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Status of perturbative QCD

Description: In this talk is discussed, within the framework of perturbative QCD, four topics which have received theoretical attention in the last year. They are: (1) jets at the CERN Sp anti p S collider, (2) power corrections to leptoproduction, (3) hard scattering off nuclear targets, and (4) the photon structure function. 28 references.
Date: August 1, 1983
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

New results in perturbative QCD

Description: Three topics in perturbative QCD important for Super-collider physics are reviewed. The topics are: (2 2) jet phenomena calculated in O( sT); new techniques for the calculation of tree graphs; and colour coherence in jet phenomena. 31 refs., 6 figs.
Date: November 1, 1985
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

QCD parton model at collider energies

Description: Using the example of vector boson production, the application of the QCD improved parton model at collider energies is reviewed. The reliability of the extrapolation to SSC energies is assessed. Predictions at ..sqrt..S = 0.54 TeV are compared with data. 21 references.
Date: September 1, 1984
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

The theory of heavy flavour production

Description: The theory of heavy quark production in hadronic reactions is reviewed. Rates for the production of charm, bottom and top quarks at energies of current interest are presented. 34 refs., 19 figs., 2 tabs.
Date: August 9, 1989
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

Heavy quark production at collider energies

Description: The theory of heavy quark production in QCD at collider energies is reviewed. The most important features of the recently published results on higher order corrections to the heavy quark production cross-section are described. The phenomenological consequences of these formulae for bottom and top quark production at Sp/bar p/S and Tevatron energies are presented. 22 refs., 13 figs., 1 tab.
Date: November 1, 1988
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

The status of perturbative QCD

Description: The advances in perturbative QCD are reviewed. The status of determinations of the coupling constant ..cap alpha../sub S/ and the parton distribution functions is presented. New theoretical results on the spin dependent structure functions of the proton are also reviewed. The theoretical description of the production of vector bosons, jets and heavy quarks is outlined with special emphasis on new results. Expected rates for top quark production at hadronic colliders are presented. 111 refs., 8 figs.
Date: October 1, 1988
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

Large transverse momentum and higher twist phenomena

Description: A brief summary of the physics of large transverse momentum and higher twist phenomena is given. Particle topics discussed are: higher twist effects in deep inelastic scattering; power suppressed effects at kinematic boundaries; heavy flavour production; vector boson production; and the running of the coupling constant. (LSP)
Date: November 1, 1988
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

Perturbative corrections to university and renormalization group behaviour

Description: The influence of weak coupling corrections on tests of the universality of lattice actions is discussed. The two loop corrections described in this paper were performed using the background field method. An estimate is also provided of the perturbative corrections to asymptotic scaling for the Wilson action. Monte Carlo simulation of Lattice QCD is carried out at finite, large values of the bare coupling g, but the continuum limit of the theory corresponds to vanishing g. When extracting physical results from lattice calculations it is therefore important to correct for the non-zero value of the coupling constant. The results of some perturbative calculations are reported, which address this question.
Date: April 1, 1984
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

Transverse momentum distributions of jets and weak bosons

Description: The theoretical description of processes leading to events at large transverse momentum is reviewed. Numerical estimates are given for jet cross-sections and for W and Z production cross-sections. The influence which uncertainties in the input parameters have on the theoretical predictions is also discussed.
Date: May 1, 1984
Creator: Ellis, R.K.
Partner: UNT Libraries Government Documents Department

Summary report of the Jet-Study Group

Description: Predictions for jet physics at SSC energies are reviewed. Comparison is made with data at CERN collider energies. The work of the Jet-Study Group had much overlap with the work of the Detector Groups and the Fragmentation Group. 22 references.
Date: October 1, 1984
Creator: Ellis, R.K. & Rohlf, J.
Partner: UNT Libraries Government Documents Department

Flight investigation at high-subsonic, transonic, and supersonic speeds to determine zero-lift drag of bodies of revolution having fineness ratio of 6.04 and varying positions of maximum diameter

Description: Report presenting a flight investigation of rocket-powered models at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized bodies of revolution differing in maximum diameter. All bodies had 6.04 fineness ratio and cut-off sterns with equal base area. The most favorable location out of the 20-percent, 40-percent, and 60-percent positions were evaluated for different speeds.
Date: August 31, 1949
Creator: Katz, Ellis R.
Partner: UNT Libraries Government Documents Department

