| 1974 — 1977 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computing Simulation of Plasmas @ University of California-Los Angeles |
0.915 |
| 1975 — 1977 |
Fried, Burton [⬀]
Dawson, John (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
A Theoretical Study of Plasma Physics @ University of California-Los Angeles |
0.915 |
| 1977 — 1981 |
Dawson, John [⬀]
Tajima, Toshiki (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulation of Plasmas @ University of California-Los Angeles |
0.915 |
| 1978 — 1980 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Numerical Studies of Magnetohydrodynamic Processes in Space @ University of California-Los Angeles |
0.915 |
| 1980 — 1986 |
Kennel, Charles (co-PI) [⬀]
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Numerical Studies of Magnetohydrodynamics Processes in Space @ University of California-Los Angeles |
0.915 |
| 1981 — 1999 |
Lin, Anthony
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulation of Plasmas At Ucla @ University of California-Los Angeles |
0.915 |
| 1982 — 1983 |
Lin, Anthony
Dawson, John (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulations of Free Electron Lasers Operated in Collective Mode @ University of California-Los Angeles |
0.915 |
| 1983 — 1985 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulation of Plasmas At U C L a (Physics) @ University of California-Los Angeles |
0.915 |
| 1983 — 1986 |
Lin, Anthony
Dawson, John (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulations of Radiation Generation From Relativistic Electron Beams (Electrical Engineering) @ University of California-Los Angeles |
0.915 |
| 1985 — 1987 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
A Plasma Booster For Linear Accelerators (Physics) @ University of California-Los Angeles |
0.915 |
| 1985 — 1992 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulation of Plasmas At Ucla (Physics) @ University of California-Los Angeles
This program has pioneered the use of computer modeling for investigating the physics of plasmas. The program is based on the philosophy of using computer simulation as a general tool to gain fundamental understanding of plasmas, to explore phenomena which are difficult or impossible to investigate in other ways, and to study interesting and potentially useful plasma behavior. A two year program is proposed to pursue studies of basic plasma physics, to investigate properties of plasma lenses and accelerators, to investigate the use of plasmas as radiation sources, to study dynamic Debye clouds in magnetized plasmas, to investigate lasing mechanisms which may have been operative in the early universe, and to develop diagnostic tools for plasma research.
|
0.915 |
| 1986 — 1990 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Plasma Applications For High Energy Physics @ University of California-Los Angeles |
0.915 |
| 1986 — 1996 |
Kennel, Charles (co-PI) [⬀]
Pritchett, Philip
Dawson, John [⬀]
Wu, Cheng-Chin |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Numerical Studies of Magnetospheric Dynamics and Related Space Plasma Processes @ University of California-Los Angeles
This proposal is for numerical studies of the magnetosphere with a focus on the properties of intermediate shock waves, the dynamics of the magnetosheath and magnetopause, reconnection and convection in the geomagnetic tail, and auroral electron acceleration by lower-hybrid wave turbulence. Scaling behavior of intermediate shocks will be handled through magnetohydrodynamics (MHD) followed by hybrid simulations extended to the high ion beta case (beta is the ratio of plasma to field energy density). MHD studies of the magnetopause will be pursued along with hybrid models to study magnetopause structure. 3D global simulations will be done including all the large-scale dynamics of the magnetosphere to test the effects of magnetosheath and magnetopause boundary conditions. Response of the magnetosphere to these inputs will be analyzed through studies of collisionless reconnection in the near- Earth plasma sheet, extended to cover more general aspects of convection and to consider the structure and stability of more distant parts of the tail current sheet. A new high beta drift- kinetic simulation code will be developed including some kinetic effects for the electrons as well as ions. This code will be used to test the hypothesis that chaotization of electron orbits can restore the universal ion tearing mode - a fundamental question for the reconnection process in space plasmas. Resonant electron acceleration by ion wave turbulence will be studied and the results compared with observations of auroral electron spectra and the structure of auroral arcs.
|
0.915 |
| 1986 — 1990 |
Lin, Anthony
Dawson, John (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Computer Simulations of Radiation Generation From Relativis-Tic Electron Beams @ University of California-Los Angeles
The PI's propose to use improved relativistic electromagnetic particle codes as well as existing codes developed under their previous NSF grant (ECS-8219105) to address crucial issues concerning the generation of coherent radiation from relativistic electron beams. The simulation studies will be carried out in the microwave range and will include the free-electron laser, electron cyclotron maser, and Cherenkov maser. The research will investigate: the effects of ac and dc space charge fields on the gain, resonant condition and nonlinear efficiency of various high current free electron devices; the transverse mode competition in various free electron devices; the effectiveness of using a background plasma for beam dc space charge and current neutralization and the feasibility of using the interaction between relativistic electron beams and plasma filled waveguides to build coherent radiation sources; and the efficiency of a Cherenkov maser in a planar dielectric waveguide and a high-harmonic gyrotron using axis-encircling large electron orbits.
