DIPAC2011 - List of Keywords (proton)

Paper	Title	Other Keywords	Page
MOPD02	The CNAO Qualification Monitor	extraction, synchrotron, power-supply, controls	32
	C. Viviani, G. Balbinot, J. Bosser, M. Caldara, H. Caracciolo, M.A. Garella, V. Lante, A. Parravicini, M. Pullia CNAO Foundation, Milan, Italy
	The CNAO (Centro Nazionale di Adroterapia Oncologica) Foundation is the first Italian center for deep hadrontherapy. It will treat patients using Protons and Carbon ions in the next coming months. Patient safety is the first priority and many diagnostics devices have been developed to guarantee it. This work presents the so-called Qualification Monitor (QM). It is mounted in the common part of the four extraction lines, in front of the Chopper Dump, and it aims to qualify the extracted beam profile and intensity, before sending it to the treatment rooms. It is made of two different detectors: the first one, called Qualification Profile Monitor (QPM), is made by two dimensional harp of scintillating fibers to measure horizontal and vertical profiles. The second one, named Qualification Intensity Monitor (QIM) is a scintillating plate for intensity measurement. At the beginning of each extracted spill the beam is dumped on the Chopper Dump and it hit the QM. Only a positive result from beam qualification allows to switch on Chopper magnets and to send the beam to the patient. The QM is working with beam from some months, first results and future upgrades are presented.

MOPD03	The Beam Safety System of the PSI UCN Source	target, kicker, neutron, power-supply	35
	D. Reggiani, B. Blarer, P.-A. Duperrex, G. Dzieglewski, F. Heinrich, A.C. Mezger, U. Rohrer, K. Thomsen, M. Wohlmuther PSI, Villigen, Switzerland
	At PSI, a new and very intensive Ultra-Cold Neutron (UCN) source based on the spallation principle was commissioned in December 2010 and will start production in 2011. From then on, two neutron spallation sources, the continuous wave SINQ and the macro-pulsed UCN source, both furnished with a solid state target, will be operating concurrently at PSI. The 590 MeV, 1.3 MW proton beam will be switched towards the new spallation target for about 8 s every 800 s. Safe operation of the UCN source is guaranteed by two independent interlock systems. In fact, beside the well established accelerator protection system, a new fast interlock system has been designed following the experience gathered with the MEGAPIE (Megawatt Pilot Target Experiment) project. The goal of this additional system is to preserve the UCN target and the complete beam line installation by ensuring correct beam settings and, at the same time, to avoid any accidental release of radioactive material. After a brief introduction of the PSI UCN source, this paper will focus on the motivations as well as the principle of operation of the UCN beam safety system.
	Poster MOPD03 [3.046 MB]

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

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

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

MOPD16	Advanced Digital Signal Processing for Effective Beam Position Monitoring	synchrotron, antiproton, monitoring, heavy-ion	74
	D.A. Liakin ITEP, Moscow, Russia P. Forck, K. Lang, R. Singh GSI, Darmstadt, Germany
	A latest experience in digital signal processing of BPM data obtained in synchrotrons of ITEP and GSI is discussed. The data in ITEP was collected by BPM processor prototype while the SIS18 in GSI uses a renovated digital system. Due to different concept of BPM architectures on those facilities it is possible to compare algorithms oriented to certain hardware. Several algorithms of position detection are compared to each other. Performances of ‘collective’ and partly distributed algorithms are estimated. Data reduction methods and visualization solutions are considered. Finally low- and wideband data evaluation for longitudinal phase space is presented.
	Poster MOPD16 [13.416 MB]

MOPD18	Embedded Collimator Beam Position Monitors	vacuum, beam-losses, collimation, impedance	80
	C.B. Boccard, A. Bertarelli, A. Dallocchio, M. Gasior, L. Gentini, A.A. Nosych CERN, Geneva, Switzerland
	The LHC collimation system is crucial for safe and reliable operation of proton beams with 350 MJ stored energy. Currently the collimator set-up is performed by observing beam losses when approaching the collimator jaws to the beam. For all 100 LHC movable collimators the procedure may take several hours and since it has to be repeated whenever the beam configuration changes significantly, the collimator setup has an important impact on the overall machine operation efficiency. To reduce the collimator setup time by two orders of magnitude the next generation of the LHC collimators will be equipped with button beam position monitors (BPMs) embedded into the collimator jaws. This paper describes the BPM design and presents prototype results obtained with beam in the CERN-SPS.
	Poster MOPD18 [1.729 MB]

MOPD49	Beam Parameters Measurements by Ionization Cross Section Monitor on Proton LINAC of INR RAS	linac, emittance, radiation, ion	161
	P.I. Reinhardt-Nickoulin, S. Bragin, A. Feschenko, S.A. Gavrilov, I.V. Vasilyev, O. Volodkevich RAS/INR, Moscow, Russia
	The ionization beam cross section monitor (BCSM) is developed and used on proton linac of INR RAS to provide non-intercepting measurements of beam parameters. Operation of the monitor is based on utilization of residual gas ionization. The BCSM configuration design and image processing system are described and estimations of influence of the linac radiation background are discussed. The monitor enables to observe beam cross section and extract from it beam profiles and position as well as their evolution in time within a wide range of beam intensities and energies. The available experimental results of beam spot, profiles and emittances measurements at the linac output are presented.

MOPD51	Progress with the Scintillation Profile Monitor at COSY	vacuum, synchrotron, power-supply, target	164
	V. Kamerdzhiev, J. Dietrich, F. Klehr, K. Reimers FZJ, Jülich, Germany
	After successful demonstration measurements with the Scintillation Profile Monitor at COSY, a dedicated vacuum chamber with two vacuum windows and supporting vacuum ports was installed in the COSY synchrotron. The chamber is blackened inside to suppress light reflection. Since residual gas pressure is too low to support reliable profile measurements based on beam induced scintillation, a piezo-electric dosing valve was installed allowing fast injections of defined amount of nitrogen. A 32-channel photomultiplier is used to detect light. Beam profile measurements and first operational experience are reported.

