scholarly journals Laser-induced cratering of a 3DCC material at mesoscale: Experiments and simulations

2018 ◽  
Vol 183 ◽  
pp. 01028
Author(s):  
Vincent Jaulin ◽  
David Hébert ◽  
Bertrand Aubert ◽  
Jean-Luc Rullier ◽  
Frédéric Malaise ◽  
...  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Dynamic Behaviour ◽  
Focal Spot ◽  
Dynamic Pressure ◽  
Dynamic Strength ◽  
Mesoscopic Scale ◽  
Spot Diameter ◽  
Laser Facility ◽  
Focal Spot Diameter

This study concerns the damaging of a 3-Dimension Carbon/Carbon (3DCC) composite material under dynamic loading. Experiments were performed with a laser facility delivering energies between 13 and 40 J with 100 nanoseconds pulse duration. The focal spot diameter was 250 μm, leading to dynamic pressure up to 10 GPa. The focal spot being smaller than the size of the composite components, it allows us to study the dynamic behaviour of the material at mesoscopic scale. The dynamic process of this cratering is then investigated via 3D numerical simulations, and a Johnson-Holmquist model is proposed. It appears that comparison of simulations with experimental results is useful to identify the dynamic strength of individual components of composite materials.

XRMF applications of a monolithic, polycapillary, focusing x-ray optic

1996 ◽  
Vol 54 ◽  
pp. 240-241
Author(s):  
D. A. Carpenter ◽  
Ning Gao ◽  
G. J. Havrilla
Keyword(s):  
Trace Elements ◽  
Point Source ◽  
Focal Spot ◽  
Fluorescence Analysis ◽  
X Rays ◽  
Focal Distance ◽  
Spot Diameter ◽  
X Ray ◽  
Focal Spot Diameter

A monolithic, polycapillary, x-ray optic was adapted to a laboratory-based x-ray microprobe to evaluate the potential of the optic for x-ray micro fluorescence analysis. The polycapillary was capable of collecting x-rays over a 6 degree angle from a point source and focusing them to a spot approximately 40 µm diameter. The high intensities expected from this capillary should be useful for determining and mapping minor to trace elements in materials. Fig. 1 shows a sketch of the capillary with important dimensions.The microprobe had previously been used with straight and with tapered monocapillaries. Alignment of the monocapillaries with the focal spot was accomplished by electromagnetically scanning the focal spot over the beveled anode. With the polycapillary it was also necessary to manually adjust the distance between the focal spot and the polycapillary.The focal distance and focal spot diameter of the polycapillary were determined from a series of edge scans.

scholarly journals Numerical Simulations of Laser-Driven Cratering Experiments into Porous Graphite

2018 ◽  
Vol 183 ◽  
pp. 01060
Author(s):  
Bertrand Aubert ◽  
David Hebert ◽  
Jean-Luc Rullier ◽  
Jean-Marc Chevalier ◽  
Laurent Berthe ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Focal Spot ◽  
Surface Velocity ◽  
Power Laser ◽  
Graphite Target ◽  
Experimental Campaign ◽  
Porous Graphite ◽  
Thin Aluminum ◽  
Laser Facility ◽  
Focal Spot Diameter

We present the results of an experimental campaign conducted on the LULI2000 laser facility. Semi-infinite targets of a commercial grade of porous graphite were submitted to high-power laser irradiation inorder to generate craters. A 15 ns pulse duration was used along with a focal spot diameter of 900 µm to deliver energies up to 750 J. Numerical simulations of these shots have been performed following a specificmethodology which can be divided in three steps. Firstly, the mechanical loading induced by the laser iscalibrated by simulating the same shot on a thin aluminum target of which free surface velocity is measured byPDV and line-VISAR. Secondly, the same shot is performed on a thin graphite target to validate the materialmodel of graphite. Thirdly, the craterization shot on semi-infinite target is simulated. Numerical results arecompared to experimental measurements of craters obtained using an interferometric profilometer.

Improving the efficiency of the SLM-process by adjusting the focal spot diameter of the laser beam

2021 ◽  
Vol 2021 (5) ◽  
pp. 18-23
Author(s):  
S.V. Adjamskyi ◽  
◽  
G.A. Kononenko ◽  
R.V. Podolskyi ◽  
◽  
...  
Keyword(s):  
Laser Beam ◽  
Focal Spot ◽  
Spot Diameter ◽  
Focal Spot Diameter

Diffractive phase element for shrinking focal spot diameter: Design, fabrication, and application to laser beam lithography

2001 ◽  
Vol 8 (6) ◽  
pp. 416-421
Author(s):  
Yusuke Ogura ◽  
Jun Tanida ◽  
Yoshiki Ichioka ◽  
Yoshiaki Mokuno ◽  
Katsunori Matsuoka
Keyword(s):  
Laser Beam ◽  
Focal Spot ◽  
Spot Diameter ◽  
Diffractive Phase Element ◽  
Focal Spot Diameter

scholarly journals Laser and target experiments on KrF GARPUN laser installation at FIAN

