(Please quote ref:0709 in all correspondence)
Two Space-technology based PhD CASE studentships, funded by STFC in association with EADS-Astrium (Stevenage), are available to start from September 2007 in the following subjects:
Instrumentation R&D for future space plasma and planetary missions proposed in the European Space Agency’s future programme (Cosmic Visions) exploiting MEMS-based (Micro-Electro Mechanical Systems) technologies
Cryogenic research, (in the temperature region of 0.05 -0.1 Kelvin) in order to successfully demonstrate, an adiabatic demagnetization refrigerator for the proposed European Space Agency mission XEUS (Exploring the Extreme Universe)
The studentships will be based at the Mullard Space Science Laboratory (Department of Space and Climate Physics, University College London), and are in collaboration with EADS Astrium, a world leader in the design and manufacture of satellite systems. Astrium’s activities cover complete civil and military telecommunications and Earth observation systems, science and navigation programmes, together with avionics and a wide range of space equipment and associated ground infrastructure.
MEMS-based instrumentation studentship
Instrumentation R&D for future space plasma and planetary missions proposed in the European Space Agency’s future programme (Cosmic Visions) exploiting MEMS-based (Micro-Electro Mechanical Systems) technologies
Recent advancements in micro fabrication techniques and sensor technology are set to revolutionise plasma analyzer systems for future space applications. The Mullard Space Science Laboratory (MSSL) has an ongoing STFC Rolling Grant funded development programme, which the student will be joining, aimed at miniaturising analyser systems and the next major focus of the programme is the development of highly integrated MEMS-based instrument/detection systems. The technologies developed on the programme will provide a generic solution framework for a wide range of mission needs, from the measurement of ionizing radiation levels on commercial (e.g. telecommunications) satellites – space weather - to the detailed scientific investigations of low energy plasmas from scientific satellites, e.g. Cross-scale, Geosail and possible Mars, Jupiter/Europa and Titan/Enceladus missions. Such instruments will provide a technology leap with considerable saving in resource, making it especially attractive for future multi-satellite, micro-satellite or planetary missions. Besides space, such analysers potentially have applications in other areas such as surface science and mass spectrometry.
The student's role in the project will be to study design concepts suitable for potential mission opportunities, carry out detailed simulations for an identified design concept followed by involvement with the build of the simulated instrument. While this will provide in-depth knowledge of the essentials of space plasma instrumentation, the development of MEMS-based technologies for these applications will provide a novel dimension and the student will be expected to play a key role in both areas
The successful candidate will also spend time at Astrium UK, gaining valuable experience from the “industrial side of the fence” whilst carrying out project related work. It is planned that the student will be co-located with the mission systems group, which carries out conceptual feasibility studies for ESA and BNSC, and act as the first interface with scientists. Project work could include instrument system engineering activities to develop the know-how and understanding of the instrument design and the interfacing/integration processes, MEMS packaging concepts, such as those in the internal programme 'EADS micropack project' or participation in concurrent solar terrestrial physics mission studies from an instrument perspective.
Students, who must meet STFC’s eligibility criteria, should have a good degree in physics or engineering and a strong interest in hardware development. Further details of STFC’s requirements are available at
http://www.stfc.ac.uk/Grants/Studs/studentships.aspx#StandResStu
Application forms may be downloaded from
http://www.ucl.ac.uk/prospective-students/graduate-study/application-admission
and should be sent to Jane Salton, Department of Space and Climate Physics, Mullard Space Science Laboratory, Holmbury St Mary, Dorking, Surrey, RH5 6NT to arrive no later than 22nd July, 2007
Cryogenics studentship
Development of an adiabatic demagnetisation refrigerator for the future ESA space mission – XEUS
We are seeking a CASE student to perform cryogenic research, both experimental and theoretical, in order to successfully demonstrate, within the three years of the studentship, an adiabatic demagnetisation refrigerator for the proposed European Space Agency mission XEUS (Exploring the Extreme Universe). The project will be performed in association with EADS Astrium - one of Europe’s largest Aerospace companies.
