ground calibrations. The spectral and spatial characteristics of the detector planes and surrounding passive materials have been determined through a series of calibration campaigns. Measurements of pixel gain, energy resolution, detection uniformity, efficiency and imaging capability are presented. The key results obtained from the ground calibration have been: - optimization of the instrument tunable parameters, - determination of energy linearity for all detection modes, - determination of energy resolution as a function of energy through the range 20 keV - 3 MeV, - demonstration of imaging capability in each mode, - measurement of intrinsic detector non-uniformity and understanding of the effects of passive materials surrounding the detector plane, and - discovery (and closure) of various leakage paths through the passive shielding system.

  18. TARGETLESS CAMERA CALIBRATION

    Directory of Open Access Journals (Sweden)

    L. Barazzetti

    2012-09-01

    Full Text Available In photogrammetry a camera is considered calibrated if its interior orientation parameters are known. These encompass the principal distance, the principal point position and some Additional Parameters used to model possible systematic errors. The current state of the art for automated camera calibration relies on the use of coded targets to accurately determine the image correspondences. This paper presents a new methodology for the efficient and rigorous photogrammetric calibration of digital cameras which does not require any longer the use of targets. A set of images depicting a scene with a good texture are sufficient for the extraction of natural corresponding image points. These are automatically matched with feature-based approaches and robust estimation techniques. The successive photogrammetric bundle adjustment retrieves the unknown camera parameters and their theoretical accuracies. Examples, considerations and comparisons with real data and different case studies are illustrated to show the potentialities of the proposed methodology.

  19. The Collaborate Calibration and Alignment of Button-type BPM

    CERN Document Server

    Yuan, Jiandong; Zhang, Bin; Yao, Junjie

    2015-01-01

    Beam position monitor (BPM) can easily reinforce the handling of beam orbits and measure the absolute beam position [1]. Its data can be used to optimize and correct beam in both first turn and closed orbit mode. In order to set the absolute center position of Button-type BPM, and formulate the offset between mechanic and electronic center precisely, we mounted BPM together with solenoid on a vertical rotated test-bench when its calibration takes out, and developed transform software to calculate the offset. This paper describes the method and process of collaborate calibration: the assembly and alignment of BPM itself on the designed work-bench; the mechanic calibration of bundle BPM-Solenoid, and the alignment of mechanic to the wire center used by Laser Tracker and Portable coordinate measurement machine (CMM) jointly; the connection of coaxial cable and read-out for electronics; the electronic calibration of bundle BPM-Solenoid. Form the above four steps, the author analyses the error sources, measures an...

  20. Iterative Magnetometer Calibration

    Science.gov (United States)

    Sedlak, Joseph

    2006-01-01

    This paper presents an iterative method for three-axis magnetometer (TAM) calibration that makes use of three existing utilities recently incorporated into the attitude ground support system used at NASA's Goddard Space Flight Center. The method combines attitude-independent and attitude-dependent calibration algorithms with a new spinning spacecraft Kalman filter to solve for biases, scale factors, nonorthogonal corrections to the alignment, and the orthogonal sensor alignment. The method is particularly well-suited to spin-stabilized spacecraft, but may also be useful for three-axis stabilized missions given sufficient data to provide observability.

  1. Geometric calibration of the circle-plus-arc trajectory.

    Science.gov (United States)

    Hoppe, Stefan; Noo, Frédéric; Dennerlein, Frank; Lauritsch, Günter; Hornegger, Joachim

    2007-12-07

    In this paper, a novel geometric calibration method for C-arm cone-beam scanners is presented which allows the calibration of the circle-plus-arc trajectory. The main idea is the separation of the trajectory into two circular segments (circle segment and arc segment) which are calibrated independently. This separation makes it possible to reuse a calibration phantom which has been successfully applied in clinical environments to calibrate numerous routinely used C-arm systems. For each trajectory segment, the phantom is placed in an optimal position. The two calibration results are then combined by computing the transformation the phantom underwent between the independent calibration runs. This combination can be done in a post-processing step by using standard linear algebra. The method is not limited to circle-plus-arc trajectories and works for any calibration procedure in which the phantom has a preferred orientation with respect to a trajectory segment. Results are presented for both simulated as well as real data acquired with a C-arm system. We also present the first image reconstruction results for the circle-plus-arc trajectory using real C-arm data.

