Study on impulse and ablation of aluminum irradiated by millimeter spot of short pulse laser

Abstract Aluminum is a high performance working medium for laser ablation micro propulsion. In order to study the propulsion performance and ablation of aluminum under millimeter light spot irradiation, a short pulse Nd: YAG laser with wavelength of 1064nm and pulse width of 8NS was used to irradiate aluminum target in atmosphere. The impulse, the impulse coupling coefficient and the ablation morphology of the aluminum target produced by 6 kinds of millimeter-level light spots are measured. The experimental results show that when the spot diameter reaches 6-7mm, the increasing trend of impulse and impulse coupling coefficient of aluminum target with the increase of laser energy slows down; A large number of ablation products began to accumulate on the surface of the target pit.

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A Study on the Plasma Plume Expansion Dynamics of Nanosecond Laser Ablating Al/PTFE

Energies ◽

10.3390/en13133321 ◽

2020 ◽

Vol 13 (13) ◽

pp. 3321

Author(s):

Sheng Tan ◽

Moge Wang ◽

Jianjun Wu ◽

Yu Zhang ◽

Jian Li

Keyword(s):

Plasma Plume ◽

Laser Energy ◽

Short Pulse ◽

Ambient Pressure ◽

Rapid Expansion ◽

Nanosecond Laser ◽

Expansion Process ◽

Plume Expansion ◽

Plume Front ◽

Short Pulse Laser

To study the plasma plume expansion dynamics of nanosecond laser ablating Al/PTFE, the Al/PTFE propellant was prepared by a molding sintering method and the rapid expansion process of the plasma plume was photographed using fast photography technology. The effects of the proportion of Al, laser energy and ambient pressure on plasma plume expansion dynamics are analyzed. The results show that the plume expansion process of laser ablating Al/PTFE plasma can be divided into three stages and this phenomenon has not been reported in the literature. The Al powder doped in PTFE will block part of the laser transmission into the propellant, thus reducing the laser absorption depth of the propellant. In the case of short pulse laser ablation, the reaction rate between Al and PTFE is optimal when the reductant is slightly higher than the oxidant. As the laser energy increases, the light intensity of the plasma becomes stronger, the plasma size becomes larger and the existence time of plasma becomes longer. In the first stage plume, the plume expands freely at the ambient pressure of 0.005 Pa and the plume expansion distance is linearly related to time, while the shock wave formed at the interface between the plume front and the ambient gas at the ambient pressure of 5 Pa and the expansion can be described by S-T theory.

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X-ray characterization of short-pulse laser illuminated hydrogen storage alloys having very high performance

10.1117/12.2186898 ◽

2015 ◽

Author(s):

Hiroyuki Daido ◽

Hiroshi Abe ◽

Takahisa Shobu ◽

Takuya Shimomura ◽

Shinnosuke Tokuhira ◽

...

Keyword(s):

Hydrogen Storage ◽

Pulse Laser ◽

High Performance ◽

Short Pulse ◽

Hydrogen Storage Alloys ◽

X Ray ◽

Short Pulse Laser ◽

Very High

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Simulation study of short-pulse laser energy conversion to x-ray line emission

10.1117/12.425554 ◽

2001 ◽

Author(s):

Jiri Limpouch ◽

A. B. Iskakov ◽

Aleksandr A. Andreev ◽

Hidetoshi Nakano

Keyword(s):

Energy Conversion ◽

Pulse Laser ◽

Simulation Study ◽

Laser Energy ◽

Short Pulse ◽

Line Emission ◽

X Ray ◽

Short Pulse Laser ◽

Pulse Laser Energy

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Nonlinear absorption of intense short pulse laser over a metal surface embedded with nanoparticles

Laser and Particle Beams ◽

10.1017/s0263034611000383 ◽

2011 ◽

Vol 29 (3) ◽

pp. 333-338 ◽

Cited By ~ 11

Author(s):

Ashok Kumar ◽

A. L. Verma

Keyword(s):

