New high time resolution mutual impedance measurements
Description
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Author : L. Bucciantini
Date : 03/11/2022
Laboratory : CNRS-LPC2E, Orléans (France)
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Dear reader, we thank you for your interest in our dataset. In this document, we describe what you will
find in it.
In case you need help with using the dataset, or if you are interested in mutual impedance experiments,
do not hesitate to contact our team in Orléans (pierre.henri@cnrs-orleans.fr, pierre.henri@oca.eu)
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Topic:
This dataset contains the outputs of numerical simulations and experimental tests performed
to test and validate two new mutual impedance instrumental modes: the chirp mode and the
multi-spectral mode. These modes have the objective of improving the time resolution of
mutual impedance measurements.
These new instrumental modes are validated by comparing their measurements to the classic
instrumental mode of mutual impedance measuremetns, the so-called frequency sweep mode.
Numerical model:
The numerical outputs are obtained from a numerical model based on the solution of the 1D-1V Vlasov-Poisson
system of equations. The scheme used to solve the model is the one developed
by Mangeney et al. (2002), A Numerical Scheme for the Integration of the Vlasov-Maxwell System of Equations. Journal of Computational Physics, (doi: https://doi.org/10.1006/jcph.2002.7071).
The 1D-1V Vlasov-Poisson version of this model is described in Henri, et al. (2010), Vlasov-Poisson
simulations of electrostatic parametric instability for localized Langmuir wave packets in the solar wind,
Journal of Geophysical Research (Space Physics), 115, 6106 (2010)
Experimental testing facility:
The experimental outputs are obtained using the testing facility of CNRS-LPC2E space laboratory. It is
composed of a vacuum chamber, a pumping system and a plasma source. The pumps make vacuum in the
chamber (p=1e-5mbar). The plasma source generates a plasma flow that we use to test mutual impedance
instruments in a medium which is representative of Earth's ionosphere (100-2000 km of altitude).
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Instrumental modes of interest
frequency sweep (FS) mode : typical mode. Implemented for DFP-COMPLIMENT onboard Comet Interceptor
chirp (CH) mode : new fast mode. It is based on the emission of only one period per frequency.
multi-spectral (MS) mode : new fast mode. It is based on the simultaneous emission of multiple frequencies.
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What is inside the dataset:
The dataset is composed of 3 numerical and 6 experimental mutual impedance measurements.
The numerical measurements are obtained for the same plasma box but for different instrumental modes.
The experimental measurements are obtained for two different plasmas, monitored using the three different
instrumental modes.
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List of directories:
Numerical_CH, Numerical_MS: Each of these outputs corresponds to a mutual impedance measurement
Numerical_FS performed using a different instrumental mode.
For MS and FS, inside the directory each folder corresponds to the
emission of a different frequency.
Experimental : It contains a txt file with inside the mutual impedance spectra obtained
for two different plasmas
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List of folders inside the directories:
In the case of the numerical measurements, folders begin with the name "000" and have increasing index.
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List of files inside the folders for the numerical measurements:
density_e.npz : electron density inside the box, in function of time (tempo)
density_p.npz : ion density inside the box, in function of time (tempo)
E.npz : electric field in the box, in function of time (tempo)
qrho.npz : electric potential in the box, in function of time (tempo)
qrho_imposed.npz : electric charge imposed at the emitting antennas, in function of time (tempo)
tempo.npz : time-vector for density, electric field, electric potential and charge vectors
TEST_Luca.dat : parameters describing the characteristics of the simulated plasma box
[
Note : the previous files can be opened as follows
import numpy as np
vector_file_name = np.load('file_name.npz') # Use these for the .npz files
characteristics_of_the_box = np.genfromtxt('TEST_Luca.dat',skip_header=1)
]
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List of files inside the folders for the experimental measurements:
data.txt : frequencies and amplitudes associated to the measurements.
[
Note : the previous file can be directly included into a python script
]
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Characteristics of the simulated plasma box (TEST_Luca.dat)
nx : amount of spatial grid points
xl : physical size of the spatial box, expressed in Debye length
tt_w : time resolution for ion and electron density, electric field, electric potential and charge
rap_m : ion-to-electron mass ratio
R_p : ion-to-electron temperature ratio
dt : time step used to evolve in time the numerical simulation
emission : emission frequency
power : amplitude of the electric charge imposed at the emitting antennas
(Note : all parameters not listed here but present inside the TEST_Luca.dat file correspond to additional
functionalities of the model. For the use of this dataset, they can be discarded.)