Accurate wavelengths for highly-ionized L-shell spectra were measured in the 10–16Å region. The purpose being to determine lines in coincidence with L-shell transitions from the elements oxygen, fluorine, and neon. L-shell transitions have been proposed for resonant photopumping of K-shell electrons in these elements to, generate lasing between upper levels in the 40–150 eV region. The current effort improves on and expands the earlier spectroscopic work performed at KMS Fusion, Inc., where possible line coincidences were identified for photoionizing in the 1–3 and 1–4 levels in fluorine. New experimental techniques have led to a wavelength accuracy now believed to be ± 2 mÅ for cases in which adequate calibration lines are available. Exact spectral line matches were found for Mn with the F H,-line at 12.643Å and for both Mn and Cr with the F He line at 14.458Å. The Mn line at 12.643Å has been identified, using ab initio atomic structure calculations, as the 1D2 − 1F3 transition in Be-like Mn XXII. The Mn line emissivity was determined to be 30 MW into 2 steradians for a conversion efficiency of 0.04%. Photopumping with Mn coated gasfilled targets is presently being tried in gain measurement experiments at LLNL.

Many laboratories are actively investigating radiation spectra emitted from high temperature/high density plasmas produced using gas-puff Z-pinch machines and high power lasers. Spectral-line intensities from these plasmas can be useful temperature and density diagnostics. In a well-diagnosed plasma, information on the emission spectrum can also be used to test the accuracy of theoretical rate coefficients.

Recently time-resolved spectra from an oxygen-like argon plasma produced in a gas-puff z-pinch were measured in the wavelength range 150–200 Å . Over this wavelength range the spectrum contains mostly the Δn = 0 (L-shell) transitions in ArX-ArXIV and some weak transitions for n = 3 to n = 4 of ArVI-ArVIII. The measured spectra show the predominance of 0-like Ar L-shell transitions.

The dielectronic recombination is one of the most important atomic processes in highly ionised plasmas. It corresponds to the simultaneous capture of a free electron and excitation of an ion, i.e.

It is a collisionally resonant process which occurs only at the energy of the corresponding autoionisation electron. We present here a preliminary theoretical analysis of the results of an experiment using a novel technique in which it is possible to observe the interaction of a given ion with an electron at a given energy and so to measure the differential dielectronic cross section corresponding to each resonant level of this ion.

We demonstrate a new high resolution grazing incidence spectrometer system for spectroscopic applications in the range 50 to 400 Å. The instrument is comprised of a laser-plasma VUV continuum source, a 1.5 m grazing incidence spectrometer, and a 1024-channel VUV optical multichannel analyzer (VUV-OMA). The VUV-OMA is of new design, featuring a special resolution-enhanced channel electron multiplier array in an overall configuration chosen to optimize the spatial resolution of the detector while maintaining single-photoelectron sensitivity. The instrument has the capability of bringing the advantages of linear response and parallel spectral detection to general VUV photoabsorption studies of atoms, ions, molecules, and thin solid samples, as well as studies involving laboratory plasmas. The instrument has the additional special capability of performing time resolved absorption spectroscopy of transient species. The characteristics of the source and detector, along with various applications of the instrument to atomic physics will be discussed.

The spectra of highly ionized Ag and Cd in the region 20–200 Å excited in laser produced plasmas were recorded and analyzed. The spectral lines identified correspond to Ag XVII - Ag XXI and Cd XVIII -Cd XXII involving transitions of the type 3dk n1 – 3dk nl' and 3dk – 3dk−l nl" where k = 9,10; n = 4,5,6; 1 = s,p,d,f; 1' = s,p,d,f,g, and 1" = p,f.

The experimental work was carried out at the Australian National University Research School of Physical Sciences. The Nd=glass laser system delivered pulsed powers of the order of 1015W/cm2 onto flat metalic targets placed in a vacuum. The target could be positioned accurately in the focal plane of the input lens. The spectra were recorded photographically on Kodak SC5 plates with a 2-m grazing incidence spectrograph (Hilger & Watts E-580) employing a 600 lines/mm grating at 88.157° incidence. A maximum of three laser pulses gave the desired plate exposure while a single shot exposure from a pure carbon target plasma provided the reference points for wavelength calibration. The well-known Lyman spectra of CVI and CV appeared strong and could be clearly identified upto their 5th order. The wavelengths of some strong lines of Ag XIX and Cd XX previously measured (1) were used as secondary wavelength standards and a best fit was then made with the wavelengths computed from the dispersion equation of the grating. The accuracy of the measured wavelengths was within 0.02A° and better than 0.005A° at points closer to the reference lines.

A new technology was developed for manufacturing of precise and low-cost X-ray grazing incidence microscopic optics.

Imaging experiments represent one of the main directions in the Czechoslovak X-ray astronomy program. The Space Research Department of the Astronomical Institute of the Czechoslovak Academy of Sciences in Ondřejov has been active in the development of X-ray mirrors since 1970. We have participated in 7 space X-ray imaging experiments. 6 experiments were flown onboard the Vertical 8, 9 and 11 rockets in the years 1979, 1981 and 1983 (Hudec et al. 1984a), one experiment was flown onboard the Soviet orbital station Salyut 7 in the year 1982 (Valníček et al. 1983 and Hudec et al. 1984b). The experiments represent both small solar X-ray imaging telescopes and big stellar X-ray telescope.