MOPD52	First Results from Beam Measurements at the 3 MeV Test Stand for CERN Linac4	emittance, solenoid, linac, rfq	167
	B. Cheymol, J.-B. Lallement, A.E. Lokhovitskiy, O. Midttun, U. Raich, F. Roncarolo, R. Scrivens, E. Zorin CERN, Geneva, Switzerland B. Cheymol Université Blaise Pascal, Clermont-Ferrand, France
	The H⁻ source and the low energy beam line will determine to a large extend the performance of Linac-4, the new machine foreseen as injector into the PS Booster. For this reason a test stand will be set up consisting of the source, Low Energy Beam Transport (LEBT), RFQ and chopper line. Up to now only the source and LEBT are installed. First measurements have been performed using a Faraday Cup to measure the total source intensity, a slit-&-grid emittance meter for transverse emittance measurements and a spectrometer for energy spread measurements. This paper discusses the results from measurements on H⁻ beams at 35kV extraction voltage as well as protons at 45 kV, showing the emittance dependence on source RF power as well as the influence of a solenoid in splitting the beam into its various constituents: protons, H0, H²⁺ and H³⁺. Energy spread measurements are also presented.

MOPD66	Upgrade of the CERN PSB/CPS Fast Intensity Measurements	linac, synchrotron, booster, status	200
	A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby CERN, Geneva, Switzerland G. Kasprowicz CREOTECH Ltd., Warsaw, Poland
	The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

MOPD83	Performance of the Fast Beam Conditions Monitor BCM1F in the CMS Experiment at the LHC	radiation, monitoring, luminosity, vacuum	239
	M.E. Castro Carballo DESY Zeuthen, Zeuthen, Germany
	In the CMS detector a series of beam condition monitors were installed and are in operation for measuring radiation doses and preventing possible damages to the detector in case of beam losses. The Fast Beam Condition Monitor, BCM1F, is installed inside the pixel volume close to the beam pipe and it consists of two planes of 4 modules each located 1.8 m away from the IP, on both sides. It uses single-crystal CVD diamond sensors and radiation hard front-end electronics, along with an optical transmission of the signal. It was designed for fast flux monitoring, measuring beam halo and collision products on a bunch by bunch basis. Early in November 2009 the LHC restarted running with beams and since then BCM1F has been recording data from beam halo, beam studies, proton-proton and lead-lead collisions. It is an invaluable tool in everyday CMS operation and, due to the high sensitivity to beam conditions, is providing the so called Background (BKGD) 1 to LHC operators. A characterization of the system on the basis of data collected during LHC operation will be presented.
	Poster MOPD83 [1.449 MB]

TUOA01	Beam Instrumentation in J-PARC	linac, feedback, impedance, septum	275
	T. Toyama J-PARC, KEK & JAEA, Ibaraki-ken, Japan
	The talk will summarize the beam instrumentation at J-PARC with a focus on MW class proton beams. The measurements of beam intensities, positions, losses, profiles, and halos at each stage of accelerator, 181 MeV LINAC (to be upgraded to 400MeV), 3 GeV RCS and 50 (30 as phase I) GeV MR will be reported. Present status, including modification and improvement of instrumentations to meet with LINAC energy upgrade and a future plan will be reported with emphasis on high beam power related issues such as radiation hardness (mechanically and electrically), beam coupling impedance, etc..
	Slides TUOA01 [22.777 MB]

TUOA03	The Fermilab HINS Test Facility and Beam Measurements of the Ion Source and 325 MHz RFQ	diagnostics, rfq, laser, linac	283
	V.E. Scarpine, S. Chaurize, B.M. Hanna, S. Hays, J. Steimel, R.C. Webber, D. Wildman Fermilab, Batavia, USA
	Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359. The Fermilab High Intensity Neutrino Source (HINS) project is intended to test new concepts for low-energy, high-intensity superconducting linacs. HINS initial design consists of a 50 KeV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ) followed by room temperature and superconducting spoke resonator acceleration sections. At present, a proton ion source and the 325 MHz RFQ, followed by a beam diagnostics section, have been operated with beam. This paper will present the beam measurement results for the proton ion source and for the 325 MHz RFQ module. In addition, this paper will discuss the role of HINS as a test facility for the development of beam diagnostic instrumentation required for future high-intensity linacs.
	Slides TUOA03 [1.864 MB]

TUPD02	Beam Diagnostics for the ESS	linac, diagnostics, target, cryomodule	302
	A. Jansson, L. Tchelidze ESS, Lund, Sweden
	The European Spallation Source (ESS) is a based on a 2.5GeV superconducting linac, producing a 5MW beam. Since it is optimized for cold neutrons, there is no accumulator ring, and hence no need for change exchange injection. Therefore, unlike most other proposed MW-class linacs, the ESS linac will accelerate protons rather than H⁻ ions. This poses a particular challenge for beam size mesurements in the superconducting section. This paper discusses the ESS beam diagnostics requirements, along with some possible instrument design options.

TUPD15	Technology Selection for the Beam Position Tuning System in Hadrontherapy Facilities	electron, photon, high-voltage, controls	332
	C. Belver-Aguilar, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós IFIC, Valencia, Spain E. Benveniste, M. Haguenauer, P. Poilleux LLR, Palaiseau, France
	Funding: CYCIT – IN2P3: AIC10-D-000518 The Beam Delivery System of some hadrontherapy facilities is characterized by having scanning magnets, which move the beam in order to irradiate all the tumor volume. To control the beam position, a Beam Position Monitor (BPM) is needed. The BPM described in this paper is a new type of BPM based on four scintillating fibers coupled to four photodiodes to detect the light produced by the fibers when intercepting the beam. We present here the study of the possible photodiodes able to read the light emitted by the scintillating fiber, and the tests performed in order to find the most suitable photodiode to measure the beam position from the variations in the beam current. The setup used for the tests comprises a Sr-90 source, which emits electrons, a scintillating fiber, converting these electrons into photons, and a photodiode, which detects the photons leaving the fiber. The photodiodes studied have been of two types: Avalanche Photodiode (APD) and Multi Pixel Photon Counter (MPPC). In this paper both photodiodes are compared and the results are presented.

