Esther Hydrocode Tutorial

Esther Hydrocode Tutorial

Overview

User tutorial / information for the hydrocode simulations package of Simex, currently utilising the Esther 1-D hydrocode program (that can be obtained upon request).

Input data and output data can be found at https://doi.org/10.5281/zenodo.883106

Table of contents

1. Introduction
2. Parameters
3. How to create a new experiment
4. Example - Plastic ablator with Fe foil
5. Run Esther
6. Utilities

Introduction

The Esther hydrocode SIMEX package consists of the following python scripts:

• Calculators/EstherExperimentConstruction.py
• Calculators/EstherPhotonMatterInteractor.py
• Parameters/EstherPhotonMatterInteractorParameters.py
• Utilities/RadHydroAnalysis.py
• Utilities/hydro_txt_to_opmd.py

Parameters

The current version allows the creation of simple target configurations, as described above. The parameters can be set for the first time using the EstherExperimentConstruction.py calculator, which calls upon the parameters class to create the Esther input file.

The materials currently available are listed below with their long name; the long name must be used when setting the material choice (e.g. sample="Iron").

• Aluminium
• Berylium
• CH
• Chromium
• Cobalt
• Copper
• Diamond
• Gold
• Iron
• Iron2*
• Kapton
• Lead
• LiF
• Magnesium
• Molybdenum
• Mylar
• Nickel
• Quartz
• Silicon
• SiliconOxide
• Silver
• Tantalum
• Tin
• Titanium
• Tungsten
• Vanadium
• Water

*2 sesame EOS tables exist for iron.

Parameters are set using the EstherPhotonMatterInteractorParameters.py class

Set parameters with {choose one option within range}

parameters = EstherPhotonMatterInteractorParameters(
    number_of_layers={2,3}
    ablator={“CH”,”Diamond”,”Kapton”,”Aluminium”}
    ablator_thickness={20,50}
    sample=”Iron”{Choose from list above}
    sample_thickness={4,25}
    window={None,”LiF”,”Quartz”}
    window_thickness={50,500}
    laser_wavelength={1064,527}
    laser_pulse={“Flat”,”Ramp”}
    laser_pulse_duration={4,20}
    laser_intensity={0.1,10}
    run_time={5,20}
    delta_time={0.01,0.05}
)

How to create a new experiment

An experiment constructor class EstherExperimentConstruction.py exists to store parameters for reuse in iterations of code. This allows quick changes to certain parameters and each input file is saved to user folder.

simName = "Fe-example"
experiment = EstherExperimentConstruction(parameters=parameters,
    esther_sims_path=self._simdir,sim_name=simName)

The self._simdir must be set at the start and should contain the root folder for simulation storage.

The EstherExperimentConstruction.py then calls the EstherPhotonMatterInteractor.py class, which serializes and saves all the relevant input files.

Example

    # Create parameters.
    parameters = EstherPhotonMatterInteractorParameters(
                                    number_of_layers=2,
                                     ablator="CH",
                                     ablator_thickness=50.0,
                                     sample="Iron",
                                     sample_thickness=5.0,
                                     window=None,
                                     window_thickness=0.0,
                                     laser_wavelength=1064.0,
                                     laser_pulse='flat',
                                     laser_pulse_duration=6.0,
                                     laser_intensity=0.33,
                                     run_time=12.0,
                                     delta_time=0.05
                                     )

    # Create experiment.
    simName = "Fe-example"
    experiment = EstherExperimentConstruction(parameters=parameters,
                                              esther_sims_path=self._simdir,
                                              sim_name=simName)

This creates a folder /Fe-Example/ in the root directory that user selected to store input files. The input files are saved in /Fe-Example/1/.

New iteration with same parameters

    experiment = EstherExperimentConstruction(parameters=parameters,
                                              esther_sims_path=self._simdir,
                                              sim_name=simName)

With the folder /Fe-Example/ already existing in the root directory, the new input files are saved in /Fe-Example/2/.

New iteration with a parameter change

    # Change the sample thickness to 4.0
    new_parameters = EstherPhotonMatterInteractorParameters(sample_thickness=4.0,
            read_from_file="/Users/richardbriggs/OneDrive/Data/Hydrocode/tmp/HPLF-Fe/2/")
    
    experiment = EstherExperimentConstruction(parameters=new_parameters,
                                              esther_sims_path=self._simdir,
                                              sim_name=simName)

With the folder /Fe-Example/3/ will contain the input files with the sample thickness now adjusted to 4.0 microns.

Run Esther

From the Esther GUI, the input file can be loaded and the simulation launched. The input files must be stored in Esther's local storage folder /ESTHER/ESTHER_entrees/

Output files will be saved to /ESTHER/ESTHER_sorties/

Convert output txt files to opmd.h5 format

The hydro_txt_to_opmd.py function converts the following .txt files, that are saved in /ESTHER/ESTHER_sorties/SimName/stock_t_m/ folder, to a single h5 format file.

• densite_massique.txt
• position_externe_relative.txt
• pression_hydrostatique.txt
• temperature_du_milieu.txt
• vitesse_moyenne.txt

The function simply takes the directory where the 5 files are stored.

convertTxtToOPMD(esther_dirname="/root/to/ESTHER_sorties/SimName/stock_t_m/")

Data visualization

Achieved with the RadHydroAnalysis.py script radHydroAnalysis(filename) where filename is the output.opmd.h5 filename in the simulation directory.

Utilities

How to calculate the laser intensity for any laser energy and focal spot size.

import SimEx    
from SimEx.Utilities.IntensityCalc import calculateLaserIntensity
calculateLaserIntensity()

Creates dialogues for entering the Energy, laser spot diameter, and laser pulse length to obtain the laser intensity in TW/cm^2

Energy (J) : 15
Spot size (diameter in um) : 300
Pulse length (ns) : 6
Intensity =  3.53677651315 TW/cm^2

Translations of frequently encountered French messages in the Esther GUI

Edition du cas

Affichage fichier log - Display log file - Recommended that this box should remained checked

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Fichiers Associes

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Fichier Log

Mise a jour du fichier log en cours de calcul - Update the log file during calculation.