Metal Surface ◽

Laser Light ◽

Laser Energy ◽

Short Pulse ◽

Laser Frequency ◽

Angle Of Incidence ◽

Arbitrary Angle ◽

Short Pulse Laser ◽

High Laser ◽

Absorb Laser Energy

AbstractThe anomalous absorption of laser, incident at an arbitrary angle of incidence on a metal surface embedded with nanoparticles, is studied. The electrons inside a nanoparticle resonantly absorb laser energy when the laser frequency equals the frequency of surface charge oscillations of the nanoparticle. A monolayer of nanoparticles of radius rnp0 ≈ 50 A with inter-particle separation d ~ 10rnp0 can cause up to 40% reduction of the reflection of p-polarized laser light. The absorption coefficient increases with the angle of incidence and has a sharp peak at a resonant frequency width of about 1%. At high laser power, even if the nanoparticles are initially off resonant with the laser, the particle heating and subsequent expansion reduces the resonance frequency, and the resonance absorption is realized after a time delay. The delay is found to be directly proportional to the cluster size and inversely proportional to the laser intensities.

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Comparison of Thermal and Non-Thermal Ablation of Tumor Using Focused Short Pulse Laser Beam

ASME 2007 Summer Bioengineering Conference ◽

10.1115/sbc2007-176225 ◽

2007 ◽

Author(s):

Ashim Dutta ◽

Megan Kramer ◽

Molly Fahey ◽

Kunal Mitra ◽

Michael S. Grace

Keyword(s):

Surgical Resection ◽

Laser Energy ◽

Short Pulse ◽

Irradiation Time ◽

The Body ◽

Healthy Tissue ◽

Laser Source ◽

Fiber Optic Probe ◽

Volumetric Heating ◽

Short Pulse Laser

For last few decades laser-induced tumor ablation has attracted significant attention of researchers. The accessibility of tumors located deep inside the body organ using fiber-optic probe without any major surgical resection has made this method an alternative for conventional surgical resection. Various minimally invasive techniques have been developed are used to ablate the tumor successfully with minimum collateral damages [1, 2]. All these techniques utilize the photo-thermal mechanism where conversion of laser energy (mainly from CW or long pulsed laser source) to heat energy leads to necrosis of the tissue through photocoagulation. Since, the necrosis of tumor is achieved by volumetric heating of the whole tumor there remains a significant chance of heat spreading out of the tumor volume damaging surrounding healthy tissue. Therefore, precise control of treatment parameters (laser pulse width, laser power, and irradiation time) is required to restrict the heat spread to the healthy tissue surrounding the tumor.

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Boosted acceleration of protons by tailored ultra-thin foil targets

Scientific Reports ◽

10.1038/s41598-019-55011-2 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 2

Author(s):

Vural Kaymak ◽

Esin Aktan ◽

Mirela Cerchez ◽

Bentsian Elkin ◽

Marc Papenheim ◽

...

Keyword(s):

Laser Energy ◽

Numerical Study ◽

Short Pulse ◽

Thin Foil ◽

High Energy ◽

High Repetition Rate ◽

Acceleration Process ◽

Short Pulse Laser ◽

Laser Systems ◽

Target Energy

AbstractWe report on a detailed experimental and numerical study on the boosted acceleration of protons from ultra-thin hemispherical targets utilizing multi-Joule short-pulse laser-systems. For a laser intensity of 1 × 1020 W/cm2 and an on-target energy of only 1.3 J with this setup a proton cut-off energy of 8.5 MeV was achieved, which is a factor of 1.8 higher compared to a flat foil target of the same thickness. While a boost of the acceleration process by additionally injected electrons was observed for sophisticated targets at high-energy laser-systems before, our studies reveal that the process can be utilized over at least two orders of magnitude in intensity and is therefore suitable for a large number of nowadays existing laser-systems. We retrieved a cut-off energy of about 6.5 MeV of proton energy per Joule of incident laser energy, which is a noticeable enhancement with respect to previous results employing this mechanism. The approach presented here has the advantage of using structure-wise simple targets and being sustainable for numerous applications and high repetition rate demands at the same time.

