Simulation of electron transport in LAr under varying electric fields. Code repository developed starting from https://github.com/zbeever/LArCADe.
Basis of simulation outlined in Wojcik, M., & Tachiya, M. (2002). Electron transport and electron–ion recombination in liquid argon: Simulation based on the Cohen–Lekner theory. Chemical Physics Letters, 363(3-4), 381-388. doi:10.1016/s0009-2614(02)01177-6
When using this software, please cite the article which describes this work:
TRANSLATE - a Monte Carlo simulation of electron transport in liquid argon
Zach Beever (Boston U. and Fermilab), David Caratelli (Fermilab and UC, Santa Barbara), Angela Fava (Fermilab), Francesco Pietropaolo (CERN), Francesca Stocker (CERN and Yale U., Math. Dept.) et al.
e-Print: 2211.12645 [physics.ins-det]
DOI: 10.1016/j.cpc.2023.109056 (publication)
Published in: Comput.Phys.Commun. 297 (2024), 109056
Running the executable for LArCADe will walk you through the parameters to be specified before the simulation begins. The resulting data is exported to the py/simulation-runs folder. Examples of studies carried out with the produced simulations can be found at
Gas cross-section data is from the BSR database, www.lxcat.net, retrieved on June 11, 2019 and Rejoub, R., Lindsay, B. G., & Stebbings, R. F. (2002). Determination of the absolute partial and total cross sections for electron-impact ionization of the rare gases. Physical Review A, 65(4). doi:10.1103/physreva.65.042713. Liquid cross-section data comes from the Wojcik, M., & Tachiya, M. paper mentioned at the top.
You'll need Numpy, Scipy, and Matplotlib. Jupyter is required to view the preprocessing notebooks. CMake makes for an easy install.
Open the Jupyter notebooks in the preprocessing directory to generate the lookup tables for cross-sections and non-uniform electric fields. After doing so, set the necessary parameters in the Constants.h file. Then, navigate to the project directory in terminal and type
mkdir build
cd build
cmake ..
make
To run the code type ./larcade and follow the prompts. To change running configuration edit the srcs/Constants.h file and specifically update the value of n, the density of argon atoms, is_diff and is_gas to choose the simulation mode.
Configurable constants:
// Liquid number density [cm^-3]
const double n = 2.11e22; // Number density of argon atoms
// Editable parameters
const bool is_diff = false; // Use differential cross-sections?
const bool is_gas = false; // Is this in gas? Or liquid? Make sure to update the number density
Default gas mode (integrated xsec): n = 1.15e19, is_diff = false, and is_gas = true.
Default liquid mode (integrated xsec): n = 2.11e22, is_diff = false, and is_gas = false.
Information for each simulated electron is stored in text files. Each iteration of the simulation for which output is stored is saved as a new row, and information in each row is arranged as described below, separated by commas:
time (ns), time-step (ns), x coordinate (um), y coordainte (um), z coordainte (um), kinetic energy (eV), drift velocity (m/s), scattering angle (degrees), distance since last interaction (meters), interaction category, total ionizations initiated
Validations of swarm parameters are carried out through the notebooks below:
lar-diffusion-simple.ipynb
gar-diffusion.ipynb
lar-drift-velocity.ipynb
gar-drift-velocity.ipynb
lar-amplification-townsend.ipynb
gar-amplification-townsend.ipynb