Measurement of Interface Strength by Laser Pulse induced Spallation

1990 ◽  
Vol 188 ◽  
Author(s):  
V. Gupta ◽  
A. S. Argon
Keyword(s):  
Free Surface ◽  
Laser Pulse ◽  
Pressure Pulse ◽  
Stress Amplitude ◽  
Threshold Level ◽  
High Energy ◽  
Piezoelectric Crystal ◽  
Critical Amplitude ◽  
Laser Spallation ◽  
Simulation Process

ABSTRACTThe strength of planar interfaces between a substrate and a thin coating (1–2 µm) can be measured quite effectively by a laser spallation technique. In this technique a laser pulse of a high energy and a predetermined length is converted into a pressure pulse of a critical amplitude and width that is sent through the substrate toward the free surface with the coating. The compressive pressure pulse is reflected into a tension pulse from the free surface of the coating and loads the coating/substrate interface in tension. The laser flux is tuned to a threshold level at which the interface comes apart. The critical stress amplitude that accomplishes the removal of the coating is determined from a computer simulation process. The simulation itself is verified by means of a piezoelectric crystal probe which is capable of mapping out the profile of the stress pulse generated by the laser pulse.

scholarly journals Signatures of the Carrier Envelope Phase in Nonlinear Thomson Scattering

Crystals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 528
Author(s):  
Marcel Ruijter ◽  
Vittoria Petrillo ◽  
Thomas C. Teter ◽  
Maksim Valialshchikov ◽  
Sergey Rykovanov
Keyword(s):  
Laser Pulse ◽  
Radiation Spectrum ◽  
Thomson Scattering ◽  
High Energy ◽  
Phase Changes ◽  
High Energy Radiation ◽  
Carrier Envelope Phase ◽  
High Intensity Laser ◽  
Experimental Parameters ◽  
Intensity Laser

High-energy radiation can be generated by colliding a relativistic electron bunch with a high-intensity laser pulse—a process known as Thomson scattering. In the nonlinear regime the emitted radiation contains harmonics. For a laser pulse whose length is comparable to its wavelength, the carrier envelope phase changes the behavior of the motion of the electron and therefore the radiation spectrum. Here we show theoretically and numerically the dependency of the spectrum on the intensity of the laser and the carrier envelope phase. Additionally, we also discuss what experimental parameters are required to measure the effects for a beamed pulse.

scholarly journals Focusing of intense laser pulse by a hollow cone

2010 ◽  
Vol 28 (2) ◽  
pp. 293-298 ◽  
Author(s):  
Wei Yu ◽  
Lihua Cao ◽  
M.Y. Yu ◽  
A.L. Lei ◽  
Z.M. Sheng ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Strong Field ◽  
High Energy ◽  
Plasma Boundary ◽  
High Energy Density ◽  
Intense Laser ◽  
Intense Laser Pulse ◽  
Hollow Cone ◽  
Conical Channel ◽  
Boundary Plasma

AbstractIt is shown that an intense laser pulse can be focused by a conical channel. This anomalous light focusing can be attributed to a hitherto ignored effect in nonlinear optics, namely that the boundary response depends on the light intensity: the inner cone surface is ionized and the laser pulse is in turn modified by the resulting boundary plasma. The interaction creates a new self-consistently evolving light-plasma boundary, which greatly reduces reflection and enhances forward propagation of the light pulse. The hollow cone can thus be used for attaining extremely high light intensities for applications in strong-field and high energy-density physics and other areas.

scholarly journals Large area high efficiency broad bandwidth 800 nm dielectric gratings for high energy laser pulse compression

2009 ◽  
Vol 17 (26) ◽  
pp. 23809 ◽  
Author(s):  
D. H. Martz ◽  
H. T. Nguyen ◽  
D. Patel ◽  
J. A. Britten ◽  
D. Alessi ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Pulse Compression ◽  
High Efficiency ◽  
High Energy ◽  
Large Area ◽  
Broad Bandwidth ◽  
Dielectric Gratings ◽  
Energy Laser ◽  
High Energy Laser

scholarly journals Conditional Wasserstein Generative Adversarial Networks for Fast Detector Simulation