XEUS is ESA’s proposed next generation x-ray telescope space mission and will fly technologically challenging instruments. XEUS is an important future mission for the UK Astronomy community and has been identified as a high priority by STFC. One of the proposed instruments will use state-of-the-art X-ray cryogenic detectors (transition edge sensors – TES) which require cooling to a temperature of 30 – 50 mK. The adiabatic demagnetisation refrigerator (ADR) is the refrigerator of choice for this, being gravity independent and containing no moving parts. The ADR achieves cooling from a bath temperature typically in the region of 4 K i.e. liquid helium temperature to millikelvin temperatures by the application and removal of a magnetic field of a few Tesla on a suitable paramagnetic material. The baseline cryogenic environment for the ADR will be provided by UK-developed cryocoolers produced by Astrium and the Rutherford Appleton Laboratory. The cryogenic systems have been identified as the most significant technological development required for XEUS during a payload study awarded to Astrium by ESA in 2006. It is expected that these early activities will enable Astrium, and UK industry, to bid for a highly significant role in the XEUS system, either as prime contractor for the detector spacecraft, or the payload module.
In order to bring the technology from the laboratory to flight-standard, Astrium and MSSL, were awarded an ESA contract to build the world’s first cryogen-free flight representative ADR, which is now nearing completion. Whilst the project has successfully built a working flight representative system, time and monetary constraints have forced the system to be non optimised. The system is large, heavy, and slow in operation and does not reach the desired temperature, achieving 90 mK rather then 30 mK.
Achieving such low temperatures is challenging especially when the system has to be designed to withstand the forces and vibrations of an Ariane 5 launch. The proposed CASE studentship will address the limiting factors found in developing the bread board system mentioned above. It will also take into account what recent studies have shown, that, to be successful, the future XEUS system must be highly integrated, and designed as a coherent system, taking into account the higher temperature cryogenic stages, as well as the impact on the whole instrument and spacecraft. Key areas of investigation are:-
- Magnet optimisation. The ADR uses 10 superconducting magnets to produce the magnetic field and to control the stray field in the potential spacecraft. A detailed investigation is required in order to identify the best way to generate the magnetic field. The current design has not been fully investigated and optimized. A detailed study is required.
- Investigation into heat flow at sub 100 mK. This is a challenging temperature region where very little is known of material properties (e.g. thermal conductivity and specific heat) and thermal boundary resistances between surfaces. These parameters have a big influence on the ultimate temperature achieved in the ADR and are likely to be the reason for our system reaching 90 mK rather then 30 mK. An understanding is needed of all these properties for the materials we use both from experimentation and theory.
- Heat switches. The ADR uses heat switches in order to extract heat from the paramagnetic during magnetisation but thermally isolate the paramagnetic when the system is cooled via demagnetisation. Current heat switches contribute a dominate heat load on the system. The magnetoresistive heat switch is an attractive solution, where a single crystal of tungsten has incredible thermal switching properties. While this has been demonstrated in bulk tungsten this is too large for our application. A detailed experimental investigation is required, and a way of implementing it in the ADR needs to be found.
The studentship is very timely. While XEUS may have a possible launch date of 2020, the ADR being an immature technology, from a space point of view, must be demonstrated by 2012 to be compatible with the system development and implementation plan. The times scale of the studentship (2007 to 2010) fits well within this project plan.
Students, who must meet STFC’s eligibility criteria, should have a good degree in physics or engineering and have some knowledge of thermodynamics or cryogenics. Further details of STFC’s requirements are available at
http://www.stfc.ac.uk/Grants/Studs/studentships.aspx#StandResStu
Application forms may be downloaded from
http://www.ucl.ac.uk/prospective-students/graduate-study/application-admission
and should be sent to Jane Salton (pjs@mssl.ucl.ac.uk), Department of Space and Climate Physics, Mullard Space Science Laboratory, Holmbury St Mary, Dorking, Surrey, RH5 6NT to arrive no later than 22nd July, 2007
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