The SuperCOSMOS Sky Survey. Paper II: Image detection, parameterisation, classification and photometry

In this, the second in a series of three papers concerning the SuperCOSMOS Sky Survey, we describe the methods for image detection, parameterisation, classification and photometry. We demonstrate the internal and external accuracy of our object parameters. Using examples from the first release of data, the South Galactic Cap survey, we show that our image detection completeness is close to 100% to within 1.5 mag of the nominal plate limits. We show that for the Bj survey data, the image classification is externally > 99% reliable to Bj = 19.5. Internally, the image classification is reliable at a level of > 90% to Bj=21, R=19. The photometric accuracy of our data is typically 0.3 mag with respect to external data for m > 15. Internally, the relative photometric accuracy in restricted position and magnitude ranges can be as accurate as 5% for well exposed stellar images. Colours (B-R or R-I) are externally accurate to 0.07 mag at Bj = 16.5 rising to 0.16 mag at Bj = 20.Comment: 22 pages, 16 figures; accepted for publication in MNRA

The performance of the jet trigger for the ATLAS detector during 2011 data taking

The performance of the jet trigger for the ATLAS detector at the LHC during the 2011 data taking period is described. During 2011 the LHC provided proton–proton collisions with a centre-of-mass energy of 7 TeV and heavy ion collisions with a 2.76 TeV per nucleon–nucleon collision energy. The ATLAS trigger is a three level system designed to reduce the rate of events from the 40 MHz nominal maximum bunch crossing rate to the approximate 400 Hz which can be written to offline storage. The ATLAS jet trigger is the primary means for the online selection of events containing jets. Events are accepted by the trigger if they contain one or more jets above some transverse energy threshold. During 2011 data taking the jet trigger was fully efficient for jets with transverse energy above 25 GeV for triggers seeded randomly at Level 1. For triggers which require a jet to be identified at each of the three trigger levels, full efficiency is reached for offline jets with transverse energy above 60 GeV. Jets reconstructed in the final trigger level and corresponding to offline jets with transverse energy greater than 60 GeV, are reconstructed with a resolution in transverse energy with respect to offline jets, of better than 4 % in the central region and better than 2.5 % in the forward direction

Comparison between simulated and observed LHC beam backgrounds in the ATLAS experiment at Ebeam =4 TeV

Results of dedicated Monte Carlo simulations of beam-induced background (BIB) in the ATLAS experiment at the Large Hadron Collider (LHC) are presented and compared with data recorded in 2012. During normal physics operation this background arises mainly from scattering of the 4 TeV protons on residual gas in the beam pipe. Methods of reconstructing the BIB signals in the ATLAS detector, developed and implemented in the simulation chain based on the \textscFluka Monte Carlo simulation package, are described. The interaction rates are determined from the residual gas pressure distribution in the LHC ring in order to set an absolute scale on the predicted rates of BIB so that they can be compared quantitatively with data. Through these comparisons the origins of the BIB leading to different observables in the ATLAS detectors are analysed. The level of agreement between simulation results and BIB measurements by ATLAS in 2012 demonstrates that a good understanding of the origin of BIB has been reached

Open data from the third observing run of LIGO, Virgo, KAGRA, and GEO

The global network of gravitational-wave observatories now includes five detectors, namely LIGO Hanford, LIGO Livingston, Virgo, KAGRA, and GEO 600. These detectors collected data during their third observing run, O3, composed of three phases: O3a starting in 2019 April and lasting six months, O3b starting in 2019 November and lasting five months, and O3GK starting in 2020 April and lasting two weeks. In this paper we describe these data and various other science products that can be freely accessed through the Gravitational Wave Open Science Center at https://gwosc.org. The main data set, consisting of the gravitational-wave strain time series that contains the astrophysical signals, is released together with supporting data useful for their analysis and documentation, tutorials, as well as analysis software packages

Full-scale in-can melter demonstration for vitrification of nuclear waste

A full-scale, nonradioactive in-can melter was made operational in April of 1977 at Pacific Northwest Laboratory (PNL). The furnace's six independently controlled hot zones are capable of providing 30 kW each at 1200/sup 0/C and are able to accommodate canisters up to 28 in. in dia and 7.5 ft tall. Several new system concepts were demonstrated with this equipment. These included supporting the canister from the bottom, placing the entire can within the furnace, and charging the melter through a water-cooled spout. These new concepts allowed one to eliminate accumulations both of batch over the top of the heat transfer plates and of unvitrified waste in the top of the can by using a test batch of simulated acid waste composition combined with borosilicate glass former; one was able to attain a melting rate of 117 kg/h in a 28-in.-dia canister. A 10-day continuous run was also made in conjunction with a heated wall spray calciner to demonstrate equipment reliability and operability. In addition, the operation of the in-can melting process was demonstrated using only remote monitoing equipment outside of the canister

Nuclear fuels technologies fiscal year 1998 research and development test plan

A number of research and development (R and D) activities are planned at Los Alamos National Laboratory (LANL) in FY98 in support of the Department of Energy Office of Fissile Materials Disposition (DOE-MD). During the past few years, the ability to fabricate mixed oxide (MOX) nuclear fuel using surplus-weapons plutonium has been researched, and various experiments have been performed. This research effort will be continued in FY98 to support further development of the technology required for MOX fuel fabrication for reactor-based plutonium disposition. R and D activities for FY98 have been divided into four major areas: (1) feed qualification/supply, (2) fuel fabrication development, (3) analytical methods development, and (4) gallium removal. Feed qualification and supply activities encompass those associated with the production of both PuO{sub 2} and UO{sub 2} feed materials. Fuel fabrication development efforts include studies with a new UO{sub 2} feed material, alternate sources of PuO{sub 2}, and determining the effects of gallium on the sintering process. The intent of analytical methods development is to upgrade and improve several analytical measurement techniques in support of other R and D and test fuel fabrication tasks. Finally, the purpose of the gallium removal system activity is to develop and integrate a gallium removal system into the Pit Disassembly and Conversion Facility (PDCF) design and the Phase 2 Advanced Recovery and Integrated Extraction System (ARIES) demonstration line. These four activities will be coordinated and integrated appropriately so that they benefit the Fissile Materials Disposition Program. This plan describes the activities that will occur in FY98 and presents the schedule and milestones for these activities

Experimental economics in antitrust

This chapter assesses the scope and the specific contribution of laboratory experiments for antitrust. It reviews experiments that have addressed specific antitrust issues, problems, and institutions. The chapter mainly covers experimental studies on collusion (tacit and explicit, conscious parallelism) and exclusionary behavior (predatory pricing, foreclosure, exclusive dealing and bundling)