TUPD24	Design Status of Beam Position Monitors for the FAIR Proton Linac	linac, simulation, cavity, vacuum	356
	C.S. Simon, F. Senée CEA/DSM/IRFU, France G. Clemente, P. Forck, W. Kaufmann, P. Kowina GSI, Darmstadt, Germany
	Beam Position Monitors (BPM) based on capacitive buttons are designed for the FAIR Proton-LINAC, constructed as an extension of the existing GSI facility. This LINAC is aiming to produce a maximum design current of 70 mA at the 70 MeV energy with an accelerating frequency of 325 MHz. At 14 locations, the BPMs will measure the transverse beam position, the relative beam current and the mean beam energy by time-of-flight method. Depending of the location, the BPM design has to be optimized, taking into account an energy range from 3 MeV to 70 MeV, a short insertion and a beam pipe aperture changes from 30 mm to 50 mm. Some of BPMs will be mounted very close to the CH cavities and special care must be taken to suppress the pickup of the strong rf-field from that cavities. In this contribution, the status of the BPM design will be presented.

TUPD46	Beam Species Fraction Measurement using Doppler Shift Method with FUJIKURA Fiberscope for IFMIF-EVEDA Injector	diagnostics, target, neutron, radiation	407
	F. Senée, B. Pottin CEA/DSM/IRFU, France G. Adroit, R. Gobin, O. Tuske CEA/IRFU, Gif-sur-Yvette, France A. Olivier IPN, Orsay, France
	To characterize high intensity ion beam in low energy beam transport line, diagnostics based on residual gas molecule excitation are commonly used. An example is CCD sensors for beam intensity, beam position and beam profile measurements. At CEA/Saclay with the SILHI injector, beam images transports from viewport to sensor have been performed with a fiberscope. Such technique will be used to transport the beam images away from the irradiated zone of the IFMIF-EVEDA tunnel which requires using hardened radiation devices. Indeed, the (D,d) reaction, due to interaction of 140 mA-100 keV deuteron beam with vacuum pipes or scrapers, leads to high neutron and gamma ray flux. As a consequence, in addition to CID cameras for online beam positioning and shape measurements, a 20 m long Fujikura fiberscope has been selected to analyze species fraction using the Doppler shift method. Preliminary measurements have been performed with the SILHI beam to characterize the fiberscope. Its spatial resolution and transmission as well as a CCD sensor and fiberscope comparison are presented. Beam species fractions with and without the use of fiberscope will be also reported.

TUPD69	Operational Experience and Improvements of the LHC Beam Current Transformers	vacuum, feedback, luminosity, diagnostics	467
	P. Odier, D. Belohrad, J-J. Gras, M. Ludwig CERN, Geneva, Switzerland
	During the 2010 run the LHC continuously improved its performance. In particular the bunch charge and number of bunches were significantly increased, which revealed certain limitations of the LHC beam current transformers. The DC current transformers (DCCT), used to measure the circulating beam current, exhibited saturation related to bunch intensity, the number of batches in the machine and their spacing. Two major issues were also discovered on the fast beam current transformers (FBCT) used to measure the individual bunch charges: discrepancies in the measured intensities when compared to the DCCTs measurements and a bunch length dependence on the measured intensity. Further analysis showed that both problems are linked to the beam position dependence of the signal acquired from the toroids used in the FBCTs. This paper presents the observed issues, discusses possible solutions and reports on the results from modification made for the 2011 run.

TUPD74	The Bunch by Bunch Feedback System in J-PARC Main Ring	feedback, injection, kicker, acceleration	482
	Y. Kurimoto, Y.H. Chin, T. Obina, M. Tobiyama, T. Toyama KEK, Ibaraki, Japan Y. Shobuda JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan
	We report the current status of the bunch by bunch feedback system for the J-PARC Main Ring. The J-PARC Main Ring is the synchrotron accelerating protons from 3 GeV to 30 GeV. It is normally operating at the intensity of 135 kW. The bunch by bunch feedback system have been developed and used for the normal operation of J-PARC Main Ring. The system aims to reduce the coherent transverse oscillation due to the instabilities or injection errors. It consists of a beam position monitor, a stripline kicker and a signal processing electronics. We've observed the injection error leading to the head-tail oscillation and succeed in damping such kind of oscillations and reducing the beam loss significantly.
	Poster TUPD74 [1.107 MB]

TUPD82	First Results of the LHC Collision Rate Monitors	luminosity, simulation, interaction-region, bunching	497
	E. Bravin, S. Bart Pedersen, A. Boccardi, S. Burger, C. Dutriat CERN, Geneva, Switzerland L.R. Doolittle, H.S. Matis, M. Placidi, A. Ratti, H. Yaver, T. stezelberger LBNL, Berkeley, California, USA R. Miyamoto BNL, Upton, Long Island, New York, USA
	Funding: This work is partially supported by the US DoE through US-LARP The aim of CERN’s large hadron collider (LHC) is to collide protons and heavy ions with centre of mass energies up to 14 zTeV. In order to monitor and optimize the collision rates special detectors have been developed and installed around the four luminous interaction regions. Due to the different conditions at the high luminosity experiments, ATLAS and CMS, and the low luminosity experiments, ALICE and LHC-b, two very different types of monitors are used, a fast ionisation chamber (BRAN-A) and a Cd-Te solid state detector (BRAN-B) respectively. Moreover in order to cope with the low collision rates foreseen for the initial run a third type of monitor, based on a simple scintillating pad, was installed in parallel with the BRAN-A. This contribution illustrates the results obtained during the 2010 run with an outlook for 2011 and beyond.

TUPD88	A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron	electron, gun, synchrotron, diagnostics	512
	A. Pertica, S.J. Payne STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.
	Poster TUPD88 [1.793 MB]

TUPD91	Comparative Studies of Reconstruction Methods to Achieve Multi-Dimensional Phase Space Information	emittance, diagnostics, ion, FEL	521
	C. Gabor STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom A.P. Letchford STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom D. Reggiani, M. Seidel PSI, Villigen, Switzerland
	High Intensity Proton Accelerators like SNS, PSI or future machines like ESS or Isis upgrade cannot tolerate high losses due to activation. Standard beam diagnostics may not provide enough information about potential loss sources like beam filamentation or halo. Moreover, the application of interceptive methods like slits or pepperpot can be seriously discouraged by either high power deposition or explicit requirements for non-destructive methods like on-line diagnostics near superconducting cavities. Reconstruction of the beam distribution with a tomography method based on Maximum Entropy could help to overcome those problems and is easily to integrate in already existing facilities because the algorithm does not depend on the experimental profile measurement technique. Furthermore beam tomography can be employed on both spatial and phase-space reconstruction. The paper compares results from two different software packages from PSI (Maximum Entropy Tomography MENT) with the code used at RAL (MemSys 5).

