Speaker - Stephen McKeever; Oklahoma State University
Thermally stimulated luminescence (TL) from insulating materials has been used in radiation dosimetry since the early 1950s, although the genesis of the techniques goes back to the early studies of radiation and radioactivity.More recently, optically stimulated luminescence (OSL) has emerged as a powerful dosimetry method.
Both TL and OSL rely on the perturbation of the material from thermodynamic equilibrium via the absorption of energy from a radiation field and the creation of point defects via ionization processes.A thorough understanding of TL and OSL in any given material would require a detailed knowledge of the nature and spatial distribution of the radiation-induced defects, and their subsequent interaction during thermal or optical stimu¬lation.However, basic, and, in many cases, sufficient understanding can be obtained via phenomenological descriptions of the electronic transitions between energy levels during the irradiation and stimulation processes.
This talk will describe the fundamentals of TL and OSL and discuss some of the processes that give rise to the phenomena in popular TL and OSL dosimetry materials.The talk will then show how this background understanding can assist in the application of these methods in traditional and emerging radiation measurement and dosimetry applications. Modern applications include Personal, Environmental, Retrospective, Neutron, Space, Medical and Emergency radiation dosimetry and measurement and descriptions of applications in these fields will be included in the talk.
Noncredit courses do not produce academic credit nor appear on a Colorado State University academic transcript.
Dr. Johnson's research in the laser research lab is focused on safety and laser injury recovery and the acute effects of ionizing radiation. Dr. Johnson received his Ph.D. in health physics from the School of Health Sciences at Purdue University.
Learn more at: http://www.cvmbs.colostate.edu/erhs/faculty/johnson/t_johnson.htm