scholarly journals Whole-beam self-focusing in fusion-relevant plasma

2020 ◽  
Vol 379 (2189) ◽  
pp. 20200159 ◽  
Author(s):  
B. T. Spiers ◽  
M. P. Hill ◽  
C. Brown ◽  
L. Ceurvorst ◽  
N. Ratan ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Hot Spot ◽  
Fusion Energy ◽  
Three Dimensional ◽  
High Gain ◽  
Fast Ignition ◽  
Intense Laser ◽  
Inertial Confinement ◽  
Proton Radiography ◽  
Self Focusing

Fast ignition inertial confinement fusion requires the production of a low-density channel in plasma with density scale-lengths of several hundred microns. The channel assists in the propagation of an ultra-intense laser pulse used to generate fast electrons which form a hot spot on the side of pre-compressed fusion fuel. We present a systematic characterization of an expanding laser-produced plasma using optical interferometry, benchmarked against three-dimensional hydrodynamic simulations. Magnetic fields associated with channel formation are probed using proton radiography, and compared to magnetic field structures generated in full-scale particle-in-cell simulations. We present observations of long-lived, straight channels produced by the Habara–Kodama–Tanaka whole-beam self-focusing mechanism, overcoming a critical barrier on the path to realizing fast ignition. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 2)’.

scholarly journals Collisionless shock acceleration in the corona of an inertial confinement fusion pellet with possible application to ion fast ignition

2020 ◽  
Vol 379 (2189) ◽  
pp. 20200039 ◽  
Author(s):  
E. Boella ◽  
R. Bingham ◽  
R. A. Cairns ◽  
P. Norreys ◽  
R. Trines ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Fusion Energy ◽  
Critical Density ◽  
High Gain ◽  
Fast Ignition ◽  
Intense Laser ◽  
Shock Acceleration ◽  
Inertial Confinement ◽  
Collisionless Shock ◽  
Confinement Fusion

Two-dimensional particle-in-cell simulations are used to explore collisionless shock acceleration in the corona plasma surrounding the compressed core of an inertial confinement fusion pellet. We show that an intense laser pulse interacting with the long scale-length plasma corona is able to launch a collisionless shock around the critical density. The nonlinear wave travels up-ramp through the plasma reflecting and accelerating the background ions. Our results suggest that protons with characteristics suitable for ion fast ignition may be achieved in this way. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 2)’.

scholarly journals Observation of a high degree of stopping for laser-accelerated intense proton beams in dense ionized matter

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Jieru Ren ◽  
Zhigang Deng ◽  
Wei Qi ◽  
Benzheng Chen ◽  
Bubo Ma ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Dominant Role ◽  
Dense Matter ◽  
High Energy ◽  
Fast Ignition ◽  
High Energy Density ◽  
Intense Laser ◽  
High Yield ◽  
Inertial Confinement ◽  
Proton Beams

Abstract Intense particle beams generated from the interaction of ultrahigh intensity lasers with sample foils provide options in radiography, high-yield neutron sources, high-energy-density-matter generation, and ion fast ignition. An accurate understanding of beam transportation behavior in dense matter is crucial for all these applications. Here we report the experimental evidence on one order of magnitude enhancement of intense laser-accelerated proton beam stopping in dense ionized matter, in comparison with the current-widely used models describing individual ion stopping in matter. Supported by particle-in-cell (PIC) simulations, we attribute the enhancement to the strong decelerating electric field approaching 1 GV/m that can be created by the beam-driven return current. This collective effect plays the dominant role in the stopping of laser-accelerated intense proton beams in dense ionized matter. This finding is essential for the optimum design of ion driven fast ignition and inertial confinement fusion.

scholarly journals Prospects for high gain inertial fusion energy: an introduction to the first special edition