TUPD94	Monitoring of GeV Deuteron Beam Parameters in ADS Experiments at the Nuclotron (JINR, Dubna)	target, neutron, monitoring, synchrotron	530
	A.A. Safronava, A.A. Patapenka JIPNR-Sosny NASB, Minsk, Belarus V.V. Sotnikov, V.A. Voronko NSC/KIPT, Kharkov, Ukraine O. Svoboda NPI, Řež near Prague, Czech Republic W. Westmeier Philipps-Universität, Marburg, Germany
	The quality of beam instrumentation is very important in the experiments on accelerator driven systems (ADS) aiming to investigate spatial and energy distribution of neutrons inside and outside the subcritical setups comprising spallation neutron sources irradiated by relativistic beams. An important source of systematic uncertainties of the experimental data is the inaccuracy of determination of the beam parameters such as total intensity of the extracted beam, beam position at the target, fraction of the beam hitting the target and beam shape. This paper reviews the experimental techniques and measurement tools for deuteron beam monitoring used within the “Energy plus Transmutation” collaboration in the ADS experiments at the accelerator complex of Nuclotron (JINR, Russia): - activation technique using Al monitors for measurement of the total intensity of the extracted beam; - solid nuclear track detectors method and activation technique using segmented activation Cu foils for determination of beam profile and position at the target.
	Poster TUPD94 [13.019 MB]

WEOA04	Synchrotron Radiation Measurements at the CERN LHC	ion, emittance, photon, booster	550
	F. Roncarolo, S. Bart Pedersen, A. Boccardi, E. Bravin, A. Guerrero, A. Jeff, T. Lefèvre, A. Rabiller CERN, Geneva, Switzerland A.S. Fisher SLAC, Menlo Park, California, USA
	The CERN LHC is equipped with two systems (one for each beam) designed to image the synchrotron radiation emitted by protons and heavy ions. After their commissioning in 2009, the detectors were extensively used and studied during the 2010 run. This allowed preliminary limits in terms of sensitivity, accuracy and resolution to be established. The upgrade to an intensified video camera capable of gating down to 25ns permitted the acquisition of single bunch profiles even with an LHC proton pilot bunch (~5·10⁹ protons) at 450 GeV or a single lead ion bunch (~10⁸ ions) from about 2 TeV. Plans for the optimization and upgrade of the system will be discussed. Since few months, part of the extracted light is deviated to the novel Longitudinal Density Monitor (LDM), consisting in an avalanche photo-diode detector providing a resolution better than 100 ps. The LDM system description will be complemented with the promising first measurement results.
	Slides WEOA04 [6.398 MB]

WEOD01	Beam Induced Fluorescence Monitors	ion, photon, diagnostics, electron	575
	F. Becker GSI, Darmstadt, Germany
	Non-intercepting diagnostic devices in hadron accelerators offer continuous online monitoring capability. They also avoid the problem of potential thermal damage in high-current applications. Taking advantage of the residual gas as active material, the Beam Induced Fluorescence (BIF) monitor exploits gas fluorescence in the visible range for transversal profile measurements. Depending on beam parameters and vacuum-constraints, BIF monitors can be operated at base-pressure or in dedicated local pressure bumps up to the mbar range. Nowadays, BIF monitors are investigated in many accelerator laboratories for hadron energies from about 100 keV up to several 100 GeV. This talk gives an introduction to the measurement principle and typical operating conditions. It summarises recent investigations, e.g. on different working gases, and it compares various technical realisations.
	Slides WEOD01 [12.701 MB]

WEOD02	LHC Beam Diagnostics - the Users Point of View	luminosity, ion, injection, instrumentation	580
	J. Wenninger CERN, Geneva, Switzerland
	The LHC started up with beam in November 2009, and within less then on year its luminosity reached 2·10³² cm^-2s⁻¹ at 3.5 TeV in October 2010. A few weeks later, in November 2010, lead ion collisions were established within little over 2 days. The fast progress and successes of the LHC commissioning and early operation would not have been possible without the excellent performance of its beam instrumentation. All essential instruments worked from the first day or were commissioned in a very short time, providing rapid diagnostics for the beam parameters. Tune and orbit feedbacks that rely on high quality measurements were used early on to achieve smooth operation with minimal beam losses. This presentation will address the performance of the LHC beam instrumentation, in particular the very large beam position and beam loss monitoring systems, both composed of many thousand channels. Present limitations and future improvements will also be discussed.
	Slides WEOD02 [11.950 MB]

Paper

Title

Other Keywords

Page

MOPD02

The CNAO Qualification Monitor

extraction, synchrotron, power-supply, controls

32

C. Viviani, G. Balbinot, J. Bosser, M. Caldara, H. Caracciolo, M.A. Garella, V. Lante, A. Parravicini, M. Pullia
CNAO Foundation, Milan, Italy

The CNAO (Centro Nazionale di Adroterapia Oncologica) Foundation is the first Italian center for deep hadrontherapy. It will treat patients using Protons and Carbon ions in the next coming months. Patient safety is the first priority and many diagnostics devices have been developed to guarantee it. This work presents the so-called Qualification Monitor (QM). It is mounted in the common part of the four extraction lines, in front of the Chopper Dump, and it aims to qualify the extracted beam profile and intensity, before sending it to the treatment rooms. It is made of two different detectors: the first one, called Qualification Profile Monitor (QPM), is made by two dimensional harp of scintillating fibers to measure horizontal and vertical profiles. The second one, named Qualification Intensity Monitor (QIM) is a scintillating plate for intensity measurement. At the beginning of each extracted spill the beam is dumped on the Chopper Dump and it hit the QM. Only a positive result from beam qualification allows to switch on Chopper magnets and to send the beam to the patient. The QM is working with beam from some months, first results and future upgrades are presented.

