scholarly journals Forward-looking insights in laser-generated ultra-intense γ-ray and neutron sources for nuclear application and science

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
M. M. Günther ◽  
O. N. Rosmej ◽  
P. Tavana ◽  
M. Gyrdymov ◽  
A. Skobliakov ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Inertial Confinement Fusion ◽  
Critical Density ◽  
Nuclear Astrophysics ◽  
Inertial Confinement ◽  
Neutron Beams ◽  
Research Fields ◽  
Enhanced Production ◽  
Diagnostic Potential ◽  
Direct Laser

AbstractUltra-intense MeV photon and neutron beams are indispensable tools in many research fields such as nuclear, atomic and material science as well as in medical and biophysical applications. For applications in laboratory nuclear astrophysics, neutron fluxes in excess of 1021 n/(cm2 s) are required. Such ultra-high fluxes are unattainable with existing conventional reactor- and accelerator-based facilities. Currently discussed concepts for generating high-flux neutron beams are based on ultra-high power multi-petawatt lasers operating around 1023 W/cm2 intensities. Here, we present an efficient concept for generating γ and neutron beams based on enhanced production of direct laser-accelerated electrons in relativistic laser interactions with a long-scale near critical density plasma at 1019 W/cm2 intensity. Experimental insights in the laser-driven generation of ultra-intense, well-directed multi-MeV beams of photons more than 1012 ph/sr and an ultra-high intense neutron source with greater than 6 × 1010 neutrons per shot are presented. More than 1.4% laser-to-gamma conversion efficiency above 10 MeV and 0.05% laser-to-neutron conversion efficiency were recorded, already at moderate relativistic laser intensities and ps pulse duration. This approach promises a strong boost of the diagnostic potential of existing kJ PW laser systems used for Inertial Confinement Fusion (ICF) research.

Linear perturbation response of self-similar ablative flows relevant to inertial confinement fusion

2008 ◽  
Vol 609 ◽  
pp. 1-48 ◽  
Author(s):  
J.-M. CLARISSE ◽  
C. BOUDESOCQUE-DUBOIS ◽  
S. GAUTHIER
Keyword(s):  
Inertial Confinement Fusion ◽  
Similarity Solutions ◽  
Linear Perturbation ◽  
Inertial Confinement ◽  
Mean Flow ◽  
Direct Laser ◽  
Confinement Fusion ◽  
Self Similar ◽  
The Mean ◽  
Compressibility Effects

A family of exact similarity solutions for inviscid compressible ablative flows in slab symmetry with nonlinear heat conduction is proposed for studying unsteadiness and compressibility effects on the hydrodynamic stability of ablation fronts relevant to inertial confinement fusion. Dynamical multi-domain Chebyshev spectral methods are employed for computing both the similarity solution and its time-dependent linear perturbations. This approach has been exploited to analyse the linear stability properties of two self-similar ablative configurations subjected to direct laser illumination asymmetries. Linear perturbation temporal and reduced responses are analysed, evidencing a maximum instability for illumination asymmetries of zero transverse wavenumber as well as three distinct regimes of ablation-front distortion evolution, and emphasizing the importance of the mean flow unsteadiness, compressibility and stratification.

scholarly journals Collective absorption of laser radiation in plasma at sub-relativistic intensities

2019 ◽  
Vol 7 ◽  
Author(s):  
Y. J. Gu ◽  
O. Klimo ◽  
Ph. Nicolaï ◽  
S. Shekhanov ◽  
S. Weber ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Stimulated Raman Scattering ◽  
Laser Energy ◽  
Brillouin Scattering ◽  
Critical Density ◽  
Plasma Waves ◽  
High Amplitude ◽  
Inertial Confinement ◽  
Hot Electron ◽  
Plasma Parameters

Processes of laser energy absorption and electron heating in an expanding plasma in the range of irradiances $I\unicode[STIX]{x1D706}^{2}=10^{15}{-}10^{16}~\text{W}\,\cdot \,\unicode[STIX]{x03BC}\text{m}^{2}/\text{cm}^{2}$ are studied with the aid of kinetic simulations. The results show a strong reflection due to stimulated Brillouin scattering and a significant collisionless absorption related to stimulated Raman scattering near and below the quarter critical density. Also presented are parametric decay instability and resonant excitation of plasma waves near the critical density. All these processes result in the excitation of high-amplitude electron plasma waves and electron acceleration. The spectrum of scattered radiation is significantly modified by secondary parametric processes, which provide information on the spatial localization of nonlinear absorption and hot electron characteristics. The considered domain of laser and plasma parameters is relevant for the shock ignition scheme of inertial confinement fusion.

