Electron Density in Flares, II: Results of Measurement
Abstract
Measurements of the electron density in 16 flares are summarized and discussed. For 13 of them the electron density has been determined by the halfwidth method discussed in Part I of this paper. In the flash phase of all disk flares of importance 1 + and higher the electron density exceeds 1013 cm−3 and increases with the flare importance. In the maximum of large flares the electron density exceeds 3 × 1013 cm−3 and declines to 1013 cm−3 and to lower values in about 20 minutes after the flash phase. In limb flares, i.e. higher than 5000 km above the solar limb, the electron density is lower than 5 × 1012 cm−3. This shows a decrease of the electron density in the flare elements situated in higher parts of the chromosphere. On the other hand, however, at least in some flares the electron density remains fairly constant within a wide range of height in the upper chromosphere and the low corona.
- Publication:
-
Solar Physics
- Pub Date:
- July 1967
- DOI:
- 10.1007/BF00155894
- Bibcode:
- 1967SoPh....2...87F
- Keywords:
-
- Flare;
- High Part;
- Solar Limb;
- Large Flare;
- Limb Flare