Results of flight tests at supersonic speeds to determine the effect of body nose fineness ratio on body and wing drag

Description: Report presenting flight tests of rocket-powered models at supersonic speeds to determine the effect of nose fineness ratio of winged bodies on total and component drag at high Mach numbers. Wingless models of three nose fineness ratios and winged models of two nose fineness ratios flown through a range of Mach numbers. Results regarding total drag, body drag, and wing drag are provided.
Date: June 26, 1947
Creator: Katz, Ellis R.
Partner: UNT Libraries Government Documents Department

Analyses of Weapons-Grade MOX VVER-1000 Neutronics Benchmarks: Pin-Cell Calculations with SCALE/SAS2H

Description: A series of unit pin-cell benchmark problems have been analyzed related to irradiation of mixed oxide fuel in VVER-1000s (water-water energetic reactors). One-dimensional, discrete-ordinates eigenvalue calculations of these benchmarks were performed at ORNL using the SAS2H control sequence module of the SCALE-4.3 computational code system, as part of the Fissile Materials Disposition Program (FMDP) of the US DOE. Calculations were also performed using the SCALE module CSAS to confirm the results. The 238 neutron energy group SCALE nuclear data library 238GROUPNDF5 (based on ENDF/B-V) was used for all calculations. The VVER-1000 pin-cell benchmark cases modeled with SAS2H included zero-burnup calculations for eight fuel material variants (from LEU UO{sub 2} to weapons-grade MOX) at five different reactor states, and three fuel depletion cases up to high burnup. Results of the SAS2H analyses of the VVER-1000 neutronics benchmarks are presented in this report. Good general agreement was obtained between the SAS2H results, the ORNL results using HELIOS-1.4 with ENDF/B-VI nuclear data, and the results from several Russian benchmark studies using the codes TVS-M, MCU-RFFI/A, and WIMS-ABBN. This SAS2H benchmark study is useful for the verification of HELIOS calculations, the HELIOS code being the principal computational tool at ORNL for physics studies of assembly design for weapons-grade plutonium disposition in Russian reactors.
Date: January 11, 2001
Creator: Ellis, R.J.
Partner: UNT Libraries Government Documents Department

Safety assessment for the S-1 Spheromak

Description: The S-1 machine is part of the Magnetic Fusion Program. The goal of the Magnetic Fusion Program is to develop and demonstrate the practical application of fusion. S-1 is an experimental device which will provide an essential link in the research effort aiming at the realization of fusion power.
Date: February 1, 1984
Creator: Ellis, R., Jr. & Stencel, J. R.
Partner: UNT Libraries Government Documents Department

Multijet final states: exact results and the leading pole approximation

Description: Exact results for the process gg ..-->.. ggg are compared with those obtained using the leading pole approximation. Regions of phase space where the approximation breaks down are discussed. A specific example relevant for background estimates to W boson production is presented. It is concluded that in this instance the leading pole approximation may underestimate the standard QCD background by more than a factor of two in certain kinematic regions of physical interest.
Date: September 1, 1984
Creator: Ellis, R.K. & Owens, J.F.
Partner: UNT Libraries Government Documents Department

Efforts to stabilize the M = 2 helical instability in ATC

Description: Experiments show that there is no difficulty about interacting with a 2/ 1 mode in ATC, and that given sufficient gain and a harmonic-free control winding the probability of stabilizing it is good. Control by steadily applied, DC quadrupole fields, on the other hand, on the basis of experiments with ATC as well as Pulsator, would seem at this juncture to have a small chance of success. Finally, the high currents achieved in gettered discharges offer the possibility that if control of wall emission can be achieved--e.g., with a divertor--one may simultaneously achieve a measure of control of the 2/1 and higher modes. (auth)
Date: January 1, 1975
Creator: Bol, K.; Ellis, R.A. Jr. & Hsuan, H.
Partner: UNT Libraries Government Documents Department

Flight Investigations at High-Subsonic, Transonic, and Supersonic Speeds to Determine Zero-Lift Drag of Fin-Stabilized Bodies of Revolution having Fineness Ratios of 12.5, 8.91, and 6.04 and Varying Positions of Maximum Diameter

