Properties of Particle Boundary Conditions

Particle boundary conditions may be set to any particle type. If a particle boundary condition is not set on a simulation boundary, it is automatically set to absorbing.

Absorbing:

This type of particle boundary condition will absorb incident particles. It will not save any data from them, so they may not be used in histories or secondary emitters.

volume

• lower x slab

• lower y slab

• lower z slab

• upper x slab

• upper y slab

• upper z slab

• cartesian 3d slab

• cylindrical 2d slab

• index 3d slab

Boundary Absorb and Save:

This type of boundary condition will absorb incident particles and save them for other uses, such as histories or secondary emission.

volume: The simulation boundary over which to apply this condition.

Boundary Accumulate:

Incident particles will be accumulated on this boundary and not allowed to move. This allows for the charging of a simulation boundary. The accumulated particles will be stored in a new particle species, appended with the prefix heavy.

volume: The simulation boundary to accumulate particles on.

Boundary Diffuse Reflector:

This type of particle boundary condition will reflect particles back into the simulation space, with an user supplied velocity. It may only be applied on simulation boundaries.

• average velocity 0

• average velocity 1

• average velocity 2

• thermal velocity 0

• thermal velocity 1

• thermal velocity 2

• volume

  lower x slab

  lower y slab

  lower z slab

  upper x slab

  upper y slab

  upper z slab

  lower r slab

  upper r slab

Cut-Cell Absorb and Save:

This type of boundary condition will absorb incident particles and save them for other uses, such as histories or secondary emission. It may be applied to geometries. In VSim9.0, only one Cut-Cell Absorb and Save boundary condition may be used per particle species. If this boundary condition is used Interior Absorb and Save boundary conditions may not be used.

volume

• object name

  The name of the geometry over which to apply this condition.

Cut-Cell Accumulate:

Incident particles will be accumulated on this boundary and not allowed to move. This allows for the charging of a shape The accumulated particles will be stored in a new particle species, appended with the prefix heavy.

volume: The shape to accumulate particles on.

Interior Absorb and Save:

This type of boundary condition will absorb incident particles and save them for use with histories or secondary emission. It may be set to an internal volume of the simulation space.

volume: Depending on simulation properties this will be either a:

• cylindrical 2D slab

• cartesian 3D slab

Interior Accumulate:

Incident particles will be accumulated on this boundary and not allowed to move. This allows for the charging of a user specified interior plane. The accumulated particles will be stored in a new particle species, appended with the prefix heavy.

volume

xMin

The minimum x position of the boundary condition.

xMax

The maximum x position of the boundary condition.

yMin

The minimum y position of the boundary condition.

yMax

The maximum y position of the boundary condition.

zMin

The minimum z position of the boundary condition.

zMax

The maximum z position of the boundary condition.

surface

The surface of the described volume to accumulate particles on.

Interior Diffuse Reflector:

This type of particle boundary condition will reflect particles back into the simulation space, with an user supplied velocity. It may only be applied on internal planes of the simulation space

average velocity 0

average velocity 1

average velocity 2

thermal velocity 0

thermal velocity 1

thermal velocity 2

orthogonal direction

Incoming direction of particles to apply the boundary condition on. Set as negative if particles are coming from the negative direction and positive if particles are coming from the positive direction

negative x

x coordinate

x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

negative y

y coordinate

y coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

negative z

z coordinate

z coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

positive x

x coordinate

x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

positive y

y coordinate

y coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

positive z

z coordinate

z coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

Interior Partial Transmitter:

An interior partial transmitter will transmit a user specified fraction of the incident particles and either absorb or reflect the remainder. If reflected the user can specify the velocity with which they are reflected. This is a one way particle boundary condition, as set by the orthognal direction.

orthogonal direction: Incoming direction of particles to apply the boundary condition on.

negative x

x coordinate

x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

negative y

y coordinate

y coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

negative z

z coordinate

z coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

positive x

x coordinate

x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

positive y

y coordinate

y coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower z coordinate

lower z coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper z coordinate

upper z coordinate of the boundary condition.

positive z

z coordinate

z coordinate of the boundary condition.

lower x coordinate

lower x coordinate of the boundary condition.

lower y coordinate

lower y coordinate of the boundary condition.

upper x coordinate

upper x coordinate of the boundary condition.

upper y coordinate

upper y coordinate of the boundary condition.

non transmitted particles

particles absorbed

particles reflected

Note that the velocity corresponding to the orthogonal direction should always be specified as a positive number. If it is not this will be automatically corrected. average velocity 0

average velocity 1

average velocity 2

thermal velocity 0

thermal velocity 1

thermal velocity 2

Specular Reflecting:

This type of particle boundary condition will reflect particles back into the simulation space. It may only be applied on simulation boundaries.

volume

• lower x slab

• lower y slab

• lower z slab

• upper x slab

• upper y slab

• upper z slab

• lower r slab

• upper r slab