The PRESETSPECIESDATA keyword below SPECIES indicates that preset species data is used. On the left of = a tag of an existent species should be used and on the right of
= a preset species data can be assigned to the existent data. The line
Ars=Ar reads: the species with tag
Ars is set with the preset species data of
Ar (which is argon). Note that ions have a tag that is different than the species name. A positive ion with name Ar+ has the tag
Ar_1p and the negative ion O- as the tag
O_1m. To see a feature’s tag, go to
Model Tree Node Text and select
Tag.
The USERDEFINED keyword below SPECIES indicates that species properties are defined manually. on the left of ! a tag of an existent species should be used and on the right of
! four numbers separated by spaces should be set. These numbers are, in order, the
Molar mass,
Potential characteristic length,
Potential energy minimum, and
Dipole moment.
It is also possible to set species thermodynamic parameters using the keyword THERMODYNAMICPARAMETERS as shown in the block below. The first line in the block is a list of species tags to which the properties are to be applied. The second line is in order: Lower temperature limit,
Middle temperature limit, and
Upper temperature limit. The third and fourth lines are the
Polynomial coefficients, low and the
Polynomial coefficients, high, respectively. The fifth and last line is the
Additional enthalpy contribution.
on the left of ! a formula is defined and on the right of
! the rate constant and other settings are defined. The first field after
! must define the
Collision type that can be
Elastic,
Excitation,
Ionization, or
Attachment. If the collision type is
The block below shows how to define heavy species reactions by providing the coefficients of the Arrhenius expression. The formula is defined on the left of ! and the Arrhenius coefficients are defined on the right of
! in sequence:
Forward frequency factor,
Forward temperature exponent, and
Forward activation energy.
For the HEAVYSPECIESREACTIONS block, the reactions are set explicitly below the keyword. The formula is defined on the left of “!” and the Arrhenius coefficients are defined on the right of
“!” in sequence:
Forward frequency factor,
Forward temperature exponent,
Forward activation energy,
Reverse frequency factor,
Reverse temperature exponent, and
Reverse activation energy. If the formula is not reversible (defined with =>), only the forward coefficients (3 parameters) are needed. If the formula is reversible (defined with <=>), both forward and reversible coefficients (6 parameters) need to be provided. If a coefficient is not needed to define the reactions it should be set as “0”.
If one wants to put different reaction sets into different Reaction Group features, for example, separate argon chemistry and oxygen chemistry into different Reaction Group features and label them directly and properly, this can be achieved by using another type of block with keyword REACTIONGROUPIMPORT.
The reaction group import block allows to separate large sets of reactions into different Reaction Group features. A reaction group import block can be defined using the keyword REACTIONGROUPIMPORT such as
Each line should contain a filename that points to a text subfile. Each subfile should contain one or more REACTIONGROUP blocks. The subfiles need to be in the same folder as the main plasma chemistry file. The data in all the blocks with the same reaction group type (Heavy species reactions or Electron impact reactions) in the same subfile will be put into the same Reaction Group feature, therefore each subfile will automatically generates one or two Reaction Group features depending on the availability of HEAVYSPECIESREACTIONS and ELECTRONIMPACTREACTIONS blocks in that subfile. It is also possible to conveniently customize the Reaction Group features’ names with user defined labels after the delimiter
“!” such as “Ar” or “Cl”, then the generated Reaction Group features will be automatically labeled such as “Ar - Electron Impact Reactions” or “Cl - Heavy Species Reactions”. If no label has been provided, the generated Reaction Group features will have the default labels such as “Reaction Group 5 - Heavy Species Reactions”.
In the Component and Interface selection choose the
Component and
Interface to which the plasma chemistry is going to be imported.
In the Plasma Chemistry Import section browse to the text file where the plasma chemistry is defined and import the plasma chemistry.
