All particle types may emit from a shape settable flux emitter. Certain emission specifications are only available based on particle type and particle weights specification. Available in cartesian coordinate simulations only.
emission specification: Specification of the emitted particles, note that the specification options vary for constant or variable/managed weight particles.
- emission current density:
Only available with variable/managed weight specified particles.
emission current density: Specify the current density of the emitter (amps/meter^2). Can be a spatial profile.
velocity coordinate system: Either global or surface. A global coordinate system will specify the emission velocities according to global axis. A surface coordinate system will set the emission directions according to the normal of the emission object. A positive value will emit particles away from the shape and a negative value will emit particles into the shape.
- average velocity 0: The average (mean) speed of particles in the x-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for the direction normal to the emitting surface.
- average velocity 1: The average (mean) speed of particles in the y-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- average velocity 2: The average (mean) speed of particles in the z-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- thermal velocity 0: A spread (standard deviation) for particle speeds in the 0 direction.
- thermal velocity 1: A spread (standard deviation) for particle speeds in the 1 direction.
- thermal velocity 2: A spread (standard deviation) for particle speeds in the 2 direction.
- emission flux:
Only available with variable/managed weight specified particles.
emission flux: Specify the flux of the emitter (particles/meter^2). Can be a spatial profile.
velocity coordinate system: Either global or surface. A global coordinate system will specify the emission velocities according to global axis. A surface coordinate system will set the emission directions according to the normal of the emission object. A positive value will emit particles away from the shape and a negative value will emit particles into the shape.
- average velocity 0: The average (mean) speed of particles in the x-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for the direction normal to the emitting surface.
- average velocity 1: The average (mean) speed of particles in the y-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- average velocity 2: The average (mean) speed of particles in the z-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- thermal velocity 0: A spread (standard deviation) for particle speeds in the 0 direction.
- thermal velocity 1: A spread (standard deviation) for particle speeds in the 1 direction.
- thermal velocity 2: A spread (standard deviation) for particle speeds in the 2 direction.
- emission current:
Only available with constant weight particles.
emission current: Specify the total emitted current per second from the emitter (amps/second).
velocity coordinate system: Either global or surface. A global coordinate system will specify the emission velocities according to global axis. A surface coordinate system will set the emission directions according to the normal of the emission object. A positive value will emit particles away from the shape and a negative value will emit particles into the shape.
- average velocity 0: The average (mean) speed of particles in the x-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for the direction normal to the emitting surface.
- average velocity 1: The average (mean) speed of particles in the y-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- average velocity 2: The average (mean) speed of particles in the z-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- thermal velocity 0: A spread (standard deviation) for particle speeds in the 0 direction.
- thermal velocity 1: A spread (standard deviation) for particle speeds in the 1 direction.
- thermal velocity 2: A spread (standard deviation) for particle speeds in the 2 direction.
- emission rate:
Only available with constant weight particles.
emission rate: Specify the total emitted particles per second from the emitter (particle/second).
velocity coordinate system: Either global or surface. A global coordinate system will specify the emission velocities according to global axis. A surface coordinate system will set the emission directions according to the normal of the emission object. A positive value will emit particles away from the shape and a negative value will emit particles into the shape.
- average velocity 0: The average (mean) speed of particles in the x-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for the direction normal to the emitting surface.
- average velocity 1: The average (mean) speed of particles in the y-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- average velocity 2: The average (mean) speed of particles in the z-direction when velocity coordinate system is set to “global”. If set to “surface” then this will be the average velocity for a direction perpendicular to the emitting surface.
- thermal velocity 0: A spread (standard deviation) for particle speeds in the 0 direction.
- thermal velocity 1: A spread (standard deviation) for particle speeds in the 1 direction.
- thermal velocity 2: A spread (standard deviation) for particle speeds in the 2 direction.
- Fowler Nordheim Emission:
Specify particle emission according to the Fowler-Nordheim model (24). Only available with variable/managed weight electron particle species.
work function [eV]: Work function of the material from which emission is occurring.
A: Coefficient A of the Fowler-Nordheim emission model.
B: Coefficient B of the Fowler-Nordheim emission model.
field enhancement: Multiplies the measured electric field by this amount.
Cv: Coefficient Cv of the Fowler-Nordheim emission model.
Cy: Coefficient Cy of the Fowler-Nordheim emission model.
- Richardson Dushman Emission:
Specify particle emission according to the Richardson-Dushman model (22). Only available with variable/managed weight electron particle species.
work function [eV]: Work function of the material from which emission is occurring. Parameter in the Richardson-Dushman model.
field evaluation offset: The offset from the surface where the field resulting from the particle is evaluated.
temperature (K): Temperature of the material from which emission is occurring. Parameter in the Richardson-Dushman model.
field enhancement: Multiplies the measured electric field by this amount.
flux multiplier: Multiplies the resulting output current by this amount.
- Child Langmuir Emission:
Specify particle emission according to the Child Langmuir model. Only available with variable/managed weight electron particle species.
space charge limited emission: This will limit the current to provide a more consistent emission current, providing higher accuracy particularly in explosive emission cases, such as a pulsed power magnetron. For non pulsed-power simulations it is not necessary.
average velocity 0: The average (mean) speed of particles in the 0 direction.
average velocity 1: The average (mean) speed of particles in the 1 direction.
average velocity 2: The average (mean) speed of particles in the 2 direction.
thermal velocity 0: A spread (standard deviation) for particle speeds in the 0 direction.
thermal velocity 1: A spread (standard deviation) for particle speeds in the 1 direction.
thermal velocity 2: A spread (standard deviation) for particle speeds in the 2 direction.
The surface off of which to emit.
object name: The name of the geometry off of which to emit.
emission offset: The distance away from the object that emitted particles are placed, as a fraction of a cell length.
Only available with variable/managed weight particles. This allows for the specification of the macroparticle emission independent of the emitted particles. Used to handle computational concerns around macroparticle weight.