scholarly journals Derivation of the Ionization Balance for Iron XIV/XXV and XXIII/XXIV Using Solar X-Ray Data

1984 ◽  
Vol 86 ◽  
pp. 13-16
Author(s):  
E. Antonucci ◽  
M.A. Dodero ◽  
A.H. Gabriel ◽  
K. Tanaka
Keyword(s):  
Solar Flares ◽  
Solar Maximum ◽  
Plasma Electron ◽  
Large Set ◽  
Spectral Emission ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Physical Conditions ◽  
Bent Crystal ◽  
Ionization Balance

The relative concentrations of different ionization stages of iron are measured using the spectral emission of plasmas formed during solar flares. This is an extension of a study on the ionization balance of heavy elements, initiated with the analysis of calcium solar spectra (Antonucci et al., 1984). The data consist of a large set of iron spectra in the wavelength range from 1.84 to 1.88 Å, detected during the recent maximum of activity with the X-ray Polychromator Bent Crystal Spectrometer (BCS) on the NASA Solar Maximum Mission satellite and on the Soft X-ray Crystal Spectrometer (SOX) on the Hinotori satellite.At the low densities typical of the solar corona, in the steady state the ionization balance of an element is a function of the plasma electron temperature. Hence, it can be measured for plasmas of known temperature and in slowly varying physical conditions, and in most cases, solar flare plasmas can be considered to be in such conditions.

High-temperature plasma in solar flares

1991 ◽  
Vol 336 (1643) ◽  
pp. 451-460 ◽  
Keyword(s):  
High Temperature ◽  
Solar Flares ◽  
Crystal Spectrometer ◽  
Temperature Plasma ◽  
X Ray ◽  
Physical Conditions ◽  
Bent Crystal ◽  
Spectroscopic Diagnostics ◽  
High Temperature Plasma ◽  
Ionization Balance

The thermal soft X-ray flare plasma is at temperatures ranging from a few million degrees up to about 40 x 10 6 K. In this paper I discuss some current problems in our understanding of the physical conditions in this plasma, particularly the ionization balance and the possible detection of non-thermal electrons. I discuss X-ray spectroscopic diagnostics that might help in resolving some of the issues, and I also discuss the possibility of addressing these problems with the bent crystal spectrometer experiment to be flown on Solar-A.

Atomic physics calculations relevant to solar flare spectra

1991 ◽  
Vol 336 (1643) ◽  
pp. 471-484 ◽  
Keyword(s):  
Solar Flare ◽  
Atomic Physics ◽  
Solar Flares ◽  
Solar Maximum ◽  
Emission Lines ◽  
Atomic Data ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Physical Conditions ◽  
Recombination Processes

Solar flare spectra in the ultraviolet and X-ray wavelength regions are rich in emission lines from highly ionized ions, formed at temperatures around 10 7 K. These lines can be used as valuable diagnostics for probing the physical conditions in solar flares. Such analyses require accurate atomic data for excitation, ionization and recombination processes. In this paper, we present a review of work which has already been carried out, in particular for the Solar Maximum Mission observations, and we look to future requirements for Solar-A .

X-ray spectra of solar flares obtained with a high-resolution bent crystal spectrometer

1981 ◽  
Vol 244 ◽  
pp. L141 ◽  
Author(s):  
J. L. Culhane ◽  
C. G. Rapley ◽  
R. D. Bentley ◽  
A. H. Gabriel ◽  
K. J. Phillips ◽  
...  
Keyword(s):  
High Resolution ◽  
Solar Flares ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Bent Crystal

scholarly journals Soft X-Ray Spectroscopy from the X-Ray Polychromator on the Newly Repaired Solar Maximum Mission

1984 ◽  
Vol 86 ◽  
pp. 9-11
Author(s):  
K.T. Strong ◽  
R.A. Stern ◽  
J.R. Lemen ◽  
K.J.H. Phillips
Keyword(s):  
Spectroscopic Data ◽  
Solar Maximum ◽  
Active Regions ◽  
Line Profiles ◽  
Crystal Spectrometer ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Bent Crystal ◽  
Mission Satellite ◽  
Short Presentation

The X-Ray Polychromator (XRP) resumed operations on 24 April 1984 following the successful in-orbit repair of the Solar Maximum Mission Satellite. Since that time the two instruments that comprise the XRP, the Flat Crystal Spectrometer (FCS) and the Bent Crystal Spectrometer (BCS), have been used to obtain new spectroscopic data from active regions and flares. The FCS, in particular, has accumulated far more observations of soft X-ray line profiles than were obtained during SMM-I in 1980. For this short presentation, we have chosen two topics to illustrate the type of data that we have obtained since the repair.

Variation of the Observed Coronal Calcium Abundance for Various X-Ray Flare Plasmas

1984 ◽  
Vol 86 ◽  
pp. 21-21
Author(s):  
J. Sylwester ◽  
J.R. Lemen ◽  
R. Mewe
Keyword(s):  
Solar Maximum ◽  
Elemental Abundance ◽  
Normalization Factor ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Bent Crystal ◽  
Similar Temperature Dependence ◽  
Similar Temperature ◽  
Abundance Variation ◽  
The Continuum

We present the first observational evidence for the variation of the coronal calcium abundance in the high-temperature solar flare plasmas. The analyzed data consists of the X-ray flare spectra observed by the Solar Maximum Mission satellite with the Bent Crystal Spectrometer. From BCS spectra we derived the ratio of the line to continuum flux IL/IC for the resonance line of Ca XIX λ = 3.1781Å and the continuum at the same wavelength as a function of the temperature. The studies of 13 flares showed similar temperature dependence during the decay phases, but the agreement of the IL/IC ratio from flare to flare could only be achieved by adjusting an overall normalization factor. As the continuum flux depends weakly on the heavy elemental abundance, this variation of the IL/IC ratio can be attributed to the variation in the calcium abundance. For the flares considered, the variation between the extreme cases represented the factor of 2.5. We stress the consequences of the observed abundance variation for the analysis and interpretation of XUV and X-ray spectra.

