Journals >High Power Laser Science and Engineering
Contents
2014
Volume: 2 Issue 3
11 Article(s)
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High Energy Density Physics and High Power Laser 2014
Ultrafast ignition with relativistic shock waves induced by high power lasers
Shalom Eliezer, Noaz Nissim, Shirly Vinikman Pinhasi, Erez Raicher, and and Jose Maria Martinez Val
In this paper we consider laser intensities greater than 1016 W cm?2 where the ablation pressure is negligible in comparison with the radiation pressure. The radiation pressure is caused by the ponderomotive force acting mainly on the electrons that are separated from the ions to create a double layer (DL). This DL is In this paper we consider laser intensities greater than 1016 W cm?2 where the ablation pressure is negligible in comparison with the radiation pressure. The radiation pressure is caused by the ponderomotive force acting mainly on the electrons that are separated from the ions to create a double layer (DL). This DL is accelerated into the target, like a piston that pushes the matter in such a way that a shock wave is created. Here we discuss two novel ideas. Firstly, the transition domain between the relativistic and non-relativistic laser-induced shock waves. Our solution is based on relativistic hydrodynamics also for the above transition domain. The relativistic shock wave parameters, such as compression, pressure, shock wave and particle flow velocities, sound velocity and rarefaction wave velocity in the compressed target, and temperature are calculated. Secondly, we would like to use this transition domain for shockwave-induced ultrafast ignition of a pre-compressed target. The laser parameters for these purposes are calculated and the main advantages of this scheme are described. If this scheme is successful a new source of energy in large quantities may become feasible..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e22 (2014)
Regular Articles
A high energy nanosecond cryogenic cooled Yb:YAG active-mirror amplifier system
Xiaojin Cheng, Jianlei Wang, Zhongguo Yang, Jin Liu, Lei Li, Xiangchun Shi, Wenfa Huang, Jiangfeng Wang, and and Weibiao Chen
A diode-pumped master oscillator power amplifier system based on a cryogenic Yb:YAG active-mirror laser has been developed. The performances of the laser amplifier at low temperature and room temperature have been investigated theoretically and experimentally. A maximum output energy of 3.05 J with an optical-to-opticaA diode-pumped master oscillator power amplifier system based on a cryogenic Yb:YAG active-mirror laser has been developed. The performances of the laser amplifier at low temperature and room temperature have been investigated theoretically and experimentally. A maximum output energy of 3.05 J with an optical-to-optical efficiency of 14.7% has been achieved by using the master amplifier system..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e18 (2014)
Progress of the 10 J water-cooled Yb:YAG laser system in RCLF
Jian-Gang Zheng, Xin-Ying Jiang, Xiong-Wei Yan, Jun Zhang, Zhen-Guo Wang, Deng-Sheng Wu, Xiao-Lin Tian, Xiong-Jun Zhang, Ming-Zhong Li, Qi-Hua Zhu, Jing-Qin Su, Feng Jing, and and Wan-Guo Zheng
The high repetition rate 10 J/10 ns Yb:YAG laser system and its key techniques are reported. The amplifiers in this system have a multi-pass V-shape structure and the heat in the amplifiers is removed by means of laminar water flow. In the main amplifier, the laser is four-pass, and an approximately 8.5 J/1 Hz/10 ns ouThe high repetition rate 10 J/10 ns Yb:YAG laser system and its key techniques are reported. The amplifiers in this system have a multi-pass V-shape structure and the heat in the amplifiers is removed by means of laminar water flow. In the main amplifier, the laser is four-pass, and an approximately 8.5 J/1 Hz/10 ns output is achieved in the primary test. The far-field of the output beam is approximately 10 times the diffraction limit. Because of the higher levels of amplified spontaneous emission (ASE) in the main amplifier, the output energy is lower than expected. At the end we discuss some measures that can improve the properties of the laser system..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e27 (2014)
Bragg accelerator optimization
[in Chinese], and [in Chinese]
