kinetic modeling of the sheath scale in the lunar plasma environment
DESCRIPTION
Kinetic Modeling of the Sheath Scale in the Lunar Plasma Environment. Peter Messmer*, Keegan Amyx, Peter Stoltz, Andrew Poppe, Mihay Horanyi, Scott Robertson, Zoltan Sternovsky [email protected]. Tech-X Corporation 5621 Arapahoe Ave., Boulder, CO 80303 http://www.txcorp.com. - PowerPoint PPT PresentationTRANSCRIPT
Kinetic Modeling of the Sheath Scale in the Lunar Plasma
Environment
Tech-X Corporation5621 Arapahoe Ave., Boulder, CO 80303
http://www.txcorp.com
Peter Messmer*, Keegan Amyx, Peter Stoltz, Andrew Poppe, Mihay Horanyi, Scott
Robertson, Zoltan Sternovsky [email protected]
CCLDAS All Hands Meeting, Boulder, CO, July 10, 2009
VORPAL -A Plasma Modeling Framework
Original target applications: Laser Wakefield Acceleration
PIC, Fluid, HybirdElectrostatic, EMMulti-Dimensional (N=1,2,3)Fully parallel
Scaling for > 32,000 PEs Flexible domain decomposition
Broad range of physics features:- Complex geometries- Ionization, recombination, CEX physics- Field ionization
http://www.txcorp.com/products/VORPAL
Code/setup Validation with 1D Photoelectron Sheath
R. Garad & J Tunaley, JGR 76(10), 2498, 1971
A. Poppe & M. Horanyi, WPDP, 2009
2D ES simulation, Y periodic ,200 x 10 cellsdx = 1050 particles per cell nominal
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Simulation
Garad&Tunaley
Monoenergetic
Maxwellian
2D Monoenergetic Sheath
2D ES simulation, left wall = 0V200 x 100 cellsElectrons, ProtonsMonoenergetic ,V0 = 200 eV (!)
electrons
protons
Scenario with Surface Charging
Surface-Charging No surface charging
(just for comparison)
2D Thermal Sheath with Surface Charging
2D ES simulation, left wall = 0V200 x 100 cellsElectronsHeavy Protons, Heavy electrons (m/m0= 5000)Vsig = 3eV, Vtherm = 3 eV
Electron impact creates“heavy electrons”
Electrons get absorbed
Electric field mainly due to positive charge of emitting
region
ChargingNon Charging
“Heavy Electrons” follow the electric field lines
2D ES simulation, left wall = 0V200 x 100 cellsElectronsHeavy Protons, Heavy electrons (m/m0= 5000)Vsig = 3eV, Vtherm = 3 eV
Initial 3D simulations
3D ES simulation, bottom wall = 0V10 x 100 x 100 cellsElectronsProtons, Heavy electrons (m/m0= 5000)Vsig = 3eV, Vtherm = 3 eV
Charging of surface
No charging of surface
Summary / Conclusions / Future work
Presented VORPAL simulations of plasma sheath Validated with kinetic theory for 1D sheath Presented 2D simulation with/without surface charging “heavy electrons” move in electrostatic field, follow (curved)
field lines
Future work: Convergence studies, more realistic parameters Inclusion of solar wind Time dependent problems, angular dependency of photo-
currents Complex geometries (crater, habitat, instrument) 3D
Work supported by CCLDAS and Tech-X Corp.