scholarly journals Laser contrast and other key parameters enhancing the laser conversion efficiency in ion acceleration regime

2018 ◽  
Vol 167 ◽  
pp. 02002 ◽  
Author(s):  
Lorenzo Torrisi
Keyword(s):  
Electric Field ◽  
Conversion Efficiency ◽  
Laser Light ◽  
Laser Intensity ◽  
Multilayered Structure ◽  
Maximum Energy ◽  
Ion Acceleration ◽  
Surface Geometry ◽  
Laser Parameters ◽  
Target Composition

Measurements of ion acceleration in plasma produced by fs lasers at intensity of the order of 1018 W/cm2 have been performed in different European laboratories. The forward emission in target-normal-sheath-acceleration (TNSA) regime indicated that the maximum energy is a function of the laser parameters, of the irradiation conditions and of the target properties.In particular the laser intensity and contrast play an important role to maximize the ion acceleration enhancing the conversion efficiency. Also the use of suitable prepulses, focal distances and polarized laser light has important roles. Finally the target composition, surface, geometry and multilayered structure, permit to enhance the electric field driving the forward ion acceleration.Experimental measurements will be reported and discussed.

scholarly journals A simple model for soft X-ray conversion efficiency from laser-irradiated gold disk targets

1984 ◽  
Vol 2 (3) ◽  
pp. 303-307 ◽  
Author(s):  
P. H. Y. Lee ◽  
H. G. Ahlstrom
Keyword(s):  
Heat Conduction ◽  
Simple Model ◽  
Conversion Efficiency ◽  
Laser Light ◽  
Laser Intensity ◽  
Laser Energy ◽  
High Irradiance ◽  
X Rays ◽  
X Ray ◽  
Laser Heated

Simple arguments are used to construct a model to explain the conversion efficiency of absorbed laser energy into soft X-rays from laser-irradiated targets. In this model, we postulate that the energy available for conversion is bounded at some low irradiance limit by heat conduction away from the laser heated spot, while at some high irradiance limit it is bounded by the energy lost in plasma blowoff. Consequently, at some appropriate laser intensity, where the sum energy of the conduction and blowoff losses is at a minimum, the X-ray conversion efficiency should reach a maximum. A specific example for gold disk targets irradiated by 0·53 μm laser light will be treated. Simple heuristic scalings of blowoff and conduction as functions of laser intensity are obtained.

scholarly journals Optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism

2020 ◽  
Vol 38 (2) ◽  
pp. 73-78
Author(s):  
Saurabh Kumar ◽  
Devki Nandan Gupta
Keyword(s):  
Laser Pulse ◽  
Pulse Duration ◽  
Laser Intensity ◽  
Laser Pulses ◽  
Maximum Energy ◽  
Rear Side ◽  
Proton Acceleration ◽  
Pulse Delay ◽  
Laser Parameters ◽  
Accelerated Protons

AbstractThe energy of protons accelerated by ultra-intense lasers in the target normal sheath acceleration (TNSA) mechanism can be greatly enhanced by the laser parameter optimization. We propose to investigate the optimization of laser parameters for proton acceleration using double laser pulses in TNSA mechanism. The sheath field generation at the rear side of the target is significantly affected by the introduction of second laser pulse in TNSA mechanism, and consequently, the energy of the accelerated protons is also modified. The second laser pulse was introduced with different delays to study its impact on proton acceleration. Our study shows that the interplay of laser intensity and pulse duration of both laser pulses affects the proton acceleration. It was found that the proton maximum energy is the function of both laser intensity and pulse duration. A number of simulations have been performed to obtain maximum proton energy data under different combinations of laser intensity and pulse duration for the two laser pulses. The simulation results account for the underline physics for the proton bunch energy and the sheath field as a function of pulse intensity and pulse delay.

scholarly journals Optimization for deuterium ion acceleration in foam targets by ultra-intense lasers

2010 ◽  
Vol 28 (2) ◽  
pp. 333-341 ◽  
Author(s):  
M.A. Bari ◽  
Z.M. Sheng ◽  
W.M. Wang ◽  
Y.T. Li ◽  
M. Salahuddin ◽  
...  
Keyword(s):  
High Energy ◽  
Hot Electrons ◽  
Energy Spectra ◽  
Ion Acceleration ◽  
Optimal Angle ◽  
Ion Energy ◽  
Particle In Cell ◽  
Laser Parameters ◽  
Target Composition ◽  
Electrostatic Fields

AbstractIn this article, we investigate the effects of foam target composition and laser parameters on deuterium ion energy spectra with particle-in-cell simulations. We find that localized electrostatic fields with multi peaks around the surfaces of lamellar layers inside foam target are induced. These fields accelerate deuterium ions from thin foam layers by restricting the flow of hot electrons. This mechanism of ion acceleration called as bulk ion acceleration generates large number of high energy deuterium ions. Deuterons inside foam target are accelerated up to 126 MeV in case of oblique optimal angle of 30° where it is much greater than the normal laser incidence energy of 88 MeV.

scholarly journals The effect of ultraviolet lasers on conversion of methane into higher hydrocarbons

2013 ◽  
Vol 31 (3) ◽  
pp. 481-486 ◽  
Author(s):  
H.A. Navid ◽  
E. Irani ◽  
R. Sadighi-Bonabi
Keyword(s):  
Conversion Efficiency ◽  
Nd:Yag Laser ◽  
Important Variable ◽  
Reaction Products ◽  
Third Harmonic ◽  
Effect Of Pressure ◽  
Laser Parameters ◽  
Conversion Of Methane ◽  
Ultraviolet Lasers ◽  
Higher Hydrocarbons

