| Paper | Title | Other Keywords | Page |
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| MOPPC018 | Single/Few Bunch Space Charge Effects at 8 GeV in the Fermilab Main Injector | space-charge, factory, simulation, proton | 163 |
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| For Project X, it is planned to inject a beam of 3 1011 particles per bunch into the Main Injector. Therefore, at 8 GeV, there will be increased space charge tune shifts and an increased incoherent tune spread. In preparation for these higher intensity bunches exploratory studies have commenced looking at the transmission of different intensity bunches at different tunes. An experiment is described with results for bunch intensities between 20 and 172 109 particles. To achieve the highest intensity bunches coalescing at 8 GeV is required, resulting in a longer bunch length. Comparisons show that similar transmission curves are obtained when the intensity and bunch length have increased by factors of 3.2 and 3.4 respectively, indicating the incoherent tune shifts are similar, as expected from theory. The results of these experiments will be used in conjugation with simulations to further study high intensity bunches in the Main Injector. | |||
| MOPPC037 | Muon Collider Detector Backgrounds | collider, electron, simulation, shielding | 211 |
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Funding: Supported in part by SBIR Grant 4738 · 10SC05447 Technological innovations in recent years have revived interest in muon colliders as the next generation energy frontier machine. Advances in muon cooling technology will make the focussing and acceleration of muons to TeV energies possible. The biggest challenge for muon colliders is that muons decay, but it is possible to build a large muon collider as a circular machine, even at multi-TeV energies, due to the greatly reduced synchrotron radiation expected from muons compared to electrons. The challenge for the detectors in such machines is overcoming the large backgrounds from muon decays in the colliding ring lattice that will inundate the interaction region (IR) and will make triggering and data reconstruction a challenge. Developing simulation tools that can reliably model the environment of the muon collider IR will be critical to physics analyses. We will need to expand the capabilities of current programs and use them to benchmark and verify results against each other. In this paper we will discuss these processes and calculate the resulting particle fluxes into the detector volume. |
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| MOPPC038 | Bethe-Heitler Muon Background at a Muon Collider | collider, electron, hadron, simulation | 214 |
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| Multi-TeV muon colliders are an important option for a future energy frontier lepton collider since synchrotron radiation in a circular machine is significantly less than that in an electron collider. For a muon collider with 750 GeV μ+μ− with 2×1012 μ per bunch we would expect 8.6×105 muon decays per meter for the two beams. Muon decays are the source of beam induced backgrounds that can affect the physics. These backgrounds include electrons from muon decays, synchrotron radiation from the decay electrons, hadrons produced by photo-nuclear interactions, coherent and incoherent beam-beam pair production and Bethe-Heitler muon production. This paper will describe a simulation of the B-H muon pair production in a muon collider. These muons can penetrate the collider ring magnets and shielding and possibly enter into the detector regions. The simulation tracks B-H muons produced from electromagnetic shower interactions in collider ring material in the range of ±200 m from the interaction point. | |||
| MOPPD084 | Optimization of Extinction Efficiency in the 8-GeV Mu2e Beam Line | proton, target, dipole, alignment | 565 |
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Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy. A muon-to-electron conversion experiment at Fermilab is being designed to probe for new physics beyond the standard model at mass scales up to 10000 TeV*. The advance in experimental sensitivity is four orders of magnitude when compared to existing data on charged lepton flavor violation. The critical requirement of the experiment is the ability to deliver a proton beam contained in short 100-ns bunches onto a muon production target, with an inter-bunch separation of about 1700 ns. In order to insure the low level of background at the muon detector consistent with the required sensitivity, protons that reach the target between bunches must be suppressed by an enormous factor, 109. This paper describes the results of numerical modeling with STRUCT and MARS codes for a beam line with a collimation system**,*** and optics that achieves an experimental extinction factor of one per billion. * R.M. Carey et al., Mu2e Proposal, Fermilab (2008). ** W. Molzon, “Proton Beam Extinction,” MECO-EXT-05-002 (2005). *** E. Prebys, Mu2e-doc-534 (2009), http://mu2e-docdb.fnal.gov. |
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| MOPPP008 | Hard X-ray Generation Experiment at Tsinghua Thomson Scattering X-Ray Source | laser, electron, photon, scattering | 583 |
