In many respects you could say SLAC National Accelerator Laboratory scientist Riti Sarangi grew up at the lab.
From 2001 to 2007 she used the facility while pursuing a PhD in chemistry at Stanford, where she had come after completing her undergraduate studies in India. Her interest in science, though, was sparked early in life.
“My father taught physics before he went into government work, and I grew up asking questions about everything,” she said. “I’d also fix things and perform flame tests on my mom’s stove. It just came naturally — always doing a little chemistry. Plus, in India, people view STEM [science, technology, engineering, medicine] jobs as more secure in the future.”
As a member of the Stanford Synchrotron Radiation Lightsource group of scientists, Riti drew on her expertise in sulfur spectroscopy to study material found on a Tudor ship, the Mary Rose, that sunk in 1545 and was excavated in 1982.
“What was really cool was that there were a lot of everyday things found on the ship, like grooming materials, clothes and medicine,” she said. “It was a kind of time capsule into a picture of an every day man’s life. In that respect, it was very cultural.”
Many of the artifacts were made of wood, and, about 20 years post excavation, yellow deposits started to appear. “Some scientists were doing research on another ship in Stockholm,” Riti said. “What they found was a large amount of a sulfur compound. Our task was to find out what it was, where is it coming from, and why is it degrading the wood.”
Riti and her fellow SLAC scientists found that sulfuric acid was being generated.
“Mary Rose was a warship and it has all sorts of iron metal, but there wasn’t any oxygen where the ship had been resting in the ocean,” she explained. “The iron and sulfur (brought by bacteria) stayed that way as along as it was under water.”
“Now we’re looking in treatment options. We’re taking calcium carbonate particles — basically limestone — grinding it up and spraying it on the wood. We’re testing it on some of the smaller artifacts.”
Riti says she enjoys her role at SLAC because “you are constantly challenging yourself to find answers about fundamental processes of life and earth.”
“The government is spending millions of dollars on these instrumenta for us to answer big questions in science,” she said. “And I’m lucky enough to be using them. Even working at a Department of Energy lab, you are independent research, you are a free thinker. That’s what’s really important to scientists.”
Photo by Scott R. Kline