READ ME File For 'Dataset for thesis: Alternative propellant performance in Hall effect thrusters'

Dataset DOI: 10.5258/SOTON/PG/D196

ReadMe Author: Thomas Munro-O'Brien, University of Southampton 0000-0002-8387-3143

This dataset supports the thesis entitled  
AWARDED BY: University of Southampton  
DATE OF AWARD: 2026

Date of data collection: 27 February 2025 to 10 August 2025

Information about geographic location of data collection:  
- Southampton data were collected at the University of Southampton, Southampton, UK.  
- Michigan and probe datasets were collected at the University of Michigan, Ann Arbor, USA.

Licence:  
Creative Commons Attribution 4.0 International (CC BY 4.0)

Related projects / Funders:  
- Southampton data: no specific funding sources.  
- Michigan testing: completed under the United Kingdom Space Agency (UKSA) International Bi‑lateral Fund (IBF) Phase‑2 project "US‑UK collaboration on the development of Hall thruster spacecraft propulsion", specifically under deliverable D4.2: "Testing of Southampton Thruster at University of Michigan".


--------------------
DATA & FILE OVERVIEW
--------------------

This dataset contains the following files (all contained within the root directory of the .zip archive):

1. Campaign 5 all test data.xlsx  
   The master data file for "Campaign 5". It contains raw and calculated performance data for a Hall effect thruster (SPT) operating primarily on Ar, Kr, and Xe. Data include discharge parameters (voltage, current, power), mass flow rates, thrust, specific impulse (Isp), anode efficiency, total efficiency, and derived quantities like channel geometry and neutral number density. The file contains sheets: Sheet1 (main test data), Sheet2 (channel geometry lookup), and Sheet3 (propellant properties).

2. ExB data.xlsx  
   Processed data from an ExB (Wien filter) probe. Provides ion species current fractions (e.g., Kr+ current, %) for different operating conditions (flow rate and anode voltage).

3. exb_results_summary.xlsx  
   Summarised and more highly processed ExB probe data. Contains results from multi‑peak fitting analysis for each condition, including mean voltage (peak_mu), width (sigma), amplitude, and current/species fraction for up to three ion peaks (e.g., Kr+, Kr+2, Kr+3). Also includes calculated overlaps and current utilisation efficiency.

4. faraday_summary.xlsx  
   Processed data from a Faraday probe. Provides beam current, axial current, and left‑hand (LH) and right‑hand (RH) beam divergence angles (in degrees and radians) for each test condition.

5. thesis dataset readme.txt  
   This file – the README for the dataset.

6. UK_Thrust_0325.xlsx  
   Intermediate data log for thrust measurements. Includes calibration file paths, test file names, and calculated thrust and efficiency for a series of tests. Represents direct output from the thrust stand.

7. All michigan test data.xlsx  
   Comprehensive dataset from tests performed at the University of Michigan. Synthesises thrust, probe (RPA, Faraday, Langmuir, ExB), and performance data into a single table. Includes columns for anode flow rate, voltage, current, power, thrust, Isp, and a wide range of efficiency terms (anode, divergence, current, voltage, mass, charge). Also includes detailed probe measurements like beam current, divergence, and ion species fractions. The "Soton comparison" sheet explicitly compares Michigan results with Southampton ("Campaign 5") data.

Relationship between files, if important for context:  
The files represent a hierarchical data structure. Raw measurement data (thrust stand, probes) were processed into intermediate files (e.g., UK_Thrust_0325.xlsx, ExB data.xlsx, faraday_summary.xlsx). These intermediate data were then synthesised into two master performance tables: Campaign 5 all test data.xlsx (for the "Campaign 5" tests) and All michigan test data.xlsx (for the Michigan tests). The latter explicitly compares its results to the Southampton data, linking the two master datasets.

If data was derived from another source, list source:  
All data are original, generated by the thesis author and research group. No external sources were used.

If there are multiple versions of the dataset, list the file updated, when and why update was made:  
No multiple versions are provided. This is the final curated version supporting the thesis.



--------------------------
METHODOLOGICAL INFORMATION
--------------------------

Description of methods used for collection/generation of data:  
A modular Hall effect thruster designed and developed at the University of Southampton was tested in the David Fearn large vacuum chamber, with diagnostics built in‑house. Detailed experimental procedures are described at length within the thesis.

Methods for processing the data:  
Raw data were processed using custom Python scripts (see Software section) and Excel. Thrust data were reduced using a calibrated thrust stand; probe data (ExB, Faraday) were fitted and integrated to obtain ion species fractions, beam currents, and divergence angles. Efficiency metrics were calculated from these measurements.

Software‑ or Instrument‑specific information needed to interpret the data:  
- Microsoft Excel (version used: Office 365).  
- Python 3 with the following libraries (specific versions are listed in the thesis but any compatible version should work):  
  numpy, matplotlib, pandas, os, scipy.stats, scipy.optimize, scipy.special, itertools, seaborn, mpl_toolkits.mplot3d, sklearn.gaussian_process, sklearn.preprocessing, sklearn.model_selection, glob, re, datetime, scipy.signal, scipy, scipy.stats.linregress, numpy.polynomial.polynomial.Polynomial.

People involved with sample collection, processing, analysis and/or submission:  
- Thomas F. Munro‑O'Brien (University of Southampton): primary data collection (both Southampton and Michigan datasets), processing, analysis, and submission.  
- Madison G. Allen (University of Michigan): collaborative data collection at Michigan.  
- William Hurley (University of Michigan): collaborative data collection at Michigan.  
- Tate Gill (University of Michigan): collaborative data collection at Michigan.  
- Dr. Benjamin Jorns (University of Michigan): supervisor for Michigan testing and data collection.  
- Dr. Charles N. Ryan (University of Southampton): supervisor for Southampton testing and data collection, overall project supervision.  


Date that the read_me file was created: May 2026  

--------------  
End of README