  2. Beam loading

    CERN Document Server

    Gamp, Alexander

    2013-01-01

    We begin by giving a description of the radio-frequency generator-cavity-beam coupled system in terms of basic quantities. Taking beam loading and cavity detuning into account, expressions for the cavity impedance as seen by the generator and as seen by the beam are derived. Subsequently methods of beam-loading compensation by cavity detuning, radio-frequency feedback and feedforward are described. Examples of digital radio-frequency phase and amplitude control for the special case of superconducting cavities are also given. Finally, a dedicated phase loop for damping synchrotron oscillations is discussed.

  3. Oberst beam test technique

    Science.gov (United States)

    Fasana, Alessandro; Garibaldi, Luigi; Giorcelli, Ermanno; Ruzzene, Massimo

    1998-06-01

    The definition of the mechanical properties of viscoelastic materials, i.e. the elastic modulus and the loss factor, is carried out, according to many national and international standards, with many different techniques, both of the resonant and non-resonant type. In this paper we focus our attention on the pros and cons of the resonant technique based on the classical Oberst beam method. When the damping material to be tested is not self-supporting, its properties are determined taking start from the measured modal frequencies and loss factors of a laminated beam, constituted by one or two metallic strips, ideally undamped, and one or two viscoelastic layers. The formulae specified on the standards hold valid under the assumptions of the theory developed by Kerwin, Ungar and Ross and we try in this paper to quantify witch deviation of the results should be expected when moving away from their ideal hypotheses.

  4. Measurement and Simulation of Beam Centering on CYCIAE-10

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    The beam centering is very important for the compact cyclotron, especially for the cyclotrons with the axial injection. It is critical that the cyclotron has a good beam centering to increase the beam current and reduce the beam loss. In the accelerating process,

  5. A self-sufficient method for calibration of Varian electronic portal imaging device

    Science.gov (United States)

    Sun, Baozhou; Yaddanapudi, Sridhar; Goddu, Sreekrishna M.; Mutic, Sasa

    2015-01-01

    Electronic portal imaging device (EPID) is currently used for dosimetric verification of IMRT fields and linac quality assurance (QA). It is critical to understand the dosimetric response and perform an accurate and robust calibration of EPID. We present the implementation of an efficient method for the calibration and the validation of a Varian EPID, which relies only on data collected with that specific device. The calibration method is based on images obtained with five shifts of EPID panel. With this method, the relative gain (sensitivity) of each element of a detector matrix is calculated and applied on top of the calibration determined with the flood-field procedure. The calibration procedure was verified using a physical wedge inserted in the beam line and the corrected profile shows consistent results with the measurements using a calibrated 2D array. This method does not rely on the beam profile used in the flood-field calibration process, which allows EPID calibration in 10 minutes with no additional equipment compared to at least 2 hours to obtain beam profile and scanning beam equipment requirement with the conventional method.

  6. Calibration of the CREAM-I calorimeter

    CERN Document Server

    Yoon, Y S; Bagliesi, M G; Bigongiari, G; Ganel, O; Han, J H; Jeon, J A; Kim, K C; Lee, M H; Lutz, L; Maestro, P; Malinin, A; Marrocchesi, P S; Nam, S; Park, I H; Park, N H; Seo, E S; Sina, R; Wu, J; Yang, J; Zei, R; Zinn, S Y

    2010-01-01

    The Cosmic Ray Energetics And Mass (CREAM) calorimeter is designed to measure the spectra of cosmic-ray particles over the energy range from ~10^11 eV to ~10^15 eV. Its first flight as part of the CREAM-I balloon-borne payload in Antarctica during the 2004/05 season resulted in a recordbreaking 42 days of exposure. Calorimeter calibration using various beam test data will be discussed in an attempt to assess the uncertainties of the energy measurements.