MOPD03

The Beam Safety System of the PSI UCN Source

target, kicker, neutron, power-supply

35

D. Reggiani, B. Blarer, P.-A. Duperrex, G. Dzieglewski, F. Heinrich, A.C. Mezger, U. Rohrer, K. Thomsen, M. Wohlmuther
PSI, Villigen, Switzerland

At PSI, a new and very intensive Ultra-Cold Neutron (UCN) source based on the spallation principle was commissioned in December 2010 and will start production in 2011. From then on, two neutron spallation sources, the continuous wave SINQ and the macro-pulsed UCN source, both furnished with a solid state target, will be operating concurrently at PSI. The 590 MeV, 1.3 MW proton beam will be switched towards the new spallation target for about 8 s every 800 s. Safe operation of the UCN source is guaranteed by two independent interlock systems. In fact, beside the well established accelerator protection system, a new fast interlock system has been designed following the experience gathered with the MEGAPIE (Megawatt Pilot Target Experiment) project. The goal of this additional system is to preserve the UCN target and the complete beam line installation by ensuring correct beam settings and, at the same time, to avoid any accidental release of radioactive material. After a brief introduction of the PSI UCN source, this paper will focus on the motivations as well as the principle of operation of the UCN beam safety system.

Poster MOPD03 [3.046 MB]

MOPD05

Beam Diagnostic Layout for SIS100 at FAIR

ion, diagnostics, pick-up, beam-losses

41

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

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

MOPD06

Capabilities and Performance of the LHC Schottky Monitors

pick-up, injection, emittance, impedance

44

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

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

Poster MOPD06 [3.484 MB]

MOPD15

Electromagnetic Simulations of an Embedded BPM in Collimator Jaws

simulation, pick-up, collimation, alignment

71

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

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

Poster MOPD15 [6.439 MB]

MOPD16

Advanced Digital Signal Processing for Effective Beam Position Monitoring

synchrotron, antiproton, monitoring, heavy-ion

74

D.A. Liakin
ITEP, Moscow, Russia
P. Forck, K. Lang, R. Singh
GSI, Darmstadt, Germany

A latest experience in digital signal processing of BPM data obtained in synchrotrons of ITEP and GSI is discussed. The data in ITEP was collected by BPM processor prototype while the SIS18 in GSI uses a renovated digital system. Due to different concept of BPM architectures on those facilities it is possible to compare algorithms oriented to certain hardware. Several algorithms of position detection are compared to each other. Performances of ‘collective’ and partly distributed algorithms are estimated. Data reduction methods and visualization solutions are considered. Finally low- and wideband data evaluation for longitudinal phase space is presented.

Poster MOPD16 [13.416 MB]

MOPD18

Embedded Collimator Beam Position Monitors

vacuum, beam-losses, collimation, impedance

80

C.B. Boccard, A. Bertarelli, A. Dallocchio, M. Gasior, L. Gentini, A.A. Nosych
CERN, Geneva, Switzerland

The LHC collimation system is crucial for safe and reliable operation of proton beams with 350 MJ stored energy. Currently the collimator set-up is performed by observing beam losses when approaching the collimator jaws to the beam. For all 100 LHC movable collimators the procedure may take several hours and since it has to be repeated whenever the beam configuration changes significantly, the collimator setup has an important impact on the overall machine operation efficiency. To reduce the collimator setup time by two orders of magnitude the next generation of the LHC collimators will be equipped with button beam position monitors (BPMs) embedded into the collimator jaws. This paper describes the BPM design and presents prototype results obtained with beam in the CERN-SPS.

Poster MOPD18 [1.729 MB]

MOPD49

Beam Parameters Measurements by Ionization Cross Section Monitor on Proton LINAC of INR RAS

linac, emittance, radiation, ion

161

P.I. Reinhardt-Nickoulin, S. Bragin, A. Feschenko, S.A. Gavrilov, I.V. Vasilyev, O. Volodkevich
RAS/INR, Moscow, Russia

The ionization beam cross section monitor (BCSM) is developed and used on proton linac of INR RAS to provide non-intercepting measurements of beam parameters. Operation of the monitor is based on utilization of residual gas ionization. The BCSM configuration design and image processing system are described and estimations of influence of the linac radiation background are discussed. The monitor enables to observe beam cross section and extract from it beam profiles and position as well as their evolution in time within a wide range of beam intensities and energies. The available experimental results of beam spot, profiles and emittances measurements at the linac output are presented.

MOPD51

Progress with the Scintillation Profile Monitor at COSY

vacuum, synchrotron, power-supply, target

164

V. Kamerdzhiev, J. Dietrich, F. Klehr, K. Reimers
FZJ, Jülich, Germany

After successful demonstration measurements with the Scintillation Profile Monitor at COSY, a dedicated vacuum chamber with two vacuum windows and supporting vacuum ports was installed in the COSY synchrotron. The chamber is blackened inside to suppress light reflection. Since residual gas pressure is too low to support reliable profile measurements based on beam induced scintillation, a piezo-electric dosing valve was installed allowing fast injections of defined amount of nitrogen. A 32-channel photomultiplier is used to detect light. Beam profile measurements and first operational experience are reported.

MOPD52

First Results from Beam Measurements at the 3 MeV Test Stand for CERN Linac4

emittance, solenoid, linac, rfq

167

B. Cheymol, J.-B. Lallement, A.E. Lokhovitskiy, O. Midttun, U. Raich, F. Roncarolo, R. Scrivens, E. Zorin
CERN, Geneva, Switzerland
B. Cheymol
Université Blaise Pascal, Clermont-Ferrand, France

The H⁻ source and the low energy beam line will determine to a large extend the performance of Linac-4, the new machine foreseen as injector into the PS Booster. For this reason a test stand will be set up consisting of the source, Low Energy Beam Transport (LEBT), RFQ and chopper line. Up to now only the source and LEBT are installed. First measurements have been performed using a Faraday Cup to measure the total source intensity, a slit-&-grid emittance meter for transverse emittance measurements and a spectrometer for energy spread measurements. This paper discusses the results from measurements on H⁻ beams at 35kV extraction voltage as well as protons at 45 kV, showing the emittance dependence on source RF power as well as the influence of a solenoid in splitting the beam into its various constituents: protons, H0, H²⁺ and H³⁺. Energy spread measurements are also presented.

