CSTool

This tool compiles cross-sections for low-energy electron scattering in a material into a .mat file that is understood by the e⁻Scatter simulator.

If you need to change anything in the physics models used by the simulator, this is the place to do it.

Currently, this module needs both the pyelsepa and cslib packages to be installed, preferably in a VirtualEnv (so that you don't muck-up your Python installation).

Installing

To setup an environment for CSTool, first make sure you have the correct version of Python (these commands may vary slightly from system to system):

> python3 --version   # version should be 3.5 or higher
Python 3.5.3

clone the needed repositories:

> git clone https://github.com/eScatter/cslib.git
...
> git clone https://github.com/eScatter/pyelsepa.git
...
> git clone https://github.com/eScatter/cstool.git
...

create a virtual environment:

> python3 -m venv cstool-env
...
> source ./cstool-env/bin/activate
(cstool-env) >

You may need to update pip at this point:

> pip install --upgrade pip

Now we need to install cslib and `pyelsepa`:

(cstool-env) > cd cslib
(cstool-env) ./cslib> pip install .
(cstool-env) ./cslib> cd ../pyelsepa
(cstool-env) ./pyelsepa> pip install .
(cstool-env) ./pyelsepa>

And we have to install the Docker image for Elsepa, make sure you have downloaded adus_v1_0.tar.gz:

(cstool-env) ./pyelsepa> docker -v  # make sure you have the latest
Docker version 1.13.1, build 092cba372
(cstool-env) ./pyelsepa> cd docker
(cstool-env) ./pyelsepa> ls
adus_v1_0.tar.gz  Dockerfile  README.md
(cstool-env) ./pyelsepa> docker build -t elsepa .
...
Successfully built <some hex-code>

Now we need to install `cstool`:

(cstool-env) ./pyelsepa> cd ../cstool
(cstool-env) ./cstool> pip install .

Now you should be ready to run the example in `examples/cs.py`:

(cstool-env) ./cstool> python examples/cs.py data/materials/silicon.yaml

Data sources

The material files contain most of the physics involved.

• [ELSEPA](http://adsabs.harvard.edu/abs/2005CoPhC.165..157S) can be downloaded from the Computer Physics communications Program library as adus_v1_0.tar.gz. It has an attribute-only license for non-commercial use. We use a dockerized ELSEPA to compute Mott cross-sections, through the pyElsepa module.
• Livermore database [ENDF/B-VII.1](http://www.nndc.bnl.gov/endf/b7.1/download.html). We use this database retrieve ionization energies, occupancy and cross-sections.
• ELF data (Energy Loss Function). This data was compiled by Kieft & Bosch (2008) for their (Geant4 based) version of the electron scattering model. It uses data from Palik (1985,1998) -"Handbook of Optical Constants of Solids"¹ - and [Henke et al.](henke.lbl.gov)². This data is included here in the /data/elf folder.
• Phonon scattering is computed by recipe from Schreiber & Fitting³.

References

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1. Palik, Edward D. Handbook of optical constants of solids. Vol. 3. Academic press, 1998.↩

2. B.L. Henke, E.M. Gullikson, and J.C. Davis. X-ray interactions: photoabsorption, scattering, transmission, and reflection at E=50-30000 eV, Z=1-92, Atomic Data and Nuclear Data Tables Vol. 54 (no.2), 181-342 (July 1993).↩

3. Schreiber, E., and H-J. Fitting. "Monte Carlo simulation of secondary electron emission from the insulator SiO 2." Journal of Electron Spectroscopy and Related Phenomena 124.1 (2002): 25-37.↩