A5047989115- Particle accelerators and beam dynamics
- Magnetic confinement fusion research
- Superconducting Materials and Applications
- Particle Accelerators and Free-Electron Lasers
- Nuclear Physics and Applications
- Fusion materials and technologies
- Nuclear reactor physics and engineering
- Particle Detector Development and Performance
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Astrophysics and Cosmic Phenomena
- Distributed and Parallel Computing Systems
- Radiation Effects in Electronics
- Spacecraft and Cryogenic Technologies
- Gyrotron and Vacuum Electronics Research
- Radiation Therapy and Dosimetry
- Particle physics theoretical and experimental studies
- Nuclear Materials and Properties
- Graphite, nuclear technology, radiation studies
- Radiation Detection and Scintillator Technologies
- Muon and positron interactions and applications
- Spacecraft Design and Technology
- High-pressure geophysics and materials
- Liver Disease and Transplantation
- Atomic and Subatomic Physics Research
Oak Ridge National Laboratory
2011-2022
Oak Ridge Associated Universities
2012-2016
Studieförbundet Näringsliv och Samhälle
2013
Computational Physics (United States)
1996-1998
United States Department of Energy
1997
Fusion Academy
1982-1989
Fusion (United States)
1982-1989
United States Department of Commerce
1989
Princeton Plasma Physics Laboratory
1985
University of Illinois Urbana-Champaign
1982-1984
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory is a pulsed source of neutrons and, as by-product this operation, an intense neutrinos via stopped-pion decay. COHERENT collaboration uses to investigate coherent elastic neutrino-nucleus scattering and other physics with suite detectors. This work includes description our geant4 simulation neutrino production the SNS flux calculation which informs studies. We estimate uncertainty $\ensuremath{\sim}10%$ level based on...
An international study conducted by technical experts from Europe, Japan, Russia, and the United States has evaluated issues required testing facilities for development of fusion blanket/first-wall systems found that some key requirements engineering feasibility blanket concepts cannot be established prior to extensive in environment. However, because availability low cost, nonfusion (e.g., fission reactors laboratory experiments) serves a critical role research (R&D) reduces risks costs...
The attractiveness of future commercial tokamak reactors is sensitive to the attainable plasma performance, notably energy confinement and allowable beta. impact varying levels beta on size cost resulting reactor systematically quantified. Several different classes are considered, designs optimized in terms electricity (COE) via a coupled physics/engineering/costing systems code. Surprisingly narrow ranges found be simultaneously useful minimizing COE, i.e. improvement only one these...
A new code, named SUPECODE, has been developed to fill the gap between currently available zero dimensional systems codes and highly sophisticated, multidimensional plasma performance codes. The former are comprehensive in content, fast execute, but rather simple terms of accuracy their physics engineering models. latter contain state-of-the-art modeling limited content time consuming run. SUPECODE upgrades reliability by calculating self consistent 1 1/2-D evolution a realistic environment....
We report on an experiment in which a negative hydrogen ion beam the Spallation Neutron Source (SNS) linear accelerator was replaced with of protons similar size and dynamics. Fractional loss superconducting part SNS measured to be at least $2\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$ for ${\mathrm{H}}^{\ensuremath{-}}$ beam, it order magnitude lower protons. Also has stronger dependence intensity than proton beams. These measurements verify recent theoretical explanation...
ORBIT (Objective Ring Beam Injection and Tracking) is a new particle tracking code for rings. Modelling capabilities include H/sup -/ foil injection mechanisms, longitudinal transverse space charge effects, second order matrix transport. Additional features programmable interactive driver shell, plotting.
The effects of Nuclear Elastic Scattering (NES) on the properties Cat-D and D-3He plasmas are investigated, with special attention given to discrete nature NES. A space-independent, linear multi-group method is used for study. It found that NES can significantly reduce nr requirements plasma ignition; characterized by relatively large cyclotron radiation losses, this reduction exceed 50%. In addition, treatment behaviour shown be essential an accurate prediction superthermal ion distribution...
XAL is an application programming framework used at the Spallation Neutron Source (SNS) project in Oak Ridge. It written Java, and provides users with a hierarchal view of accelerator. Features include database configuration accelerator structure, online envelope model that configurable from design or live machine values, for quickstart GUI development, scripting interface algorithm common toolkit shared resources. To date, about 25 applications have been written, many which are extensively...
The Spallation Neutron Source (SNS) at Oak Ridge National Laboratory (ORNL) is preparing for the Proton Power Upgrade (PPU) project to increase output energy of accelerator from 1.0 GeV 1.3 GeV. As part this with combination increasing and beam current, power capability will be doubled 1.4MW 2.8MW. In project, seven new high beta cryomodules housing 28 superconducting niobium cavities added LINAC tunnel. Lessons learned over ten years operation incorporated into cryomodule cavity design....
Uncontrolled beam losses due to space-charge-induced halo generation are a concern in high intensity rings, which characterized by intensities and low uncontrolled loss requirements. It is therefore important investigate the dynamics of space charge rings. We report here results extensive calculations using particle-tracking approach with self-consistent particle-in-cell model alternatively particle core model. find that inclusion forces provides agreement between calculated experimentally...
The Oak Ridge Spallation Neutron Source comprises a 1 GeV, 1.5 MW linear accelerator followed by an accumulator ring and liquid mercury target. To manage the beam loss caused ${H}^{0}$ excited states created during ${H}^{\ensuremath{-}}$ charge-exchange injection into ring, stripper foil is located inside one of chicane dipoles. This has some interesting consequences that were not fully appreciated until power reached about 840 kW. One consequence was sudden failure system due to convoy...
The D-3He ignition and burn criteria for tokamaks spherical torus reactors are examined in a global analysis with profile corrections. Particle confinement ash buildup effects included the power balance, which results an increased sensitivity of to losses via bremsstrahlung synchrotron radiation. Plasma beta scaling ɛβp limit provides needed aspect ratio (A) dependence permits all A values first second stability regimes. Energy time (τE) associated particle diffusion (τp) energy conduction...
The Spallation Neutron Source (SNS) radio-frequency quadrupole (RFQ) had resonance control instabilities at duty factors higher than approximately 4%. Systematic investigations have been carried out to understand the cause of instability and ensure operational stability RFQ. most critical source is revealed be an interaction between hydrogen released by beam bombardments RFQ rf field resulting in a discharge, which consumes additional power could operate unstable region. This paper reports...
Transverse beam profiles are observed to broaden with increasing intensity in the Proton Storage Ring at Los Alamos Neutron Scattering Center. Measured simulated an ${\mathrm{H}}^{\ensuremath{-}}$ injection model that includes a 2D particle-in-cell space charge calculation. Inclusion of effects simulation improves agreement between experimentally and calculated profiles. The comparisons made for range injected intensities.