MOPD66

Upgrade of the CERN PSB/CPS Fast Intensity Measurements

linac, synchrotron, booster, status

200

A. Monera Martinez, M. Andersen, D. Belohrad, L.K. Jensen, L. Søby
CERN, Geneva, Switzerland
G. Kasprowicz
CREOTECH Ltd., Warsaw, Poland

The CERN Proton Synchrotron Booster (PSB) and Proton Synchrotron (CPS) complex fast intensity measurement is undergoing a major upgrade. The old analogue electronics no longer provides enough accuracy, resolution and versatility to perform accurate beam intensity measurements. It has also become less reliable due to the ageing equipment. A new measurement system - Transformer Integrator Card (TRIC) - replaces these obsolete acquisition systems. TRIC is a generic platform used to measure the intensity in different transfer lines at CERN. Five TRICs were installed during the year 2010 in order to evaluate their performance with different beam types, from the low intensity pilot (5×10⁹ charges per bunch) to high intensity beams (1×10¹³ charges per bunch). The aim of this article is to present the technical aspects of the new system and the different measurement scenarios. It discusses possible sources of measurement errors and presents some statistical data acquired during this period.

MOPD83

Performance of the Fast Beam Conditions Monitor BCM1F in the CMS Experiment at the LHC

radiation, monitoring, luminosity, vacuum

239

M.E. Castro Carballo
DESY Zeuthen, Zeuthen, Germany

In the CMS detector a series of beam condition monitors were installed and are in operation for measuring radiation doses and preventing possible damages to the detector in case of beam losses. The Fast Beam Condition Monitor, BCM1F, is installed inside the pixel volume close to the beam pipe and it consists of two planes of 4 modules each located 1.8 m away from the IP, on both sides. It uses single-crystal CVD diamond sensors and radiation hard front-end electronics, along with an optical transmission of the signal. It was designed for fast flux monitoring, measuring beam halo and collision products on a bunch by bunch basis. Early in November 2009 the LHC restarted running with beams and since then BCM1F has been recording data from beam halo, beam studies, proton-proton and lead-lead collisions. It is an invaluable tool in everyday CMS operation and, due to the high sensitivity to beam conditions, is providing the so called Background (BKGD) 1 to LHC operators. A characterization of the system on the basis of data collected during LHC operation will be presented.

Poster MOPD83 [1.449 MB]

TUOA01

Beam Instrumentation in J-PARC

linac, feedback, impedance, septum

275

T. Toyama
J-PARC, KEK & JAEA, Ibaraki-ken, Japan

The talk will summarize the beam instrumentation at J-PARC with a focus on MW class proton beams. The measurements of beam intensities, positions, losses, profiles, and halos at each stage of accelerator, 181 MeV LINAC (to be upgraded to 400MeV), 3 GeV RCS and 50 (30 as phase I) GeV MR will be reported. Present status, including modification and improvement of instrumentations to meet with LINAC energy upgrade and a future plan will be reported with emphasis on high beam power related issues such as radiation hardness (mechanically and electrically), beam coupling impedance, etc..

Slides TUOA01 [22.777 MB]

TUOA03

The Fermilab HINS Test Facility and Beam Measurements of the Ion Source and 325 MHz RFQ

diagnostics, rfq, laser, linac

283

V.E. Scarpine, S. Chaurize, B.M. Hanna, S. Hays, J. Steimel, R.C. Webber, D. Wildman
Fermilab, Batavia, USA

Funding: This work was supported by the U.S. Department of Energy under contract No. DE-AC02-07CH11359.
The Fermilab High Intensity Neutrino Source (HINS) project is intended to test new concepts for low-energy, high-intensity superconducting linacs. HINS initial design consists of a 50 KeV ion source, a 2.5 MeV Radiofrequency Quadrupole (RFQ) followed by room temperature and superconducting spoke resonator acceleration sections. At present, a proton ion source and the 325 MHz RFQ, followed by a beam diagnostics section, have been operated with beam. This paper will present the beam measurement results for the proton ion source and for the 325 MHz RFQ module. In addition, this paper will discuss the role of HINS as a test facility for the development of beam diagnostic instrumentation required for future high-intensity linacs.

Slides TUOA03 [1.864 MB]

TUPD02

Beam Diagnostics for the ESS

linac, diagnostics, target, cryomodule

302

A. Jansson, L. Tchelidze
ESS, Lund, Sweden

The European Spallation Source (ESS) is a based on a 2.5GeV superconducting linac, producing a 5MW beam. Since it is optimized for cold neutrons, there is no accumulator ring, and hence no need for change exchange injection. Therefore, unlike most other proposed MW-class linacs, the ESS linac will accelerate protons rather than H⁻ ions. This poses a particular challenge for beam size mesurements in the superconducting section. This paper discusses the ESS beam diagnostics requirements, along with some possible instrument design options.

TUPD15

Technology Selection for the Beam Position Tuning System in Hadrontherapy Facilities

electron, photon, high-voltage, controls

332

C. Belver-Aguilar, C. Blanch Gutierrez, A. Faus-Golfe, J.J. García-Garrigós
IFIC, Valencia, Spain
E. Benveniste, M. Haguenauer, P. Poilleux
LLR, Palaiseau, France

Funding: CYCIT – IN2P3: AIC10-D-000518
The Beam Delivery System of some hadrontherapy facilities is characterized by having scanning magnets, which move the beam in order to irradiate all the tumor volume. To control the beam position, a Beam Position Monitor (BPM) is needed. The BPM described in this paper is a new type of BPM based on four scintillating fibers coupled to four photodiodes to detect the light produced by the fibers when intercepting the beam. We present here the study of the possible photodiodes able to read the light emitted by the scintillating fiber, and the tests performed in order to find the most suitable photodiode to measure the beam position from the variations in the beam current. The setup used for the tests comprises a Sr-90 source, which emits electrons, a scintillating fiber, converting these electrons into photons, and a photodiode, which detects the photons leaving the fiber. The photodiodes studied have been of two types: Avalanche Photodiode (APD) and Multi Pixel Photon Counter (MPPC). In this paper both photodiodes are compared and the results are presented.

