scholarly journals Direct-drive target designs as energetic particle sources for the Laser MégaJoule facility

2021 ◽  
Vol 87 (2) ◽  
Author(s):  
Mauro Temporal ◽  
Benoit Canaud ◽  
Rafael Ramis
Keyword(s):  
Parametric Study ◽  
Energetic Particle ◽  
Shell Thickness ◽  
Laser Intensity ◽  
Fast Particle ◽  
Glass Layer ◽  
Direct Drive ◽  
Time Resolved ◽  
Inner Radius ◽  
Particle Spectra

This work aims to analyse the possibility of directly driven imploding spherical targets in order to create a source of energetic particles (neutrons, protons, alphas, tritium and 3He ions) for the Laser MégaJoule facility. D3He gas-filled spherical SiO2 glass pellets, irradiated by an absorbed laser intensity of 1014 W cm−2 or 1015 W cm−2 have been considered. Depending on the absorbed laser intensity and the amount of the ablated glass layer two distinct regimes have been identified: a massive pusher and an exploding pusher. Both regimes are analysed in terms of hydrodynamics and fast particle spectra. Energetic particle time-resolved spectra are calculated and used to infer ionic temperatures and total areal densities. A parametric study has been performed by varying the shell thickness and target inner radius for both laser absorbed intensities.

scholarly journals Investigating the longitude dependence of solar energetic particle spectra

2012 ◽  
Author(s):  
C. M. S. Cohen ◽  
G. M. Mason ◽  
R. A. Mewaldt ◽  
R. A. Leske
Keyword(s):  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Particle Spectra

Buckling Strength of Pressurized Cylindrical Shells under Axial Compression

2014 ◽  
Vol 638-640 ◽  
pp. 1750-1753
Author(s):  
Yu Chao Zheng ◽  
Yang Yan ◽  
Pei Jun Wang
Keyword(s):  
Numerical Simulation ◽  
Internal Pressure ◽  
Axial Compression ◽  
Parametric Study ◽  
Shell Thickness ◽  
Steel Shell ◽  
Plastic Buckling ◽  
Buckling Strength ◽  
Elastic Plastic ◽  
Steel Strength

A systematic parametric study was carried out to investigate the elastic and elastic-plastic buckling behaviors of imperfect steel shell subject to axial compression and internal pressure. Studied parameters include the magnitude of internal pressure, steel strength, and ratio of cylinder radius to shell thickness. Design equations were proposed for calculating the elastic and elastic-plastic buckling strength of imperfect steel shells under combination of axial compression and internal pressure. The buckling strength predicated by proposed equations agrees well with that from the numerical simulation.

Use of surface-barrier silicon detectors for measuring fast-particle spectra

1965 ◽  
Vol 19 (5) ◽  
pp. 1414-1415 ◽  
Author(s):  
G. F. Bogdanov ◽  
B. P. Maksimenko
Keyword(s):  
Fast Particle ◽  
Surface Barrier ◽  
Silicon Detectors ◽  
Particle Spectra

scholarly journals Experimental and numerical study of ultra-short laser-produced collimated Cu Kα X-ray source

2017 ◽  
Vol 35 (3) ◽  
pp. 442-449 ◽  
Author(s):  
R. Rathore ◽  
V. Arora ◽  
H. Singhal ◽  
T. Mandal ◽  
J.A. Chakera ◽  
...  
Keyword(s):  
Laser Intensity ◽  
Numerical Study ◽  
Low Cost ◽  
Laser Pulses ◽  
Photon Flux ◽  
X Rays ◽  
X Ray Diffraction ◽  
Time Resolved ◽  
X Ray ◽  
Short Laser Pulses

