1,721,349 research outputs found
X-RAY-EMISSION FROM THIN-FOIL LASER-PRODUCED PLASMAS
No full textWe studied X-ray emission from laser plasmas produced by irradiation of thin plastic foils with 1.064-mu-m Nd laser light at intensity up to 2 x 10(13) W/cm2 with 3-ns pulses. The level of X-ray emission at different spectral windows was measured versus laser intensity and foil thickness. The electron temperature of the X-ray source was also measured. At intensity above 6 x 10(12) W/cm2 our data showed the formation of nonthermal tails in the X-ray spectrum, which has been related to two plasmon decay instability
Measurement and characterization of cellular metabolic activity by CO2 production and soft X-ray irradiation
No full textX-ray emission from thin-foil laser-produced plasmas
No full textWe studied X-ray emission from laser plasmas produced by irradiation of thin plastic foils with 1.064-mu-m Nd laser light at intensity up to 2 x 10(13) W/cm2 with 3-ns pulses. The level of X-ray emission at different spectral windows was measured versus laser intensity and foil thickness. The electron temperature of the X-ray source was also measured. At intensity above 6 x 10(12) W/cm2 our data showed the formation of nonthermal tails in the X-ray spectrum, which has been related to two plasmon decay instability
Advances in target normal sheath acceleration theory
No full textA theoretical model of the Target Normal Sheath Acceleration (TNSA) process, able to go beyond the limits of available descriptions, is developed. It allows to achieve a more satisfactory interpretation of TNSA. The theory, also supported by two dimensional particle-in-cell simulations, elucidates the role played by the main laser and target parameters. Comparison between model predictions and experimental data related to the target thickness dependence of the maximum ion energy is discussed, showing satisfactory agreement. The model can be used as a simple but effective tool to guide the design of future experiments. © 2013 AIP Publishing LLC
Target normal sheath acceleration analytical modeling, comparative study and developments
No full textUltra-intense laser interaction with solid targets appears to be an extremely promising technique to accelerate ions up to several MeV, producing beams that exhibit interesting properties for many foreseen applications. Nowadays, most of all the published experimental results can be theoretically explained in the framework of the target normal sheath acceleration (TNSA) mechanism proposed by Wilks [Phys. Plasmas 8(2), 542 (2001)10.1063/1.1333697]. As an alternative to numerical simulation various analytical or semi-analytical TNSA models have been published in the latest years, each of them trying to provide predictions for some of the ion beam features, given the initial laser and target parameters. However, the problem of developing a reliable model for the TNSA process is still open, which is why the purpose of this work is to enlighten the present situation of TNSA modeling and experimental results, by means of a quantitative comparison between measurements and theoretical predictions of the maximum ion energy. Moreover, in the light of such an analysis, some indications for the future development of the model proposed by Passoni and Lontano [Phys. Plasmas 13(4), 042102 (2006)10.1063/1.2184067] are then presented. © 2012 American Institute of Physics
Studies on laser-plasma interaction physics for shock ignition
No full textWe realized a series of experiments to study the physics of laser-plasma interaction in an intensity regime of interest for the novel "Shock Ignition" approach to Inertial Fusion. Experiments were performed at the Prague Asterix Laser System laser in Prague using two laser beams: an "auxiliary" beam, for pre-plasma creation, with intensity around 7 × 1013 W/cm2 (250 ps, 1ω, λ = 1315 nm) and the "main" beam, up to 1016 W/cm (250 ps, 3ω, λ = 438 nm), to launch a shock. The main goal of these experiments is to study the process of the formation of a very strong shock and the influence of hot electrons in the generation of very high pressures. The shock produced by the ablation of the plastic layer is studied by shock breakout chronometry. The generation of hot electrons is analyzed by imaging Kα emission
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