DIPAC 2007 - List of Keywords (proton)

A B C D E F G H I K L M O P Q R S T U V

proton

Paper	Title	Other Keywords	Page
MOO3A01	Optical Transition Radiation Monitor for High Intensity Proton Beam at the J-PARC	background, radiation, target, beam-losses	30
	A. Toyoda, A. Agari, E. Hirose, M. Ieiri, Y. Katoh, M. Minakawa, H. Noumi, Y. Sato, Y. Suzuki, H. Takahashi, M. Takasaki, K. H. Tanaka, H. Watanabe, Y. Yamanoi KEK, Tsukuba
	The OTR is a powerful tool to observe 2-dimensional information of beam profile at the high intensity beamline because the OTR intensity only depends on the screen reflectivity so that we can minimize a beam loss. However, it is necessary to overcome large background due to the Cerenkov radiation and low radiation tolerance of camera system. The purpose of the present effort is to achieve small background and good S/N and to prolong the lives of the camera system. This requires that amount of potential Cerenkov radiator be minimized and radiation level at the camera system be suppressed. For this requirement, we design and develop an OTR monitor with the optical system of a Newtonian telescope type. Detail design of the optical system and a result of background measurement performed at one of primary proton beam lines of our old 12 GeV Proton Synchrotron will be presented.

TUO1A01	Bunched Beam Stochastic Cooling for RHIC	kicker, ion, pick-up, beam-losses	39
	J. M. Brennan, M. Blaskiewicz, F. Severino BNL, Upton, Long Island, New York
	Stochastic cooling is an effective and well-established accelerator technology for improving beam quality. However, stochastic cooling of high frequency bunched beam has always proved problematic. We have built a stochastic cooling system for heavy ions in RHIC that is used on bunched beam. The purpose is to counteract Intra-Beam Scattering and improve integrated luminosity. The chief technical challenge of bunched beam is the strong coherent frequency components in the beam that contaminate the Schottky spectrum. Technical solutions for overcoming this problem are described. Results from commissioning in one ring of RHIC are reported.

TUPB28	A Large Scintillating Screen for the LHC Dump Line	radiation, kicker, photon, controls	132
	T. Lefèvre, C. B. Bal, E. Bravin, S. Burger, B. Goddard, S. C. Hutchins, T. Renaglia CERN, Geneva
	7 TeV proton beam from the LHC is ejected through a long transfer line to a beam dump block. Approximately 100 m downstream of the ejection septa, a series of dilution kicker magnets provide a sweeping deflection spreading the extracted beam over a 40 cm diameter area on the face of the beam dump core. During normal operation, the quality of each dump event must be recorded and verified. The so called “Post-Mortem” data-set will include information from the beam dumping system as well as from the beam diagnostics along the extraction line. For this purpose, a profile monitor in front of the dump block is permanently available during machine operation. With more than 10¹⁴ protons stored in LHC, the thermal properties of the screen have to be considered as beam energy deposition becomes an issue. This paper presents the design of this device, which is original due to its very large size. We introduce the different technical considerations involved in the design of the system and present the complete layout of its installation with a special emphasis on the mechanical design, the screen assembly and the choice of the radiation-hard video camera used to capture the image.

TUPB31	The Beam Position System of the CERN Neutrino to Gran Sasso Proton Beam Line	pick-up, target, radiation, controls	141
	T. Bogey, O. R. Jones CERN, Geneva
	The CERN Neutrino to Gran Sasso (CNGS) experiment uses 400GeV protons extracted from the SPS, which travel along 825 meters of beam line before reaching the CNGS target. This beam line is equipped with 23 BPMs capable of measuring both the horizontal and vertical position of the beam. The final BPM is linked to the target station and due to radiation constraints has been designed to work in air. This contribution will give an overview of the BPMs used in the tansfer line. It will also provide a detailed explanation of their logarithmic amplifier based acquisition electronics, which consists of an auto-triggered sequencer controlling an integrator, the A/D conversion and the Manchester encoded transmission of the digital data to the surface. At the surface the digital data is aquired using the Digital Acquisition Board (DAB) developed by TRIUMF (Canada) for the LHC BPM system. Results from both laboratory measurements and beam measurements during the 2006 CNGS run will also be presented.

