The second seminar of the series, Thursday 25 January at 15:00 CET, is given by Yueng-Kay Martin Peng on the topic "Spherical Torus p-11B Fusion Plasma Physics Challenges and Opportunities"
Link: https://us06web.zoom.us/j/88175881905?pwd=Xo6I1o7BYmBjnT2B8bg1PN7VIsGEZA.1
Spherical Torus p-11B Fusion Plasma Physics Challenges and Opportunities
Y.-K.M. Peng1 on behalf of the ENN Fusion Technology Research and Collaboration Team1
Abstract:
Research toward commercial p-11B fusion power in a Spherical Torus (ST) takes advantage of the aneutronic reaction to permit a slender toroidal field coil center-post, and retain high performance, compact size and modular design. Challenges to be overcome include non-inductive plasma sustainment, reaching beyond 100keV plasma temperatures, sufficient densities for adequate fusion power, and high energy confinement times while limiting the Bremsstrahlung radiation loss to sustain fusion burn.
A mid-size ST p-B experiment, EXL-50, operated during 2019-2023 to explore the physics of ECRH current initiation, ramp-up, heating and sustainment without a central solenoid. Progress in physics basis included an improved equilibrium model for p-B plasmas including a low- density supra-thermal electron component to reproduce the observed plasma parameters. Under ECRH power only, the plasma exhibited transitions to a quiescent state (see, Figure), promising improved ST turbulence and confinement of increased parameters under strong auxiliary heating.
New physics behaviors are hereby expected for such plasmas regarding equilibrium; supra-thermal particle kinetics; macroscopic stability; neoclassical transport; microscopic turbulence and transport including boron isotope effects; heating and current drive via ECRH, ICRH, NBI and the fusion alphas; and plasma-material interactions of limiter and divertor surfaces involving copious boron fueling. A new p-11B physics scenario is needed to ignite the plasma while allowing a centralized fusion a heating to far exceed the local Bremsstrahlung radiation and transport losses, in open, thermally un-equilibrated plasma system model.
An EXL-50U open research platform is being commissioned in Winter 2024 to test the p-B plasma properties at ³0.5MA current, several-keV central temperatures, and ~1020/m3 central densities, providing opportunities for investigating these new physics issues. An EHL-2 platform will follow to achieve substantial p-11B fusion reactions in plasmas of 3MA current and 3T toroidal field at 1.05m major radius.
[1] http://ennresearch.com/researchfield/Compactfusion/; [2] https://step.ukaea.uk/; [3] https://tokamakenergy.com.
A self-organized transition from a turbulent state (left, 1.18s, 28 + 50GHz, ~250kW) to a quiescent state (right, 1.80-1.90s, 50GHz, ~100kW) of the EXL-50 ECRH-only p-B plasma under boron powder fueling with Ip ~ 100kA and nel ~ 1.5´1018/m2.
Speaker:
Dr. Yueng-Kay Martin Peng, a graduate of Stanford University in the USA, is a renowned scientist in the field of magnetically confined fusion research. He is the proponent of the Spherical Torus (also known as Spherical Tokamak) magnetic confinement concept, has dedicated 40 years to fusion energy technology development at the Oak Ridge National Laboratory in the USA, and has served as the director of the National Spherical Torus Experiment Program at the Princeton Plasma Physics Laboratory. He has published over 200 papers in international journals, conference proceedings, and laboratory reports. Dr. Peng held for 2013 visiting professorships at the University of Tokyo in Japan, and for 2015-2017 at the University of Science and Technology of China. As the Chief Scientist for Fusion at the ENN Energy Research Institute since 2019, he has dedicated his R&D efforts to commercialize p-B11 fusion energy of the spherical torus configuration.
