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The Australian National University
Honours, Masters, PhD
Analysis of Alfvén eigenmode data from H-1 plasma

One of the major concerns in predictions of the plasma parameters required for next step fusion experiments (e.g. ITER) is the possible deleterious effect of the excitation of large amplitude Alfvén eigenmodes, manifesting as magnetic field fluctuations which can cause energy transport across the confining magnetic field. Similar fluctuations are observed in high temperature H-1 plasmas. You would analyse some of the substantial data set of frequency vs. time data (`voiceprint´) looking for agreement or otherwise with a few simple theories, or for different characteristic phenomena. We have data viewing and data mining software already, which you are encouraged to use, or you could improve this, or develop your own approach. For Honours and Vacation students, a senior research student or Postdoc would be able to provide close support with software and analysis. There are many directions in which this work could be extended to a PhD, including sophisticated data analysis and data mining, theoretical analysis/basic plasma stability studies, or extension of the probe/detector/signal processing hardware.

Contacts:
A/Prof Boyd Blackwell
Professor John Howard
PhD, Masters, Honours, Vacation Scholar
Fast switching polarization interferometers for high resolution spectroscopic imaging

The AIIM group has pioneered a range of novel optical instruments for coherence imaging applications in both science and industry. Using spatial or temporal multiplex methods, the systems are designed to capture only the essential 2-d colour information necessary to characterise the physical properties of a given scene. This project would continue and extend this work to the development of hybrid spatio-temporal mutliplex systems for the characterisation of more complex spectral scenes. The work would involve optical design and testing, LabVIEW software development and some signal processing.

Contacts:
Professor John Howard
Honours, Masters, PhD
Data Quality Assessment

A smaller data-mining project is the Data Quality Assessment Project (V,H,MPh) . This is more of a software-oriented project, creating a set of rules and a procedure for checking the quality of the data and plasma parameters recorded each time we pulse H-1. Our data are numerous and diverse, and expensive to acquire, so if a data set is flawed, we would like to know quickly, to save wasting resources, and avoid the need to repeat the data taking. The set of rules or classifications that define ‘good’ data should be developed from two directions: a/ experts write some simple rules, and then fine tune them on old data, and new data is at arrives. b/ experts classify good and bad data, pulse by pulse and machine learning techniques are used to discover new rules that define bad data.

Contacts:
A/Prof Boyd Blackwell
Dr David Pretty
Honours, Masters, PhD
Application of Data-Mining Techniques to Plasma Phenomena in H-1

Recent advances in databases and intelligent algorithms have enabled machine-based ‘trawling’ of very large databases, to find both prescribed or already known phenomena, and by looking for data that does not fit known patterns, discover new behaviour. Association rules or clustering algorithms even allow machines to discern patterns without human guidance. H-1 provides a rich variety of instability phenomena, from the drift frequency range (low kHz) to higher magnetohydrodynamic (MHD) frequencies up to ~ 1MHz, from several types of sensor array sets. These include two 20 channel magnetic probe arrays (‘Mirnov’), two arrays of visible light detectors (miniature photomultiplier arrays) two `soft´ X-ray arrays and spatially scanning scanning plasma density interferometers. The data mining project is a combination of development of algorithms as described above, and physical understanding of the phenomena, with a weighting to best fit the student's interest and ability.

Contacts:
A/Prof Boyd Blackwell
Dr David Pretty
Honours, Masters, PhD
D-H experiments in H-1

The difference in physical behaviour of normal and ‘heavy’ Hydrogen (Deuterium [1p,1n]) ions in a magnetised plasma is much greater than for other elemental isotopes because the mass disparity is so great. For example, H is much more strongly adsorbed into vacuum vessel metallic surfaces than D, while D typically shows a 20-40% longer ion energy confinement time than H.  Coherence interferometry is a very sensitive and efficient way to monitor the relative concentrations of H and D, which can be also be controlled by individual gas feeds, gas puff valves and supersonic injectors. The project will involve development of fast imaging spectroscopic systems based on coherence interferometry to measure and study the spatial evolution of the relative concentration of the isotopes in 0.5T radio-frequency heated H-1 plasmas.

Contacts:
Professor John Howard

Updated:  30 June 2010/Responsible Officer:  H-1 Facility Manager /Page Contact:  H-1 Website Administrator