What matters to a new assistant research professor in nuclear engineering

Author: Gina Vozenilek
Scientists theorize that the visible universe is composed of more than 99 percent plasma, the fourth state of matter after the triumvirate of solid, liquid, and gas. But one new research assistant professor in nuclear engineering, Sivanandan Harilal, is 100 percent focused on understanding the basic science of plasma and finding ways to make plasmas work for the world outside the laboratory.

Sivanandan HarilalHarilal has worked all over the globe himself. He received his degree in physics from Cochin University in Cochin, India, in 1998, and became the Alexander Humboldt fellow at Ruhr Universitat in Bochum, Germany, where he continued his pursuit of plasma. He came to the United States via the University of California, San Diego and later as a visiting scientist at Argonne National Laboratory.

Harilal even worked a short while in the world of industry, developing X-ray and extreme ultraviolet (EUV) sources from laser-produced plasmas as chief scientist at Hyperion Scientific in Madison, Wisconsin. He came to Purdue in January, drawn to “a well-known university where academic and research environments are excellent.” In the laboratory, nuclear engineers like Harilal create plasma using intense lasers. “Our focus at Purdue,” Harilal explains, “is to utilize this laser-produced plasma for practical applications.”

One such use for laser-produced plasma is EUV lithography. As current optical lithographic technology for creating semiconductor chips approaches its physical limit, it will soon become impossible to create computers
that are any faster or more cost-competitive. Manufacturers of semiconductor chips are hoping to implement EUV lithography by the year 2012, which will require the development of a reliable high-power light source of just the right wavelength (13.5 nm). The answer, Harilal believes, lies in plasma.

Harilal is also working on a plasma application for the medical industry. Biomedical researchers and cell biologists stand to benefit from a new kind of imaging called water window transmission X-ray microscopy (WW-TXM). A microscope operating in the so-called water window wavelength range (2.3-4.4 nm) provides high resolution and large depth of focus, enabling valuable three-dimensional imaging. Microscopy at this level uses a strong natural contrast between water and carbon-rich tissues such as proteins and lipids. Harilal aims to develop a patentable table-top WW-TXM microscope using laser-produced plasma as a safe and reliable light source.

Keeping the population safe from the threat of nuclear terrorism is another of Harilal’s concerns, so he and his colleagues are working on laser-induced breakdown spectroscopy (LIBS). “[The Department of] Homeland Security likes this technology,” explains Harilal, noting that current applications of gamma rays and alpha-particles provide insufficient screening modalities.

“Unfortunately, we’ve got to be thinking about nuclear bombs in a bag,” he says. The LIBS technique uses a single pulse of energy directed at the material in question, and the light emitted from the plasma plume is collected and analyzed with a spectrograph. “We will create a LIBS database of quantitative information for nuclear materials,” proposes Harilal. “The expected outcome of the project is a highly sensitive LIBS sensor capable of detecting traces of radioactive materials.”

Although relatively new to Purdue, Harilal is already feeling at home. He likes his new colleagues, whom he describes succinctly as “really cool,” and he is happy with the small-town feel of West Lafayette. “The winters are better than in Madison, too,” he points out. So is the academic environment; his laboratory research keeps him plugged into many practical advances in industry, science, and technology.

“I am also expanding my research fields to colliding plasmas, plasma diagnostics, and surface and interfacial science,” he says. It seems for this researcher, Purdue is not only a comfortable place to work. It is also a good place to grow.