AbstractKα X-ray sources generated from the interaction of ultra-short laser pulses with solids are compact and low-cost source of ultra-short quasi-monochromatic X-rays compared with synchrotron radiation source. Development of collimated ultra-short Kα X-ray source by the interaction of 45 fs Ti:sapphire laser pulse with Cu wire target is presented in this paper. A study of the Kα source with laser parameters such as energy and pulse duration was carried out. The observed Kα X-ray photon flux was ~2.7 × 108 photons/shot at the laser intensity of ~2.8 × 1017 W cm−2. A model was developed to analyze the observed results. The Kα radiation was coupled to a polycapillary collimator to generate a collimated low divergence (0.8 mrad) X-ray beam. Such sources are useful for time-resolved X-ray diffraction and imaging studies.

scholarly journals Measurements of the ablation-front trajectory and low-mode nonuniformity in direct-drive implosions using x-ray self-emission shadowgraphy

2015 ◽  
Vol 3 ◽  
Author(s):  
D.T. Michel ◽  
A.K. Davis ◽  
W. Armstrong ◽  
R. Bahr ◽  
R. Epstein ◽  
...  
Keyword(s):  
Plasma Phys ◽  
X Rays ◽  
Direct Drive ◽  
Time Resolved ◽  
X Ray ◽  
Laser Facility ◽  
Omega Laser ◽  
Control Fusion ◽  
Pm 10 ◽  
Ablation Front

Self-emission x-ray shadowgraphy provides a method to measure the ablation-front trajectory and low-mode nonuniformity of a target imploded by directly illuminating a fusion capsule with laser beams. The technique uses time-resolved images of soft x-rays ( ${>}1$  keV) emitted from the coronal plasma of the target imaged onto an x-ray framing camera to determine the position of the ablation front. Methods used to accurately measure the ablation-front radius ( ${\it\delta}R=\pm 1.15~{\rm\mu}\text{m}$ ), image-to-image timing ( ${\it\delta}({\rm\Delta}t)=\pm 2.5$  ps) and absolute timing ( ${\it\delta}t=\pm 10$  ps) are presented. Angular averaging of the images provides an average radius measurement of ${\it\delta}(R_{\text{av}})=\pm 0.15~{\rm\mu}\text{m}$ and an error in velocity of ${\it\delta}V/V=\pm 3\%$ . This technique was applied on the Omega Laser Facility [Boehly et al., Opt. Commun. 133, 495 (1997)] and the National Ignition Facility [Campbell and Hogan, Plasma Phys. Control. Fusion 41, B39 (1999)].

scholarly journals Time evolution of stream interaction region energetic particle spectra in the inner heliosphere

2021 ◽  
Author(s):  
C. J. Joyce ◽  
D. J. McComas ◽  
N. A. Schwadron ◽  
E. R. Christian ◽  
M. E. Wiedenbeck ◽  
...  
Keyword(s):  
Time Evolution ◽  
Energetic Particle ◽  
Interaction Region ◽  
Particle Spectra ◽  
Inner Heliosphere

scholarly journals Diffraction line profiles of spherical hollow nanocrystals

2019 ◽  
Vol 9 ◽  
pp. 184798041983238
Author(s):  
Emiliano Burresi ◽  
Leander Tapfer
Keyword(s):  
Particle Size ◽  
Explicit Formula ◽  
Shell Thickness ◽  
Diffraction Line ◽  
Crystallographic Structure ◽  
Line Profiles ◽  
Integral Breadth ◽  
Analytical Expression ◽  
Inner Radius ◽  
Spherical Hollow

An analytical expression of diffraction line profiles of spherical hollow nanocrystals (NCs) is derived. The particular features of the profile lines, enhanced peak tail intensity, are analyzed and discussed as a function of the NC size parameters (outer and inner radius, shell thickness). The explicit formula for the integral breadth, the Fourier particle size, and the Scherrer constants are also obtained and discussed in detail. The diffraction line profiles of hollow CdS NCs of zincblende and wurtzite crystallographic structure are calculated and compared with Debye scattering profiles. The diffraction profiles of both approaches exhibit an enhanced peak tail intensity that can be considered as a fingerprint of the hollow NC structure.

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