TUPD24

Design Status of Beam Position Monitors for the FAIR Proton Linac

linac, simulation, cavity, vacuum

356

C.S. Simon, F. Senée
CEA/DSM/IRFU, France
G. Clemente, P. Forck, W. Kaufmann, P. Kowina
GSI, Darmstadt, Germany

Beam Position Monitors (BPM) based on capacitive buttons are designed for the FAIR Proton-LINAC, constructed as an extension of the existing GSI facility. This LINAC is aiming to produce a maximum design current of 70 mA at the 70 MeV energy with an accelerating frequency of 325 MHz. At 14 locations, the BPMs will measure the transverse beam position, the relative beam current and the mean beam energy by time-of-flight method. Depending of the location, the BPM design has to be optimized, taking into account an energy range from 3 MeV to 70 MeV, a short insertion and a beam pipe aperture changes from 30 mm to 50 mm. Some of BPMs will be mounted very close to the CH cavities and special care must be taken to suppress the pickup of the strong rf-field from that cavities. In this contribution, the status of the BPM design will be presented.

TUPD46

Beam Species Fraction Measurement using Doppler Shift Method with FUJIKURA Fiberscope for IFMIF-EVEDA Injector

diagnostics, target, neutron, radiation

407

F. Senée, B. Pottin
CEA/DSM/IRFU, France
G. Adroit, R. Gobin, O. Tuske
CEA/IRFU, Gif-sur-Yvette, France
A. Olivier
IPN, Orsay, France

To characterize high intensity ion beam in low energy beam transport line, diagnostics based on residual gas molecule excitation are commonly used. An example is CCD sensors for beam intensity, beam position and beam profile measurements. At CEA/Saclay with the SILHI injector, beam images transports from viewport to sensor have been performed with a fiberscope. Such technique will be used to transport the beam images away from the irradiated zone of the IFMIF-EVEDA tunnel which requires using hardened radiation devices. Indeed, the (D,d) reaction, due to interaction of 140 mA-100 keV deuteron beam with vacuum pipes or scrapers, leads to high neutron and gamma ray flux. As a consequence, in addition to CID cameras for online beam positioning and shape measurements, a 20 m long Fujikura fiberscope has been selected to analyze species fraction using the Doppler shift method. Preliminary measurements have been performed with the SILHI beam to characterize the fiberscope. Its spatial resolution and transmission as well as a CCD sensor and fiberscope comparison are presented. Beam species fractions with and without the use of fiberscope will be also reported.

TUPD69

Operational Experience and Improvements of the LHC Beam Current Transformers

vacuum, feedback, luminosity, diagnostics

467

P. Odier, D. Belohrad, J-J. Gras, M. Ludwig
CERN, Geneva, Switzerland

During the 2010 run the LHC continuously improved its performance. In particular the bunch charge and number of bunches were significantly increased, which revealed certain limitations of the LHC beam current transformers. The DC current transformers (DCCT), used to measure the circulating beam current, exhibited saturation related to bunch intensity, the number of batches in the machine and their spacing. Two major issues were also discovered on the fast beam current transformers (FBCT) used to measure the individual bunch charges: discrepancies in the measured intensities when compared to the DCCTs measurements and a bunch length dependence on the measured intensity. Further analysis showed that both problems are linked to the beam position dependence of the signal acquired from the toroids used in the FBCTs. This paper presents the observed issues, discusses possible solutions and reports on the results from modification made for the 2011 run.

TUPD74

The Bunch by Bunch Feedback System in J-PARC Main Ring

feedback, injection, kicker, acceleration

482

Y. Kurimoto, Y.H. Chin, T. Obina, M. Tobiyama, T. Toyama
KEK, Ibaraki, Japan
Y. Shobuda
JAEA/J-PARC, Tokai-Mura, Naka-Gun, Ibaraki-Ken, Japan

We report the current status of the bunch by bunch feedback system for the J-PARC Main Ring. The J-PARC Main Ring is the synchrotron accelerating protons from 3 GeV to 30 GeV. It is normally operating at the intensity of 135 kW. The bunch by bunch feedback system have been developed and used for the normal operation of J-PARC Main Ring. The system aims to reduce the coherent transverse oscillation due to the instabilities or injection errors. It consists of a beam position monitor, a stripline kicker and a signal processing electronics. We've observed the injection error leading to the head-tail oscillation and succeed in damping such kind of oscillations and reducing the beam loss significantly.

Poster TUPD74 [1.107 MB]

TUPD82

First Results of the LHC Collision Rate Monitors

luminosity, simulation, interaction-region, bunching

497

E. Bravin, S. Bart Pedersen, A. Boccardi, S. Burger, C. Dutriat
CERN, Geneva, Switzerland
L.R. Doolittle, H.S. Matis, M. Placidi, A. Ratti, H. Yaver, T. stezelberger
LBNL, Berkeley, California, USA
R. Miyamoto
BNL, Upton, Long Island, New York, USA

Funding: This work is partially supported by the US DoE through US-LARP
The aim of CERN’s large hadron collider (LHC) is to collide protons and heavy ions with centre of mass energies up to 14 zTeV. In order to monitor and optimize the collision rates special detectors have been developed and installed around the four luminous interaction regions. Due to the different conditions at the high luminosity experiments, ATLAS and CMS, and the low luminosity experiments, ALICE and LHC-b, two very different types of monitors are used, a fast ionisation chamber (BRAN-A) and a Cd-Te solid state detector (BRAN-B) respectively. Moreover in order to cope with the low collision rates foreseen for the initial run a third type of monitor, based on a simple scintillating pad, was installed in parallel with the BRAN-A. This contribution illustrates the results obtained during the 2010 run with an outlook for 2011 and beyond.

TUPD88

A Micro-Channel Plate Based RFA Electron Cloud Monitor for the ISIS Proton Synchrotron

electron, gun, synchrotron, diagnostics

512

A. Pertica, S.J. Payne
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Electron clouds produced inside a particle accelerator vacuum chamber by the passage of the beam can compromise the operation of the accelerator. The build up of electron clouds can produce strong transverse and longitudinal beam instabilities which in turn can lead to high levels of beam loss often requiring the accelerator to be run below its design specification. To study the phenomena of electron clouds at the ISIS Proton Synchrotron, a Micro-Channel Plate (MCP) based electron cloud detector has been developed. The detector is based on the Retarding Field Analyser (RFA) design and consists of a retarding grid, which provides energy analysis of the electron signal, and a MCP assembly placed in front of the collector plate. The MCP assembly provides a current gain over the range 300 to 25K, thereby increasing the signal to noise ratio and dynamic range of the measurements. In this paper, we describe the lab based experiment used to test our detector using a low energy electron gun. Results from our MCP based detector installed in the ISIS accelerator ring are discussed and compared to a RFA detector, installed at the same location, which has no MCP fitted.