AbstractConversion of CH4molecule into higher hydrocarbons using two different wavelengths of 248 nm KrF laser and 355 nm of third harmonic of Nd:YAG laser is studied experimentally and theoretically. The stable products are analyzed and the effect of pressure on conversion of methane is measured. The detected reaction products are C2H2, C2H4, and C2H6. The conversion efficiency of 33.5% for 355 nm in comparison to 2.2% conversion for 248 nm for C2H2is achieved. The potential of laser parameters as an important variable in controlling of final products is investigated.

scholarly journals Analysis of Curvature in Fiber Optic Cable for Macrobending-Based Slope Sensor

2021 ◽  
Vol 3 (1) ◽  
pp. 45-56
Author(s):  
Imam Mulyanto
Keyword(s):  
Fiber Optics ◽  
Optical Fibers ◽  
Fiber Optic ◽  
Laser Light ◽  
Laser Intensity ◽  
Single Mode ◽  
Power Losses ◽  
Fiber Optic Cable ◽  
Power Meter ◽  
Working Principle

The analysis of fiber optics for macro bending-based slope sensors using SMF-28 single-mode optical fibers has been successfully conducted. Fiber optics were treated to silicon rubber molding and connected with laser light and power meters to measure the intensity of laser power generated. The working principle was carried out using the macrobending phenomenon on single-mode optical fibers. The intensity of laser light in fiber optic cables decreases in the event of indentation or bending of the fiber optic cable. Power losses resulting from the macrobending process can be seen in the result of the information sensitivity of fiber optics to the change of angle given. From the results of the study, the resulting fiber optic sensitivity value is -0.1534o/dBm. The larger the angle given, the lower the laser intensity received by the power meter.

scholarly journals Dielectric elastomer generator with diaphragm configuration

2018 ◽  
Vol 192 ◽  
pp. 01032
Author(s):  
Zhen-Qiang Song ◽  
Sriyuttakrai Sathin ◽  
Wei Li ◽  
Kazuhiro Ohyama ◽  
ShiJie Zhu
Keyword(s):  
Energy Density ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Energy Conversion Efficiency ◽  
Dielectric Elastomer ◽  
Maximum Energy ◽  
Constant Voltage ◽  
Low Viscosity ◽  
65 J ◽  
Low Efficiency

The dielectric elastomer generator (VHB 4905, 3M) with diaphragm configuration was investigated with the constant-voltage harvesting scheme in order to investigate its energy harvesting ability. The maximum energy density and energy conversion efficiency is measured to be 65 J/kg and 5.7%, respectively. The relatively low efficiency indicates that higher energy conversion efficiency is impeded by the viscosity of the acrylic elastomer, suggesting that higher conversion efficiency with new low-viscosity elastomer should be available.

Energy conversion efficiency of thermoelectric power generators with cylindrical legs

2021 ◽  
pp. 1-23
Author(s):  
Dandan Pang ◽  
Aibing Zhang ◽  
Zhenfei Wen ◽  
Baolin Wang ◽  
Ji Wang
Keyword(s):  
Theoretical Model ◽  
Impact Factor ◽  
Energy Conversion ◽  
Conversion Efficiency ◽  
Heat Sink ◽  
Energy Conversion Efficiency ◽  
Maximum Energy ◽  
Factor H ◽  
Heat Convection ◽  
Power Generators

Abstract Thermoelectric power generators (TEGs) have been attracted increasing attention recently due to their capability of converting waste heat into useful electric energy without hazardous emissions. This paper develops a theoretical model to analyze the thermoelectric performance of TEGs with cylindrical legs. The influence of heat convection loss between lateral surfaces of thermoelectric legs and ambient environment on the energy conversion efficiency is investigated. For the idealized model, closed-form solutions of optimal electric current, maximum power output and maximum energy conversion efficiency are obtained, a new dimensionless impact factor H is introduced to capture the heat convection effect. The impact factor H depends on the ratio of heat conductivity to heat convection coefficient and geometry size of thermoelectric legs, as well as the temperature ratio of heat sink to hot source. The performance can be evaluated by the figure of merit, impact factor H and temperature gradient across the hot source and heat sink for a well-designed TEG with cylindrical legs. For the case of considering contact resistance, it is found that there exists an optimal leg's height for maximum energy conversion efficiency due to the heat convection on lateral surfaces of thermoelectric leg. The proposed theoretical model in this paper will be very helpful in the designing of actual TEG devices.

scholarly journals Enhancement of the laser-driven proton source at PHELIX

2020 ◽  
Vol 8 ◽  
Author(s):  
J. Hornung ◽  
Y. Zobus ◽  
P. Boller ◽  
C. Brabetz ◽  
U. Eisenbarth ◽  
...  
Keyword(s):  
Conversion Efficiency ◽  
Proton Energy ◽  
Incidence Angle ◽  
Normal Incidence ◽  
Laser Pulses ◽  
Ion Acceleration ◽  
Laser Polarization ◽  
Temporal Contrast ◽  
Proton Source ◽  
Accelerated Particles

We present a study of laser-driven ion acceleration with micrometre and sub-micrometre thick targets, which focuses on the enhancement of the maximum proton energy and the total number of accelerated particles at the PHELIX facility. Using laser pulses with a nanosecond temporal contrast of up to $10^{-12}$ and an intensity of the order of $10^{20}~\text{W}/\text{cm}^{2}$ , proton energies up to 93 MeV are achieved. Additionally, the conversion efficiency at $45^{\circ }$ incidence angle was increased when changing the laser polarization to p, enabling similar proton energies and particle numbers as in the case of normal incidence and s-polarization, but reducing the debris on the last focusing optic.

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