K-alpha conversion efficiency measurements for X-ray scattering in inertial confinement fusion plasmas

2007 ◽  
Vol 3 (1-2) ◽  
pp. 156-162 ◽  
Author(s):  
A.L. Kritcher ◽  
P. Neumayer ◽  
M.K. Urry ◽  
H. Robey ◽  
C. Niemann ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Inertial Confinement Fusion ◽  
Inertial Confinement ◽  
Fusion Plasmas ◽  
X Ray ◽  
X Ray Scattering ◽  
Confinement Fusion ◽  
Ray Scattering

scholarly journals Generation of pre-formed plasma and its reduction for fast-ignition

2012 ◽  
Vol 30 (1) ◽  
pp. 95-102 ◽  
Author(s):  
Atsushi Sunahara ◽  
Tomoyuki Johzaki ◽  
Hideo Nagatomo ◽  
Kunioki Mima
Keyword(s):  
Inertial Confinement Fusion ◽  
Arrival Time ◽  
Critical Density ◽  
Fast Ignition ◽  
Intense Laser ◽  
Inertial Confinement ◽  
Plasma Expansion ◽  
Hydrodynamic Simulations ◽  
Confinement Fusion ◽  
Cone Target

AbstractWe investigated generation of pre-formed plasma on plates and inside cone targets due to a pre-pulse before the arrival of the main ultra-intense laser pulse in the fast-ignition scheme of the inertial confinement fusion. We estimated the pre-pulse level to be 130 mJ for LFEX laser used in the 2009 FIREX experiment, and the density gradient scale length of the pre-formed plasma inside the cone target to be 27–47 microns between the critical and 1/10 of the critical density, based on the two-dimensional radiation hydrodynamic simulations. In order to reduce the generation of pre-formed plasma, we investigated a thin CH foil pre-pulse absorber, and proposed using a cone target with a pointed tip. We simulated CH plasma expansion to show that the CH foils works as a pre-pulse absorber. We also show the aluminum pointed tip of the cone target can delay the shock arrival time by 20 ps, much longer than the delay for the 10 micron thickness gold tip used in the typical implosion of GXII at Osaka University.

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 Mitigating laser-imprint effects in direct-drive inertial confinement fusion implosions with an above-critical-density foam layer

2018 ◽  
Vol 25 (8) ◽  
pp. 082710 ◽  
Author(s):  
S. X. Hu ◽  
W. Theobald ◽  
P. B. Radha ◽  
J. L. Peebles ◽  
S. P. Regan ◽  
...  
Keyword(s):  
Inertial Confinement Fusion ◽  
Critical Density ◽  
Inertial Confinement ◽  
Direct Drive ◽  
Foam Layer ◽  
Confinement Fusion ◽  
Fusion Implosions

Analysis of electroless nickel thin films

1991 ◽  
Vol 49 ◽  
pp. 510-511 ◽  
Author(s):  
C. W. Price ◽  
E. F. Lindsey
Keyword(s):  
Thin Films ◽  
Inertial Confinement Fusion ◽  
Electroless Nickel ◽  
Inertial Confinement ◽  
Plating Bath ◽  
X Ray ◽  
Nickel Thin Films ◽  
Nickel Deposits ◽  
Confinement Fusion ◽  
Thickness Measurements

Thickness measurements of thin films are performed by both energy-dispersive x-ray spectroscopy (EDS) and x-ray fluorescence (XRF). XRF can measure thicker films than EDS, and XRF measurements also have somewhat greater precision than EDS measurements. However, small components with curved or irregular shapes that are used for various applications in the the Inertial Confinement Fusion program at LLNL present geometrical problems that are not conducive to XRF analyses but may have only a minimal effect on EDS analyses. This work describes the development of an EDS technique to measure the thickness of electroless nickel deposits on gold substrates. Although elaborate correction techniques have been developed for thin-film measurements by x-ray analysis, the thickness of electroless nickel films can be dependent on the plating bath used. Therefore, standard calibration curves were established by correlating EDS data with thickness measurements that were obtained by contact profilometry.

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