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| Recently, there is increasing industrial and scientific interesting in ultra-fast, high peak brightness, tunable energy and polarization, monochromatic hard X-ray source. The X-ray source based on the Thomson scattering between the relativistic electron beam and TW laser pulse is the suitable candidate for its compact and affordable alternatives for high brightness hard monochromatic X-ray generation. Accelerator laboratory in Tsinghua University al so proposed and built Tsinghua Thomson scattering X-ray source. The hard x-ray pulse has been generated in experiment with 47 MeV electron and 20 TW laser in this year, and the parameters of the X-ray have been measured preliminarily. The experimental results are presented and discussed in this paper. | |||
| MOPPR014 | Installation and Test of a Beam Loss Monitor System for the S-DALINAC | electron, controls, monitoring, radiation | 804 |
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Funding: This work is supported by the DFG through SFB 634. The superconducting Darmstadt linear accelarator S-DALINAC is designed for accelerating electrons up to energies of 130 MeV for measurements in nuclear physics at small momentum transfers. For the purpose of machine protection and in order to increase reliability and efficiency an efficient tool for on-line measurements of beam losses down to electron energies of 1 MeV is desirable. Therefore a system of beam-loss monitors has been developed, installed, and tested. The system consists of commercially availiable PIN-diods and newly developed electronics. Implementation in the S-DALINAC's control system is done via EPICS IOC. We will report on the setup of the beam-loss monitoring system and on its initial performance in first tests. |
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| MOPPR036 | Correlation Analysis of Beam Diagnostic Measurements in SSRF | status, lattice, diagnostics, feedback | 858 |
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Funding: Supported by National Natural Science Foundation of China (11075198) Signals from various probes of the beam diagnostic system in Shanghai Synchrotron Radiation Facility (SSRF) were processed with correlation analysis algorithms. The resulting data allowed us to sort the probes by confidence, which means the stable and accurate signals could be separated from the faulty or noisy ones. And the beam dynamics measurements became electronic instrument free at the same time. This makes it possible to eliminate bad Beam Position Monitors (BPM) from the feedback system, offer a more confident set of beam parameters and estimate useful global information by extracting the relationship between some probes. |
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| MOPPR046 | CLIC Luminosity Monitoring | photon, simulation, luminosity, monitoring | 885 |
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| The CLIC post-collision line is designed to transport the un-collided beams and the products of the collided beams with a total power of 14MW to the main beam dump. Luminosity monitoring for CLIC is based on high energy muons produced by bremsstrahlung photons in the main dump. Threshold Cherenkov counters are proposed for the detection of these muons. The expected rates and layout for these detectors is presented. Another method for luminosity monitoring is to directly detecting the bremsstrahlung photons in the post-collision line; Full Monte Carlo simulation has been performed to address its feasibility. | |||
| MOPPR087 | Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center | quadrupole, electron, emittance, linac | 990 |
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| A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV. | |||
| TUPPC055 | Development of an Automatic MATLAB based Emittance Measurement Tool for the IAC Accelerators | emittance, quadrupole, EPICS, controls | 1296 |
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| At the Idaho Accelerator Center (IAC) of Idaho State University, we have been operating fifteen low energy accelerators. To optimize those accelerators properly, we have to measure the transverse beam emittance. To measure the transverse beam emittance of an S-band linear accelerator with the quadrupole scan technique, we installed an Optical Transition Radiation (OTR) screen and a digital CCD camera in the bealime of the accelerator. From the images of the digital CCD camera, the transverse beam profile on the OTR screen can be acquired. To extract the transverse beam size and to estimate the transverse emittance, we have developed a MATLAB program. This paper describe the details of the MATLAB program and performance of our MATLAB based emittance measurement tool. | |||
| TUPPD048 | Optical Emission Spectroscopy Studies of the Spallation Netron Source (SNS) H− Ion Source | ion, ion-source, plasma, neutron | 1512 |
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| A Cs enhanced, RF-driven H− ion source feeds the SNS accelerator with a 65 keV H− beam at 60 Hz with a pulse length of up to 1.0 ms. The ion source beam intensity and reliability are critical to the SNS operational power level and availability. The 1-MW level routine operation of the SNS requires ~38 mA beam in the linac. This requirement is normally met by the ion source in a persistent manner for a 4-5 weeks service-cycle of the ion source. But, in some occasions, the ion source either falls short of the beam current or fails to keep the beam current persistent. The key factor in achieving high current, persistent H− beam is to have a proper coverage of Cs on the ion converter surface near the source outlet. To quantify the amount of Cs put into the system during cesiation(s) and to monitor the Cs migration during the source operation, an experimental study is under way with an optical spectrometer monitoring the emission lights from the ion source plasma. Another possible use of this emission spectroscopy study is to detect the indication of the ion source antenna deterioration before it develops into a total failure. The progress and some preliminary results are presented. | |||
| TUPPR007 | Beam Background and MDI Design for SuperKEKB/Belle-II | luminosity, scattering, neutron, radiation | 1825 |
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| The Belle experiment, operated at the asymmetric electron-positron collider KEKB, had accumulated a data sample with an integrated luminosity of more than 1 ab−1 before the shutdown in June 2010. We have started upgrading both the accelerator and the detector, SuperKEKB and Belle-II, to achieve the target luminosity of 8×1035 cm−2 s−1. With the increased luminosity, the beam background will be severe. The development of Machine- Detector Interface (MDI) design is crucial to cope with the increased background and protect Belle-II detector. We will present the estimation of impact from each beam background sources at SuperKEKB, such as Touschek-scattering, Beam-gas scattering, radiative Bhabha process, etc.. We will also present our countermeasures against them, such as collimators to stop scattered beam particles, Tungsten shield to protect inner detectors from shower particles, and dedicated beam pipe design around interaction point to stop synchrotron radiation, etc. | |||
| TUPPR020 | Updates to the CLIC Post-collision Line | simulation, radiation, scattering, shielding | 1855 |
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| The 1.5 TeV Compact Linear Collider (CLIC) beams, with a total power of 14 MW per beam, are disrupted at the interaction point due to the very strong beam-beam effect. The disrupted beam has a power of 10 MW. Some 3.5 MW reaches the main dump in the form of beamstrahlung photons, and about 0.5 MW of e+ and e- coherent pair particles with a very broad energy spectrum as well as the lower energy disrupted beam particles need to be disposed of along the post collision line. Calculations for the energy deposition in the magnet coils and the resulting magnet lifetimes for various shielding configurations are presented. | |||
| WEEPPB013 | Direct Wind Superconducting Corrector Magnets for the SuperKEKB IR | dipole, quadrupole, octupole, multipole | 2191 |
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| Upgrade of the KEKB asymmetric e+e− collider for a forty-fold luminosity increase, denoted SuperKEKB, is now underway. For SuperKEKB the beam crossing angle is increased to provide separate focusing channels for the incoming and outgoing electron and positrons beams in new superconducting Interaction Region (IR) magnets. Two functional classes of superconducting corrector magnets are needed to meet SuperKEKB beam optics goals. Dipole, skew-dipole, skew-quadrupole and octupole coil windings will be inserted inside the bores of the main IR quadrupoles to make magnet center alignments, roll adjustments and non-linear optics corrections. A second class of high-order magnetic multipole corrector coils is needed to compensate the non-linear fringe field experienced by the circulating beam that passes just outside the main quadrupole coils that are closest to the Interaction Point (IP). Near the IP there is no space for magnetic yokes or other passive shielding to diminish the fringe field. At the time of this conference the SuperKEKB corrector magnet production will be under way. The SuperKEKB correction coil design and our production technique are reviewed in this paper. | |||
| WEPPC004 | PLM-Based Quality Assurance in the Series Production of the Superconducting Cavities for the European XFEL | cavity | 2209 |
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| This presentation describes the acceptance procedure in the series production of the superconducting cavities for the European XFEL. The cavities are produced by two manufacturers. To ensure they satisfy their performance requirements, the cavities have to pass more than 50 quality inspections, which are combined into four acceptance levels. Part of the inspections are done by the manufacturers, the remaining tests are conducted in a test facility at DESY. The inspections are recorded and processed based on DESY's Product Lifecycle Management (PLM) system, aka DESY EDMS. The DESY EDMS tracks all the individual cavities, keeps their entire production history, and associates all certificates and inspection results with the appropriate parts. The two manufacturers are integrated in the solution and can automatically and promptly upload inspections results to the DESY EDMS. The solution enables DESY to monitor the production progress and to ensure production quality. | |||
| WEPPD008 | Recondenser Performance: Impact on the Superconducting Undulator Magnet at Argonne National Laboratory | undulator, ion, cryogenics, factory | 2513 |
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Funding: This work is supported by Argonne National Laboratory, subcontract number 9F-31982. The current sharing temperature of 6.5 K for the superconducting undulator magnet being developed at Argonne National Laboratory drives the thermal design of the magnet’s cooling system. In order to remain below the current sharing temperature, a thermo-siphon cooling loop is being developed to sweep the anticipated heat load away from the magnet windings and deposit it in the associated liquid helium reservoir located above the magnet. Performance of the magnet’s cooling system is crucially dependent on the ability of the re-condenser to maintain the reservoir’s saturation temperature near 4 K, despite thermal stratification and slowly varying thermal profiles within the vapor region above the liquid in the reservoir. Here we report the results of an experimental investigation of the impact of various geometric configurations for the re-condenser and the thermal resistance associated with the film layer at the re-condensing surface, on the time-varying saturation temperature within the helium reservoir. The resulting temporal thermal variations in the superconducting winding are highlighted as well as the impact they have on the magnet’s stability. |
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| WEPPD025 | LHC Detector Vacuum System Consolidation for Long Shutdown 1 (LS1) in 2013-2014 | vacuum, ion, radiation, electron | 2555 |
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| The LHC has ventured into unchartered territory for Particle Physics accelerators. A dedicated consolidation program is required between 2013 and 2014 to ensure optimal physics performance. The experiments, ALICE, ATLAS, CMS, and LHCb, will utilise this shutdown, along with the gained experience of three years of physics running, to make optimisations to the detectors. New vacuum technologies have been developed for the experimental areas, to be integrated during this first phase shutdown. These technologies include bellows, vacuum chambers and ion pumps in aluminium, new beryllium vacuum chambers, and composite mechanical supports. An overview of this first phase consolidation program for the LHC experiments is presented. | |||
| WEPPP040 | Progress Report on Development of Novel Ultrafast Mid-IR Laser System | laser, acceleration, FEL, wakefield | 2810 |
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| Finding alternate acceleration mechanisms that can provide very high gradients is of particular interest to the accelerator community. Those mechanisms are often based on either dielectric laser acceleration or laser wakefield acceleration techniques, which would greatly benefit from mid-IR ultrafast high peak power laser systems. The approach of this proposed work is to design a novel ultrafast mid-IR laser system based on optical parametric chirped-pulse amplification (OPCPA). OPCPA is a technique ideally suited for production of ultrashort laser pulses at the center wavelength of 2μm-5μm. Some of the key features of OPCPA are the wavelength agility, broad spectral bandwidth and negligible thermal load. This paper reports on the progress of the development of the ultrafast mid-IR laser system. | |||
| WEPPR014 | Recovering Measured Dynamics from a DC Circulating Space-Charge-Dominated Storage Ring | electron, space-charge, diagnostics, storage-ring | 2967 |
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Funding: This work is supported by the US Dept. of Energy Offices of High Energy Physics and Fusion Energy Sciences, and by the US Dept. of Defense Office of Naval Research and Joint Technology Office. Space-charge is increasingly significant at high beam intensities such as in FEL injectors and heavy ion inertial fusion drivers, where it dominates the beam dynamics. The University of Maryland Electron Ring (UMER) is a high intensity circular machine that is dedicated to the study of long path length space-charge-dominated beam physics on a small scale. Over multiple turns, longitudinal space charge effects cause the tail and head of an electron bunch to expand and interpenetrate, eventually resulting in a “DC beam”. This leads to complications when trying to measure the beam with UMER’s AC coupled diagnostics. Three techniques are developed to recover the information within the beam. Two “knockout” techniques implement invasive pulsed electric kicks to the beam in combination with either a fluorescent imaging screen or a current monitor. A third technique based on integration of the wall-current signal provides a non-invasive method to study the DC beam dynamics. Experimental results from all three methods are compared. The DC beam profile can then be studied over long trajectories and the existence of any loss mechanisms can be determined. |
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| WEPPR028 | An Estimate of Out of Time Beam Upon Extraction for Mu2e | septum, extraction, scattering, proton | 2994 |
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Funding: U.S. Dept. of Energy. A bunched beam with specific structure is crucial to attaining the experimental sensitivity desired by the Mu2e collaboration. The final goal is a ratio of in-time to out-of-time beam, known as beam extinction, of 10-10. An AC dipole system is in development to attain the final goal by sweeping out-of-time beam onto a collimation system, but it is still necessary to achieve something on the order of 10-5 when beam is extracted from the Fermilab Debuncher ring to the experiment hall. Several sources of out-of-time beam in the Debuncher ring are analyzed, including: intrabeam scattering, RF noise, beam-gas interaction and scattering off of the extraction septum. Estimates are given for each source as well as a final estimate of total out-of-time beam expected upon extraction. |
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| THPPD026 | Splice Resistance Measurements in the LHC Main Superconducting Magnet Circuits by the New Quench Protection System | dipole, monitoring, injection, controls | 3557 |
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| The interconnections between the LHC main magnets are made of soldered joints (splices) of two superconducting cables stabilized by a copper bus bar. After the 2008 LHC incident, caused by a defective interconnection, a new layer of high resolution magnet circuit quench protection (nQPS) has been developed and integrated with the existing systems. It allowed mapping of the resistances of all superconducting splices during the 2009 commissioning campaign. Since April 2010, when the LHC was successfully restarted at 3.5TeV, every bus bar interconnection is constantly monitored by the nQPS electronics. The acquired data are saved to the LHC Logging Database. The paper will briefly describe the data analysis method and will present the results from the two years of resistance measurements. Although no splice was found with resistance higher than 3.3nOhm and no significant degradation in time was observed so far, the monitoring of splices will stay active till the end of LHC 3.5TeV run. The detected outliers will be repaired during the Splice Consolidation Campaign in 2013-2014. | |||
| THPPD033 | Using Permanent Magnets to Boost the Dipole Field for the High-energy LHC | permanent-magnet, dipole, cryogenics, radiation | 3578 |
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Funding: Work supported by the European Commission under the FP7 Research Infrastructures project EuCARD, grant agreement no. 227579. The High-Energy LHC (HE-LHC) will be a new accelerator in the LHC tunnel based on novel dipole magnets, with a field up to 20 T, which are proposed to be realized by a hybrid-coil design, comprising blocks made from Nb-Ti, Nb3Sn and HTS, respectively. Without the HTS the field would be only 15 T. In this note we propose and study the possibility of replacing the inner HTS layer by (weaker) permanent magnets that might contribute a field of 1-2 T, so that the final field would reach 16-17 T. Advantages would be the lower price of permanent magnets compared with HTS magnets and their availability. |
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| THPPD035 | Magnets for Interaction Regions of a 1.5×1.5 TeV Muon Collider | dipole, quadrupole, collider, luminosity | 3584 |
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Funding: Work supported by Fermi Research Alliance, LLC, under contract No. DE-AC02-07CH11359 with the U.S. Department of Energy The updated IR optics and conceptual designs of large aperture superconducting quadrupole magnets for a muon collider with a c.o.m. energy of 3 TeV and an average luminosity of 4·1034 cm-2 s-1 are presented. All magnets are based on the Nb3Sn superconductor and designed to provide an adequate operation field gradient in the given aperture with the critical current margin required for reliable machine operation. Special dipole coils were added to quadrupole designs to provide ~2 T bending field and thus facilitate chromaticity correction and dilute decay electron fluxes on the detector. Magnet cross-sections were optimized to achieve the best possible field quality in the magnet aperture occupied with beams. Magnet parameters are reported and compared with the requirements. Energy deposition calculations with the MARS code have allowed to optimize parameters of inner absorbers, collimators in interconnect regions and Machine-Detector Interface. |
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| THPPR015 | CESR Control System Upgrade to Linux High Availability Cluster | controls, monitoring, status, synchrotron | 3999 |
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Funding: Supported by U.S. National Science Foundation, Award PHY-0734867 and Award PHY-1002467, as well as, U.S. Department of Energy, Award DE-FC02-08ER41538. The Cornell Electron Storage Ring (CESR) accelerator complex is used to support the Cornell High Energy Synchrotron Source (CHESS) x-ray user facility and the CESR Test Accelerator (CESRTA) ILC development program. Several hundred electro-magnetic elements as well as several thousand sensors are controlled and monitored in real-time via a Multi-Port Memory device (MPM). MPM access and control programs have used Hewlett Packard (originally DEC) Alpha and VAX computers running OpenVMS since 1988. Due to the demanding throughput, computational and storage requirements of the CESRTA experimental program, as well as a desire to upgrade to more supportable hardware, we have implemented a new Linux control cluster based on an Infortrend 10 GbE Internet Small Computer System Interface (iSCSI) storage device and the Red Hat Cluster Suite. This paper will describe the hardware and software changes required to upgrade our VMS cluster to a high availability, high performance, Linux control cluster. |
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