  7. Calibrating the HXMT collimators using diffuse illumination

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    We propose a new method to calibrate the HXMT collimators by measuring the optical point spread function(PSF) of the hard X-ray modulation telescope(HXMT).The light transmission of the collimator at different viewing angles with a camera and a diffuse backlight placed behind the collimator is measured.This method is much easier to accomplish than measuring the PSF with a parallel optical beam.The experimental results are very consistent with the simulations.The PSF of the collimator of the high energy X-ray telescope on HXMT is found to be in good agreement with the design,with accuracy better than 1 arcmin.

  8. Calibration of cathode strip gains in multiwire drift chambers of the GlueX experiment

    Energy Technology Data Exchange (ETDEWEB)

    Berdnikov, V. V.; Somov, S. V.; Pentchev, L.; Somov, A.

    2016-07-01

    A technique for calibrating cathode strip gains in multiwire drift chambers of the GlueX experiment is described. The accuracy of the technique is estimated based on Monte Carlo generated data with known gain coefficients in the strip signal channels. One of the four detector sections has been calibrated using cosmic rays. Results of drift chamber calibration on the accelerator beam upon inclusion in the GlueX experimental setup are presented.

  9. Smart Calibration of Excavators

    DEFF Research Database (Denmark)

    Bro, Marie; Døring, Kasper; Ellekilde, Lars-Peter

    2005-01-01

    Excavators dig holes. But where is the bucket? The purpose of this report is to treat four different problems concerning calibrations of position indicators for excavators in operation at concrete construction sites. All four problems are related to the question of how to determine the precise ge...

  10. Calibrating Communication Competencies

    Science.gov (United States)

    Surges Tatum, Donna

    2016-11-01

    The Many-faceted Rasch measurement model is used in the creation of a diagnostic instrument by which communication competencies can be calibrated, the severity of observers/raters can be determined, the ability of speakers measured, and comparisons made between various groups.

  11. Entropic calibration revisited

    Energy Technology Data Exchange (ETDEWEB)

    Brody, Dorje C. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)]. E-mail: d.brody@imperial.ac.uk; Buckley, Ian R.C. [Centre for Quantitative Finance, Imperial College, London SW7 2AZ (United Kingdom); Constantinou, Irene C. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom); Meister, Bernhard K. [Blackett Laboratory, Imperial College, London SW7 2BZ (United Kingdom)

    2005-04-11

    The entropic calibration of the risk-neutral density function is effective in recovering the strike dependence of options, but encounters difficulties in determining the relevant greeks. By use of put-call reversal we apply the entropic method to the time reversed economy, which allows us to obtain the spot price dependence of options and the relevant greeks.

  12. Calibration with Absolute Shrinkage

    DEFF Research Database (Denmark)

    Øjelund, Henrik; Madsen, Henrik; Thyregod, Poul

    2001-01-01

    is suggested to cope with the singular design matrix most often seen in chemometric calibration. Furthermore, the proposed algorithm may be generalized to all convex norms like Sigma/beta (j)/(gamma) where gamma greater than or equal to 1, i.e. a method that continuously varies from ridge regression...

  13. Measurement System & Calibration report

    DEFF Research Database (Denmark)

    Kock, Carsten Weber; Vesth, Allan

    This Measurement System & Calibration report is describing DTU’s measurement system installed at a specific wind turbine. A major part of the sensors has been installed by others (see [1]) the rest of the sensors have been installed by DTU. The results of the measurements, described in this report...

  14. NVLAP calibration laboratory program

    Energy Technology Data Exchange (ETDEWEB)

    Cigler, J.L.

    1993-12-31

    This paper presents an overview of the progress up to April 1993 in the development of the Calibration Laboratories Accreditation Program within the framework of the National Voluntary Laboratory Accreditation Program (NVLAP) at the National Institute of Standards and Technology (NIST).

  15. Beam halo studies in LEHIPA DTL

    Science.gov (United States)

    Roy, S.; Pande, R.; Rao, S. V. L. S.; Krishnagopal, S.; Singh, P.

