Diagnosis of high powered pulsed plasmas for the synthesis of new materials
New high speed optical and electronic diagnostics methods will be developed to probe ultra fast plasma phenomena in promising new plasma discharges for the synthesis of metastable materials.
High power pulsed magnetron sputtering (HIPPIMS) is a new method for producing a highly ionised flux of material from a solid target for coating applications. Indications are that it produces a high ionized flux (approaching that of the cathodic arc described above). The nature of the plasma produced when high power pulses are applied to a sputtering target will underpin commercial application of this source for materials synthesis and is still not understood. In this project high speed optical and electronic diagnostic tools capable of probing the rapidly changing discharge will be developed and deployed. The optical method will be high speed high dispersion optical spectroscopy involving coupling a Fizeau interferometer to a spectrograph and high speed intensified CCD camera. This will enable the analysis of line shapes associated with species in the plasma to determine their densities and velocities. Complementary information will be obtained by time and energy resolved mass spectrometry. Langmuir probes will be used to investigate the electron temperature. The ultimate aim is to understand whether the discharge is similar to a high current arc or is a new kind of glow discharge operating at a much higher current density than previously known. An arc involves a localised emission site on either the cathode or the anode whereas a glow discharge has a distributed current on the electrodes. A glow discharge is more controlled than an arc and does not produce macroparticles.The Applied and Plasma group has recently developed and commissioned a high current (1-5 kA) pulsed cathodic arc plasma source. This source is the only one of its kind and produces a much higher instantaneous ion flux than any other deposition system currently available. The range of parameters which can be accessed make it an ideal instrument for investigating the basic physics of plasma transport in magnetic and electric fields. This project will utilize high-tech plasma diagnostic equipment, such as time resolved Langmuir probes, microwave and laser interferometry and tomography, and CIS spectroscopy) developed in collaboration with the fusion research group at the ANU, Canberra, on a two million dollar ARC infrastructure grant awarded to the consortium. The questions to be investigated include the identification of instabilities associated with transport of a high density fully ionized drifting plasma in magnetic fields, the development of enhanced charged states in the rapidly expanding plasma region. Recent simulation work has predicted that the charge state distribution is coupled to the energy distribution in a specific way and we are now in a unique position to test this.
This research field is very large and rapidly evolving so there are a number of projects available for PhD, Masters and Honours students. Students involved in the work will learn how to design, build and use a range of high tech diagnostic instruments, including high resolution spectrometers, a range of interferometers, electrostatic probes and mass energy analyzers. Top up scholarships are available for students with sufficiently high grades or other relevant experience.
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The opportunity ID for this research opportunity is: 712
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