Semester of Graduation

Spring 2020

Degree

Master of Science (MS)

Department

Physics & Astronomy

Document Type

Thesis

Abstract

The Center for Advanced Microstructures and Devices (CAMD) is a 1.5 giga-electron volt (GeV) electron synchrotron research facility under the jurisdiction of Louisiana State University (LSU). When originally constructed in 1992, CAMD was surrounded by pasture and woodland. Over the past several years, urban development of the area has found CAMD bracketed by a shopping center, apartment complex, and business offices. These developments raised concerns amongst the CAMD radiation safety personnel regarding an increased potential for public exposure to radiation. To ensure compliance with the annual public effective dose equivalent limit of 1 milli-sievert (mSv), the radiation monitoring program was reviewed. The outside perimeter has a series of Optically Stimulated Luminescence (OSL) dosimeters that are exchanged quarterly, OSL’s with neutron detecting chips are placed inside the experimental hall and exchanged monthly, and several real-time radiation monitoring devices are located around the shield wall. Measurements from these devices and hand-held detectors have confirmed that the annual public effective dose equivalent limits are not exceeded beyond the CAMD site. However, the most well documented sources of radiation dose at CAMD all relate to the plane of the accelerator ring and emissions which occur during acceleration, beam turns, and beam dumping. Another concern is skyshine radiation, which is any radiation particle that scatters in air back to the ground. Measurements and physics suggest that the overwhelming majority of skyshine radiation originates from the two 90˚ turns leading from the underground linear accelerator tunnel up to the plane of the ring for injection. The FLUKA (FLUktuierende KAskade or Fluctuating Cascade) Monte Carlo code developed by the Italian National Institute for Nuclear Physics (INFN) and the European Organization for Nuclear Research (CERN) was selected to model CAMD radiation emissions. Through FLUKA, the particle tracks and effective dose equivalent from skyshine radiation can be simulated. The potential exposure to neighboring properties and any future construction can be estimated to complement CAMD’s existing, well-established radiation safety program.

Committee Chair

Wang, Wei-Hsung

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