After obtaining his PhD in plasma physics at the Flinders University of South Australia, Professor Cheetham spent fifteen years working in the field of plasma diagnostic systems in nuclear fusion energy research laboratories, including the Institute for Plasma Research, University of Stuttgart (Germany), the Centre for Research in Plasma Physics, École Polytechnique Fédérale de Lausanne (Switzerland), the Plasma Research Laboratory, ANU (Australia) and ultimately as a Principal Scientific Officer at the Euratom nuclear fusion project, the Joint European Torus (JET), UK.
In 1990 he returned to Australia and joined the then School of Electronics Engineering and Applied Physics at the University of Canberra where he has taught physics, electronics, power systems, signal processing, computer controlled instrumentation and automatic control systems.
At the University of Canberra Professor Cheetham established a small Plasma Technology research laboratory. He went on to be Head of the School of Electronics and Telecommunications Engineering, Deputy Director of the Division of Business and Information Sciences and finally PVC - Research and Information Management. He was Pro Vice-Chancellor (Research) at the University of Western Sydney since 2007 until 2013 when he became Deputy Vice-Chancellor Research until his retirement in 2014..