History
On May 22, 2017, the Department of Physics and Astronomy at James Madison University (JMU) officially opened the doors at the Madison Accelerator Laboratory (MAL). The department acquired a medical electron linear accelerator (linac) and an X-ray imaging machine from the former Cancer Therapy Center of the Rockingham Memorial Hospital in Harrisonburg, Virginia, when the hospital moved to a new location off of JMU’s campus and bought new equipment for the new site. On March 22, 2018, MAL officially began operation.
The electron linac at MAL is a magnetron-powered Siemens Mevatron MD2 and operates in a modulated pulsed regime with 6 µs bursts of electrons at a 200 Hz pulse repetition frequency. It was clinically used with electron energies of 5, 7, 8, 10, 12, and 14 MeV and with X-ray beam energies of 6 and 15 MeV. The X-ray photons, also known as bremsstrahlung radiation, are produced by directing the electron beam into a tungsten target. Thus, the 6 or 15 MeV energy refers to the energy of the monoenergetic electron beam and the highest energy of photons produced (referred to as the endpoint energy). The bremsstrahlung radiation at MAL is a photon energy distribution that ranges from roughly 50 keV at the lower limit (due to filters in the beam path) to the endpoint energy of 6 or 15 MeV. The equipment acquired with the opening of MAL allows the electron linac to be tunable to a range of intermediate energies and the beam to be characterized in the new operational energy domain.
MAL’s (40-140 kV) X-ray imaging facility has been repurposed to do research in a wide range of areas – including material science, geology, history, and museum studies. Using a state-of-the-art Carestream HPX-DR digital imager, it allows for routine X-ray 2-D imaging of even large pieces of art down to 100 μm (0.1mm) spatial resolution. We recently acquired Digitome 3-D imaging software, which allows 3-D imaging to be done by combining CT-like slices (flat-plane imagery in TIFF format) into 3-D datasets. This can help researchers image and model the detailed internal structure of objects.
Madison Accelerator Laboratory also provides a unique platform for teaching undergraduate students in an accelerator-based environment. This will create a multitude of opportunities for students considering careers in experimental nuclear/particle physics, nuclear engineering, or medical physical as well as for those directly entering the workforce in nuclear industry or government.
Mission
Our mission is two-fold, research focused, and education focused. Our research-focused mission is to repurpose and transform an “off-the-shelf” medical electron linear accelerator, originally used for clinical operations, into a multidisciplinary user-research facility available for all JMU faculty and students as well as for other higher-education institutions and research facilities in Virginia and beyond.
Our education-focused mission is to forge collaborations between the physics, nuclear engineering and health science departments across the state of Virginia and beyond that focus on the development of a broad educational curriculum in applied photon science and accelerator physics.