Beecroft Building, Department of Physics, University of Oxford, Parks Road, Oxford, OX1 3PU
Professor Farhat Beg, University of California, San Diego
Abstract
Proton fast ignition (PFI) is an alternative inertial confinement fusion (ICF) concept that promises
high gain suitable for inertial fusion energy applications. In this concept, a short-pulse, highintensity laser is used to generate an energetic proton beam that efficiently couples’ energy into a
pre-compressed fuel assembly. This enables ignition conditions to be reached with less stringent
symmetry and driver energy requirements than in the conventional hot-spot approach.
We report on the first integrated PFI campaign at the Omega Laser Facility that included both the
compression and ignition phases to measure the temperature increase in the compressed core due
to proton heating. In the recent experiment, we increased the short-pulse laser intensity by a factor
of 6 and observed a 3× improvement in the proton maximum cutoff energy and a 6× enhancement
in the yield of >10 MeV protons that primarily heat the core. X-ray spectroscopy data reveal
dominant Heα and Heβ features consistent with heating of the compressed core. Implosion
trajectories obtained from radiation-hydrodynamics simulations agree well with experiments and
indicate an implosion velocity of approximately 70 km/s for an implosion energy of 10 kJ. A
detailed comparison of the measured implosion trajectories, velocities, and proton energy spectra
with radiation-hydrodynamics and PIC simulations will be presented.
Experiments were conducted at the Omega Laser Facility with beam time through the NLUF user program. Material
is based upon work supported by the Department of Energy [NNSA] University of Rochester “National Inertial
Confinement Fusion Program” under Award Number(s) DE-NA0004144. Work was also performed under the
auspices of the U.S. Department of Energy by General Atomics under NNSA Contract 89233124CNA000365 and
was supported by the U.S. Department of Energy, Office of Science, Office of Fusion Energy Sciences, under the IFESTAR program through the STARFIRE grant DOE-SCW1835.
[1] J.C. Fernandez et al., “Fast ignition with laser-driven proton and ion beams,” Nucl. Fusion 49,
065004 (2009).
Bio: Prof. F. N. Beg
Farhat Beg is a Shao-Chi and Lily Lin Chancellor’s Endowed Chair in Engineering Science at the
Department of Mechanical and Aerospace Engineering. His expertise is in the field of laser plasma
interaction, inertial confinement fusion, inertial fusion energy, pulsed power-driven Z-pinches, and
neutron sources. He has published over 300 papers in refereed journals, including Nature, Nature
Physics, Nature Photonics and Physical Review Letters, with total citations exceeding 10,000 with
and H-index of 55, according to the Web of Science. He is the fellow of the American Physical
Society, Institute of Electrical and Electronics Engineers (IEEE) and the American Association for
the Advancement of Science. He has been a winner of the Department of Junior Faculty Award
(2005) and IEEE Early Career Award (2008). He was the recipient of the Plasma Science and
Applications Committee (PSAC) Award by the IEEE in 2021 for his outstanding contributions on
both laser- and Z-pinch-driven plasma physics including energetic particle production, ultra-high
magnetic field generation and formation of well diagnosed high energy density plasmas.