Milli Arcsecond Imaging of the Solar Corona

2016-07-30
Joseph, Davila
Öktem, Sevinç Figen
Farzad, Kamalabadi
Dissipation in the solar corona is believed to occur in extremely thin current sheets of order 1-100 km. Emission from these hot but thin current sheets is visible in coronal EUV emission lines, however, this spatial scale is unresolved in existing imaging instruments. Conventional optics cannot be easily manufactured with sufficient surface figure accuracy to obtain the required resolution. A photon sieve, a diffractive imaging element similar to a Fresnel zone plate, can be manufactured to provide a few milli-arcsec (mas) resolution, with much more relaxed tolerances than conventional imaging technology. Images from photon sieves will not only show the structure of the corona at a resolution never before obtained, they will also allow a study of the temperature structure in the dissipation region. Several photon sieves have been designed, fabricated, and tested by us at Goddard Space Flight Center. To fully exploit the potential of these devices two new technologies, (1) formation flying and (2) computational image deconvolution must be used. Recent progress on photon sieve development as well as these issues will be discussed. A simple design for a sounding rocket payload is presented that obtains 80 mas (0.080 arcsec) imaging with a 100 mm diameter photon sieve to image Fe XIV 334 and Fe XVI 335 which would provide a demonstration of this technology.

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Citation Formats
D. Joseph, S. F. Öktem, and K. Farzad, “Milli Arcsecond Imaging of the Solar Corona,” presented at the 41st COSPAR Scientific Assembly, İstanbul, Türkiye, 2016, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/77472.