Anirudha "Ani" Sumant has earned a research hat trick with his recent win of a TechConnect Innovation Award. This is the third year in a row that Sumant, a researcher at the U.S. Department of Energy's (DOE) Argonne National Laboratory, has received this honor.
Presented on May 14, 2018, at TechConnect's annual World Innovation Conference and Expo, the award recognizes Sumant's work on nitrogen-incorporated ultrananocrystalline diamonds [(N)UNCDs] for application as a portable electron source in field emission cathodes.
The technology was developed in partnership with Euclid Techlabs under the DOE Technology Commercialization project to create a superior field emission electron source for use in linear accelerators, or linacs, outpacing photoemission and thermionic emission technologies. Euclid, an R&D company specializing in conventional, dielectric and superconducting RF accelerators, has a long history of successful collaboration with Argonne.
With this technology, a thin film inserted into a cathode cartridge, (N)UNCD distinguishes itself through its ability to increase stability and output emission current, and reduce costs by eliminating microfabrication processes, explained Sumant, a nanoscientist in Argonne's Nanoscience and Technology division.
Beyond its development for linacs, the technology has prospective applications ranging from medical diagnostics and security to semiconductor fabrication.
"I think one of the things that make Ani a successful candidate for these awards is his development as a well-renowned expert in the novel nano-carbon space," said John Harvey, a business development executive in Argonne's Technology Commercialization and Partnerships division. "He's always thinking about the customers in that space, and reconfiguring tried technologies to suit new applications."
Sumant's interest in creating electrically conducting diamonds began in 1998, during his postdoctoral fellowship at Argonne. Through those studies, Sumant and his colleagues established that nitrogen likes to sit at the grain boundaries rather than in the diamond lattice, providing good electrical conductivity and field emission properties.
This configuration, he later found, helps increase a local electric field, allowing electrons to escape into an accelerator's vacuum chamber more easily. It also proved a key point in differentiating the technology from other diamond films.
The conventional method was to fabricate sharp tips in order to enhance local electric field for more efficient release of electrons. Sumant's team found that using a planar geometry worked equally well for the technology and dramatically reduced microfabrication time and costs in the process.
"That was a major breakthrough, and once we established that, it simplified everything," said Sumant. "Since the field is not concentrated at one point, the configuration reduces thermal load and does not result in the degradation of the emitting sites, which ultimately leads to stable field emissions for extended periods."
In fact, the technology has demonstrated 1,000 hours of continuous field emission stability, more than any other diamond yet.
These were the types of features that Euclid was looking for when it collaborated with Sumant's team in further developing a technology that allows linac operators to easily replace existing emission sources with a plug-in field emission cathode. Euclid designed and fully commissioned a field emission imager to determine the actual field emission distribution on cathode surfaces, an innovation that will speed up UNCD cathode development.
Successfully testing their cathode in the Argonne Wakefield electron accelerator, the Argonne-Euclid team also developed and demonstrated its use as a field emitter cartridge for miniature high-gradient radio frequency X-band electron injectors.
Harvey points to its potential use in the localized production of radioisotopes for medical diagnostics and theranostics, and in providing a more consistent and cost-effective means of producing computer chips through lithography.
Sumant sees the technology playing a role in national security as well. Useful anywhere an efficient electron source is required, it can be used in electron accelerators for medical sterilization technologies or in portable X-ray scanners for airports and naval dock security.
The team has published several papers and holds one granted patent on this technology. Part of the work was funded under an award from the DOE Technology Commercialization Fund, with collaboration between Argonne and Euclid.
"This collaboration between Ani and our company has set the pace and the bar for the development of UNCD cathodes. The possibilities for this technology are far-reaching and well-deserving of the TechConnect award," said Euclid's president and CEO Alexei Kanareykin.
The TechConnect World Innovation Conference and Expo provides an opportunity for inventors to present their work to potential funders and commercial partners. The TechConnect Innovation Awards select the top 15 percent of early-stage innovations submitted from around the world through an industry-review process.
Past TechConnect awards have recognized Sumant's work in nanodiamond-graphene technology for superlubricity (2016) and in developing a time- and cost-effective method for creating wafer-scale graphene films (2017).
Argonne National Laboratoryseeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.
The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit the Office of Science website.