29 Feb 2024
Job Information
- Organisation/Company
CNRS - National Center for Scientific Research- Research Field
Physics » Applied physics- Researcher Profile
First Stage Researcher (R1)- Country
France- Application Deadline
12 Apr 2024 - 12:00 (Europe/Paris)- Type of Contract
Temporary- Job Status
Full-time- Offer Starting Date
1 Mar 2024- Is the job funded through the EU Research Framework Programme?
Not funded by an EU programme- Is the Job related to staff position within a Research Infrastructure?
No
Offer Description
Hall thrusters (HTs) are ion thrusters for satellites and space probes that use a magnetized plasma discharge to create and accelerate ions. Today, they represent the most advanced and by far the most widely used technology for all satellite categories and orbits. HTs nominally use xenon as propellant, as this noble gas is heavy, relatively easy to ionize, non-reactive and non-toxic. However, the large-scale use of this gas, combined with a complex and tense global geopolitical situation, has led to a sharp rise in the price of xenon (above 10 k€/kg) and even to supply shortages. Satellite manufacturers and the space industry in general are therefore looking for alternatives to xenon for HTs and other types of propulsion devices. Krypton, another rare gas, appears to be a simple and immediate alternative. However, the performance of HTs is degraded with Kr, and its large-scale use would undoubtedly lead to a situation similar to that currently experienced with Xe. We must therefore turn to other, more original alternatives.
In this experimental thesis, we propose to study a non-organic, non-metallic molecular propellant, water (H2O). Water is abundant (even outside the Earth), storable in liquid or solid form, non-explosive and non-toxic. Although Hall thruster performance is certainly degraded with water (light molecule, dissociation), its ease of use, abundance and cost could make it an attractive molecule. Two injection schemes can be employed for water: vaporization and direct injection of H2O vapour and/or electrolysis with injection of H2 and O2. In this study only the first path will be considered. Testing and thrust measurements will be carried out in the NExET cryogenic pumped vacuum chamber. A low-power Hall thruster (~ 200 W) will be designed, built and optimized for use with H2O; additional operation with Xe and Kr will serve as a reference.
The plasma discharge produced in the thruster cavity will also be studied with great interest, using electrostatic, optical and laser diagnostics. This second, more fundamental, aspect of the project is highly relevant because, as well as helping to optimize the thruster, it will provide new results, since little work has been done to date on low-pressure water plasmas. Comparisons with another alternative propellant, ammonia NH3, can be envisaged, as this molecule is being studied at ICARE as an energy carrier by several teams. NH3 has a mass close to H2O and contains no oxidizing agent. However, its cost, low natural abundance and toxicity make it less attractive.
Works will be performed in the ICARE laboratory of the CNRS in Orleans, France. The PhD student will join the EP team of the laboratory. He will have access to dedicated labs and to all equipment and instruments (eg vacuum chamber, diagnostic tools...).
Requirements
- Research Field
- Physics » Applied physics
- Education Level
- Master Degree or equivalent
Skills/Qualifications
The candidate's profile must correspond to the description of the PhD thesis research project.
The candidate must :
- hold an engineering degree or a master's degree in physics.
- have experience in plasma physics and/or electric propulsion
- have knowledge of space propulsion
- have skills in experimental physics, vacuum technologies, electrical diagnostics and measurement techniques
- show ability to work as part of a team,
- be able to commit fully to the project, with a strong motivation for the proposed subject and, more generally, for the field of space propulsion.
- show intellectual curiosity, conscientiousness and diligence.
A good level of English is essential, as the candidate will be interacting regularly with foreign researchers.
- Languages
- ENGLISH
- Level
- Good
- Research Field
- Physics » Applied physics
Additional Information
Work Location(s)
- Number of offers available
- 1
- Company/Institute
- CNRS ICARE laboratory
- Country
- France
- City
- Orleans
- Postal Code
- 45100
- Geofield
Where to apply
[email protected]
Contact
- City
ORLEANS- Website
https://icare.cnrs.fr/- Street
1C, avenue de la recherche scientifique- Postal Code
45071
[email protected]
STATUS: EXPIRED