2020 ◽  
Vol 378 (2184) ◽  
pp. 20200006 ◽  
Author(s):  
P. A. Norreys ◽  
C. Ridgers ◽  
K. Lancaster ◽  
M. Koepke ◽  
G. Tynan
Keyword(s):  
Inertial Confinement Fusion ◽  
Fusion Energy ◽  
High Gain ◽  
Inertial Fusion ◽  
Inertial Fusion Energy ◽  
Inertial Confinement ◽  
Energy Part ◽  
Confinement Fusion ◽  
Alternative Approaches ◽  
Basic Studies

A European consortium of 15 laboratories across nine nations have worked together under the EUROFusion Enabling Research grants for the past decade with three principle objectives. These are: (a) investigating obstacles to ignition on megaJoule-class laser facilities; (b) investigating novel alternative approaches to ignition, including basic studies for fast ignition (both electron and ion-driven), auxiliary heating, shock ignition etc.; and (c) developing technologies that will be required in the future for a fusion reactor. The Hooke discussion meeting in March 2020 provided an opportunity to reflect on the progress made in inertial confinement fusion research world-wide to date. This first edition of two special issues seeks to identify paths forward to achieve high fusion energy gain. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

scholarly journals Intense light-ion beams provide a robust, common-driver path toward ignition, gain, and commercial fusion energy

1993 ◽  
Vol 11 (2) ◽  
pp. 423-430 ◽  
Author(s):  
J.J. Ramirez ◽  
D.L. Cook ◽  
J.K. Rice ◽  
M.K. Matzen ◽  
D.L. Johnson ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Ion Beam ◽  
Fusion Energy ◽  
Particle Beam ◽  
High Gain ◽  
Ion Beams ◽  
High Yield ◽  
Inertial Confinement ◽  
Design Concepts ◽  
Intense Light

Intense light-ion beams are being developed for investigations of inertial confinement fusion (ICF). This effort has concentrated on developing the Particle Beam Fusion Accelerator II (PBFA II) at Sandia as a driver for ICF target experiments, on design concepts for a high-yield, high-gain Laboratory Microfusion Facility (LMF), and on a comprehensive system study of a light-ion beam-driven commercial fusion reactor (LIBRA). This article reports on the status of design concepts and research in these areas.

scholarly journals Generation of shock waves in dense plasmas by high-intensity laser pulses

Nukleonika ◽  
2015 ◽  
Vol 60 (2) ◽  
pp. 193-198 ◽  
Author(s):  
John Pasley ◽  
I. A. Bush ◽  
Alexander P. L. Robinson ◽  
P. P. Rajeev ◽  
S. Mondal ◽  
...  
Keyword(s):  
Shock Waves ◽  
Laser Plasma ◽  
Inertial Confinement Fusion ◽  
Laser Pulses ◽  
Fast Ignition ◽  
Intense Laser ◽  
Inertial Confinement ◽  
Relative Significance ◽  
Wide Range ◽  
Confinement Fusion

Abstract When intense short-pulse laser beams (I > 1022 W/m2, τ < 20 ps) interact with high density plasmas, strong shock waves are launched. These shock waves may be generated by a range of processes, and the relative significance of the various mechanisms driving the formation of these shock waves is not well understood. It is challenging to obtain experimental data on shock waves near the focus of such intense laser–plasma interactions. The hydrodynamics of such interactions is, however, of great importance to fast ignition based inertial confinement fusion schemes as it places limits upon the time available for depositing energy in the compressed fuel, and thereby directly affects the laser requirements. In this manuscript we present the results of magnetohydrodynamic simulations showing the formation of shock waves under such conditions, driven by the j × B force and the thermal pressure gradient (where j is the current density and B the magnetic field strength). The time it takes for shock waves to form is evaluated over a wide range of material and current densities. It is shown that the formation of intense relativistic electron current driven shock waves and other related hydrodynamic phenomena may be expected over time scales of relevance to intense laser–plasma experiments and the fast ignition approach to inertial confinement fusion. A newly emerging technique for studying such interactions is also discussed. This approach is based upon Doppler spectroscopy and offers promise for investigating early time shock wave hydrodynamics launched by intense laser pulses.