Description: Rocket-powered models were flown at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized parabolic bodies of revolution differing in fineness ratio and in position of maximum diameter. The present paper presents the results for fineness ratio 12.5, 8.91 and 6.04 bodies having maximum diameters located at stations of 20, 40, 60, and 80 percent of body length. All configurations had cut-off sterns and all had equal base, frontal, and exposed fin areas. For most of the supersonic-speed range models having their maximum diameters at the 60-percent station gave the lowest values of drag coefficient. At supersonic speeds, increasing the fineness ratio generally reduced the drag coefficient for a given position of maximum diameter.
Date: November 30, 1949
Creator: Hart, Roger G. & Katz, Ellis R.
Partner: UNT Libraries Government Documents Department

Improved system for perpendicular electron-cyclotron emission measurements on TMX-Upgrade

Description: Perpendicular electron-cyclotron emission (PECE) is used on TMX-U to diagnose thermal-barrier hot electrons (T/sub H/ approx. 100 to 400 keV); yielding the time history of the temperature of these relativistic electrons. We describe an improved quasi-optical viewing system for these measurements that uses high sensitivity superheterodyne receivers at fixed frequencies of 60, 98, 130, and 196 GHz. The improved viewing and transport system consists of an off-axis ellipsoidal mirror that images the plasma onto a V-band conical collection horn, an overmoded circular waveguide (7/8'' diam) that transports the radiation outside the vacuum vessel where the polarization is selected, and a high absorptivity Macor beam dump to prevent internal wall reflections from entering the viewing system. A relativistic code is used to calculate optically thin PECE signals from relativistic electrons for various energy and pitch angle distributions. 4 refs., 4 figs.
Date: March 7, 1986
Creator: Lasnier, C.J.; Ellis, R.F. & James, R.A.
Partner: UNT Libraries Government Documents Department

Optically thin perpendicular electron-cyclotron emission from hot electrons in TMX-U

Description: Perpendicular electron-cyclotron emission (PECE) from relativistic (T/sub H/ approx. 100 to 400 keV) hot electrons within the thermal-barrier region of TMX-U is detected at 35, 60, 94 and 98 GHz. For the operating regime of TMX-U these signals are optically thin (tau<<1) and thus proportional to the radial hot electron line density. A relativistic code is used to calculate the theoretical temperature dependence of the perpendicular emission coefficient, j perpendicular(..omega..,T/sub H/), for each of the detected frequencies. This dependence has been verified experimentally by x-ray measurements of the hot electron temperature, T/sub H/. The observed qualitative agreement demonstrates that optically thin PECE signals can be used to determine the temporal evolution of T/sub H/. An inability to absolutely calibrate the present PECE waveguide system has prevented quantitative agreement.
Date: March 4, 1986
Creator: James, R.A.; Lasnier, C.J. & Ellis, R.F.
Partner: UNT Libraries Government Documents Department

PU Disposition in Russian VVERs: Physics Studies of Lead Test Assembly Design

Description: As part of Fissile Materials Disposition Program (FMDP) physics support was given to the design of a MOX lead test assembly (LTA) for use in Russian VVER nuclear reactors. This paper discusses some of the pertinent findings and assessments for two distinct LTA designs for weapons-grade (WG) Pu dispositioning in Russian VVER-1000 nuclear reactors. The two assessed MOX LTA designs are the graded-zone full MOX LTA and the Island LTA (2 central zones of MOX pins surrounded by UO{sub 2} pins). The process of optimizing the graded Pu-content by zone in the fuel assembly is discussed. Eigenvalue and power peaking comparisons are made as a function of fuel burnup. Zero-power reactivity effects were calculated for the different LTA options. For the ORNL results, the n,{gamma}-transport lattice physics code HELIOS-1.4 was used with nuclear data libraries (based on ENDF/B-VI) in 89 and 190 neutron energy groups. Some comparisons are made between the ORNL HELIOS results and corresponding Russian LTA calculations by the RRC-KI (Kurchatov Institute) using the code TVS-M. Also in this paper, pertinent results are discussed from a study of void reactivity effects for LEU, RG MOX and WG MOX fuels in PWR and VVER-1000 nuclear reactors. These void reactivity calculations were performed for a large range of LEU enrichments (2-20 wt% {sup 235}U), and large ranges of Pu-content (2-20 wt% Pu) in RG and WG MOX fuel.
Date: May 7, 2000
Creator: Ellis, R. J.
Partner: UNT Libraries Government Documents Department