Three physicists from the University of Nevada at Reno have received grants for high energy density plasma research from the Department of Energy, more awards this year than any other institution in the country under this program .
The Department of Energy has awarded $ 9.35 million to 21 institutions across the country to conduct research on high energy density laboratory plasmas. Of the 21 scholarships awarded, the University received three scholarships, the only institution in the country to receive three. Others who received funding included MIT, Princeton, Cornell, and John Hopkins University.
“It’s another feather in the hat of our high energy density plasma physics group,” said Paul Neill, chair of the physics department. âWith the Zebra Pulsed Power Lab, we are able to perform high-quality basic research experiments on-site at one of the only such university facilities in the country. “
The field of high energy density physics – the study of matter under extreme conditions of temperature and density – is a rapidly developing field that explores the fourth state of matter, called plasma, under similar conditions to those that occur inside stars, nuclear fusion reactors and lightning.
The group has carried out significant research in the university’s huge Zebra pulsed energy laboratory with its two terawatt Zebra pulsed energy generator, the Leopard laser, an ultra-intense and ultra-short hybrid laser system, and the Falcon optical compressor which modifies the beam of light before it enters the experimental chambers.
The three are: Thomas White, assistant professor of physics; Hiroshi Sawada, associate professor and expert in high intensity, short pulse laser-matter experiments; and Roberto Mancini, professor of physics and expert in atomic and radiological physics of plasmas.
Plasmas powered by intense light sources are present in many astrophysical scenarios, including accreting disks around black holes, heat absorbers, and active galactic nuclei. With the advent of the Chandra and XMM-Newton orbiting telescopes, new X-ray astronomical observations have challenged our knowledge of photoionized plasmas. Thus, laboratory experiments have become essential to guide our understanding as well as to test the interpretation of data and theoretical models.
The objective of his research is to perform experimental and theoretical / modeling studies in order to study the radiant heating, temperature and ionization of laboratory photoionized plasmas relevant to astrophysics. The majority of the experiments will be carried out using two already established platforms: a supersonic neon gas jet driven by the flow of X-rays produced during the collapse of a network of z-wires in the generator of pulsed energy Zebra from 1 mega-amphere at the University of Nevada, Reno; and a sample of expanding packed silicon foil driven by the X-ray flux produced by an array of copper cavities irradiated by the OMEGA EP laser facility at the University of Rochester Laser Energy Laboratory, also known as X-ray name “GatlingGun” the source. Experiments will also be performed at the National Ignition Facility at Lawrence Livermore National Laboratory for photoionized iron plasmas which require the large drive energy available at the NIF.
Mega-amp pulsed power generators such as Zebra at University of Nevada, Reno are an essential engine for creating high energy density states of matter. The pulsed current can compress a solid material to a high density without significant heating. The material properties of these high density, low temperature plasmas, known as hot dense matter or WDMs, are critical information in models for the interiors of giant planets and laser fusion cores. To date, diagnostics for probing high density plasmas and WDM are limited.
The objective of Sawada’s experimental program is to develop and demonstrate short-pulse laser-based diagnostics for pulsed electrically driven cylindrical compressed wires. The experiments will be conducted using both the Leopard laser and Zebra pulsed power in a joint operation. In this work, he will focus specifically on the development of high resolution x-ray radiography using wideband and monochromatic x-rays produced by laser.
This program will also help local undergraduate and graduate students gain a variety of hands-on training experiences, including participating in the experiments, collecting data, and analyzing.
He will study electron-ion equilibration in dense and quantum plasmas. White and his group will use high-resolution X-ray scattering techniques developed at the Linac coherent light source and European XFEL free electron lasers. This work will advance our understanding of out-of-equilibrium systems by making the first direct measurement of the temperature of ions inside a dense plasma.
By unambiguously determining the electron-ion equilibration rate during the solid-plasma phase transition, we will differentiate competing theoretical models in several metals where there are order of magnitude differences. By combining this temperature measurement with structural diffraction data, they will resolve the controversy surrounding the hardening of bonds in dense, hot gold. Experimental work is supported by balancing rate predictions using new advanced simulations that integrate electron dynamics within a complex framework of quantum mechanics.
The Department of Energy’s Office of Science and the National Nuclear Security Administration’s Joint Program on High Energy Density Laboratory Plasmas were created to leverage the expertise of the NNSA to manage the progress of HEDLP science within the Ministry of Energy.
âThis joint program between SC and NNSA is a great example of resource mobilization within the Department of Energy to advance discovery-driven science,â said James Van Dam, Associate Director of Science for Fusion Energy Sciences. “These projects at the frontier of high energy density plasma science also have the potential to advance industrial capabilities and homeland security in our country.”