Optical design of the COSMO large coronagraph

摘要

The Coronal Solar Magnetism Observatory (COSMO) is a facility dedicated to measuring magneticfields in the corona and chromosphere of the Sun. It will be located on a mountaintop in the HawaiianIslands and will replace the current Mauna Loa Solar Observatory (MLSO). COSMO will employ asuite of instruments to determine the magnetic field and plasma conditions in the solar atmosphere andwill enhance the value of data collected by other observatories on the ground (SOLIS, ATST, FASR)and in space (SDO, Hinode, SOHO, GOES, STEREO, DSCOVR, Solar Probe+, Solar Orbiter). Thedynamics and energy flow in the corona are dominated by magnetic fields. To understand theformation of Coronal Mass Ejections (CMEs), their relation to other forms of solar activity, and theirprogression out into the solar wind requires measurements of coronal magnetic fields. The COSMOsuite includes the Large Coronagraph (LC), the Chromosphere and Prominence Magnetometer(ChroMag) and the K-Coronagraph. The Large Coronagraph will employ a 1.5 meter fuse silica singletlens and birefringent filters to measure magnetic fields out to two solar radii. It will observe over awide range of wavelengths from 500 to 1100 nm providing the capability of observing a number ofcoronal, chromospheric, and photospheric emission lines. Of particular importance to measuringcoronal magnetic fields are the forbidden emission lines of Fe XIII at 1074.7 nm and 1079.8 nm. Theselines are faint and require the very large aperture. NCAR and NSF have provided funding to bring theCOSMO Large Coronagraph to a preliminary design review (PDR) state by the end of 2013.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.