We present the first steps of a design of the optimal parameters for a full Bragg X-Ray free electron laser (BX-FEL). Aiming towards a future source of coherent X-ray radiation, operating in the strong Compton regime, we envisage the system to be the seed for an advanced light source or compact medical X-ray source. HeWe present the first steps of a design of the optimal parameters for a full Bragg X-Ray free electron laser (BX-FEL). Aiming towards a future source of coherent X-ray radiation, operating in the strong Compton regime, we envisage the system to be the seed for an advanced light source or compact medical X-ray source. Here we focus on the design of the accelerator parameters: maximum gradient, optimal accelerated charge, maximum efficiency, and ‘wake coefficient’, which relates to the decelerating electric field generated due to the motion of a charged-line or train of charged-lines. Specifically, we demonstrate that the maximum efficiency has optimal value and given the fluence of the materials, the maximum accelerated charge in the train is constant. These two results might be important in any future design..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e24 (2014)
EUV ablation of organic polymers at a high fluence
Chiara Liberatore, Klaus Mann, Matthias Muller, Ladislav Pina, Libor Juha, Jorge J. Rocca, Akira Endo, and and Tomas Mocek
A preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate) (PMMA) and poly (1,4-phenylene ether ether-sulfone) (PPEES) by extreme ultraviolet (EUV) radiation at 13.5 nm using a table-top laserproduced plasma from a gas-puff target at LLG (Gottingen) and at 46.9 nm by a 10 Hz desktoA preliminary investigation on short-wavelength ablation mechanisms of poly(methyl methacrylate) (PMMA) and poly (1,4-phenylene ether ether-sulfone) (PPEES) by extreme ultraviolet (EUV) radiation at 13.5 nm using a table-top laserproduced plasma from a gas-puff target at LLG (Gottingen) and at 46.9 nm by a 10 Hz desktop capillary discharge laser operated at the Institute of Physics (Prague) is presented. Ablation of polymer materials is initiated by photoinduced polymer chain scissions. The ablation occurs due to the formation of volatile products by the EUV radiolysis removed as an ablation plume from the irradiated material into the vacuum. In general, cross-linking of polymer molecules can compete with the chain decomposition. Both processes may influence the efficiency and quality of micro(nano)structuring in polymer materials. Wavelength is a critical parameter to be taken into account when an EUV ablation process occurs, because different wavelengths result in different energy densities in the near-surface region of the polymer exposed to nanosecond pulses of intense EUV radiation..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e26 (2014)
Nonlinear wake amplification by an active medium in a cylindrical waveguide using a modulated trigger bunch
Zeev Toroker, Miron Voin, and and Levi Schachter
Cerenkov wake amplification can be used as an accelerating scheme, in which a trigger bunch of electrons propagating inside a cylindrical waveguide filled with an active medium generates an initial wake field. Due to the multiple reflections inside the waveguide, the wake may be amplified significantly more strongly thCerenkov wake amplification can be used as an accelerating scheme, in which a trigger bunch of electrons propagating inside a cylindrical waveguide filled with an active medium generates an initial wake field. Due to the multiple reflections inside the waveguide, the wake may be amplified significantly more strongly than when propagating in a boundless medium. Sufficiently far away from the trigger bunch the wake, which travels with the same phase velocity as the bunch, reaches saturation and it can accelerate a second bunch of electrons trailing behind. For a CO2 gas mixture our numerical and analytical calculations indicate that a short saturation length and a high gradient can be achieved with a large waveguide radius filled with a high density of excited atoms and a trigger bunch that travels at a velocity slightly above the Cerenkov velocity. To obtain a stable level of saturated wake that will be suitable for particle acceleration, it is crucial to satisfy the single-mode resonance condition, which requires high accuracy in the waveguide radius and the ratio between the electron phase velocity and the Cerenkov velocity. For single-mode propagation our model indicates that it is feasible to obtain gradients as high as GV m?1 in a waveguide length of cm..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e29 (2014)
Generation of high-energy neutrons with the 300-ps-laser system PALS
J. Krasa, D. Klir, A. Velyhan, E. Krousky, M. Pfeifer, K. R ezac, J. Cikhardt, K. Turek, J. Ullschmied, and and K. Jungwirth