2021 ◽  
Vol 251 ◽  
pp. 03055
Author(s):  
John Blue ◽  
Braden Kronheim ◽  
Michelle Kuchera ◽  
Raghuram Ramanujan
Keyword(s):  
High Energy Physics ◽  
High Energy ◽  
Generative Models ◽  
Generative Adversarial Networks ◽  
Detector Response ◽  
Event Simulation ◽  
Simulation Process ◽  
Adversarial Networks ◽  
Wide Range ◽  
Detector Simulation

Detector simulation in high energy physics experiments is a key yet computationally expensive step in the event simulation process. There has been much recent interest in using deep generative models as a faster alternative to the full Monte Carlo simulation process in situations in which the utmost accuracy is not necessary. In this work we investigate the use of conditional Wasserstein Generative Adversarial Networks to simulate both hadronization and the detector response to jets. Our model takes the 4-momenta of jets formed from partons post-showering and pre-hadronization as inputs and predicts the 4-momenta of the corresponding reconstructed jet. Our model is trained on fully simulated tt events using the publicly available GEANT-based simulation of the CMS Collaboration. We demonstrate that the model produces accurate conditional reconstructed jet transverse momentum (pT) distributions over a wide range of pT for the input parton jet. Our model takes only a fraction of the time necessary for conventional detector simulation methods, running on a CPU in less than a millisecond per event.

The Doppler Aerosol Wind (DAWN) Airborne, Wind-Profiling Coherent-Detection Lidar System: Overview and Preliminary Flight Results

2014 ◽  
Vol 31 (4) ◽  
pp. 826-842 ◽  
Author(s):  
Michael J. Kavaya ◽  
Jeffrey Y. Beyon ◽  
Grady J. Koch ◽  
Mulugeta Petros ◽  
Paul J. Petzar ◽  
...  
Keyword(s):  
Laser Pulse ◽  
High Energy ◽  
Coherent Detection ◽  
Lidar System ◽  
Airborne Measurements ◽  
Secondary Mirror ◽  
Wind Measurements ◽  
Wind Lidar ◽  
Aerosol Backscatter ◽  
Flight Measurements

Abstract The first airborne wind measurements of a pulsed, 2-μm solid-state, high-energy, wind-profiling lidar system for airborne measurements are presented. The laser pulse energy is the highest to date in an eye-safe airborne wind lidar system. This energy, the 10-Hz laser pulse rate, the 15-cm receiver diameter, and dual-balanced coherent detection together have the potential to provide much-improved lidar sensitivity to low aerosol backscatter levels compared to earlier airborne-pulsed coherent lidar wind systems. Problems with a laser-burned telescope secondary mirror prevented a full demonstration of the lidar’s capability, but the hardware, algorithms, and software were nevertheless all validated. A lidar description, relevant theory, and preliminary results of flight measurements are presented.

scholarly journals Direct Amplification of High Energy Pulsed Laser in Fiber-Single Crystal Fiber with High Average Power

Crystals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 216
Author(s):  
Feng Li ◽  
Zhi Yang ◽  
Zhiguo Lv ◽  
Yang Yang ◽  
Yishan Wang ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Single Crystal ◽  
Stimulated Raman Scattering ◽  
Average Power ◽  
High Energy ◽  
Laser Source ◽  
High Average Power ◽  
Double Pass ◽  
Two Stage ◽  
Crystal Fiber

A laser master oscillator power amplifier (MOPA) system consisting of a fiber amplifier and a two-stage Yb:YAG single crystal fiber (SCF) is experimentally studied. The nonlinear stimulated Raman scattering (SRS) is avoided by limiting the output power of the fiber preamplifier to 600 mW. Due to the benefit from the low nonlinearity and high amplification gain of the SCF, a laser pulse duration of 16.95 ps and a high average power of 41.7 W at a repetition rate of 250 kHz are obtained by using a two-stage polarization controlled double-pass amplification of Yb:YAG SCF, corresponding to an output energy of 166.8 μJ and a peak power of 9.84 MW, respectively. The polarization controlled SCF amplification scheme achieved a gain as high as more than 69 times. During the amplification, the spectra gain narrowing effect and the polarization controlled four-pass amplification setup are also studied. The laser spectrum is narrowed from over 10 nm to less than 3 nm, and the pulse width is also compressed to hundreds of femtosecond by dechirping the laser pulse. This compact-sized, cost-effective laser source can be used in laser micromachining, or as the seeder source for generating much higher power and energy laser for scientific research. For some applications which need femtosecond laser, this laser source can also be compressed to femtosecond regime.

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