Accession Number : AD0676264

Title :   ENHANCEMENT OF THE SOLAR X-RAY SPECTRUM BELOW 25 A DURING SOLAR FLARES,

Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s) : Walker,Arthur B. C. ; Rugge,Hugo R.

Report Date : JUN 1968

Pagination or Media Count : 27

Abstract : The scanning Bragg crystal spectrometer flown aboard the satellite 1966-111B observed the solar x-ray spectrum between 8 and 25 A shortly after the occurrence of a class 3 flare on 13 February 1967. Comparison of this spectrum with x-ray spectra obtained during periods of moderate solar activity shows that while the low ionization potential lines of O VII and N VII increase only 50% in intensity, the higher ionization potential lines of Fe XVII, Ne X, Mg XI, Fe XVIII, and Ni XIX increase in intensity from three to ten times. The lines of Mg XII and Na XI, which were indistinguishable from the continuum before, become prominent in the flare spectra. A number of new lines were observed, which are of the proper wavelength to be identified with the transitions of Fe XIX through Fe XXIV recently observed on the sun by OSO III and since observed in laboratory spark spectra. Absolute intensities of emission lines and of the x-ray continuum for the 13 February flare spectra and for a more typical spectrum are reported. (Author)

Descriptors :   (*SOLAR RADIATION, X RAYS), (*SOLAR FLARES, X RAYS), (*SOLAR SPECTRUM, X RAY SPECTROSCOPY), NUCLEAR RADIATION SPECTROMETERS, SCIENTIFIC SATELLITES, ATOMIC SPECTROSCOPY, ATOMIC ENERGY LEVELS, LINE SPECTRA, IRON, NEON, NICKEL, MAGNESIUM, SODIUM

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE