2,602 research outputs found

    A Simple Multiprocessor Management System for Event-Parallel Computing

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    Offline software using TCP/IP sockets to distribute particle physics events to multiple UNIX/RISC workstations is described. A modular, building block approach was taken, which allowed tailoring to solve specific tasks efficiently and simply as they arose. The modest, initial cost was having to learn about sockets for interprocess communication. This multiprocessor management software has been used to control the reconstruction of eight billion raw data events from Fermilab Experiment E791.Comment: 10 pages, 3 figures, compressed Postscript, LaTeX. Submitted to NI

    Exploration of a High Luminosity 100 TeV Proton Antiproton Collider

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    New physics is being explored with the Large Hadron Collider at CERN and with Intensity Frontier programs at Fermilab and KEK. The energy scale for new physics is known to be in the multi-TeV range, signaling the need for a future collider which well surpasses this energy scale. We explore a 10 34^{\,34} cm−2^{-2} s−1^{-1} luminosity, 100 TeV ppˉp\bar{p} collider with 7×\times the energy of the LHC but only 2×\times as much NbTi superconductor, motivating the choice of 4.5 T single bore dipoles. The cross section for many high mass states is 10 times higher in ppˉp\bar{p} than pppp collisions. Antiquarks for production can come directly from an antiproton rather than indirectly from gluon splitting. The higher cross sections reduce the synchrotron radiation in superconducting magnets and the number of events per beam crossing, because lower beam currents can produce the same rare event rates. Events are more centrally produced, allowing a more compact detector with less space between quadrupole triplets and a smaller β∗\beta^{*} for higher luminosity. A Fermilab-like pˉ\bar p source would disperse the beam into 12 momentum channels to capture more antiprotons. Because stochastic cooling time scales as the number of particles, 12 cooling ring sets would be used. Each set would include phase rotation to lower momentum spreads, equalize all momentum channels, and stochastically cool. One electron cooling ring would follow the stochastic cooling rings. Finally antiprotons would be recycled during runs without leaving the collider ring by joining them to new bunches with synchrotron damping.Comment: 11 pages, 20 figures, SESAPS 2015 Conference. Reference correcte

    A Complete Scheme of Ionization Cooling for a Muon Collider

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    A complete scheme for production and cooling a muon beam for three specified muon colliders is presented. Parameters for these muon colliders are given. The scheme starts with the front end of a proposed neutrino factory that yields bunch trains of both muon signs. Emittance exchange cooling in slow helical lattices reduces the longitudinal emittance until it becomes possible to merge the trains into single bunches, one of each sign. Further cooling in all dimensions is applied to the single bunches in further slow helical lattices. Final transverse cooling to the required parameters is achieved in 50 T solenoids using high Tc superconductor at 4 K. Preliminary simulations of each element are presented.Comment: 3 pages, 6 figure

    Prevalence of refractive errors, corneal arcus, and blood pressure readings in 2656 Indonesian subjects

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    On a recent eye care mission to Indonesia, epidemiological information was collected on 2656 indigenous patients. Prevalence of refractive errors, corneal arcus and blood pressure readings were recorded and evaluated. The data from three different sites on the island of Java presented with a definite increased pattern of myopia amongst the youth ages 8 to 19. When compared to other nations, the average refractive error of Indonesians was slightly less hyperopic. Against-the- rule astigmatism had the highest occurrence when compared to other axis orientations, yet the overall occurrence of astigmatism was less than that found in western nations. An elevated prevalence of corneal arcus was discovered in this population. Blood pressure was found to be within normal limits when compared to western clinical standards

    Working with arrays of inexpensive eide disk drives

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    Abstract: In today's marketplace, the cost per Terabyte of disks with EIDE interfaces is about a third that of disks with SCSI. Hence, three times as many particle physics events could be put online with EIDE. The modern EIDE interface includes many of the performance features that appeared earlier in SCSI. EIDE bus speeds approach 33 Megabytes s and need only be shared between two disks rather than seven disks. The internal I O rate of very fast and expensive SCSI disks is only 50 per cent greater than EIDE disks. Hence, two EIDE disks whose combined cost is much less than one very fast SCSI disk can actually give more data throughput due to the advantage of multiple spindles and head actuators. We explore the use of 12 and 16 Gigabyte EIDE disks with motherboard and PCI bus card interfaces on a number of operating systems and CPUs. These include Red Hat Linux and Windows 95 98 o n a P entium, MacOS and Apple's Rhapsody NeXT UNIX on a PowerPC, and Sun Solaris on a UltraSparc 10 workstation
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