scholarly journals Short pulse interaction experiments for fast ignitor applications

2000 ◽  
Vol 18 (3) ◽  
pp. 389-397 ◽  
Author(s):  
M. BORGHESI ◽  
A.J. MACKINNON ◽  
R. GAILLARD ◽  
G. MALKA ◽  
C. VICKERS ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Short Pulse ◽  
Laser Pulses ◽  
Inertial Confinement ◽  
Laser Plasma Interaction ◽  
Fast Ignitor ◽  
Underdense Plasmas ◽  
Confinement Fusion ◽  
Electron Propagation ◽  
Series Of Experiments

A detailed investigation of many aspects of the physics of laser–plasma interaction at very high laser intensities is required in order to assess the feasibility and the promise of the fast ignitor scheme for inertial confinement fusion. Relevant results, obtained in a series of experiments carried out at the Rutherford Appleton Laboratory, Chilton (UK) and at the Centre d'Etudes Atomique, Limeil Valenton (France), are presented and discussed here. In particular, the formation of plasma channels was observed following the propagation of relativistically intense, ps laser pulses through underdense plasmas. The channels persist long after the interaction, and their expansion has been measured. Efficient guiding of ultraintense laser pulses, both through preformed density channels and through solid guides, has been demonstrated. Finally, indication of collimated fast electron propagation through solid targets has been obtained from the observation of filamentary ionization tracks in laser irradiated solid targets.

scholarly journals An overview of Aurora: a multi-kilojoule KrF laser system for inertial confinement fusion

1986 ◽  
Vol 4 (1) ◽  
pp. 55-70 ◽  
Author(s):  
Louis A. Rosocha ◽  
Pleas S. Bowling ◽  
Michael D. Burrows ◽  
Michael Kang ◽  
John Hanlon ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Large Scale ◽  
Short Pulse ◽  
Laser System ◽  
Laser Pulses ◽  
Inertial Confinement ◽  
Laser Amplifiers ◽  
Krf Laser ◽  
Confinement Fusion ◽  
Laser Systems

Aurora is a short-pulse high-power krypton-fluoride laser system that serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems of interest for short wavelength inertial confinement fusion (ICF) studies. The system is designed to employ optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers to deliver 248 nm, 5-ns duration multi-kilojoule laser pulses to ICF targets using a beam train of approximately 1 km in length.In this paper, we will discuss the goals for the system and summarize the design features of the major system components: front-end lasers, amplifier train, optical train, and the alignment and controls systems.

scholarly journals Fast electron propagation and energy deposition in laser shock compressed plasmas

1999 ◽  
Vol 17 (3) ◽  
pp. 519-528 ◽  
Author(s):  
A. BERNARDINELLO ◽  
D. BATANI ◽  
V. MASELLA ◽  
T.A. HALL ◽  
S. ELLWI ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Intense Laser ◽  
Inertial Confinement ◽  
Hot Electron ◽  
Fast Electrons ◽  
Fast Ignitor ◽  
Confinement Fusion ◽  
Laser Facility ◽  
Chirped Pulse Amplification ◽  
Electron Propagation

The first experimental study of the propagation of electrons created by an intense laser in shock-compressed matter has been performed with the VULCAN laser facility at the Rutherford Appleton Laboratory, to investigate one of the fundamental phases of the fast ignitor concept for inertial confinement fusion. Plastic plane targets were irradiated on one side with two pulsed laser beams, each with I ≈ 1014 W/cm2, t ≈ 2 ns, E ≈ 80 J per pulse, to generate a planar shock wave; on the opposite side of the target, a chirped pulse amplification (CPA) laser beam (I ≈ 1016 W/cm2, t ≈ 3 ps, E ≈ 10 J) was focused to generate the fast electrons. The results show an increase of hot electron penetration in compressed matter with respect to an ordinary one. Experimental results have been analyzed with computer simulations.

Single-event high-compression inertial confinement fusion at low temperatures compared with two-step fast ignitor

2003 ◽  
Vol 69 (5) ◽  
pp. 413-429 ◽  
Author(s):  
H. HORA ◽  
G. H. MILEY ◽  
F. OSMAN ◽  
P. EVANS ◽  
P. TOUPS ◽  
...  
Keyword(s):  
Solid State ◽  
Inertial Confinement Fusion ◽  
Laser Pulses ◽  
High Gain ◽  
State Density ◽  
Inertial Confinement ◽  
Single Event ◽  
Fast Ignitor ◽  
Confinement Fusion ◽  
Volume Ignition

Compression of plasmas with laser pulses in the 10-kJ range produced densities in the range of 1000 times that of the solid state, where however the temperatures within a few hundred eV were rather low. This induced the fast ignitor scheme for central or peripheral deposition of some 10-kJ ps laser pulses on conventional $n_{\rm s}$-precompressed DT plasma of 3000 times solid-state density. We present results where the ps ignition is avoided and only a single-event conventional compression is used. Following our computations of volume ignition and the excellent agreement with measured highest fusion gains of volume compression, we found conditions where compression to 5000 times that of the solid state and by using laser pulses of 10 MJ produce volume ignition with temperatures between 400 and 800 eV only for high-gain volume ignition.