Deuteron Beam Driven Fast Ignition

2010 ◽  
Author(s):  
Xiaoling Yang ◽  
George H. Miley ◽  
Kirk A. Flippo ◽  
Henrich Hora
Keyword(s):  
Inertial Confinement Fusion ◽  
Traditional Approach ◽  
Hot Spot ◽  
Cluster Structure ◽  
Deuteron Beam ◽  
High Energy ◽  
Fast Ignition ◽  
Proton Flux ◽  
Intense Laser ◽  
Laser Generation

Fast Ignition is recognized as the most promising approach to achieving the high energy gain target performance needed for commercial inertial confinement fusion (ICF). However, there are great difficulties related to the traditional approach of generating a relativistic electron beam and then focusing it on the hot “spark” region (hot spot) of the compressed target. One promising alternate approach that has been proposed by researchers at LLNL and LANL is the laser generation of a proton beam in an “interaction foil” to ignite the target. However, the total proton flux supplied from hydrogen adsorbed on the foil surface is too small to generate the desired proton flux threshold. In more recent studies it has been found that ions heavier than protons would provide better focusing on the hot spot if ways to efficiently generate them can be found. Here we propose to utilize a new “Deuterium Cluster ”type structure as the laser interaction foil to generate an energetic deuteron beam as the fast igniter. The ultra high density deuterium in the cluster structure promises much higher total flux for deuterons than for traditional protons. Also, deuterons will serve very important dual purposes — the deuteron deposition in the target hot spot will not only provide heating but also fuse with fuel as they slow down in the target. The resulting fusion alphas serve to provide added heating, reducing the input requirement. If the physics works as anticipated, this novel type of interaction foil can efficiently generate energetic deuterons during intense laser pulses. The massive yield of deuterons generated from our cluster material through laser acceleration, should turn out to be the most efficient way of FI of the DT fuel, and making the dream of near-term commercialization of FI fusion more achievable.

scholarly journals Modelling burning thermonuclear plasma

2020 ◽  
Vol 378 (2184) ◽  
pp. 20200014 ◽  
Author(s):  
S. J. Rose ◽  
P. W. Hatfield ◽  
R. H. H. Scott
Keyword(s):  
Quantum Electrodynamics ◽  
Inertial Confinement Fusion ◽  
Fusion Energy ◽  
High Gain ◽  
Big Bang ◽  
Inertial Confinement ◽  
Energy Part ◽  
Confinement Fusion ◽  
The Usa ◽  
The Big Bang

Considerable progress towards the achievement of thermonuclear burn using inertial confinement fusion has been achieved at the National Ignition Facility in the USA in the last few years. Other drivers, such as the Z-machine at Sandia, are also making progress towards this goal. A burning thermonuclear plasma would provide a unique and extreme plasma environment; in this paper we discuss (a) different theoretical challenges involved in modelling burning plasmas not currently considered, (b) the use of novel machine learning-based methods that might help large facilities reach ignition, and (c) the connections that a burning plasma might have to fundamental physics, including quantum electrodynamics studies, and the replication and exploration of conditions that last occurred in the first few minutes after the Big Bang. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

Three-dimensional electromagnetic relativistic particle-in-cell code VLPL (Virtual Laser Plasma Lab)

1999 ◽  
Vol 61 (3) ◽  
pp. 425-433 ◽  
Author(s):  
A. PUKHOV
Keyword(s):  
Laser Plasma ◽  
Inertial Confinement Fusion ◽  
Three Dimensional ◽  
Inertial Confinement ◽  
Particle In Cell ◽  
Laser Plasma Interactions ◽  
Electromagnetic Simulations ◽  
Self Focusing ◽  
Confinement Fusion ◽  
Pic Code

The three-dimensional particle-in-cell (PIC) code VLPL (Virtual Laser Plasma Lab) allows, for the first time, direct fully electromagnetic simulations of relativistic laser–plasma interactions. Physical results on relativistic self-focusing in under-dense plasma are presented. It is shown that background plasma electrons are accelerated to multi-MeV energies and 104 T magnetic fields are generated in the process of self-focusing at high laser intensities. This physics is crucial for the fast ignitor concept in inertial confinement fusion. Advances in the numerical PIC algorithm used in the code VLPL are reviewed here.