TUPC12	FPGA based Frame Grabber for Video Beam Diagnostics	controls, radiation, diagnostics, injection	174
	I. Krouptchenkov, K. Wittenburg DESY, Hamburg
	TV-based accelerator diagnostics are widely used for machine operation and beam diagnostics. It is planned to renew the video memory modules of the TV monitor data acquisition systems for the injection and transfer lines at DESY. New FPGA based Frame Grabber (FG) modules were developed within this project. The modules are required to be able to work with different analog signal formats, to capture video frames on trigger and to provide live mode operation. The main feature of this FG is the possibility of reprogramming. This allows us to optimize its functionality, for example to operate with non-standard or corrupted video signals. This has proved especially useful for grabbing images from CCD-cameras suffering from radiation damage.

WEPB19	Digital Analysis of Beam Diagnostic Noise	diagnostics, coupling, instrumentation, pick-up	271
	P.-A. Duperrex, G. G. Gamma, B. Keil, M. U. Müller PSI, Villigen
	Results will be presented of recently developed, VME-based electronic modules, a digital beam position monitor (dBPM) and a logarithmic current measurement electronics (VME-LogIV). The dBPM is based on digital receiver technology and processes the signals from 4 pick-up coils. Features of the dBPM are the direct frequency down-converting of the RF 2nd harmonic 10¹.26MHz) signals (no analogue LO), the remote control of the front end amplifier and the online measurement of individual channel overall gain using 10¹.31 MHz pilot signals. Various data rates for position measurements at up to 10 kHz are possible. The VME-LogIV can simultaneously measure up to 32 channels at an effective sampling frequency of 5 kHz for the multiple wire profile monitors, also called harps. Fluctuations up to a few kHz of the beam intensity and beam position can thus be analyzed in detail with both of these new systems. Fluctuations from different dBPMs can be compared using coherence spectra measurement. The origin of the VME-LogIV noise can be analyzed using power and coherence spectra, and compared to the noise of the ion source. The results of this analysis will be discussed.

WEPC03	Secondary Electron Emission Beam Loss Monitor for LHC	electron, simulation, beam-losses, radiation	313
	D. K. Kramer, B. Dehning, G. Ferioli, E. B. Holzer CERN, Geneva
	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. The prototypes were calibrated by proton beams in CERN PS Booster dump line, SPS transfer line and in PSI Optis line. The results were compared to the simulations.

WEPC09	Classification of the LHC BLM Ionization Chamber	simulation, space-charge, radiation, target	328
	M. Stockner, B. Dehning, C. Fabjan, E. B. Holzer CERN, Geneva D. K. Kramer TUL, Liberec
	The LHC beam loss monitoring (BLM) system must prevent the super conducting magnets from quenching and protect the machine components from damage. The main monitor type is an ionization chamber. About 4000 of them will be installed around the ring. The lost beam particles initiate hadronic showers through the magnets and other machine components. These shower particles are measured by the monitors installed on the outside of the accelerator equipment. For the calibration of the BLM system the signal response of the ionization chamber to all relevant particles types and energies (keV to TeV range) is simulated in GEANT4. For validation, the simulations are compared to measurements using protons, neutrons, photons, muons and mixed radiation fields at various energies and intensities. This paper will focus on the signal response of the ionization chamber to various particle types and energies including recombination effects in the chamber gas at high ionization densities.

WEPC20	A Real-Time Beam Monitor for Hadrontherapy Applications Based on Thin Foil Secondary Electron Emission and a Back-Thinned Monolithic Pixel Sensor	electron, focusing, cyclotron, monitoring	352
	L. Badano, L. Badano ELETTRA, Basovizza, Trieste K. Abbas, P. N. Gibson, U. Holzwarth JRC, Ispra M. Caccia, C. Cappellini, V. Chmill, M. Jastrzab Univ. Insubria and INFN Milano, Como O. Ferrando Ente Ospedaliero Ospedali Galliera, Genova G. Molinari CERN, Geneva
	A novel, non-disruptive beam profile monitor for low intensity light-ion beams has been constructed and tested. The system is designed for use in medical hadrontherapy centers where real-time monitoring of the beam intensity profile is of great importance for optimization of the accelerator operation, patient safety and dose delivery. The beam monitor is based on the detection of secondary electrons emitted from a submicron thick Al2O3/Al foil placed in the beam at an angle of 45 degrees. The present paper reports the latest results achieved with a customized monolithic active pixel array, which provides the beam intensity and position with a precision of better than 1 mm at a 10 kHz frame rate. The sensor chip is back-thinned to achieve the required sensitivity to short-range secondary electrons focused onto the sensor surface. The monitor performance has been tested with a patterned beam, produced with a multi-hole collimator, with the results indicating that the system performs according to its design specifications.

