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Investigation of low-temperature plasmas formed in low-density gases surrounding laser-produced plasmas

Majszyk Mateusz, Bartnik Andrzej, Skrzeczanowski Wojciech, Fok Tomasz, Węgrzyński Łukasz, Szczurek Mirosław, Fiedorowicz Henryk

Nukleonika

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2023

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Vol. 68, No. 1

11--17

EN

Low-temperature plasma production is possible as a result of photoionization using high-intensity extreme ultraviolet (EUV) and soft X-ray (SXR) pulses. Plasma of this type is also present in outer space, e.g., aurora borealis. It also occurs when high-velocity objects enter the atmosphere, during which period high temperatures can be produced locally by friction. Low-temperature plasma is also formed in an ambient gas surrounding the hot laser-produced plasma (LPP). In this work, a special system has been prepared for investigation of this type of plasma. The LPP was created inside a chamber fi lled with a gas under a low pressure, of the order of 1–50 mbar, by a laser pulse (3–9 J, 1–8 ns) focused onto a gas puff target. In such a case, the SXR/EUV radiation emitted from the LPP was partially absorbed in the low-density gas. In this case, high- and low-temperature plasmas (Te ~100 eV and ~1 eV, respectively) were created locally in the chamber. Investigation of the EUV-induced plasmas was performed mainly using spectral methods in ultraviolet/visible (UV/VIS) light. The measurements were performed using an echelle spectrometer, and additionally, spatial–temporal measurements were performed using an optical streak camera. Spectral analysis was supported by the PGOPHER numerical code.

2

Elementy optyczne pracujące w widmowym zakresie obejmującym ultrafiolet próżniowy i miękkie promieniowanie rentgenowskie

Wardzińska Martyna, Wachulak Przemysław

Biuletyn Wojskowej Akademii Technicznej

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2022

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Vol. 71, nr 2

49--83

PL

W artykule zawarto podstawy fizyczne i przegląd elementów optycznych do pracy w zakresie obejmującym ultrafiolet próżniowy (eUV) oraz miękkie promieniowanie rentgenowskie (SXr). Pierwszy rozdział obejmuje wprowadzenie do analizowanej tematyki i podstawy fizyczne. W drugim rozdziale przedstawione zostały podstawy działania optyki związanej z zakresem eUV/SXr wraz z wyróżnieniem jej wad oraz zalet. W trzecim rozdziale szczegółowo omówiono elementy optyczne, takie jak: filtry optyczne, zwierciadła (m.in. wielowarstwowe), siatki dyfrakcyjne, płytki strefowe Fresnela oraz rozwiązania hybrydowe. rozdział czwarty przedstawia szeroki obszar zastosowań optyki eUV/SXr. W ostatnim rozdziale znajduje się podsumowanie przedstawionych wcześniej informacji.

EN

The article presents the physical basis and overview of optical elements for the range including extreme ultraviolet (eUV) and soft X-ray (SXr). The first chapter contains an introduction to the subject under review and physical fundamentals. The second chapter presents the basics of optics for the eUV/SXr range, along with highlighting its advantages and disadvantages. The third chapter discusses in detail optical components such as optical filters, mirrors (including multilayers), diffraction gratings, Fresnel zone plates, and hybrid solutions. The fourth chapter presents a wide range of applications of eUV/SXr optics. The final chapter summarises the information presented earlier.

3

Wideband spectral emission measurements from laser-produced plasma EUV/SXR source based on a double gas puff target

Arikkatt Antony Jose, Wachulak Przemysław, Fiedorowicz Henryk, Bartnik Andrzej, Czwartos Joanna

Metrology and Measurement Systems

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2020

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Vol. 27, nr 4

701--719

EN

We present spectral emission characteristics from laser-plasma EUV/SXR sources produced by irradiation of < 1 J energy laser pulse on eleven different double stream gas puff targets, with most intense electronic transitions identified in the spectral range from 1 nm to 70 nm wavelength which corresponds to photon energy from 18 eV to 1240 eV. The spectra were obtained using grazing incidence and transmission spectrographs from laser-produced plasma emission, formed by the interaction of a laser beam with a double stream gas puff target. Laser pulses with a duration of 4 ns and energy of 650 mJ were used for the experiment. We present the results obtained from three different spectrometers in the wavelength ranges of SXR (1-5.5 nm), SXR/EUV (4-15.5 nm), and EUV (10-70 nm). In this paper, detailed information about the source, gas targets under investigation, the experimental setup, spectral measurements and the results are presented and discussed. Such data may be useful for the identification of adequate spectral emissions from gasses in the EUV and SXR wavelength ranges dedicated to various experiments (i.e. broadband emission for the X-ray coherence tomography XCT) or may be used for verification of magnetohydrodynamic plasma codes.

4

Recent advancements in the “water-window” microscopy with laser-plasma SXR source based on a double stream gas-puff target

Wachulak P. W.

