News

New Physics Imaging Device Will Help Reveal the Past

by Bill Giduz
Digitome
The Digitome® team includes (front) Phillip Wall ’14, (back) professor Dan Boye, Rebecca Garner ’16 and Ryan Kozlowski ’16.

Blackbeard's infamous pirate ship, The Queen Anne's Revenge (QAR), lay lost on the ocean floor off the North Carolina coast for almost 300 years. It was discovered in 1996, but most of the relics of colonial culture aboard its decks, such as specks of gold, glass beads, firearms and brass pins, remain hidden inside a thick crust of muddy sand and shells.

With the help of the Davidson Research Initiative, Ryan Kozlowski '16 and Professor of Physics Dan Boye hope to shed some light on those items by using their Digitome® non-destructive x-ray imaging system. Their examination of a half-dozen items from the pirate ship this month at the N.C. Department of Cultural Resources lab located at Eastern Carolina University could add to the evidence that this was indeed Blackbeard's ship.

The NC Cultural Resources department's QAR team has thus far retrieved, catalogued and stored 3,000 encrusted objects from the wreck. But the two-dimensional film x-rays of those objects they produce are not as revealing and helpful as a Digitome® inspection can be.

The Digitome® system, which was purchased by the Davidson physics department, gives students access to a cutting-edge imaging device. Professor Boye, who is managing the project, said the system has application in many liberal arts disciplines.

"Digitome Corporation wanted to see uses that may emerge when they put the Digitome® system in the hands of liberal arts students rather than engineers," Boye explained. "This is a great opportunity for us in applied physics research."

Game Changer

The way in which the Digitome® system creates a three-dimensional image of an object leads Boye to hail it as a "cross-disciplinary game changer" for Davidson. He said, "We believe we can apply Digitome® to help understand topics of interest in the humanities and social sciences as well as the sciences."

During the past school year two students learned the system and explored applications throughout the curriculum. Phillip Wall '14 created an examination of a common gaming die that vividly displayed the system's capabilities. The captured three-dimensional image began on the one-dot side of the cube. Wall then moved straight through the die until the six dots on the opposite side came into view on the screen. Through rotation and controlled movement, he revealed all the other sides of the die. "It's a graphic way to demonstrate its volumetric capability," Wall said.

Student researchers have experimented with a variety of objects in honing their examination techniques, including skulls of a baboon, a wolverine, a snapping turtle and a python. Examination of a novel Chinese ceramic wine cup revealed the internal structure of a self-priming siphon. An examination of a brittle prayer pouch from the library verified the existence of a scroll inside without having to open it.

Steven Keller '14 provided support for a project by students in an animal physiology class taught by Professor of Biology Michael Dorcas. Keller examined the rate of mouse digestion when corn snakes are kept at different environmental temperatures, and he also examined flawed welds in steel plates.

Two other students are conducting Digitome® research this summer. In preparation for work at the QAR Lab, Kozlowski has been creating high-resolution images of the nearly flat surface of coins, even when encased in over an inch of plaster. Rebecca Garner '16 is making paintings with Old World pigments to see how the system might be used to reveal artistic techniques, modifications and even underpaintings.

Three Main Parts

"Digitome® imaging can be done on a laptop," explained Kozlowski '15. The configuration at Davidson consists of three main parts. A source shoots x-rays into the cabinet. The object of the examination rests inside the cabinet on a circular plastic plate attached to the image plate. The object and image plate can be tilted and the plastic plate can be rotated to record as many as 32 different perspectives of the object, though just eight views are commonly captured. The system's proprietary software immediately assembles the different views such that any mathematically-defined contour can be viewed.

Though the Digitome® exams are most easily accomplished in the cabinet, the mounting fixture and image plate are removable and easily portable to remote locations such as a museum for off-site examination of fragile or valuable pieces. To test its portability, the team twice this spring took the system to a room-sized x-ray vault at Central Piedmont Community College. It allowed them to do a test examination with a moveable x-ray source, whereas in the past they employed a fixed source and moved the object. East Carolina University's QAR Lab, where the Davidson team is working, is also room-sized.

Davidson students are a crucial part of the Digitome® project because learning to properly use the system requires some training and experimentation, according to Kozlowski. "There are adjustments to make in frame rate, frame count, beam energy, gamma, contrast and histogram," he explained. "Another challenge is learning to view with your mind's eye an image in three dimensions rather than the usual two."

Boye will continue to enlist students to learn the system so they can handle requests from other departments and external agents. He noted that the experience and skills they develop through using Digitome® prepares them well for work with almost any imaging system, and gives them valuable experience for careers in a wide variety of fields. Last year's student assistants prove that point. Steven Keller '14 has been accepted into the UVA medical school for studies in biophysics and biomedical imaging, and Phillip Wall '14 will be pursuing graduate work in medical physics at LSU.

Agreement Breaks Ground

Digitome Corporation is a tightly held 30-year-old business that has, until now, supplied its imaging devices almost exclusively to the defense industry and government-related organizations. One of their exams was instrumental in determining the cause of the Space Shuttle Columbia disaster, and led to the solution for the return to space after the grounding of the shuttle missions. Other Digitome Corporation examinations revealed that a music stand owned by Mozart had pieces screwed together with reverse threading, that the handle of an invaluable Japanese national treasure had been modified, and that the general absence of cracks in the intricate enamel of a Ming vase resulted from expansion joints on the inside surface. An examination of a jet engine turbine blade revealed cracks that could have been dangerous.

In a unique agreement facilitated by Digitome Corporation, the college has entered into a licensing agreement to sell Digitome® systems and software to educational institutions and museums. Davidson will receive a percentage of the revenue on the sale. This is the first time Davidson has tried to set up a self-supporting, profitable entity.

"It's a new venture for Davidson," said Boye. "We received startup funds from the college to get the project rolling, but we're expecting to be self-supporting soon. Revenues we generate will go back into the project, supporting student employment and training, equipment procurement, marketing and presentation of our findings at professional meetings."

The system's portability, cost, scalability, rapid results and ability to measure any aspect of tested subjects make it comparable if not superior to other imaging techniques such as computed tomography (CT), positron electron tomography (PET), ultrasound and magnetic resonance imaging (MRI).

Boye is inviting about two dozen museum curators and academicians to attend the first comprehensive Digitome® marketing showcase, which will occur soon in Washington, D.C. Following that kickoff event, the system will be promoted online, and with demonstrations at Davidson and other locations.