Alumnus' Diagnostic Research Earns Cover Spot

Tuesday, February 7, 2017

Research from a Department of Energy National Nuclear Security Administration Stewardship Science Graduate Fellowship (DOE NNSA SSGF) recipient provided the featured cover image for a recent American Institute of Physics journal.

The November 2016 AIP Review of Scientific Instruments (from the Proceedings of the 21st Topical Conference on High-Temperature Plasma Diagnostics) displayed X-ray radiograph images captured by Hong Sio’s Particle X-ray Temporal Diagnostic (PXTD) instrument. Sio, A DOE NNSA SSGF recipient from 2012 to 2016, developed the tool as part of his doctoral thesis work at the Massachusetts Institute of Technology.

The PXTD measures nuclear products and X-rays produced in inertial confinement fusion (ICF) and high energy density plasma experiments. In indirect-drive ICF, powerful lasers generate X-rays that crush a sphere about the size of a pea. The capsule is filled with a frozen mixture of two hydrogen isotopes, deuterium and tritium. If all goes well, the X-rays squeeze the isotopes so tightly their nuclei fuse, releasing tremendous energy. A similar process, on a grand scale, fuels the sun and other stars.

Review of Scientific Instruments cover, November 2016

The PXTD is designed to help understand what’s happening in ICF and similar experiments. In research on the OMEGA laser facility at the University of Rochester, PXTD took time-resolved, high-precision measurements of multiple products from nuclear reactions happening in the target. The diagnostic simultaneously measured X-rays the target emitted over time.

The instrument, Sio wrote in the journal article, has precision measured in tens of picoseconds (10-11 seconds) between the nuclear and X-ray signals. It allows, for the first time, accurate and simultaneous measurement of the peak X-ray emission time and peak nuclear production time, their time differences, and other experimental properties.

Sio was invited to present the paper at the high-temperature plasma diagnostics conference in June 2016 at Madison, Wisconsin. Sio also will make a presentation on the diagnostic and associated data analysis at NNSA headquarters in Washington on May 9. His doctoral advisor is Richard Petrasso.