This study is designed to examine the temperature/density structure within a coronal hole. Coronal holes contain structure such as macrospicules as well as supergranulation, at low altitudes, and features such as coronal rays. The precise relationship between these features and the predominantly open field of the coronal hole is unknown. This study includes observations over a large field of view using a broad range of bright Fe emission lines, a selection of density sensitive ratios, and the Mg X line as an established identifier of the coronal hole boundary.
Spectrometer: Normal incidence Slit: 2 x 240 arcsec Raster area: 4 x 4 arcmin Step (DX, DY): 2 arcsecond, 0 arcsecond Raster locations: 120 x 1= 120 Exposure time: 22 seconds Duration of raster: 3000 seconds Number of rasters: open Total duration: open Line selection: Coronal hole line selection 1 Fe VIII 370.43Å - log Te 5.6 Fe X 365.57Å - log Te 6.1 Fe XI 356.54Å - log Te 6.1 Fe XII 364.47 - log Te 6.2 Fe XII 338.26Å - log Te 6.2 Fe XIII 348.18 - log Te 6.2 Fe XIV 334.17Å - log Te 6.3 Fe XVI 335.40Å - log Te 6.4 Si IX 349.87Å - log Te 6.0 Si IX 341.95 - log Te 6.0 Si X 347.40Å - log Te 6.0 Si X 356.04Å - log Te 6.0 Mg IX 368.06Å - log Te 6.0 Bins across line: 11 Pointing: to a selected portion of a coronal hole on the disc Frequency: to be run on a number of occasions during mission Product: 4 x 4 arcmin maps of a coronal hole in a selection of lines, including density and temperature information, every 50 minutes.
This page last updated 15th November 1995