    2015-11-01

    The Low Energy High Intensity Proton Accelerator (LEHIPA) project at Bhabha Atomic Research Centre (BARC) consists of a 20 MeV, 30 mA proton linac. The accelerator comprises of a 3 MeV Radio Frequency Quadrupole (RFQ) and a 20 MeV Drift Tube Linac (DTL). In such high intensity accelerators, beam halos are of concern as they not only cause an increase in emittance, but also lead to beam loss and radio activation. We have studied the effect of beam mismatch at the DTL input on halo formation and propagation. The particle core model is used to excite the three envelope eigen modes; the quadrupole mode, the fast mode and the slow mode by giving input beam mismatch. These modes get damped as the beam progresses through the DTL. The damping mechanism is clearly Landau damping and leads to increase in rms emittance of the beam. The evolution of these modes and the corresponding increase in beam emittance and maximum beam extent, as the beam propagates through the DTL, has been studied for different space charge tunes. The halo parameter based on the definition of Allen and Wangler has been calculated. It is seen that beam halos are very important for LEHIPA DTL, even at 20 MeV and leads to emittance and beam size increase and also to beam loss in some cases. The longitudinal halo is present even without mismatch and transverse halos arise in the presence of beam mismatch.

  16. Study on Radiation Field Caused by Proton Beam Loss in High Intensity Heavy-ion Accelerator%强流重离子加速器中由于质子束流损失引起的次级辐射场计算研究

    Institute of Scientific and Technical Information of China (English)

    庞成果; 苏有武; 徐俊奎; 李武元; 姚泽恩

    2015-01-01

    The second radiation field outside the vacuum tube caused by proton beam loss in high intensity heavy‐ion accelerator facility (HIAF) with Monte Carlo method was calculated .The energy of proton beam is within 50 MeV to 12 GeV .The basic problems such as second particle yield ,energy spectrum and angular distribution were also discussed .T hese results are beneficial to selecting the detector type and its location and determining its dynamic range for beam loss detector ,as well as to building the beam loss monitor system .Furthermore ,they are meaningful in some way for the radia‐tion protection of accelerator .%本文利用蒙特卡罗方法计算了强流重离子加速器中质子能量在50 M eV~12 GeV能量范围内由于束流损失引起的真空管壁外的次级辐射场,分别就次级粒子的产额、能谱及角分布等方面进行了基本研究。本文的研究结果在束流损失探测器的选择、安装位置以及动态范围的确定上有着重要的参考价值,对于束流损失监测系统的建立有着极为重要的意义。同时,对于加速器的辐射防护问题也有一定的参考价值。

  17. Mercury CEM Calibration

    Energy Technology Data Exchange (ETDEWEB)

    John F. Schabron; Joseph F. Rovani; Susan S. Sorini

    2007-03-31

    The Clean Air Mercury Rule (CAMR) which was published in the Federal Register on May 18, 2005, requires that calibration of mercury continuous emissions monitors (CEMs) be performed with NIST-traceable standards. Western Research Institute (WRI) is working closely with the Electric Power Research Institute (EPRI), the National Institute of Standards and Technology (NIST), and the Environmental Protection Agency (EPA) to facilitate the development of the experimental criteria for a NIST traceability protocol for dynamic elemental mercury vapor generators. The traceability protocol will be written by EPA. Traceability will be based on the actual analysis of the output of each calibration unit at several concentration levels ranging from about 2-40 ug/m{sup 3}, and this analysis will be directly traceable to analyses by NIST using isotope dilution inductively coupled plasma/mass spectrometry (ID ICP/MS) through a chain of analyses linking the calibration unit in the power plant to the NIST ID ICP/MS. Prior to this project, NIST did not provide a recommended mercury vapor pressure equation or list mercury vapor pressure in its vapor pressure database. The NIST Physical and Chemical Properties Division in Boulder, Colorado was subcontracted under this project to study the issue in detail and to recommend a mercury vapor pressure equation that the vendors of mercury vapor pressure calibration units can use to calculate the elemental mercury vapor concentration in an equilibrium chamber at a particular temperature. As part of this study, a preliminary evaluation of calibration units from five vendors was made. The work was performed by NIST in Gaithersburg, MD and Joe Rovani from WRI who traveled to NIST as a Visiting Scientist.

