Dielectronic satellite spectra for highly-charged helium-like ions - VII. Calcium spectra - theory and comparison with SMM observations

Bely‐Dubau, F.; Dubau, J.; Faucher, P.; Gabriel, A. H.; Loulergue, M.; Steenman-Clark, L.; Volonté, S.; Antonucci, E.; Rapley, C. G.

doi:10.1093/mnras/201.4.1155

Cited by 121 publications

(63 citation statements)

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“…Thus, the fitting uses detailed atomic physics data for the transitions that produce lines in the wavelength ranges of the two channels. Atomic data for the fits are primarily from Bely-Dubau et al (1982a, 1982b and Vainshtein & Safronova (1978. The required ionization equilibrium calculations are from Arnaud & Rothenflug (1985).…”

Section: Bcs Observationsmentioning

confidence: 99%

Characteristics of Solar Flare Doppler‐Shift Oscillations Observed with the Bragg Crystal Spectrometer onYohkoh

Mariska

2006

ApJ

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, and inferred displacements of 1070 AE 1710 km, where the listed errors are the standard deviations of the sample means. For some of the flares, intensity fluctuations are also observed. These lag the Dopplershift oscillations by 1/4 period, strongly suggesting that the oscillations are standing slow-mode waves. The relationship between the oscillation period and the decay time is consistent with conductive damping of the oscillations.

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Section: Bcs Observationsmentioning

confidence: 99%

Characteristics of Solar Flare Doppler‐Shift Oscillations Observed with the Bragg Crystal Spectrometer onYohkoh

Mariska

2006

ApJ

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“…The spectra were then integrated over the line of sight using electron temperature profiles measured by ECE, density profiles from the scaling with the safety factor q according to Schueller et al,20 and assuming coronal equilibrium for the charge state distribution. The excitation rates which were used to fit the w, x, y, and z lines were obtained by an extrapolation of the data for calcium calculated by Bely-Dubau et al 21 to argon according to Mewe et al 22,23 The wavelengths and satellite intensities were calculated by Vainsthein et al 24,25 Figure 11 shows a comparison of the central electron temperature measured by x rays to that measured by ECE for a series of discharges in hydrogen, deuterium, and helium with electron densities ranging from 1.0ϫ10 13 -4.0 ϫ10 13 cm Ϫ3 and central electron temperatures ranging from 1.0 to 2.4 keV. The agreement between the two diagnostics is remarkably good for a wide range of plasma conditions in TEXTOR-94.…”

Section: B Electron Temperaturementioning

confidence: 99%

High-resolution x-ray crystal spectrometer/polarimeter at torus experiment for technology oriented research-94

Weinheimer

Ahmad

Herzog

et al. 2001

Review of Scientific Instruments

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A high-resolution x-ray polarimeter has been installed at the torus experiment for technology oriented research ͑TEXTOR-94͒. The instrument consists of two spectrometers in Johann geometry, utilizing the dependence of Bragg reflection on the polarization. The dispersion plane of the so-called horizontal spectrometer coincides with the midplane of the tokamak, whereas the dispersion plane of the so-called vertical spectrometer lies perpendicular to the midplane of the tokamak. Both spectrometers operate with cylindrically bent quartz crystals of dimensions 153 mmϫ38 mmϫ0.7 mm with a 2d spacing of 4.9130 Å. The radii of curvature of the horizontal and vertical spectrometer crystals are 3820 mm and 4630 mm, respectively. The detectors are multiwire proportional counters having a large entrance window of 180 mmϫ90 mm, with a high count rate capability of up to 2.5ϫ10 5 photons/s, and a spatial resolution of 0.4-0.65 mm, depending on the count rate. The unique data acquisition system makes it possible to record up to 8192 spectra per TEXTOR-94 discharge to study fast events and impurity transport. The instruments are sensitive to spurious amounts of argon in hydrogen or deuterium discharges and aim for x-ray polarization measurements and other core plasma diagnostics like electron temperature, ion temperature, plasma rotation, impurity transport, and relative abundance of Ar 15ϩ /Ar 16ϩ . The first measurements of toroidal rotation speed, ion and electron temperatures show a very good agreement with charge exchange recombination spectroscopy ͑XRS͒ and electron cyclotron emission ͑ECE͒ diagnostics available at TEXTOR-94. The measured values of the ratio Ar 15ϩ /Ar 16ϩ are higher than that predicted from coronal equilibrium. The ratio depends strongly upon the electron density both for ohmic and neutral beam injection cases. This suggests that the charge state distribution is also dependent on diffusion and charge exchange processes in the plasmas.

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“…Satellite lines have been widely used for plasma diagnostics of solar flares~e.g., Dubau & Volonte, 1980;Bely-Dubau et al, 1982!, Tokamak plasmas~e.g., Bitter et al, 1984Kato et al, 1987!, andlaser-produced plasmas~Fujimoto et al, 1981;Demir et al, 1997!, espe-cially for dielectronic satellite lines of Li-like ions. In this article we study the satellite lines of He-like ions in detail.…”

Section: Introductionmentioning

confidence: 99%

X-ray spectral diagnostics for satellite lines of H-like Mg ions measured by a high resolution spectrometer

Katō

Yamamoto

Rosmej³

2004

Laser Part. Beams

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X-ray spectra of H-like Mg ions produced in a laser plasma have been measured by space-resolved high-resolution spectroscopy. We identified satellite lines near Lya lines, 2lnl' Ϫ1snl ' ϩ hn for n ϭ 2, 3, and 4. We construct a collisional radiative model including the doubly excited states for the intensity ratios of satellite lines. We use atomic data calculated by different methods for satellite lines and compare the results. We derive the electron temperature and density of the laser-produced plasma by a new technique using intensity ratios of only satellite lines. This technique is useful because the Lya lines are often affected by opacity.

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Dielectronic satellite spectra for highly-charged helium-like ions - VII. Calcium spectra - theory and comparison with SMM observations

Cited by 121 publications

References 0 publications

Characteristics of Solar Flare Doppler‐Shift Oscillations Observed with the Bragg Crystal Spectrometer onYohkoh

Characteristics of Solar Flare Doppler‐Shift Oscillations Observed with the Bragg Crystal Spectrometer onYohkoh

High-resolution x-ray crystal spectrometer/polarimeter at torus experiment for technology oriented research-94

X-ray spectral diagnostics for satellite lines of H-like Mg ions measured by a high resolution spectrometer

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