1999 ◽  
Vol 17 (1) ◽  
pp. 69-88 ◽  
Author(s):  
V.D. ZVORYKIN ◽  
I.G. LEBO
Keyword(s):  
Inertial Confinement Fusion ◽  
Focal Spot ◽  
Laser Pulses ◽  
Inertial Confinement ◽  
Power Laser ◽  
Spot Diameter ◽  
Confinement Fusion ◽  
Short Laser Pulses ◽  
Focal Spot Diameter ◽  
Laser Installation

Multistage, e-beam-pumped, 100 J-class KrF laser installation “GARPUN” is described with the emphases to high-power laser beam control and target irradiation experiments. The ablation pressures in the megabar range were measured and hydrodynamic flow was investigated both experimentally and by numerical simulations for laser intensities up to 5×1012 W/cm2, pulse duration of 100 ns, and focal spot diameter 150 μm. Graphite-diamond phase transformation under laser loading was observed by dynamic and Raman scattering methods. Some approaches to the fast ignition inertial confinement fusion, using the simultaneous amplification of long and short laser pulses in KrF drivers, are considered.

scholarly journals Influence of focal spot diameter and beam oscillation on the process efficiency of laser beam welding utilizing a direct diode laser

Procedia CIRP ◽  
2018 ◽  
Vol 74 ◽  
pp. 466-469 ◽  
Author(s):  
Kerstin Schaumberger ◽  
Vincent Mann ◽  
Michael Mödl ◽  
Konstantin Hofmann ◽  
Stefan Stein ◽  
...  
Keyword(s):  
Laser Beam ◽  
Diode Laser ◽  
Focal Spot ◽  
Laser Beam Welding ◽  
Process Efficiency ◽  
Spot Diameter ◽  
Focal Spot Diameter ◽  
Beam Oscillation

scholarly journals High-precision small-scale laser focal spot measurements

2013 ◽  
Vol 31 (1) ◽  
pp. 177-183 ◽  
Author(s):  
Z.W. Lu ◽  
X.Y. Liu ◽  
X. Wang ◽  
D.X. Ba ◽  
Z.H. Jiang ◽  
...  
Keyword(s):  
Background Noise ◽  
Measurement Accuracy ◽  
Focal Spot ◽  
Small Scale ◽  
Two Dimensional ◽  
Charge Coupled Device ◽  
Spot Diameter ◽  
Focal Spot Diameter ◽  
Laser Focal Spot ◽  
Better Than

AbstractIn this paper, a method of two-dimensional fine-scanning with charge coupled device has been conducted to precisely measure spatial position and intensity distribution of small-scale focal spot (diameter in microns). The measurement accuracy of the small-scale focal spot position is better than 1 µm when the fluctuations of the light energy and background noise are relatively small. The theoretical analysis is consistent with the experimental results.

Improving the efficiency of the SLM-process by adjusting the focal spot diameter of the laser beam

2021 ◽  
Vol 2021 (5) ◽  
pp. 21-27
Author(s):  
S.V. Adjamskiy ◽  
◽  
G.A. Kononenko ◽  
R.V. Podolskyi ◽  
◽  
...  
Keyword(s):  
Laser Beam ◽  
Focal Spot ◽  
Spot Diameter ◽  
Focal Spot Diameter

An investigation of the mechanoluminescence of composite materials based on a polymer and a phosphor powder excited by the action of a mechanical striker, stylus and laser pulse

2020 ◽  
Vol 6 ◽  
pp. 62-68
Author(s):  
A.F. Banishev ◽  
◽  
A.A. Banishev ◽  
Keyword(s):  
Composite Material ◽  
Composite Materials ◽  
Polymethyl Methacrylate ◽  
High Efficiency ◽  
Dynamic Pressure ◽  
Composite Layer ◽  
Laser Pulses ◽  
Visible Spectral Region ◽  
Mechatronic Systems ◽  
Short Laser Pulses

The mechanoluminescence of the composite materials based on polymethyl-methacrylate and fine-dispersed powders of Sr4Al14O25:(Eu2+,Dy3+) phosphor with a centrosymmetric crystal structure of microcrystals and SrAl2O4:(Eu2+, Dy3+) phosphor with noncentrosymmetric crystalline structure were investigated. To study of mechanoluminescence, the composite layer with a thickness of ~250-300 μm was deposited on the surface of polymethyl-methacrylate substrate transparent in the visible spectral region. The mechanoluminescence of the composite layer was excited by the action of a mechanical striker, short laser pulses in air and water, and dynamic pressure of the stylus sliding over the surface of the mechanoluminescent layer. It is shown that the composite material based on a polymer and SrAl2O4:(Eu2+,Dy3+) powder with a noncentrosymmetric crystal lattice has a pronounced mechanoluminescence, while the composite material with Sr4Al14O25:(Eu2+,Dy3+) powder does not exhibit of the mechanoluminescent properties. It was shown that the excitation of mechanoluminescence in water begins at a much lower power density of the laser pulses than in air. The produced composite layer is shown to exhibit a high efficiency of “mechanooptical” transformation and can be used for recording and visualizing mechanical effects in mechatronic systems.

Sign in / Sign up

Export Citation Format

Share Document