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Postgraduate and honours research projects - detector developmentReal time data acquisition and measurement for nuclear medical imaging
Dr Chris Hall, Monash Centre for Synchrotron Science The Monash Centre for Synchrotron Science Instrumentation Group is involved in many areas of high energy photon detection. Applications such as coherent x-ray imaging or nuclear medicine require the detection of photons from the soft X-ray regime (3 keV) to low energy gamma radiation (1 MeV) respectively. The process of detector design and optimisation is coupled to the methods used in data acquisition, experimental setup and data sorting and image reconstruction. The Generic Data AcQuisition (GDAQ) card has been designed and developed by the Monash Centre for Synchrotron Science Instrumentation Group, and is in the final stages of testing for deployment to different detection systems. As opposed to analogue systems, all pulse shape processing may be conducted in firm/soft ware using the ultra-high sampling rate of these cards. This project looks to conduct final testing of these cards using physical detection systems. The project involves using BGO/Other detectors to acquire multi-channel pulse-shape data using the GDAQ cards. The detector-card interface will be exploited to carry out detector characterisation with the intended result of implementing pulse-shape algorithms in real-time using the GDAQ FPGA logic. The resulting system can be used to measure interactions of single photons. Measurements taken from the detector and DAQ will be used to form a Compton camera, PET or SPECT demonstrator, and optimise its geometry. Imaging without lenses - semiconductor detector pulse shape analysis
Prof Rob Lewis, Monash Centre for Synchrotron Science Orthogonal strip semiconductor detection of gamma rays is an excellent method of measurement of location and energy of an incident photon. Electronic collimation (finding the direction of the incident photon) of gamma rays [1] requires that this information is recorded for progressive Compton scattering and photoelectric interactions of the same photon. Using gamma tracking [2] this may be accomplished in a single detection volume. However, events that scatter twice in the detector are often separated by only a small distance. The full details of these events are contained in the final pulse shape formed at the electrodes. The question you will attempt to answer is whether two or more interactions of this type can be recognised as such and subsequently de-convolved by the detector data acquisition system? Furthermore, you will investigate what the error introduced by this process is, and how can it be minimised? This project will make progress towards answering these questions as part of an international collaboration aimed at producing a novel method of collinear gamma detection for use in nuclear emission imaging. References
[1] Phillips, G.W., Gamma-ray imaging with Compton cameras. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials & Atoms, 1995. B99(1-4): p. 674-7. Imaging without lenses - semiconductor detector modelling
Prof Rob Lewis, Monash Centre for Synchrotron Science It has been proposed to use a single germanium crystal semiconductor detector utilising gamma tracking as a Compton camera for use in medical imaging [1]. However, an analysis of the variation of charge collection over the volume of the detector is required. This project will look at how the electric field applied over the detector coupled with the interactions of the photons produce charge at the electrodes. You will look at the process from interaction location and energy deposit, through electron/hole cloud formation, to pulse shape generation at the strips, over the entire volume of the detector. This will enable the complete simulation of the emission/detection/data-acquisition/image-reconstruction process. As part of an international collaboration the ideas will be implemented in a prototype detector under current design by the group. References [1] Hall, C.J., et al., A gamma-ray tracking detector for molecular imaging. Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2003. 510(1-2): p. 116-121. Novel imaging applications for photon counting high spatial and spectroscopic resolution X-ray detectors
Prof Rob Lewis, Monash Centre for Synchrotron Science The Monash Centre for Synchrotron Science is developing a energy resolving pixel xray detector for medical imaging application via its CRC in BID program. The ability to detect both X-ray energy and positional information open a range of new applications for this detector, which be applied to possible new industrial products in areas such as home land security, non destructive testing, product quality control, advanced sorting, foreign object identification and baggage scanning. This project allows the individual, the opportunity to use tools being developed within the group to show proof of principle of any of these or other novel application through model simulation and hands on experimentation . This work will require use of the Australian Synchrotron as a source of 'gold standard' X-rays. Spectroscopic resolution improvement in room temperature X-ray detectors
Prof Rob Lewis, Monash Centre for Synchrotron Science The Monash Centre for Synchrotron Science is developing a energy resolving pixel X-ray detector for medical imaging application via its CRC in BID program. The ability to detect both X-ray energy and positional information open a range of new applications for this detector. The intrinsic energy resolution is currently around 5-10% dE/E. We would like to develop techniques which take into account the processes that limit the intrinsic resolution to effectively deconvolve these effects by calibration using monochromic X-rays at various rates. This project allows the individual, the opportunity to develop these ideas using model simulation tools being developed within the group and hands on experimentation . This work will require use of the Australian Synchrotron as a source of 'gold standard' X-rays. For further information, please contact:
Dr Chris Hall
Mr Andy Berry A list of undergraduate engineering research projects in the field of detector development is available here. |