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X-ray emission from hollow atoms produced by collisions of multiply charged ions with a solid

Laser and Particle Beams ◽

10.1017/s0263034601194115 ◽

2001 ◽

Vol 19 (4) ◽

pp. 643-646 ◽

Cited By ~ 4

Author(s):

KENGO MORIBAYASHI ◽

KEIKO SUTO ◽

A. ZHIDKOV ◽

AKIRA SASAKI ◽

TAKASHI KAGAWA

Keyword(s):

Pulse Laser ◽

Laser Energy ◽

Short Pulse ◽

Multiply Charged Ions ◽

Atomic Process ◽

High Conversion Efficiency ◽

X Ray ◽

Short Pulse Laser ◽

Multiply Charged ◽

Charged Ions

The X-ray emission from hollow atoms produced by collisions of multiply charged ions accelerated by a short pulse laser with a solid or foil is studied theoretically. The possibility of obtaining a high conversion efficiency X-ray source in an ultrafast atomic process (∼1 fs) is demonstrated using the multistep-capture-and-loss (MSCL) model. Such an X-ray source has a clear advantage for the spectral range around a few kiloelectron volts over the conventional Kα X-ray source. Namely, the number of X-ray photons increases as the laser energy becomes larger and could reach 3 × 1011 photons for a laser energy of about 10 J.

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Effects of Focusing Condition on Micro-Welding Characteristics of Borosilicate Glass by Picosecond Pulsed Laser

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.656-657.461 ◽

2015 ◽

Vol 656-657 ◽

pp. 461-467 ◽

Cited By ~ 2

Author(s):

Tomohiro Takekuni ◽

Yasuhiro Okamoto ◽

Takahiro Fujiwara ◽

Akira Okada ◽

Isamu Miyamoto

Keyword(s):

Laser Energy ◽

Short Pulse ◽

Spherical Aberration ◽

Energy Condition ◽

Pulsed Laser ◽

Aberration Correction ◽

Short Pulse Laser ◽

Heating And Cooling ◽

High Space ◽

Ultra Short Pulse

Glass materials are widely used in products such as optical components and semiconductor devices. In these products, precision welding techniques of glass are required to manufacture small and complicated shape. The laser welding method can perform the joining without an intermediate layer and an adhesive agent. In addition, an ultra-short pulse laser can reduce the heat affected zone with the high space accuracy. However, heating and cooling cycles are repeated even in the case of ultra-short pulsed laser. The temperature distribution and change of molten area are influenced not only by laser energy condition but also focusing condition. Therefore in this study, effects of focusing condition of laser beam on micro-welding characteristics of glass were experimentally investigated by using a picosecond pulsed laser. A usage of object lens with the spherical aberration correction led to a large molten area even at the same pulse energy, which related to the efficient welding of glass materials. An optical system with the spherical aberration correction led to stabilizing the shape of molten area, which resulted in the reliable weld joint.

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Solving a System of Differential Equations Containing a Diffusion Equation with Nonlinear Terms on the Example of Laser Heating in Silicon

Applied Sciences ◽

10.3390/app10051853 ◽

2020 ◽

Vol 10 (5) ◽

pp. 1853

Author(s):

Vladimir Lipp ◽

Baerbel Rethfeld ◽

Martin Garcia ◽

Dmitry Ivanov

Keyword(s):

Differential Equations ◽

Diffusion Equation ◽

Laser Energy ◽

Short Pulse ◽

Silicon Film ◽

System Of Differential Equations ◽

Time Step ◽

Integration Algorithm ◽

Short Pulse Laser ◽

Predictor Corrector

We present a finite-difference integration algorithm for solution of a system of differential equations containing a diffusion equation with nonlinear terms. The approach is based on Crank–Nicolson method with predictor–corrector algorithm and provides high stability and precision. Using a specific example of short-pulse laser interaction with semiconductors, we give a detailed description of the method and apply it to the solution of the corresponding system of differential equations, one of which is a nonlinear diffusion equation. The calculated dynamics of the energy density and the number density of photoexcited free carriers upon the absorption of laser energy are presented for the irradiated thin silicon film. The energy conservation within 0.2 % has been achieved for the time step 10 8 times larger than that in case of the explicit scheme, for the chosen numerical setup. The implemented Fortran source code is available in the Supplementary Materials. We also present a few examples of successful application of the method demonstrating its benefits for the theoretical studies of laser–matter interaction problems. Finally, possible extension to 2 and 3 dimensions is discussed.

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