EEDL interface

EEDL: Particle collision is an important physical process in simulations of various plasma applications, such as plasma discharges, magnetron sputtering and low temperature plasma processing. Vsim allows user defined cross-section in the Monte Carlo Interactions Package. The Evaluated Electron Data Library [article{perkins1991tables], includes data to describe the transport of electrons, as well as the initial generation of secondary particles, such as the primary photon due to bremmsstrahlung, as well as the primary electron due to inelastic scattering and electroionization.

These cross-sections can be downloaded from the International Atomic Energy Agency Nuclear Data Services website. You can download either the complete library or individual evaluations. Vorpal currently uses the eedl/endl format for the libraries, so please be sure to download the right one.

The EEDL cross-section database supports minimum energy value from 10 eV (or from the threshold value in inelastic interactions) and maximum up to 100 GeV. In VSim, when used an elastic interaction with the “eedl” option, a constant cross-section value is taken for energy values below 10 eV, i.e. it uses the cross-section value of 10 eV for low energy particles. The EEDL datasets are available for Z=1 to 100 elements.

They work with the following collision types: impactElastic, impactExcitation impactIonization and negativeIonDetachment as described in MonteCarloInteractions.

Import scattering cross-section from EEDL data file

<Interaction ElecImpElastic>
  kind = impactElastic
  neutralGas     = ArNeutralGas
  impactSpecies = electrons
  crossSection = eedl
  crossSectionDataFile = eedlAr.dat
</Interaction>

After the EEDL data for a particular material is downloaded, it can be directly read in any Vsim Monte Carlo interactions of the kinds specified in the interactions table that require a cross-section. In order to use an EEDL cross-section in the Interaction block, the crossSection should be set as eedl, then the crossSectionDataFile should be set to the name of the file you intend to use.

EEDL Data Format

An example set of data is given below in the EEDL/ENDL format.

Note

It is very important to make sure you are using the proper format. Vorpal currently uses the eedl/endl format for the libraries, so please be sure to download the right one.

18000  9  0  0.00000e+00 8912015 2  0.00000e+00  0.00000e+00  0.00000e+00
7  0  0  0.00000e+00  0.00000e+00  0.00000e+00  0.00000e+00  0.00000e+00
1.00000e-05 2.49353e+09
1.25893e-05 2.02388e+09
1.58489e-05 1.64269e+09
1.99526e-05 1.33330e+09
2.51189e-05 1.08218e+09
3.16228e-05 8.78354e+08
1.99526e+04 3.02448e-06
2.51189e+04 1.93916e-06
3.16228e+04 1.24298e-06
3.98107e+04 7.96534e-07
5.01187e+04 5.10324e-07
6.30957e+04 3.26874e-07
7.94328e+04 2.09326e-07
.
.
.
1.00000e+05 1.34020e-07
                                                                      1
18000  9  0  0.00000e+00 8912015 2  0.00000e+00  0.00000e+00  0.00000e+00
8  0  0  0.00000e+00  0.00000e+00  0.00000e+00  0.00000e+00  0.00000e+00
1.00000e-05 2.49353e+09
1.25893e-05 2.15264e+09
1.58489e-05 1.85836e+09
1.99526e-05 1.60430e+09
2.51189e-05 1.38498e+09
3.16228e-05 1.19564e+09
3.98107e-05 1.03266e+09
5.01187e-05 8.91897e+08
6.30957e-05 7.70321e+08
7.94328e-05 6.65469e+08
1.00000e-04 5.75282e+08
1.25893e-04 4.97317e+08
1.58489e-04 4.29918e+08
1.99526e-04 3.71654e+08
2.51189e-04 3.21434e+08
3.16228e-04 2.78264e+08
3.98107e-04 2.40892e+08
5.01187e-04 2.08539e+08
6.30957e-04 1.80556e+08

If you wish to write your own cross-section data files in EEDL/ENDL format, please refer to [PC02] which describes the format. All EEDL data distributed with VSim is freely available to all users.