scholarly journals Plasma Parameters and Structures of the X4 Flare of 19 May 1984 as Observed by SMM-XRP

1989 ◽  
Vol 104 (2) ◽  
pp. 165-168
Author(s):  
J.T. Schmelz ◽  
J.L.R. Saba ◽  
K.T. Strong
Keyword(s):  
Solar Maximum ◽  
Coronal Plasma ◽  
The Sun ◽  
Plasma Parameters ◽  
Crystal Spectrometer ◽  
Solar Maximum Mission ◽  
X Ray ◽  
Bent Crystal ◽  
East Limb ◽  
Large Flare

AbstractThe eruption of a large flare on the east limb of the Sun was observed by the X-Ray Polychromator (XRP) on board the Solar Maximum Mission (SMM) on 19 May 1984. The XRP Flat Crystal Spectrometer (FCS) made polychromatic soft X-ray images during the preflare, flare and postflare phases. The XRP Bent Crystal Spectrometer (BCS) provided information on the temperature and dynamics of the hot (Te > 8 x 106K) coronal plasma from spectra integrated spatially over the whole region.

Elliptically Bent Crystal Spectrometer for Z-Pinch Plasma X-Ray

2009 ◽  
Vol 36 (1) ◽  
pp. 115-118
Author(s):  
王洪建 Wang Hongjian ◽  
肖沙里 Xiao Shali ◽  
施军 Shi Jun ◽  
黄显宾 Huang Xianbin ◽  
杨礼兵 Yang Libing ◽  
...  
Keyword(s):  
Crystal Spectrometer ◽  
X Ray ◽  
Pinch Plasma ◽  
Bent Crystal ◽  
Z Pinch

Some New Methods of Precision X-Ray Spectrometry

1972 ◽  
Vol 16 ◽  
pp. 251-259 ◽  
Author(s):  
K. Das Gupta ◽  
Herbert Welch ◽  
P.F. Gott ◽  
John F. Priest ◽  
Sunny Cheng ◽  
...  
Keyword(s):  
Focal Point ◽  
Spectral Lines ◽  
Background Intensity ◽  
List Type ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Bent Crystal ◽  
The Third ◽  
Light Gathering Power ◽  
In Series

AbstractThree novel methods of x-ray spectrometry have been developed in recent years at Texas Tech University. These are:1. Three crystal spectrometer2. Two curved crystal spectrometer3. Spherically bent crystal spectrometer.In this paper the new design features, and experimental results will be discussed to indicate the usefulness of the new instruments. The three crystal spectrometer is a modified two crystal instrument. A third crystal is used to analyze the output of the two crystal spectrometer. The first two crystals are operated as a standard two crystal spectrometer. The third crystal is swept through the spectrum transmitted by the first two crystals for each setting of the first two crystals. The peak intensity of the third crystal sweep corresponds to the energy setting of the two crystal spectrometer, and is the intensity used to plot the spectral lines. The two curved crystal spectrometer utilizes two transmission spectrographs with radii having a 2:1 ratio in series, the crystal with the smaller radius being set so that its focal point falls on the Rowland circle of the larger radius crystal, This instrument has a very low background intensity and is suitable for precision scattering and diffraetion work. The spherically bent crystal spectrometer makes use of high light gathering power and high orders of reflection to allow high resolution studies of weak spectral lines. It also has the advantage of ease of alignment and operation.

scholarly journals Flares on the Sun: Selected Results from SMM

1983 ◽  
Vol 71 ◽  
pp. 289-305
Author(s):  
G.M. Simnett
Keyword(s):  
Solar Flares ◽  
Solar Maximum ◽  
Electromagnetic Spectrum ◽  
Significant Progress ◽  
X Ray ◽  
Spatially Resolved ◽  
Red Dwarfs ◽  
Important Diagnostic Tool ◽  
Flare Stars ◽  
Made In

Observationally the study of solar flares has reached the stage where intensity-time distributions of emission over broad and resolved regions of the electromagnetic spectrum are obtained for spatially resolved parts of the flare. Polarization measurements add an important diagnostic tool in some wavebands but we shall not report on these here. In the optical band good ground based observations have been available for many years, whereas in the UV, soft X-ray and hard X-ray (> 5 keV) bands recent spacecraft have greatly extended the data base. Good high resolution maps are being made in the microwave region with the ground based VIA. We are now at the point where significant progress into understanding the flare problem has been made, and will continue to be made, during the current solar maximum. This coincides with the development of soft X-ray instruments sensitive enough to detect transient and quiescent emission from flare stars, particularly red dwarfs in the solar neighbourhood (e.g. Kahn et al,1979, Haisch et al, 1980) which previously had only been detected in the optical and radio wavebands.

scholarly journals Bent crystal spectrometer for both frequency and wavenumber resolved x-ray scattering at a seeded free-electron laser

2014 ◽  
Vol 85 (9) ◽  
pp. 093106 ◽  
Author(s):  
Ulf Zastrau ◽  
Luke B. Fletcher ◽  
Eckhart Förster ◽  
Eric Ch. Galtier ◽  
Eliseo Gamboa ◽  
...  
Keyword(s):  
Free Electron ◽  
Free Electron Laser ◽  
Crystal Spectrometer ◽  
X Ray ◽  
Bent Crystal ◽  
X Ray Scattering ◽  
Ray Scattering
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