scholarly journals Target alignment in the Shen-Guang II Upgrade laser facility

2018 ◽  
Vol 6 ◽  
Author(s):  
Lei Ren ◽  
Ping Shao ◽  
Dongfeng Zhao ◽  
Yang Zhou ◽  
Zhijian Cai ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Short Pulse ◽  
Three Dimensional ◽  
Nanosecond Laser ◽  
Alignment Error ◽  
Inertial Confinement ◽  
Pulse Beam ◽  
Rotation Sensor ◽  
Confinement Fusion ◽  
Laser Facility

The Shen-Guang II Upgrade (SG-II-U) laser facility consists of eight high-power nanosecond laser beams and one short-pulse picosecond petawatt laser. It is designed for the study of inertial confinement fusion (ICF), especially for conducting fast ignition (FI) research in China and other basic science experiments. To perform FI successfully with hohlraum targets containing a golden cone, the long-pulse beam and cylindrical hohlraum as well as the short-pulse beam and cone target alignment must satisfy tight specifications (30 and $20~\unicode[STIX]{x03BC}\text{m}$ rms for each case). To explore new ICF ignition targets with six laser entrance holes (LEHs), a rotation sensor was adapted to meet the requirements of a three-dimensional target and correct beam alignment. In this paper, the strategy for aligning the nanosecond beam based on target alignment sensor (TAS) is introduced and improved to meet requirements of the picosecond lasers and the new six LEHs hohlraum targets in the SG-II-U facility. The expected performance of the alignment system is presented, and the alignment error is also discussed.

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.

scholarly journals Volume ignition of laser driven fusion pellets and double layer effects

1988 ◽  
Vol 6 (2) ◽  
pp. 163-182 ◽  
Author(s):  
L. Cicchitelli ◽  
S. Eliezer ◽  
M. P. Goldsworthy ◽  
F. Green ◽  
H. Hora ◽  
...  
Keyword(s):  
Electric Fields ◽  
Inertial Confinement Fusion ◽  
Laser Pulses ◽  
Spark Ignition ◽  
State Density ◽  
Double Layers ◽  
Inertial Confinement ◽  
Confinement Fusion ◽  
Volume Compression ◽  
Volume Ignition

The realization of an ideal volume compression of laser-irradiated fusion pellets (by C. Yamanaka) opens the possibility for an alternative to spark ignition proposed for many years for inertial confinement fusion. A re-evaluation of the difficulties of the central spark ignition of laser driven pellets is given. The alternative volume compression theory, together with volume burn and volume ignition (discovered in 1977), have received less attention and are re-evaluated in view of the experimental verification by Yamanaka, generalized fusion gain formulas, and the variation of optimum temperatures derived at self-ignition. Reactor-level DT fusion with MJ-laser pulses and volume compression to 50 times the solid-state density are estimated. Dynamic electric fields and double layers at the surface and in the interior of plasmas result in new phenomena for the acceleration of thermal electrons to suprathermal electrons. Double layers also cause a surface tension which stabilizes against surface wave effects and Rayleigh–Taylor instabilities.

scholarly journals Laser-plasma interaction in direct-drive inertial confinement fusion

2016 ◽  
Vol 717 ◽  
pp. 012040 ◽  
Author(s):  
J F Myatt ◽  
J Shaw ◽  
V N Goncharov ◽  
J Zhang ◽  
A V Maximov ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Inertial Confinement Fusion ◽  
Inertial Confinement ◽  
Direct Drive ◽  
Plasma Interaction ◽  
Laser Plasma Interaction ◽  
Confinement Fusion

scholarly journals Direct observation of imploded core heating via fast electrons with super-penetration scheme

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
T. Gong ◽  
H. Habara ◽  
K. Sumioka ◽  
M. Yoshimoto ◽  
Y. Hayashi ◽  
...  
Keyword(s):  
Electron Beam ◽  
Direct Observation ◽  
Inertial Confinement Fusion ◽  
Short Pulse ◽  
Coupling Efficiency ◽  
High Energy ◽  
Inertial Confinement ◽  
Particle In Cell ◽  
Short Pulse Laser ◽  
Confinement Fusion

AbstractFast ignition (FI) is a promising approach for high-energy-gain inertial confinement fusion in the laboratory. To achieve ignition, the energy of a short-pulse laser is required to be delivered efficiently to the pre-compressed fuel core via a high-energy electron beam. Therefore, understanding the transport and energy deposition of this electron beam inside the pre-compressed core is the key for FI. Here we report on the direct observation of the electron beam transport and deposition in a compressed core through the stimulated Cu Kα emission in the super-penetration scheme. Simulations reproducing the experimental measurements indicate that, at the time of peak compression, about 1% of the short-pulse energy is coupled to a relatively low-density core with a radius of 70 μm. Analysis with the support of 2D particle-in-cell simulations uncovers the key factors improving this coupling efficiency. Our findings are of critical importance for optimizing FI experiments in a super-penetration scheme.

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