Two PPPL physicists, David Johnson and Charles Skinner, named ITER Scientist Fellows
David Johnson and Charles Skinner, principal research physicists at the U.S. Department of Energy’s Princeton Plasma Physics Laboratory (PPPL), have been appointed to three-year terms as ITER Scientist Fellows. They will join a network of internationally recognized researchers who will consult with ITER, the international fusion experiment under construction in France, on plans and components for the project, which is designed to demonstrate the practicality of fusion energy.
Both physicists expressed excitement on learning of their appointments. “It’s always fun to be recognized and I am looking forward to contributing to design review activities and other areas,” Skinner said. For Johnson, the position creates a new opportunity “for forging new territory, and that can be exciting.”
The appointments, approved by ITER Director-General Bernard Bigot, bring to three the number of PPPL scientists named to the prestigious positions. PPPL Physicist Francesca Poli became an ITER Scientist Fellow last year.
Fusion, the merging of light elements that powers the sun and most stars, creates massive amounts of energy. Scientists seek to replicate fusion on Earth in a “star in a jar” for a virtually inexhaustible supply of power to generate electricity.
Johnson and Skinner, who are retiring this year, have extensive experience developing and employing diagnostic instruments to measure the behavior of the hot, charged plasma that fuels fusion reactions. Johnson, a 42-year veteran of PPPL, served as head of the PPPL diagnostics division from 1997 to 2006 and head of the laboratory’s ITER Fabrication Department from 2006 to 2015. Skinner, a 37-year veteran, conducted the first-ever measurements of tritium in the Tokamak Fusion Test Reactor (TFTR), which used the hydrogen isotope and its sister deuterium as plasma ingredients in the 1990s to generate 10 million watts of fusion power.
The two physicists have worked together on projects at PPPL and enjoy hiking trips together. (See photo.) Johnson is retiring Feb. 1; Skinner will leave in July following the biennial International Conference on Plasma-Surface Interactions in Controlled Devices that will be held in June at Princeton University. Skinner chairs the local organizing committee for the week-long event.
Here is a brief look at some of the two scientists’ PPPL achievements:
An international leader in the field of high temperature plasma diagnostics, David Johnson has contributed diagnostic measurements to major fusion devices at PPPL since 1975, with emphasis on development of what are called high-resolution Thomson scattering systems. During TFTR deuterium-tritium experiments he served as deputy head of TFTR diagnostics in charge of some 30 systems. He has managed diagnostic development for the National Spherical Torus Experiment (NSTX), which has since been upgraded, and has led development of diagnostic equipment that the United States is supplying to ITER. Since 2015 he has continued to work part-time providing technical expertise and oversight to the ITER diagnostic project.
Charles Skinner was raised in the United Kingdom, where he earned his doctorate. As a diagnostician and inventor, he developed a laser-based method for rapid tritium removal from TFTR tiles. He has also developed a detector that led to the first detection of dust during experimental operations on NSTX, and a method for assessing techniques for cleaning mirrors in optical diagnostic systems and detecting any surface damage. More recently, he has devoted attention to such activities as studying the use of boron and lithium to condition plasma-facing components. He was elected a fellow of the American Physical Society in 2013, with the APS citing his “innovations in magnetic fusion issues” and “seminal contributions” to fields ranging from x-ray lasers to plasma-lithium interactions.
PPPL, on Princeton University's Forrestal Campus in Plainsboro, N.J., is devoted to creating new knowledge about the physics of plasmas — ultra-hot, charged gases — and to developing practical solutions for the creation of fusion energy. The Laboratory is managed by the University for the U.S. Department of Energy’s Office of Science, which is the largest single 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, please visit science.energy.gov.
Princeton Plasma Physics Laboratory is a U.S. Department of Energy national laboratory managed by Princeton University.
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