|
0.915 |
| 1990 — 1992 |
Kennel, Charles (co-PI) [⬀]
Pritchett, Philip
Dawson, John [⬀]
Wu, Cheng-Chin |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Numerical Studies of Magnetospheric Dynamics & Related Spaceplasma Processes @ University of California-Los Angeles
Numerical simulations are important tools for the study of space plasma physics. This grant is for continued research support to study the properties of shock waves and discontinuities in dissipative MHD and kinetic theory, the dynamics of the magnetosphere, and collisionless tearing instability in the magnetotail. Hybrid and implicit particle simulations will be used to study the kinetic properties of intermediate shocks and the possible role of such structures in dayside reconnection in the Earth's magnetotail will be investigated using increasingly realistic models of the near Earth plasma sheet. The principal aim will be to understand how and when a new neutral line forms within the pre-existing closed field lines of the plasma sheet.
|
0.915 |
| 1997 — 2000 |
Dawson, John [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Collective Absorption Processes of Neutrinos in Supernovae @ University of California-Los Angeles
AST- 9713234 ABSTRACT - J. M. Dawson COLLECTIVE ABSORPTION PROCESSES OF NEUTRINOS IN SUPERNOVAE A program to investigate the influence of collective interactions of the intense neutrino flux from the core of a supernova with the plasma of it's surrounding stellar envelope will be carried out. The mechanism is similar to the Forward Raman Instability that occurs when intense light interacts with plasma by generating electron plasma waves. In the neutrino case, the instability is much weaker due to the weakness of the neutrino electron interaction. Recent work at UCLA has shown that because of the extreme conditions that exist in a supernova, the forward Raman instability takes place. In the photon plasma case this instability increases the interaction with the plasma by many orders of magnitude. By analogy, large enhancements of the neutrino plasma coupling can be expected. The neutrinos carry away most of the energy of the supernova (100 times the light output). Models of supernova explosions have run into problems explaining how the supernova explodes if so much energy is carried off by the neutrinos and additional energy must be expended in dissociating iron and other heavy nuclei. Explosions can be made to occur if a few percent of the neutrino energy can be deposited in the stellar envelope. The forward Raman instability appear to be strong enough to do this and thus to influence the dynamics of the supernova. Techniques for computing the transport of the neutrinos through the stellar plasma and the resulting energy transfer will be developed. This will involve two quasi-linear equations, one for neutrinos and one for electrons, plus an equation for the evolution of plasma waves. The quasi-linear equation for the neutrinos describe the evolution of the neutrino spectrum due to their interaction with the plasma waves. The plasma wave equation computes the spectrum of plasma waves produced by the neutrinos and includes damping by electrons and the r esultant flow of energy from neutrinos to electrons. The quasi linear equation for the electrons describes the evolution of the electron distribution function; this is primarily a heating. When the electrons become hot enough (~ 500Kev) the Forward Raman Instability becomes the Forward Stimulated Compton Instability because the waves become heavily Landau damped. It is expected that the Forward Stimulated Compton Instability will be much weaker and to effectively turn off. Computer software codes to solve these coupled equations will be written and then used to explore the neutrino energy deposited in the electrons and the electron temperatures reached as a function of position in the star. The effects of the interaction on the neutrino energy distribution will be calculated to explore possible signatures of the process that might be detectable.
|
0.915 |
| 2001 — 2004 |
Decyk, Viktor
Dawson, John (co-PI) [⬀] |
N/AActivity Code Description:
No activity code was retrieved: click on the grant title for more information |
Numerical Investigation of Plasma Quantum Effects in Stellar Interiors @ University of California-Los Angeles
It is intended to study quantum effects in basic plasma processes (as occur in stellar interiors), and their consequences for plasma reaction rates and equations of state, with applications in stellar evolution (including the solar neutrino problem) and in the early universe (its energy density). The studies will utilize the novel multiparticle quantum code recently developed at UCLA, which is designed to handle hundreds of quantum particles.
|
0.915 |
