Solid state physicists from the School of Physical Sciences in DCU have worked with the Isotope mass Separator On-Line (ISOLDE) facility in CERN, which provides a unique source of low-energy beams of radioactive nuclides. The ISOLDE facility uses protons from CERN’s accelerator complex to produce exotic nuclei of most of the elements. These radioactive nuclei are used for basic research in many areas of science: nuclear physics, nuclear astrophysics, atomic physics, condensed matter physics, radiobiology, and elementary particle physics. ISOLDE is the foremost of a network of radioactive beam facilities in Europe, with excellent mass resolution enabling very pure beams of single isotopes to be produced. DCU researchers have used the facility for fundamental and applied studies of defects in semiconductor materials such as silicon, GaAs and ZnO. They combine sophisticated spectroscopic methods with radioactivity to pinpoint the involvement of specific impurity elements in a range of solid state processes. This research involves significant preparatory work in DCU combined with periods of intensive experimental work at CERN usually as part of international collaborations with other users from across Europe and beyond. The impact on individual students is transformative, broadening and deepening their knowledge and skills.
Three PhD degrees and one MSc degree by research have been awarded to DCU students for their work at ISOLDE, these funded by IRC/IRCSET, the (now disbanded) SFI Research Frontier Programme, by earlier national funding programmes, and through EU collaboration grants. A large number of other DCU undergraduate and postgraduate research students have also worked at ISOLDE as part of research internships or on short projects during their studies. In addition, several international students from other universities (e.g. the Universities of Potsdam and Konstanz in Germany) have worked with DCU staff on projects in ISOLDE.
Finally, strong and long-standing links also exist between DCU and ISOLDE in terms of professional interactions. The current ISOLDE Physics Coordinator (and former ISOLDE Solid State Physics Coordinator), Dr. Karl Johnston, is a DCU graduate (BSc in Applied Physics in 1996) and he also worked as a postdoctoral researcher in DCU for a period of time. Prof. Enda McGlynn from DCU has served as a project proposal reviewer and member of the CERN ISOLDE and Neutron Time-of-Flight Experiments Committee (INTC) from January 2013 to November 2017. Prof. McGlynn also served as the Irish representative on the CERN ISOLDE Collaboration Committee (ISCC) from March 2016 until February 2017, and prior to this Prof. Martin Henry from DCU served in the same role over the period 2010 to 2016.
Sample Publications
J. Cullen et al., The Hg isoelectronic defect in ZnO (see also Joseph Cullen's PhD thesis)
J. Cullen et al., Chemical identification of luminescence due to Sn and Sb in ZnO (see also Joseph Cullen's PhD thesis)
J. Cullen et al., Uniaxial stress and Zeeman spectroscopy of the 3.324-eV Ge-related photoluminescence in ZnO (see also Joseph Cullen's PhD thesis)
M. Steger et al., Photoluminescence of deep defects involving transition metals in Si: New insights from highly enriched Si-28
K. Johnston et al., Evidence for As lattice location and Ge bound exciton luminescence in ZnO implanted with As-73 and Ge-73
M. Steger et al., Isotopic fingerprints of Pt-containing luminescence centers in highly enriched Si-28
K. Johnston et al., Identification of donor-related impurities in ZnO using photoluminescence and radiotracer techniques (see Deirdre McCabe's PhD thesis)
M.O. Henry et al., The evolution of point defects in semiconductors studied using the decay of implanted radioactive isotopes (see James Fryar's MSc thesis)
J. Bollmann et al., Deep level anomalies in silicon doped with radioactive Au atoms
M.O. Henry et al., Radioactive isotope identifications of Au and Pt photoluminescence centres in silicon
Postgraduate student career positions include the following:
Joseph Cullen (PhD, 2013): Senior Process Engineer at Intel Ireland
Deirdre McCabe (PhD, 2007): Research Integration Coordinator, Insight Centre for Data Analytics (DCU)
James Fryar (MSc, 2001): Senior Hardware and Integration Engineer, Ambisense, Dublin
Siobhan Daly (PhD, 1994): Senior Lecturer/Assistant Head of Physics & Clinical & Optometric Sciences, TU Dublin