DATA from: Time-varying reconstruction of the plume cross-section of a Pulsed Plasma Thruster

Data from: Time-varying reconstruction of the plume cross-section of a Pulsed Plasma Thruster

Authors: Scherezade Barquero, Jaume Navarro-Cavallé, Mario Merino

Contact email: [e-mail], [e-mail]

Date: 2024-09-20

Keywords: plasma diagnostics, pulsed plasma thrusters, transient plume, divergence angle.

Version: 1.1

License: This dataset is made available under the Open Data Commons Attribution License

Abstract

The dataset in this repository contains the measured data used in the article "Time-varying reconstruction of the plume cross-section of a Pulsed Plasma Thruster". The article describes a novel diagnostic system consisting of a grid of electrostatic wire probes working in the ion saturation regime to time-resolve the cross-sectional expansion of the exhaust of unsteady electric thrusters. This experimental technique is used to characterize the exhaust of a small ablative pulsed plasma thruster (PPT) fed with polytetrafluoroethylene. The 2D ion current distribution is reconstructed from the probe data using a variable separation algorithm and least squares. The PPT, operated at 1000 V of discharge voltage and 6 μF, exhibits three separate ion groups, with the second one carrying the major part of the ion current. The ion beam is single-peaked in the direction perpendicular to the electrodes, while in the direction parallel to them it is more outspread and shows two peaks. Asymmetries are present in the time-varying plume, showing a small deviation of the current towards the cathode and one of the lateral sides of the channel.

For information on the experimental setup please refer to the article. The provided data presents, for the whole exhaust cross-section:

1) the current measurements from each grid probe, showing the mean and standard deviation over multiple firings, and

2) the reconstructed time-varying current density distribution, according to the algorithm presented in the article.

Data Files

1) The current measurements are uploaded in MATLAB MAT-file format (SBarquero_et_al_EP2_PPTPlume_cross_section_ZENODO_database.mat), organized in a MATLAB structure named: SBarquero_PPTplume_cross_section_dataset.  The structure above 5 fields, with 4 of those correspondingly refering to the four frame positionings to scan the exhaust cross section, and another one (t) referring to the time vector applying to any measurement.

           t: [0 1.0000e-08 2.0000e-08 3.0000e-08 … ]    positionRB: [1×1 struct] (RIGHT-BOTTOM frame position)    positionLB: [1×1 struct] (LEFT-BOTTOM frame position)    positionRT: [1×1 struct] (RIGHT-TOP frame position)    positionLT: [1×1 struct] (LEFT-TOPframe position)

Each one of the 4 current-measurement fields are structures. Each includes the frame position horizontal and vertical measurements  as subfields, which are arranged as structures too. The "H" (or "V") field contains the time-series means and  standard deviation of each probe, again as fields and structures. Example:

SBarquero_PPTplume_cross_section_dataset.positionLT:

    H: [1×1 struct]    V: [1×1 struct]

with  SBarquero_PPTplume_cross_section_dataset.positionLT.H:

     means: [1×1 struct]    stddev: [1×1 struct]

Finally,  SBarquero_PPTplume_cross_section_dataset.positionLT.H.means (or V.means) is a structure with fields referring to each one of the probes. At each frame position, "plus0" refers to the central "cross-hair" location x=0 (or y=0 when dealing with vertical measurements), and "plusX" corresponds to a probe location belonging to the same frame position but offset by X cm from the central probe location. 

     plus0: [0.1769 0.3878 0.5440 0.6423 0.6839 0.6742 … ]     plus2: [-2.2552 -1.5866 -0.9009 -0.2333 0.3846 … ]     plus4: [-0.0684 -0.0346 -0.0147 -0.0079 -0.0124 … ]     plus6: [-0.8000 -1.8070 -1.9400 -0.0455 0.3500 … ]     plus8: [-1.8562 -2.0107 -2.1030 -2.1101 -2.0131 … ]    plus10: [-1.3708 -1.2773 -1.1413 -0.9649 -0.7522 … ]    plus12: [-0.0067 0.1060 0.1901 0.2413 0.2581 0.2425 … ]    plus14: [0.1938 0.1278 0.0455 -0.0485 -0.1481 … ]

and, analogously,  SBarquero_PPTplume_cross_section_dataset.positionLT.H.stddev:

     plus0: [2.3997 2.2704 2.1173 1.9504 1.7827 1.6282 … ]     plus2: [1.5536 1.2657 0.9482 0.6273 0.3617 0.3325 … ]     plus4: [1.1218 1.0517 0.9672 0.8744 0.7802 0.6914 … ]     plus8: [0.4335 0.4450 0.5267 0.6799 0.8786 1.0941 … ]    plus10: [1.0087 1.0744 1.1487 1.2231 1.2897 1.3421 … ]    plus12: [1.5607 1.4330 1.2918 1.1496 1.0203 0.9173 … ]    plus14: [2.1748 2.1797 2.2589 2.3865 2.5313 2.6661 … ]

2) The time-varying current density distribution is uploaded trhough a video-file named SBarquero_et_al_EP2_PPTPlume_cross_section_ZENODO_jdistribution.avi

Citation

Any works using this dataset or any part of it in any form shall cite it as follows:

The preferred means of citation is to reference the publication associated with the article:  "Time-varying reconstruction of the plume cross-section of a Pulsed Plasma Thruster" (currently under review)

Optionally the dataset can be cited by referencing the corresponding  DOI: 10.5281/zenodo.13820946.

Acknowledgments

This work was been supported by the MARTINLARA project, funded by the Comunidad de Madrid, under Grant reference P2018/NMT-4333 MARTINLARA-CM. Additional support came from the ADAPT project, funded by the Agencia Estatal de Investigación (Spanish National Research Agency).