The laser system PALS, as a driver of a broad-beam ion source, delivered deuterons which generated neutrons with energies higher than 14 MeV through the 7Li(d, n)8Be reaction. Deuterons with sub-MeV energy were accelerated from the front surface of a massive CD2 target in the backward direction with respect to the laseThe laser system PALS, as a driver of a broad-beam ion source, delivered deuterons which generated neutrons with energies higher than 14 MeV through the 7Li(d, n)8Be reaction. Deuterons with sub-MeV energy were accelerated from the front surface of a massive CD2 target in the backward direction with respect to the laser beam vector. Simultaneously, neutrons were emitted from the primary CD2 target and a secondary LiF catcher. The total maximum measured neutron yield from 2D(d, n)3He, 7Li(d, n)8Be, 12C(d, n)13N reactions was ~3.5(±0.5) × 108 neutrons/shot..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e19 (2014)
Review
Wavefront measurement techniques used in high power lasers
Haiyan Wang, Cheng Liu, Xiaoliang He, Xingchen Pan, Shenlei Zhou, Rong Wu, and and Jianqiang Zhu
The properties of a series of phase measurement techniques, including interferometry, the Hartmann-Shack wavefront sensor, the knife-edge technique, and coherent diffraction imaging, are summarized and their performance in high power laser applications is compared. The advantages, disadvantages, and application ranges The properties of a series of phase measurement techniques, including interferometry, the Hartmann-Shack wavefront sensor, the knife-edge technique, and coherent diffraction imaging, are summarized and their performance in high power laser applications is compared. The advantages, disadvantages, and application ranges of each technique are discussed..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e25 (2014)
The all-diode-pumped laser system POLARIS-an experimentalist’s tool generating ultra-high contrast pulses with high energy
Marco Hornung, Hartmut Liebetrau, Andreas Seidel, Sebastian Keppler, Alexander Kessler, Jorg Korner, Marco Hellwing, Frank Schorcht, Diethard Klopfel, Ajay K. Arunachalam, Georg A. Becker, Alexander Savert, Jens Polz, Joachim Hein, and and Malte C. Kaluza
The development, the underlying technology and the current status of the fully diode-pumped solid-state laser system POLARIS is reviewed. Currently, the POLARIS system delivers 4 J energy, 144 fs long laser pulses with an ultra-high temporal contrast of 5×1012 for the ASE, which is achieved using a so-called doublThe development, the underlying technology and the current status of the fully diode-pumped solid-state laser system POLARIS is reviewed. Currently, the POLARIS system delivers 4 J energy, 144 fs long laser pulses with an ultra-high temporal contrast of 5×1012 for the ASE, which is achieved using a so-called double chirped-pulse amplification scheme and cross-polarized wave generation pulse cleaning. By tightly focusing, the peak intensity exceeds 3.5×1020 W cm-2. These parameters predestine POLARIS as a scientific tool well suited for sophisticated experiments, as exemplified by presenting measurements of accelerated proton energies. Recently, an additional amplifier has been added to the laser chain. In the ramp-up phase, pulses from this amplifier are not yet compressed and have not yet reached the anticipated energy. Nevertheless, an output energy of 16.6 J has been achieved so far..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e20 (2014)
Challenges of high power diode-pumped lasers for fusion energy
Bruno Le Garrec
This paper reviews the different challenges that are encountered in the delivery of high power lasers as drivers for fusion energy. We will focus on diode-pumped solid-state lasers and we will highlight some of the main recent achievements when using ytterbium, cryogenic cooling and ceramic gain media. Apart from some This paper reviews the different challenges that are encountered in the delivery of high power lasers as drivers for fusion energy. We will focus on diode-pumped solid-state lasers and we will highlight some of the main recent achievements when using ytterbium, cryogenic cooling and ceramic gain media. Apart from some existing fusion facilities and some military applications of diode-pumped solid-state lasers, we will show that diode-pumped solid-state lasers are scalable to inertial fusion energy (IFE)’s facility level and that the all-fiber laser scheme is very promising..
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e28 (2014)
Corrigendum
Design of kJ-class HiLASE laser as a driver for inertial fusion energy-CORRIGENDUM
Antonio Lucianetti, Magdalena Sawicka, Ondrej Slezak, Martin Divoky, Jan Pilar, Venkatesan Jambunathan, Stefano Bonora, Roman Antipenkov, and and Tomas Mocek
High Power Laser Science and Engineering
- Publication Date: Jan. 01, 1900
- Vol. 2, Issue 3, 03000e23 (2014)
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