Plasma astronomical

Utilization of data obtained from various plasma sources (e.g. beam-foil, tokamak and laser-produced plasma [287]) enabled the identification with high accuracy of the lines of highly ionized atoms in solar spectra. A special commision No 14 on Atomic and Molecular Data of the International Astronomical Union coordinates the activity on systematization of spectroscopic data, informs the astrophysics community on new developments and provides assessments and recommendations. It also provides reports which highlight these new developments and list all important recent literature references on atomic spectra and wavelength standards, energy level analyses, line classifications, compilations of laboratory data, databases and bibliographies. 

Within the last 25 years of X-ray spectroscopy on fusion devices, the theory of He-like ions has been developed to an impressive precision. The spectra can be modeled with deviations not more than 10% on all lines. For the modeling, only parameters with physical meaning and no additional approximation factors are required. Even the small effects due to recombination of H-like atoms, which contribute only a few percent to the line intensity, can be used to explain consistently the recombination processes and hence the charge state distribution in a hot plasma. The measurements on fusion devices such as tokamaks or stellarators allow the comparison to the standard diagnostics for the same parameters. As these diagnostics are based on different physical processes, they provide sensitive tests for the atomic physics used for the synthetic spectra. They also allow distinguishing between different theoretical approaches to predict the spectra of other elements within the iso-electronic series. The modeling of the X-ray spectra of astronomical objects or solar flares, which are now frequently explored by X-ray satellite missions, is now more reliable. In these experiments, the statistical quality of the spectra is limited due to the finite observation time or the lifetime of... 

Charge coupled detectors These devices are not yet commonly available in commercial instrumentation for analytical spectrophotometry although they are used in applications in inductively coupled plasma atomic emission spectrometry. However, they have found extensive application in imaging and astronomical applications. Essentially they are two-dimensional photodiode arrays which allow many spectra to be acquired in one readout. A typical array sensor is shown in Figure 9. 

Historically, the configuration was first studied theoretically [7,8,9] in an astronomical context in the 1950 s. Later it was reported that the spheromak configuration was formed in a laboratory experiment [10]. In the late 1960 s some theoretical calculations were carried out from the view point of plasma confinement [11]. 

If the g-factors (polarizabilities) are known in advance, it is possible to measure a static magnetic (electric) field by means of the Zeeman (Stark) effect. This is useful particularly in such situations as in hot plasma and in astronomical objects where the standard field-measuring probes, e.g. a nuclear magnetic resonance probe and a Hall probe, are unusable. 

The observation of molecular ions such as CO+, HCO+ (see Table HI), HOC+, HNN+, NO+, and HCS+ represents a relatively new area of study by microwave spectroscopy. These ions have also been detected in outer space by microwave astronomers. Molecular ions represent a significant challenge to microwave spectroscopists, as attested to by the small number of ions so far analyzed. The major problem is in the production of a sufficient concentration of ions for detection (see Section XI). The chemistry produced by molecular ions is important to a number of areas such as plasmas, flames, the upper atmosphere, and the interstellar medium. In the latter case, they play a role in the... 

Prior to the 1960s, comets were investigated primarily using visible-wavelength observations. The first infrared detection of a comet was achieved in the mid-1960s. Although radio astronomers had attempted to detect cometary emissions since the 1950s, the first widely accepted radio detection of a comet is that of the 18-cm OH transitions in Comet Kohoutek (1973). Radio observations of comets have been used to study all of the major components of comets nucleus, dust, neutral gas, and the plasma. 

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