Paper | Title | Other Keywords | Page |
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MOPP084 | Nondestructive Diagnostics of Proton Beam Halo and Transverse Bunch Position by Cerenkov Slow Wave Structures | proton, simulation, monitoring, electron | 251 |
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An appearance of the halo around bunch of particles is very undesirable destructive phenomenon in high-intensity proton accelerators. We suggest using built-in short BWO section in form of the corrugated metallic waveguide, in order to control particle distribution in real time. In BWO low velocity proton bunch has synchronism with slow spatial harmonic of TM01 wave. Fields of slow harmonic sharply grow in direction from axis to walls and rf power, generated by flying bunch of the given charge, critically depends on transverse bunch size. Results of the simulation, carried out for 20 pC proton bunch of 10 ps duration, show that in 5 GHz BWO of 30 cm length the output rf pulse of several nanosecond duration is varied from mW- level (for 1 mm transverse bunch size) to several tens of mW (for bunch of 20 mm radius). This power level is high enough to control halo appearance in each single proton bunch. The producible rf power in a BWO is also dependent on bunch deflection from axis. This effect we plan to use, in order to provide transverse bunch position monitoring by means of two additional rectangular slow wave section which have corrugations on mutually perpendicular walls. | |||
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Poster MOPP084 [0.732 MB] | ||
MOPP096 | Current Status of the Mainz Energy-Recovering Superconducting Accelerator Project | experiment, linac, feedback, operation | 282 |
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Funding: Work supported by the German Federal Ministery of Education and Research (BMBF) and German Research Foundation (DFG) under the Cluster of Excellence "PRISMA" The Mainz Energy-Recovering Superconducting Accelerator (MESA) project at Johannes Gutenberg-Universtitaet Mainz has started in 2012 and is in full swing now. This presentation shows the current status of the project with a glance on cryogenics, superconducting RF, accelerator lattice design and the normal conducting injector. |
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TUPP029 | Diagnostics and Analysis Techniques for High Power X-Band Accelerating Structures | timing, controls, klystron, operation | 490 |
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The study of high gradient limitations due to RF breakdowns is extremely important for the CLIC project. A series of diagnostic tools and analysis techniques have been developed in order to monitor and characterize the behaviour of CLIC accelerating structures under high power operation in the first CERN X-band klystron-based test stand (Xbox1). The data collected during the last run on a TD26r05 structure are presented in this paper. From the analysis of the RF power and phases, the location of the breakdowns inside the structure could be determined. Other techniques based on the field emitted dark current signals collected by Faraday cups placed at the two extremities of the structure have also been investigated. The results of these analyses are reported and discussed. | |||
TUPP034 | Commissioning of the CERN LINAC4 Wire Scanner, Wire Grid and Slit-Grid Monitors at 3 and 12 MeV | linac, electron, emittance, space-charge | 502 |
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The CERN LINAC4 has been commissioned up to 12 MeV. The H− beam transverse profile distributions were measured by both wire grids and wire scanners. A slit-grid system located on a temporary diagnostics bench was used to characterize the transverse emittance during the two different stages of commissioning: at the exit of the RFQ (3 MeV) and DTL1 (12 MeV). The wire signal is a balance between the negative charge deposited by the stripped electrons from the H− and the charge lost due to secondary emission. Optimal settings were found for the repelling plates used to suppress secondary emission, which were confirmed by electromagnetic simulations. In addition, suppression of the secondary emission due to the beam space charge was observed. The benefit of changing the wire scanner geometry in order to minimize the cross-talk between horizontal and vertical wires and the observation of thermionic emission on carbon wires are also discussed. | |||
THIOB03 | Results From the LCLS X-Band Transverse Deflector With Femtosecond Temporal Resolution | electron, FEL, undulator, photon | 819 |
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An X-band RF transverse deflector composed of two 1-m-long X-band deflecting structures has been recently commissioned at the Linac Coherent Light Source (LCLS) at SLAC National Accelerator Laboratory. Located downstream of the FEL undulator, this device provides electron beam longitudinal phase space diagnostics in both time and energy which enables reconstruction of the X-ray FEL power profiles with an unprecedented resolution. This talk reports on the progress of this new LCLS X-band transverse deflector, first usage experience and measured results. | |||
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Slides THIOB03 [3.508 MB] | ||
THPP015 | Status of the FAIR Proton Source and LEBT | linac, ion, proton, ion-source | 863 |
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The unique Facility for Antiproton and Ion Research – FAIR will deliver stable and rare isotope beams covering a huge range of intensities and beam energies. A significant part of the experimental program at FAIR is dedicated to antiproton physics that requires an ultimate number 7x1010 cooled pbar/h. The high-intensity proton beam that is necessary for antiproton production will be deliver by a dedicated 75 mA/70 MeV proton linac. The injector section of this accelerator is composed by an ECR source, delivering a pulsed 100 mA H+ beam (4 Hz) at 95 keV and a low energy beam transport (LEBT) line required to match the beam for the RFQ injection. The proposed design for the LEBT is based on a dual solenoids focusing scheme. A dedicated chamber containing several diagnostics (Alisson scanner, Wien filter, SEM grid, Iris, Faraday Cup) will be located between the two solenoids. At the end of the beam line, an electrostatic chopper system is foreseen to inject up to 50μseconds long beam pulses into the RFQ. The status of LEBT simulations, design and fabrication of the FAIR proton injector will be presented. | |||
THPP063 | Beam Diagnostics Layout for the FAIR Proton Linac | linac, proton, emittance, beam-diagnostic | 998 |
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The planned proton Linac for FAIR (Facility of Antiproton an Ion Research) will be - additionally to the existing GSI UNILAC - a second injector for the FAIR accelerator chain. It will inject a 70 MeV, (up to) 70 mA proton beam with a nominal pulse length of 30 us into the SIS18. The beam diagnostics system for the proton Linac comprises nine current transformers for pulse current determination and fourteen BPMs for position, mean beam energy and relative current measurement. SEM-Grids and stepping motor driven slits will be used for profile as well as for emittance measurements. A wire-based bunch shape monitor is foreseen, additionally a bending magnet for longitudinal emittance determination during commissioning. Presently, main efforts are conducted concerning the BPM system. Detailed signal simulations with the finite element code CST are performed. An electronics board using digital signal processing is evaluated by detailed lab-based characterization and beam-based measurements at the UNILAC. In this paper we present the general layout and the status of the diagnostics systems as well as key results from our measurements and simulations. | |||
THPP067 | Status of the SPP RFQ Project | rfq, ion, ion-source, cavity | 1004 |
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The SPP project at TAEA will use 352.2 MHz 4-vane Radio Frequency Quadrupole (RFQ) to accelerate H+ ions from 20 KeV to 1.5 MeV. With the design already complete the project is at the test production phase. To this effect, a so called "cold model" of 50cm length has been produced to validate the design approach, to perform the low power RF tests and to evaluate possible production errors. This paper will report on the current status of the low energy beam transport line (LEBT) and RFQ cavity of the SPP project. It will also discuss the design and manufacturing of the RF power supply and its transmission line. In addition, the test results from some of the LEBT components will be shown and the final RFQ design will be shared. | |||
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Poster THPP067 [6.947 MB] | ||