Milli Arcsecond MAS Imaging of the Solar Corona

2016-05-01
Davila, Joseph M
Öktem, Sevinç Figen
Kamalabadi, Farzad
Oneill, John
Gradac, Anne Marie Novo
Daw, Adrian N
Rabin, Douglas M
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 should be visible in coronal EUV emission lines. However, this spatial scale is far below the resolution of existing imaging instruments, so these dissipation sites have never been observed individually. Conventional optics cannot be manufactured with sufficient surface figure accuracy to obtain the required spatial resolution in the extreme-ultraviolet where these hot plasmas radiate. 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 readily achievable tolerances than with conventional imaging technology. Prototype photon sieve elements have been fabricated and tested in the laboratory. A full-scale ultra-high resolution instrument will require formation flying and computational image deconvolution. Significant progress has been made in overcoming these challenges, and some recent results in these areas are discussed. A simple design for a sounding rocket concept demonstration 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. These images will show the structure of the corona at a resolution never before obtained, and they will also allow a study of the temperature structure in the dissipation region.
AAS/Solar Physics Division Meeting, (31 Mayıs-03 Haziran 2016)

Suggestions

Milli Arcsecond Imaging of the Solar Corona
Joseph, Davila; Öktem, Sevinç Figen; Farzad, Kamalabadi (null; 2016-07-30)
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 m...
Estimation of total solar radiation from bright sunshine hours in Turkey
Taşdemiroğlu, Erol; Sever, Rita (Elsevier BV, 1989-12)
Measurements of total solar radiation and bright sunshine hours in six different climatological locations in Turkey are used to develop an Angstrom type equation. The coefficients are found for a linear equation from regression analysis for these locations. A simple overall equation, which yields the solar radiation in any location in Turkey for bright sunshine hours, is developed. The results of this equation, together with the results obtained from five similar, internationally accepted correlations, are ...
Excitation intensity- and temperature-dependent photoluminescence in layered structured Tl2GaInSe2S2 crystals
Hasanlı, Nızamı (AIP Publishing, 2013-02-21)
Photoluminescence spectra of Tl2GaInSe2S2 layered crystals have been registered in the temperature range of 17-62 K and in the wavelength region of 525-690 nm. A broad visible photoluminescence band centered at 590 nm (2.10 eV) was observed at T 17 K. Variation of emission band has been studied as a function of laser excitation intensity in the 0.1-55.7 mW cm(-2) range. The analysis of the spectra reveals that the peak energy position changes with excitation intensity (blue shift). The radiative transitions...
Refractive index and oscillator parameters in TlGaS2, TlGaSe2 and TlInS2 layered crystals
Hasanlı, Nızamı (2011-01-01)
The optical properties of TlGaS2, TlGaSe2, and TlInS2 crystals have been investigated through the transmission and reflection measurements at room temperature in the wavelength range of 400-1100 nm. These measurements allowed determination of spectral dependence of the refractive index for all crystals studied. The dispersion of the refractive index is discussed in terms of the Wemple-DiDomenico single-effective-oscillator model. The refractive index dispersion parameters: the oscillator energies, the dispe...
Periodicities in the Daily Proton Fluxes from 2011 to 2019 Measured by the Alpha Magnetic Spectrometer on the International Space Station from 1 to 100 GV
Aguilar, M.; et. al. (2021-12-01)
We present the precision measurement of the daily proton fluxes in cosmic rays from May 20, 2011 to October 29, 2019 (a total of 2824 days or 114 Bartels rotations) in the rigidity interval from 1 to 100 GV based on 5.5 x 10(9) protons collected with the Alpha Magnetic Spectrometer aboard the International Space Station. The proton fluxes exhibit variations on multiple timescales. From 2014 to 2018, we observed recurrent flux variations with a period of 27 days. Shorter periods of 9 days and 13.5 days are o...
Citation Formats
J. M. Davila et al., “Milli Arcsecond MAS Imaging of the Solar Corona,” presented at the AAS/Solar Physics Division Meeting, (31 Mayıs-03 Haziran 2016), 2016, Accessed: 00, 2021. [Online]. Available: http://adsabs.harvard.edu/abs/2016SPD....47.0310D.