  18. Field calibration of cup anemometers

    DEFF Research Database (Denmark)

    Schmidt Paulsen, Uwe; Mortensen, Niels Gylling; Hansen, Jens Carsten

    2007-01-01

    A field calibration method and results are described along with the experience gained with the method. The cup anemometers to be calibrated are mounted in a row on a 10-m high rig and calibrated in the free wind against a reference cup anemometer. The method has been reported [1] to improve...... the statistical bias on the data relative to calibrations carried out in a wind tunnel. The methodology is sufficiently accurate for calibration of cup anemometers used for wind resource assessments and provides a simple, reliable and cost-effective solution to cup anemometer calibration, especially suited...

  19. Mercury Calibration System

    Energy Technology Data Exchange (ETDEWEB)

    John Schabron; Eric Kalberer; Joseph Rovani; Mark Sanderson; Ryan Boysen; William Schuster

    2009-03-11

    U.S. Environmental Protection Agency (EPA) Performance Specification 12 in the Clean Air Mercury Rule (CAMR) states that a mercury CEM must be calibrated with National Institute for Standards and Technology (NIST)-traceable standards. In early 2009, a NIST traceable standard for elemental mercury CEM calibration still does not exist. Despite the vacature of CAMR by a Federal appeals court in early 2008, a NIST traceable standard is still needed for whatever regulation is implemented in the future. Thermo Fisher is a major vendor providing complete integrated mercury continuous emissions monitoring (CEM) systems to the industry. WRI is participating with EPA, EPRI, NIST, and Thermo Fisher towards the development of the criteria that will be used in the traceability protocols to be issued by EPA. An initial draft of an elemental mercury calibration traceability protocol was distributed for comment to the participating research groups and vendors on a limited basis in early May 2007. In August 2007, EPA issued an interim traceability protocol for elemental mercury calibrators. Various working drafts of the new interim traceability protocols were distributed in late 2008 and early 2009 to participants in the Mercury Standards Working Committee project. The protocols include sections on qualification and certification. The qualification section describes in general terms tests that must be conducted by the calibrator vendors to demonstrate that their calibration equipment meets the minimum requirements to be established by EPA for use in CAMR monitoring. Variables to be examined include linearity, ambient temperature, back pressure, ambient pressure, line voltage, and effects of shipping. None of the procedures were described in detail in the draft interim documents; however they describe what EPA would like to eventually develop. WRI is providing the data and results to EPA for use in developing revised experimental procedures and realistic acceptance criteria based on

  20. First Demonstration of ECHO: an External Calibrator for Hydrogen Observatories

    Science.gov (United States)

    Jacobs, Daniel C.; Burba, Jacob; Bowman, Judd D.; Neben, Abraham R.; Stinnett, Benjamin; Turner, Lauren; Johnson, Kali; Busch, Michael; Allison, Jay; Leatham, Marc; Serrano Rodriguez, Victoria; Denney, Mason; Nelson, David

    2017-03-01

    Multiple instruments are pursuing constraints on dark energy, observing reionization and opening a window on the dark ages through the detection and characterization of the 21 cm hydrogen line for redshifts ranging from ∼1 to 25. These instruments, including CHIME in the sub-meter and HERA in the meter bands, are wide-field arrays with multiple-degree beams, typically operating in transit mode. Accurate knowledge of their primary beams is critical for separation of bright foregrounds from the desired cosmological signals, but difficult to achieve through astronomical observations alone. Previous beam calibration work at low frequencies has focused on model verification and does not address the need of 21 cm experiments for routine beam mapping, to the horizon, of the as-built array. We describe the design and methodology of a drone-mounted calibrator, the External Calibrator for Hydrogen Observatories (ECHO), that aims to address this need. We report on a first set of trials to calibrate low-frequency dipoles at 137 MHz and compare ECHO measurements to an established beam-mapping system based on transmissions from the Orbcomm satellite constellation. We create beam maps of two dipoles at a 9° resolution and find sample noise ranging from 1% at the zenith to 100% in the far sidelobes. Assuming this sample noise represents the error in the measurement, the higher end of this range is not yet consistent with the desired requirement but is an improvement on Orbcomm. The overall performance of ECHO suggests that the desired precision and angular coverage is achievable in practice with modest improvements. We identify the main sources of systematic error and uncertainty in our measurements and describe the steps needed to overcome them.