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We present a detailed analysis of the spectrum of satellite transitions to the n = 23 and n = 2–4 Ne-like yttrium resonance lines. Satellite lines from the double excited 2s22p53l3l', 2s22p53l4l', 2s2p63l3l' and 2s2p63l4l' levels of Na-like Y as well as from 2s22p53l3l'3l" and 2s2p63l3l'3l" levels of Mg-like Y were observed in spectra from a laser-produced plasma. The x-ray spectra were recorded with high spectral resolution λ/Δλ ≈ 3500–5000 in the wavelength region of the n = 2–3 Ne-like resonance lines and with λ/Δλ > 1000 in the region of the n = 2–4 Ne-like resonance lines. A total of more than 50 spectral features were identified, and their wavelengths were measured. A simple intensity model was developed, which agreed well with the measured spectra and assisted the line identification. The consistency of the model for different spectral regions demonstrates the potential of the Na-like and Mg-like satellite lines for diagnosing plasma conditions.

X-Ray spectroscopy methods were used in an investigation of the spectra of plasmas formed from Mg, Al, Ge, Mo, and Ta targets by heating with iodine laser radiation of power density (3-5)x10{sup 14} W cm{sup {minus}2}. In the case of Ta targets the presence of Ta{sup 45+,46+} ions was detected. This information should help in the development of laser-plasma sources of multiply charged ions. The spectra were identified and the plasma parameters were measured. 18 refs., 4 figs., 3 tabs.

An investigation was made of a plasma formed by heating a gas target with neodymium gas laser radiation of ~15 GW power. The working substance was gaseous SF6. The x-ray emission spectra of sulfur and fluorine ions were investigated with one- and two-dimensional spatial resolution. These spectra were recorded by a high-resolution high-luminosity spectrograph with a mica crystal bent to form a sphere with a radius of R = 10 cm. Laser breakdown of a gas puff produced a sufficiently compact near-spherical plasma formation of ~2.5 mm size and with the electron temperature at least 470 eV.

We present an analysis of dielectronic satellite spectra of 2p6-2s2p63p Ne-like krypton resonance lines. The satellite structure was registered with high (better than ?/?? > 3500) spectral resolution in the emission of a laser irradiated gas puff target. We perform an unambiguous identification of satellite lines caused by radiative transitions from autoionizing states of sodium-like krypton ions. A total of about 20 spectral features are identified, most of them for the first time. Very good agreement between the satellite structure calculations and experimental emission spectra is obtained.

We present an analysis of dielectronic satellite spectra of Ne-like ion resonance lines for elements from Cr to Ni. For these low-Z elements, we use spectra from strongly underionized CO2-laser produced plasma to minimize the emission from open L-shell ions. This simplifies the spectra and allows the identification of satellite lines caused by radiative transitions from autoionizing states of sodium like ions. Good agreement between the satellite structure calculations and the experimental emission spectra is obtained.

The spectrum of dielectronic satellites of resonance lines of the neon-like selenium ion was analyzed experimentally and theoretically. The satellite line spectrum resulting from stabilizing radiative transitions from doubly excited states of the sodium-like selenium ion to nonautoionizing states was obtained using a laser plasma and a record spectral resolution of λ/Δλ ≈ 5000–8000. A detailed analysis is given of the laser plasma x-ray emission spectrum in the range 7.2–8.8 A, more than 300 lines or compact groups of spectral lines were identified, and their wavelengths were measured with an error of ±5−10−4 A.The good agreement between the modeled and experimental spectra indicates that the emission spectrum of Na-like ions shows promise for use in high-temperature plasma diagnostics.

Precision measurements were made of the wavelengths of the satellites of the resonance line of the H-like Mg XII ion as well as of a number of transitions in the Ne-like Ge XXIII ion and their satellites in a plasma created by radiation generated in an Nd-glass laser. The measurements were carried out with a high-resolution, high-luminosity spectrograph containing a mica crystal bent to a spherical surface with a radius R = 100 mm. The absolute wavelength obtained for the 2s22p6 1So—2s2p63p 3P1 transition in Ge XXIII was λ = 842.08 ± 0.09 pm. The results demonstrated that the short-wavelength component of the Lyman doublet of Mg XII (λ = 841.92 pm) could be used to pump optically a short-wavelength laser by transitions in the Ge XXIII ion.

A high luminosity spectrometer with a spherically bent mica crystal has been used to obtain H- and He-like spectra of Al and Si ions in X-pinch plasma with high spectral (λ/Δλ ∼ 3000) and spatial (∼ 30 μm) resolution. The electron density (up to 2.1024 cm-3) and the temperature (up to 950 eV) in the “hot point” were measured by means of X-ray spectroscopy methods. The estimates show, that the emission of K-line radiation can be up to 1 J, the power being 109 W). The total energy emitted in the spectral region 5–100 A is about 1 kJ.

A study has been made of the x-ray emission spectra of zinc ions (λ ~0.65–1.18 nm) excited in a plasma produced by the beam from a Nd laser. The wavelengths were measured within ±0.3 pm. The observed spectra have been identified. Detailed calculations have made it possible to identify, for the first time, some spectra lines due to the radiative decal of autoionizing states of Na-like zinc ions.

The properties of a magnesium plasma heated by picosecond laser pulses have been determined by x-ray spectral methods. Experiments were carried out at a laser power density ~ 1.5 1018 W/cm2. The x-ray spectra were detected by spectrographs with a plane CsAP crystal and a mica crystal bent into part of a spherical surface 10 cm in radius. The experimental data are compared with predictions of a calculation on the time-varying kinetics of multiply charged magnesium ions.

A high-transmission spectrograph equipped with a spherical mica crystal was used to study x-ray emission from an X-pinch plasma at high spectral (?/?? ~ 3000) and spatial (~30 ?m) resolutions. H- and He-like spectra of Al and Si ions generated in the X-pinch were detected both in the stage of maximum compression and in the dispersal stage. The electron temperature (up to 950 eV) and density (up to 2 ? 1024 cm?3 ) of the plasma at the hot point and also in the dispersal stage were measured by x-ray spectral methods. Energy estimates show that the radiation output in the K lines can reach 1 J (the corresponding power is 1 GW). The overall energy radiated in the wavelength region 0.5 to 10 nm is ~1 kJ. This result indicates that the radiation from the hot point of an X-pinch plasma can be an effective pumping source for the active medium of an x-ray laser. It also indicates that the recombining plasma dispersing out of the hot region can itself be used as an active medium for short-wavelength lasers.

We have investigated the kinetics of doubly excited sodium‐like copper states with 3131’ and 3141’ configurations, and the feasibility of photopumped x‐ray lasing schemes and plasma diagnostics using transitions from these levels. These x‐ray lasing schemes, like similar lasing schemes in Li‐like ions, have high quantum efficiency and potentially reduced radiative trapping effects. In addition, the satellite transitions emitted by these sodium‐like levels may provide valuable diagnostics of x‐ray laser plasmas.

The review of X‐pinch investigations in high current diode of BIN facility (250 kA, 100 ns) is presented. The main purposes were to investigate pinch forming processes and hot dense plasma properties. X‐pinch is also considered as a source for multiple charged ions spectroscopy and for X‐ray optics testing. The set of diagnostics applied in these experiments allowed us to investigate the pinch forming processes in different configurations of crossed wires loads. High spectral and space resolved measurements of plasma radiation in 1–200 A range, absolute energy measurements and electron beam registration were provided. Plasma parameters were obtained from relative intensities and shapes of multiple charged ions spectral lines. Electron density of plasma with the temperature Te = 0.2–1 keV variated from 1023 cm−3 in hot spot to 1018 cm−3 during plasma expansion. In recombining plasma, an inversion of Al He‐like ions levels population was registrated. Total radiation output of 0.5 mm pinch reached hundreds Joules in 2–100 A range during 100 ns.The review of X‐pinch investigations in high current diode of BIN facility (250 kA, 100 ns) is presented. The main purposes were to investigate pinch forming processes and hot dense plasma properties. X‐pinch is also considered as a source for multiple charged ions spectroscopy and for X‐ray optics testing. The set of diagnostics applied in these experiments allowed us to investigate the pinch forming processes in different configurations of crossed wires loads. High spectral and space resolved measurements of plasma radiation in 1–200 A range, absolute energy measurements and electron beam registration were provided. Plasma parameters were obtained from relative intensities and shapes of multiple charged ions spectral lines. Electron density of plasma with the temperature Te = 0.2–1 keV variated from 1023 cm−3 in hot spot to 1018 cm−3 during plasma expansion. In recombining plasma, an inversion of Al He‐like ions levels population was registrated. Total radiation output of 0.5 mm pinch reached hundreds J...

Transitions from the doubly excited 2s22p53l4l′ and 2s2p63l4l′ levels of Na-like Kr25+ were observed in spectra from plasmas produced in laser-irradiated gas-puff targets. These transitions produce satellites to n = 3–2 and n = 4–2 Ne-like Kr26+ resonance lines. High-resolution x-ray spectra were measured with a relative uncertainty of ±0.001 A by means of a spherical crystal spectrograph. A simple kinetics model was successfully used to model the experimental spectra, to assist the line identification, and to demonstrate the potential of these lines for diagnosing the plasma conditions. In addition, contributions of these lines to x-ray spectra should be taken into account in the analysis of n = 4–2 Ne-like linewidth diagnostics proposed for electron density measurements in compressed inertial confinement fusion plasmas.

A comparative analysis was made of the various methods for heating a laser plasma with Nd laser radiation. Methods of heating with the first and second harmonic pulses of different durations were compared. Diagnostics by x-ray spectroscopy yielded the parameters of a recombining plasma (temperature and density) and the populations of excited levels of the Al XII ion at different distances from the surface of an aluminum target. The experimental results on population inversion of the excited levels were compared with theoretical calculations.

Experiments are described in which a high-current electron accelerator is used to generate, by Al wire explosion, super-high-density (Ne=5*1022 cm-3), high-temperature (Te approximately=400 eV) plasmas. The X-ray emission characteristics of the plasma are analysed.

An experimental investigation was made of the expansion of an aluminum laser plasma into vacuum. X-ray spectral methods were used to determine the plasma parameters (temperature, density, and ionization state) and the ion distribution in terms of excited levels. A qualitative and quantitative interpretation of the experimental data is given and an estimate is obtained for the gains due to far ultraviolet (λ = 76–280 A) transitions in the Al XII ion.

An investigation was made of the formation of the active medium of a recombination laser utilizing the 4f–5g transition in the Be IV ion in an expanding laser plasma formed from a solid-state target. Spectroscopic methods were used to determine the electron density and temperature in the lasing zone. These parameters were used to find the gain due to the 4f–5g transition in the Be IV ion: at distances x 0.4 cm from the target the gain was 5 × 10 − 2–10 −1 cm −1. These values were close to the gain deduced experimentally from the threshold characteristics of the lasing process.