Poster TUPD88 [1.793 MB]

TUPD91

Comparative Studies of Reconstruction Methods to Achieve Multi-Dimensional Phase Space Information

emittance, diagnostics, ion, FEL

521

C. Gabor
STFC/RAL/ASTeC, Chilton, Didcot, Oxon, United Kingdom
A.P. Letchford
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
D. Reggiani, M. Seidel
PSI, Villigen, Switzerland

High Intensity Proton Accelerators like SNS, PSI or future machines like ESS or Isis upgrade cannot tolerate high losses due to activation. Standard beam diagnostics may not provide enough information about potential loss sources like beam filamentation or halo. Moreover, the application of interceptive methods like slits or pepperpot can be seriously discouraged by either high power deposition or explicit requirements for non-destructive methods like on-line diagnostics near superconducting cavities. Reconstruction of the beam distribution with a tomography method based on Maximum Entropy could help to overcome those problems and is easily to integrate in already existing facilities because the algorithm does not depend on the experimental profile measurement technique. Furthermore beam tomography can be employed on both spatial and phase-space reconstruction. The paper compares results from two different software packages from PSI (Maximum Entropy Tomography MENT) with the code used at RAL (MemSys 5).

TUPD94

Monitoring of GeV Deuteron Beam Parameters in ADS Experiments at the Nuclotron (JINR, Dubna)

target, neutron, monitoring, synchrotron

530

A.A. Safronava, A.A. Patapenka
JIPNR-Sosny NASB, Minsk, Belarus
V.V. Sotnikov, V.A. Voronko
NSC/KIPT, Kharkov, Ukraine
O. Svoboda
NPI, Řež near Prague, Czech Republic
W. Westmeier
Philipps-Universität, Marburg, Germany

The quality of beam instrumentation is very important in the experiments on accelerator driven systems (ADS) aiming to investigate spatial and energy distribution of neutrons inside and outside the subcritical setups comprising spallation neutron sources irradiated by relativistic beams. An important source of systematic uncertainties of the experimental data is the inaccuracy of determination of the beam parameters such as total intensity of the extracted beam, beam position at the target, fraction of the beam hitting the target and beam shape. This paper reviews the experimental techniques and measurement tools for deuteron beam monitoring used within the “Energy plus Transmutation” collaboration in the ADS experiments at the accelerator complex of Nuclotron (JINR, Russia): - activation technique using Al monitors for measurement of the total intensity of the extracted beam; - solid nuclear track detectors method and activation technique using segmented activation Cu foils for determination of beam profile and position at the target.

Poster TUPD94 [13.019 MB]

WEOA04

Synchrotron Radiation Measurements at the CERN LHC

ion, emittance, photon, booster

550

F. Roncarolo, S. Bart Pedersen, A. Boccardi, E. Bravin, A. Guerrero, A. Jeff, T. Lefèvre, A. Rabiller
CERN, Geneva, Switzerland
A.S. Fisher
SLAC, Menlo Park, California, USA

The CERN LHC is equipped with two systems (one for each beam) designed to image the synchrotron radiation emitted by protons and heavy ions. After their commissioning in 2009, the detectors were extensively used and studied during the 2010 run. This allowed preliminary limits in terms of sensitivity, accuracy and resolution to be established. The upgrade to an intensified video camera capable of gating down to 25ns permitted the acquisition of single bunch profiles even with an LHC proton pilot bunch (~5·10⁹ protons) at 450 GeV or a single lead ion bunch (~10⁸ ions) from about 2 TeV. Plans for the optimization and upgrade of the system will be discussed. Since few months, part of the extracted light is deviated to the novel Longitudinal Density Monitor (LDM), consisting in an avalanche photo-diode detector providing a resolution better than 100 ps. The LDM system description will be complemented with the promising first measurement results.

Slides WEOA04 [6.398 MB]

WEOD01

Beam Induced Fluorescence Monitors

ion, photon, diagnostics, electron

575

F. Becker
GSI, Darmstadt, Germany

Non-intercepting diagnostic devices in hadron accelerators offer continuous online monitoring capability. They also avoid the problem of potential thermal damage in high-current applications. Taking advantage of the residual gas as active material, the Beam Induced Fluorescence (BIF) monitor exploits gas fluorescence in the visible range for transversal profile measurements. Depending on beam parameters and vacuum-constraints, BIF monitors can be operated at base-pressure or in dedicated local pressure bumps up to the mbar range. Nowadays, BIF monitors are investigated in many accelerator laboratories for hadron energies from about 100 keV up to several 100 GeV. This talk gives an introduction to the measurement principle and typical operating conditions. It summarises recent investigations, e.g. on different working gases, and it compares various technical realisations.

Slides WEOD01 [12.701 MB]

WEOD02

LHC Beam Diagnostics - the Users Point of View

luminosity, ion, injection, instrumentation

580

J. Wenninger
CERN, Geneva, Switzerland

The LHC started up with beam in November 2009, and within less then on year its luminosity reached 2·10³² cm^-2s⁻¹ at 3.5 TeV in October 2010. A few weeks later, in November 2010, lead ion collisions were established within little over 2 days. The fast progress and successes of the LHC commissioning and early operation would not have been possible without the excellent performance of its beam instrumentation. All essential instruments worked from the first day or were commissioned in a very short time, providing rapid diagnostics for the beam parameters. Tune and orbit feedbacks that rely on high quality measurements were used early on to achieve smooth operation with minimal beam losses. This presentation will address the performance of the LHC beam instrumentation, in particular the very large beam position and beam loss monitoring systems, both composed of many thousand channels. Present limitations and future improvements will also be discussed.

Slides WEOD02 [11.950 MB]