WEPC24	A Self Calibrating Real Time Multi-Channel Profile Monitor for the Isis Proton Synchrotron	electron, ion, controls, acceleration	364
	S. J. Payne, P. G. Barnes, G. M. Cross, A. Pertica, S. A. Whitehead STFC/RAL/ISIS, Chilton, Didcot, Oxon
	A (+ion) gas ionisation profile monitor (GIPM) has been developed at the Rutherford Appleton Laboratory to capture 'real time' beam profile data within the accelerating ring of the 800MeV ISIS proton sychrotron. The GIPM uses an array of 40 Channeltron detectors, operating at a gain of ~10⁴, to measure the transverse beam profile in the horizontal plane. The data obtained is an average of two rotations of the beam bunch, a limitation due soley to the speed of the +ions. Fast electronics and a multi-channel PXI / LabView data acquisition system are used to simultaneously process and display the 40 channels of beam profile information. Variations in the Channeltrons gain are dealt with using an independent motor driven +ion detector. The beam profiles obtained from this single detector are stored and used as a calibration file to correct data from the new multi-channel profile monitor.

WEPC27	Segmented Foil SEM Grids for High-Intensity Proton Beams at Fermilab	beam-losses, vacuum, booster, radiation	370
	Z. Pavlovic, D. Indurthy, S. E. Kopp, M. Proga, R. M. Zwaska The University of Texas at Austin, Austin, Texas B. B. Baller, S. C. Childress, R. D. Ford, D. Harris, C. L.K. Kendziora, C. D. Moore, G. R. Tassotto Fermilab, Batavia, Illinois
	The extracted beam transport lines and transfer lines between accelerators at Fermilab must operate at ever higher proton fluences to service the neutrino program and the production of antiprotons for the Tevatron collider program. The high proton fluences place stringent criteria on invasive instrumentation to measure proton beam profiles. Based on a design from CERN, we have built SEM's consisting of Ti foils segmented at either 1.0mm or 0.5mm pitch. The foils are 5um thick Titanium, and two planes of the segmented foils per SEM chamber provides both horizontal and vertical beam profiles. The foil SEM's provide several features over the Au-plated 75 um Ø W-wire SEM's previously in use at Fermilab: (1) a factor 50-60 lower fractional beam loss; (2) greater longevity of Ti signal yield, as compared with W or Au-W; (3) a 'bayonnette'-style frame permitting insertion/retraction from the beam without interruption of operations; and (4) reduced calculated beam-heating from the high-intensity proton-pulses, which results in less sag of the wires/foils. Experience with these detectors after two years' operations in 8 and 120GeV beams will be summarized.

WEO3A02	Diagnostic Instrumentation for Medical Accelerator Facilities	ion, synchrotron, diagnostics, linac	381
	M. Schwickert, A. Peters GSI, Darmstadt
	A number of accelerator facilities are presently emerging for the medical treatment of tumour patients using proton and light ion-beams. Both, the development of relatively compact accelerators and extensive studies on ion-therapy carried out at various accelerator laboratories were prerequisites for the layout of dedicated medical accelerator facilities. This paper focuses on the special demands for beam diagnostic devices during the commissioning and routine operation of a medical accelerator. The proton-therapy project PROSCAN at the Paul-Scherrer-Institute in Villigen/Switzerland exemplifies medical treatment in the frame of a research institute. As examples for dedicated ion-therapy projects the beam diagnostic layout is presented for the CNAO project (Centro Nazionale Adroterapia Oncologica) located in Pavia/Italy and the HIT facility (Heidelberger Ionen Therapie) in Heidelberg/Germany. Beam diagnostic devices of HIT are illustrated and the underlying concept for the type and precision of the devices is explained. Additionally, measurement results of the HIT linac and synchrotron commissioning are presented.