Radiation, Medical & Health Physics

Regina DeWitt uses thermally (TL) and optically stimulated luminescence (OSL) to study radiation in the environment. Dr. DeWitt’s group works in a variety of research areas that include environmental, medical, and planetary/space applications. The group also investigates the properties of new materials and develops novel luminescence instrumentation. Furthermore, a setup in the Accelerator Laboratory is used to learn more about the basic physical processes of luminescence. Her group develops new techniques for accident dosimetry that enable a rapid response in the event of radiation-related emergencies. Additionally, they use TL and OSL to better understand the radiation environment in sediment and permafrost, or other extreme environments where microbial life may be found. Dr. DeWitt’s OSL Laboratory accepts samples for sediment-dating as part of ongoing projects (both undergraduate and graduate) at field sites in Antarctica, the Outer Banks in North Carolina, and other locations.

Optically Stimulated Luminescence Laboratory

The principle of luminescence (top left) along with a variety of projects from Dr. DeWitt’s lab.

Michael Dingfelder seeks to understand how ionizing radiation affects biological matter. This includes the calculation of interaction cross sections and the development of transport models. These cross sections and models are implemented into Monte Carlo track-structure simulation codes that are used to simulate and predict radiation damage to biological targets, such as DNA or cell constituents. This is part of an ongoing investigation into radiotherapy, where DNA single- and double-strand breaks in large numbers are considered essential for cell termination. This is important because misrepaired DNA damage can lead to mutations and possibly the onset of cancer.

The Radiation Instrumentation Laboratory is focused on the inventive field of medical and health physics. The laboratory uses a variety of techniques such as Monte Carlo simulation, advanced imaging and dosimetry, and radiation risk analysis to understand how radiation affects human physiology. Projects involve four-dimensional dose reconstruction during radiotherapy, secondary cancer risk assessment after radiation treatment, heart structure modeling, tumor tracking in Cyberknife, and microsphere brachytherapy. The laboratory houses primarily graduate-level projects; numerous students have presented their research at local meetings, international conferences, and in peer-reviewed journals.

Radiation Instrumentation Laboratory

The measurement of absorbed dose profiles using an anthropomorphic phantom at a medical-grade linear accelerator is part of the work done in the Radiation Instrumentation Laboratory.

The collision of two gold nuclei at high energy as calculated from A Multi-Phase Transport (AMPT) model. The length of the box is 60 fm (6×10−14 m), while time covers the first 30 fm/c (1×10−22 s) of the collision.

Zi-Wei Lin performs research in theoretical and computational physics. His interests include

  • high-energy heavy ion physics and the development of Monte Carlo transport models,
  • radiation physics and space radiation protection, and
  • medical physics in pseudo-CT methods for MRI-only radiotherapy.

These projects involve undergraduate and graduate students, postdoctoral researchers, as well as visiting students and professors.

Learn more about Dr. Lin’s research