Accession Number : ADA290000

Title :   Si XIII Emission Lines in Solar Flare X-Ray Spectra Obtained with the P78-1 Satellite,

Corporate Author : AEROSPACE CORP EL SEGUNDO CA TECHNOLOGY OPERATIONS

Personal Author(s) : Keenan, F. P. ; Conlon, E. S. ; McKenzie, D. L. ; Phillips, K. J.

PDF Url : ADA290000

Report Date : 01 NOV 1994

Pagination or Media Count : 9

Abstract : Theoretical Si XIII electron-temperature-sensitive emission-line ratios, which include satellite-line contributions to the intensities of the forbidden (f) 1s2 (1)S-1s2s(3)S, intercombination (i) 1s2 (1)S-1s2p(3)P sub 2, and resonance (r) 1s2 (1)S-1s2p (1)p transitions, are presented for G = (I(f) + I(i))/I(r), R = I(f)/I(i), R1 = I(1s 2 (1)S-1s3p(1)p)/I(r), and R2 = I(1s2 (1)S-1s4p(1)P)/I(r). These ratios are significantly different from those calculated assuming that satellites do not contribute to f, i, and r, and, in addition, are more temperature-sensitive over the range log T sub e = 6.4-7.4. Electron temperatures deduced using the new diagnostics in conjunction with observed values of G, R1, and R2 from solar-flare spectra obtained by the SOLEX spectrometers aboard the P78-1 satellite are found to be generally consistent. This provides support for the validity of the theoretical R1 and R2 diagnostics and also resolves discrepancies noted previously when the line ratios were compared with observation from the Solar Maximum Mission spectrometers. The R ratio, which is in the low-density limit under solar flare conditions, is found not to be a useful T sub e diagnostic when satellite contributions to f and i are included in the theoretical line ratios. However, the observed values of R from the SOLEX spectra are in good agreement with theoretical predictions, which provides additional support for the accuracy of the line-ratio calculations. (jg)

Descriptors :   *EMISSION SPECTRA, *X RAY SPECTRA, *ARTIFICIAL SATELLITES, *SOLAR FLARES, *LINE SPECTRA, RATIOS, PREDICTIONS, TEMPERATURE, ELECTRONS, LIMITATIONS, SILICON, GAMMA RAYS, DIAGNOSIS(GENERAL), LOW DENSITY, ATOMIC PROPERTIES, SPECTROMETERS, SOLAR X RAYS, SUN.

Subject Categories : Inorganic Chemistry
      Astrophysics
      Atomic and Molecular Physics and Spectroscopy

Distribution Statement : APPROVED FOR PUBLIC RELEASE