scholarly journals Towards ML-Based Diagnostics of Laser–Plasma Interactions

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 6982
Author(s):  
Yury Rodimkov ◽  
Shikha Bhadoria ◽  
Valentin Volokitin ◽  
Evgeny Efimenko ◽  
Alexey Polovinkin ◽  
...  
Keyword(s):  
Data Augmentation ◽  
Data Extraction ◽  
Synthetic Data ◽  
Simulated Data ◽  
Principal Component ◽  
Analysis Data ◽  
Feature Identification ◽  
Laser Plasma Interactions ◽  
High Intensity Laser ◽  
Intensity Laser

The power of machine learning (ML) in feature identification can be harnessed for determining quantities in experiments that are difficult to measure directly. However, if an ML model is trained on simulated data, rather than experimental results, the differences between the two can pose an obstacle to reliable data extraction. Here we report on the development of ML-based diagnostics for experiments on high-intensity laser–matter interactions. With the intention to accentuate robust, physics-governed features, the presence of which is tolerant to such differences, we test the application of principal component analysis, data augmentation and training with data that has superimposed noise of gradually increasing amplitude. Using synthetic data of simulated experiments, we identify that the approach based on the noise of increasing amplitude yields the most accurate ML models and thus is likely to be useful in similar projects on ML-based diagnostics.

scholarly journals High-repetition-rate ( kHz) targets and optics from liquid microjets for high-intensity laser–plasma interactions

2019 ◽  
Vol 7 ◽  
Author(s):  
K. M. George ◽  
J. T. Morrison ◽  
S. Feister ◽  
G. K. Ngirmang ◽  
J. R. Smith ◽  
...  
Keyword(s):  
Laser Plasma ◽  
Repetition Rate ◽  
High Intensity ◽  
High Repetition Rate ◽  
Plasma Interactions ◽  
Laser Plasma Interactions ◽  
High Repetition ◽  
High Intensity Laser ◽  
Liquid Microjets ◽  
Intensity Laser

High-intensity laser–plasma interactions produce a wide array of energetic particles and beams with promising applications. Unfortunately, the high repetition rate and high average power requirements for many applications are not satisfied by the lasers, optics, targets, and diagnostics currently employed. Here, we aim to address the need for high-repetition-rate targets and optics through the use of liquids. A novel nozzle assembly is used to generate high-velocity, laminar-flowing liquid microjets which are compatible with a low-vacuum environment, generate little to no debris, and exhibit precise positional and dimensional tolerances. Jets, droplets, submicron-thick sheets, and other exotic configurations are characterized with pump–probe shadowgraphy to evaluate their use as targets. To demonstrate a high-repetition-rate, consumable, liquid optical element, we present a plasma mirror created by a submicron-thick liquid sheet. This plasma mirror provides etalon-like anti-reflection properties in the low field of 0.1% and high reflectivity as a plasma, 69%, at a repetition rate of 1 kHz. Practical considerations of fluid compatibility, in-vacuum operation, and estimates of maximum repetition rate are addressed. The targets and optics presented here demonstrate a potential technique for enabling the operation of laser–plasma interactions at high repetition rates.

scholarly journals Single-shot electrons and protons time-resolved detection from high-intensity laser–solid matter interactions at SPARC_LAB

2019 ◽  
Vol 7 ◽  
Author(s):  
F. Bisesto ◽  
M. Galletti ◽  
M. P. Anania ◽  
M. Ferrario ◽  
R. Pompili ◽  
...  
Keyword(s):  
Intense Laser ◽  
Test Facility ◽  
Particle Accelerators ◽  
Single Shot ◽  
X Rays ◽  
Time Resolved ◽  
Laser Plasma Interactions ◽  
High Intensity Laser ◽  
Set Up ◽  
Intensity Laser

Laser–plasma interactions have been studied in detail over the past twenty years, as they show great potential for the next generation of particle accelerators. The interaction between an ultra-intense laser and a solid-state target produces a huge amount of particles: electrons and photons (X-rays and $\unicode[STIX]{x03B3}$ -rays) at early stages of the process, with protons and ions following them. At SPARC_LAB Test Facility we have set up two diagnostic lines to perform simultaneous temporally resolved measurements on both electrons and protons.

scholarly journals Multivariate Features Extraction and Effective Decision Making Using Machine Learning Approaches

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 609 ◽  
Author(s):  
Sondes Gharsellaoui ◽  
Majdi Mansouri ◽  
Shady S. Refaat ◽  
Haitham Abu-Rub ◽  
Hassani Messaoud
Keyword(s):  
Machine Learning ◽  
Air Conditioning ◽  
Synthetic Data ◽  
Simulated Data ◽  
Principal Component ◽  
Features Extraction ◽  
Fault Detection And Isolation ◽  
Fault Classification ◽  
Learning Approaches ◽  
Multiscale Representation