scholarly journals Double-cone ignition scheme for inertial confinement fusion

2020 ◽  
Vol 378 (2184) ◽  
pp. 20200015 ◽  
Author(s):  
J. Zhang ◽  
W. M. Wang ◽  
X. H. Yang ◽  
D. Wu ◽  
Y. Y. Ma ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Energy Requirement ◽  
Fusion Energy ◽  
Laser Pulses ◽  
High Gain ◽  
Double Cone ◽  
Inertial Confinement ◽  
Fast Heating ◽  
Isentropic Compression ◽  
Confinement Fusion

While major progress has been made in the research of inertial confinement fusion, significant challenges remain in the pursuit of ignition. To tackle the challenges, we propose a double-cone ignition (DCI) scheme, in which two head-on gold cones are used to confine deuterium–tritium (DT) shells imploded by high-power laser pulses. The scheme is composed of four progressive controllable processes: quasi-isentropic compression, acceleration, head-on collision and fast heating of the compressed fuel. The quasi-isentropic compression is performed inside two head-on cones. At the later stage of the compression, the DT shells in the cones are accelerated to forward velocities of hundreds of km s –1 . The head-on collision of the compressed and accelerated fuels from the cone tips transfer the forward kinetic energy to the thermal energy of the colliding fuel with an increased density. The preheated high-density fuel can keep its status for a period of approximately 200 ps. Within this period, MeV electrons generated by ps heating laser pulses, guided by a ns laser-produced strong magnetic field further heat the fuel efficiently. Our simulations show that the implosion inside the head-on cones can greatly mitigate the energy requirement for compression; the collision can preheat the compressed fuel of approximately 300 g cm −3 to a temperature above keV. The fuel can then reach an ignition temperature of greater than 5 keV with magnetically assisted heating of MeV electrons generated by the heating laser pulses. Experimental campaigns to demonstrate the scheme have already begun. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)’.

scholarly journals Inertial confinement fusion: a defence context

2020 ◽  
Vol 378 (2184) ◽  
pp. 20200012 ◽  
Author(s):  
Andrew Randewich ◽  
Rob Lock ◽  
Warren Garbett ◽  
Dominic Bethencourt-Smith
Keyword(s):  
Inertial Confinement Fusion ◽  
High Performance ◽  
Fusion Energy ◽  
High Gain ◽  
High Energy ◽  
High Energy Density ◽  
Inertial Confinement ◽  
Science And Engineering ◽  
Confinement Fusion ◽  
The Uk

Almost 30 years since the last UK nuclear test, it remains necessary regularly to underwrite the safety and effectiveness of the National Nuclear Deterrent. To do so has been possible to date because of the development of continually improving science and engineering tools running on ever more powerful high-performance computing platforms, underpinned by cutting-edge experimental facilities. While some of these facilities, such as the Orion laser, are based in the UK, others are accessed by international collaboration. This is most notably with the USA via capabilities such as the National Ignition Facility, but also with France where a joint hydrodynamics facility is nearing completion following establishment of a Treaty in 2010. Despite the remarkable capability of the science and engineering tools, there is an increasing requirement for experiments as materials age and systems inevitably evolve further from what was specifically trialled at underground nuclear tests (UGTs). The data from UGTs will remain the best possible representation of the extreme conditions generated in a nuclear explosion, but it is essential to supplement these data by realizing new capabilities that will bring us closer to achieving laboratory simulations of these conditions. For high-energy-density physics, the most promising technique for generating temperatures and densities of interest is inertial confinement fusion (ICF). Continued research in ICF by the UK will support the certification of the deterrent for decades to come; hence the UK works closely with the international community to develop ICF science. UK Ministry of Defence © Crown Owned Copyright 2020/AWE. This article is part of a discussion meeting issue ‘Prospects for high gain inertial fusion energy (part 1)'.

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