Opto-Electronics Review

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2016

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Vol. 24, No. 3

144--154

EN

An overview of our recent developments, regarding “water−window” soft X−ray (SXR) microscopy based on a laser−plasma double stream gas puff target sources is presented. The work, presented herein, describes two approaches to SXR microscopy. The first one is a low spatial resolution, achromatic SXR microscopy, employing Wolter type−I objective. The second one is a nanometer spatial resolution SXR microscopy, with the use of a Fresnel zone plate objective, for imaging various objects with quasimonochromatic light, emitted from a double stream gas puff target based short wavelength source. The developments regarding both systems are presented, as well as the possible applications, for which the SXR microscope was already employed. Such compact, table−top size, laboratory type microscopy setups may be employed in the near future for complementary−like studies to other, often used, microscopy techniques.

5

Optimization of soft X-ray tomography on the COMPASS tokamak

Imríšek M., Mlynář J., Löffelmann V., Weinzettl V., Odstrčil T., Odstrčil M., Tomeš M.

Nukleonika

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2016

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Vol. 61, No. 4

403--408

EN

The COMPASS tokamak is equipped with the soft X-ray (SXR) diagnostic system based on silicon photodiode arrays shielded by a thin beryllium foil. The diagnostic is composed of two pinhole cameras having 35 channels each and one vertical pinhole camera with 20 channels, which was installed recently to improve tomographic inversions. Lines of sight of the SXR detectors cover almost complete poloidal cross section of the COMPASS vessel with a spatial resolution of 1–2 cm and temporal resolution of about 3 s. Local emissivity is reconstructed via Tikhonov regularization constrained by minimum Fisher information that provides reliable and robust solution despite limited number of projections and ill-conditionality of this task. Improved border conditions and numerical differentiation matrices suppressing artifacts in reconstructed radiation were implemented in the code. Furthermore, a fast algorithm eliminating iterative processes was developed, and it is foreseen to be tested in real-time plasma control.

6

Laser-plasma extreme ultraviolet and soft X-ray sources based on a double stream gas puff target : interaction of the radiation pulses with matter

Bartnik A.

Opto-Electronics Review

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2015

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Vol. 23, No. 2

172-186

EN

In this work a review of investigations concerning interaction of intense extreme ultraviolet (EUV) and soft X-ray (SXR) pulses with matter is presented. The investigations were performed using laser-produced plasma (LPP) EUV/SXR sources based on a double stream gas puff target. The sources are equipped with dedicated collectors allowing for efficient focusing of the EUV/SXR radiation pulses. Intense radiation in a wide spectral range, as well as a quasi-monochromatic radiation can be produced. In the paper different kinds of LPP EUV/SXR sources developed in the Institute of Optoelectronics, Military University of Technology are described. Radiation intensities delivered by the sources are sufficient for different kinds of interaction experiments including EUV/SXR induced ablation, surface treatment, EUV fluorescence or photoionized plasma creation. A brief review of the main results concerning this kind of experiments performed by author of the paper are presented. However, since the LPP sources cannot compete with large scale X-ray sources like synchrotrons, free electron lasers or high energy density plasma sources, it was indicated that some investigations not requiring extreme irradiation parameters can be performed using the small scale installations. Some results, especially concerning low temperature photoionized plasmas are very unique and could be hardly obtained using the large facilities.

7

Second order reflection from crystals used in soft X-ray spectroscopy

Książek I.

Nukleonika

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2015

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Vol. 60, No. 2

263--265

EN

In this note the ratio of the second to the first order reflection is determined for the KAP and PbSt crystals, for wavelengths corresponding to the Al K-line emission. The source of the radiation was a low-voltage stabilized X-ray tube. The X-rays were detected with a Bragg spectrometer equipped with a proportional counter detector. The signal measured by the proportional counter was subsequently pulse height analyzed.

8

XUV and soft X-ray laser radiation from nickel-like lanthanide

Abdelaziz W. S., Hamed H. M., Farrag A. A. H.

Optica Applicata

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2011

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Vol. 41, nr 4

971--978

EN

Atomic structure data and effective collision strengths for 1s2 2s2 2p6 3s2 3p6 3d10 and 54 fine-structure levels contained in the configurations 1s2 2s2 2p6 3s2 3p6 3d9 4l (l = s, p, d, f) for the nickel-like La ion have been investigated. These data are used in the determination of the reduced population for the 55 fine structure levels over a wide range of electron densities (from 1020 to 1022) and at various electron plasma temperatures. The gain coefficients for those transitions with positive population inversion factor are determined and plotted against the electron density.

9

Conceptual design of Light Impurity Monitor for Wendelstein 7-X

Książek I., Burhenn R., Musielok J.

Nukleonika

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2011

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Vol. 56, No. 2

155-160

EN

As plasma impurity ions can significantly influence the properties of a fusion plasma by dilution and enhancement of the radiation losses, the process of monitoring of their concentrations is one of the most important tasks. A Light Impurity Monitor is needed for monitoring the contamination of the stellarator plasma by carbon, nitrogen, boron, and oxygen impurities, which are indicators for the overload of the plasma facing components, leakage of the vacuum vessel, or wall condition, respectively. Their concentration will be estimated on the basis of emission intensities of their hydrogen-like ions. In this paper a conceptual design of such a spectrometer is presented, including the description of the geometry, the acquisition system and safety systems.