Fault Detection and Isolation (FDI) in Heating, Ventilation, and Air Conditioning (HVAC) systems is an important approach to guarantee the human safety of these systems. Therefore, the implementation of a FDI framework is required to reduce the energy needs for buildings and improving indoor environment quality. The main goal of this paper is to merge the benefits of multiscale representation, Principal Component Analysis (PCA), and Machine Learning (ML) classifiers to improve the efficiency of the detection and isolation of Air Conditioning (AC) systems. First, the multivariate statistical features extraction and selection is achieved using the PCA method. Then, the multiscale representation is applied to separate feature from noise and approximately decorrelate autocorrelation between available measurements. Third, the extracted and selected features are introduced to several machine learning classifiers for fault classification purposes. The effectiveness and higher classification accuracy of the developed Multiscale PCA (MSPCA)-based ML technique is demonstrated using two examples: synthetic data and simulated data extracted from Air Conditioning systems.

scholarly journals Burst behavior due to the quasimode excited by stimulated Brillouin scattering in high-intensity laser–plasma interactions

2019 ◽  
Vol 7 ◽  
Author(s):  
Q. S. Feng ◽  
L. H. Cao ◽  
Z. J. Liu ◽  
C. Y. Zheng ◽  
X. T. He
Keyword(s):  
Laser Plasma ◽  
High Intensity ◽  
Brillouin Scattering ◽  
Low Frequency ◽  
Stimulated Brillouin Scattering ◽  
Plasma Interactions ◽  
Laser Plasma Interactions ◽  
High Intensity Laser ◽  
Stimulated Brillouin ◽  
Intensity Laser

The strong-coupling mode, called the “quasimode”, is excited by stimulated Brillouin scattering (SBS) in high-intensity laser–plasma interactions. Also SBS of the quasimode competes with SBS of the fast mode (or slow mode) in multi-ion species plasmas, thus leading to a low-frequency burst behavior of SBS reflectivity. Competition between the quasimode and the ion-acoustic wave (IAW) is an important saturation mechanism of SBS in high-intensity laser–plasma interactions. These results give a clear explanation of the low-frequency periodic burst behavior of SBS and should be considered as a saturation mechanism of SBS in high-intensity laser–plasma interactions.

scholarly journals The Alfvén limit revisited and its relevance to laser-plasma interactions

2006 ◽  
Vol 24 (2) ◽  
pp. 299-310 ◽  
Author(s):  
J.R. DAVIES
Keyword(s):  
Conservation Of Energy ◽  
Laser Plasma Interactions ◽  
Current Limit ◽  
Original Estimate ◽  
High Intensity Laser ◽  
Uniform Current ◽  
Current Densities ◽  
A Charge ◽  
Intensity Laser ◽  
Laser Solid Interactions

Alfvén's derivation of his current limit is given. It demonstrates that it does not give the maximum possible current of a beam, but the maximum current that can propagate for an indefinite distance and time, from a source, in a charge neutral beam. Furthermore, the value Alfvén obtained applies to a uniform current density and to particles initially moving in the direction of the beam. It is also shown that Alfvén predicted that beams which exceed the limit will filament as a result of the particles that are turned back by the magnetic field. His work is extended to beams with particles that have transverse momentum, to beams with non-uniform current densities, to beams that are not charge neutral and to the time dependent case. These extensions of Alfvén's work are found to require numerical calculations in most cases and to give ambiguous results in some cases. A general formula for the current limit is given based on the conservation of energy. It is calculated for the cases considered previously and found to confirm the accuracy of Alfvén's original estimate. The relevance of the current limit to high intensity laser-solid interactions and fast ignition is then discussed.

High-intensity laser-plasma interactions in the refluxing limit

2008 ◽  
Vol 15 (5) ◽  
pp. 056308 ◽  
Author(s):  
P. M. Nilson ◽  
W. Theobald ◽  
J. Myatt ◽  
C. Stoeckl ◽  
M. Storm ◽  
...  
Keyword(s):  
Laser Plasma ◽  
High Intensity ◽  
Plasma Interactions ◽  
Laser Plasma Interactions ◽  
High Intensity Laser ◽  
Intensity Laser

scholarly journals Enhancement of monoenergetic proton beamsviacone substrate in high intensity laser pulse-double layer target interactions

2010 ◽  
Vol 28 (4) ◽  
pp. 585-590 ◽  
Author(s):  
Weimin Zhou ◽  
Yuqiu Gu ◽  
Wei Hong ◽  
Leifeng Cao ◽  
Zongqing Zhao ◽  
...  
Keyword(s):  
Double Layer ◽  
High Intensity ◽  
Laser Light ◽  
Surface Current ◽  
Hot Electrons ◽  
Two Dimensional ◽  
Particle In Cell ◽  
Laser Plasma Interactions ◽  
High Intensity Laser ◽  
Intensity Laser

AbstractA scheme capable of enhancing the energy of monoenergetic protons in high intensity laser-plasma interactions is proposed and demonstrated by two dimensional particle-in-cell simulations. The focusing of laser light pulse and the guiding of surface currentviathe highZmaterial cone-shaped substrate increase the temperature of hot electrons, which are responsible for the electrostatic field accelerating protons. Moreover, the sub-micron proton layer coated on the cone-shaped substrate makes the total proton beam experience the same accelerating field, thus the monochromaticity is maintained. Compared to the normal film double layer target, the energy of monoenergetic proton beams can be improved about three times.

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