128 research outputs found
Modelling and Measurement of the Opto-Galvanic Effect in the Positive Column of a Krypton Discharge.
No full text
Short-wavelength experiments on laser pulse interaction with extended pre-plasma at the PALS-installation
No full textThe paper is a continuation of research carried out at Prague Asterix Laser System (PALS) related to the shock ignition (SI) approach in inertial fusion, which was carried out with use of 1ω main laser beam as the main beam generating a shock wave. Two-layer targets were used, consisting of Cu massive planar target coated with a thin polyethylene layer, which, in the case of two-beam irradiation geometry, simulate conditions related to the SI scenario. The investigations presented in this paper are related to the use of 3ω to create ablation pressure for high-power shock wave generation. The interferometric studies of the ablative plasma expansion, complemented by measurements of crater volumes and K α emission, clearly demonstrate the effect of changing the incident laser intensity due to changing the focal radius on efficiency of laser energy transfer to a shock wave and fast electron emission. The efficiency of the energy transfer increases with the radius of the focused laser beam. The pre-plasma does not significantly change the character of this effect. However, it unambiguously results in the increasing temperature of fast electrons, the total energy of which remains very small (<0.1% of the laser energy). This study shows that the optimal radius from the point of view of 3ω radiation energy transfer to the shock wave is the maximal one used in these experiments and equal to 200 m that corresponds to the minimal effect of two-dimensional (2D)-expansion. Such a result is typical for the ablation process determined by electron conductivity energy transfer under the conditions of one-dimensional or 2D matter expansion without any appreciable effect due to energy transfer by fast electrons. The 2D simulations based on application of the ALANT-HE code and an analytical model that includes generation and transport of hot electrons has been used to support of experimental data
Bezpieczeństwo i higiena pracy w stosunkach pracy z wykorzystaniem nowoczesnych technologii
No full textThe article discusses the impact of modern technologies on the safety of the work process. The author indicates areas in which the technology (remote communication means, artificial intelligence algorithms) may threaten workers’ broadly understood safety. The author suggests problems such as excessive workload, difficulties in effectively using the right to rest, or isolation of employees. He emphasizes the need to ensure protection for workers. From this perspective, he assesses the existing legal framework and formulates conclusions for the future (e.g., the right to disconnect). He refers to supranational standards, European Union law, and national regulations.Artykuł analizuje wpływ nowoczesnych technologii na bezpieczeństwo procesu pracy. Autor wskazuje wybrane obszary, w których nowoczesne technologie (środki komunikacji na odległość, algorytmy sztucznej inteligencji) mogą stwarzać zagrożenie dla szeroko rozumianego bezpieczeństwa pracujących. Autor wskazuje takie problemy, jak nadmierne obciążanie pracą, trudności w efektywnym korzystaniu z prawa do wypoczynku czy izolacja pracowników. Podkreśla potrzebę zapewnienia ochrony pracującym. Z tej perspektywy ocenia istniejące ramy prawne oraz formułuje wnioski na przyszłość. Odnosi się do regulacji ponadnarodowych, w tym prawa Unii Europejskiej oraz przepisów krajowych
Legal expert opinion on the bill amending the Act – Labour Code and some other acts (Sejm Paper No. 3288) (BAS-791/15)
No full textThe bill is an important step toward combining professional activity with family responsibilities. The opinion confirms that the bill considerably improves the organization of the work process and introduces significant changes in the sphere of rights related to parenthood, including leave pooling in order to provide care. Despite this positive assessment, the author points out that the bill does not constitute culmination of a long evolution of the provisions of Section VIII of the Labour Code and that the actions of the legislature should be more intensive
Pre-plasma effect on laser beam energy transfer to a dense target under conditions relevant to shock ignition
No full textThis paper reports on properties of a plasma formed by sequential action of two laser beams on a flat target, simulating the conditions of shock-ignited inertial confinement fusion target exposure. The experiments were performed using planar targets consisting of a massive copper (Cu) plate coated with a thin plastic (CH) layer, which was irradiated by the 1ω PALS laser beam (λ = 1.315 μm) at the energy of 250 J. The intensity of the fixed-energy laser beam was scaled by varying the focal spot radius. To imitate shock ignition conditions, the lower-intensity auxiliary 1ω beam created CH-pre-plasma which was irradiated by the main beam with a delay of 1.2 ns, thus generating a shock wave in the massive part of the target. To study the parameters of the plasma treated by the two-beam irradiation of the targets, a set of various diagnostics was applied, namely: (i) Two-channel polaro-interferometric system irradiated by the femtosecond laser (∼40 fs), (ii) spectroscopic measurements in the X-ray range, (iii) two-dimensional (2D)-resolved imaging of the Kα line emission from Cu, (iv) measurements of the ion emission by means of ion collectors, and (v) measurements of the volume of craters produced in a massive target providing information on the efficiency of the laser energy transfer to the shock wave. The 2D numerical simulations have been used to support the interpretation of experimental data. The general conclusion is that the fraction of the main laser beam energy deposited into the massive copper at two-beam irradiation decreases in comparison with the case of pre-plasma. The reason is that the pre-formed and expanding plasma deteriorates the efficiency of the energy transfer from the mai Copyright © Cambridge University Press 2015
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