Exploring the application of image slicers for the EUV for the next generation of solar space missions

Abstract

The Sun is a privileged place to study particle acceleration, a fundamental astrophysical problem throughout the universe. The extreme ultra-violet (EUV) contains a number of narrow emission lines formed in all layers of the solar atmosphere whose profiles allow the measurement of plasma properties like density and temperature, along with the presence of non-Maxwellian particle distributions to be diagnosed. The only way to observe is from space, since EUV radiation is absorbed by the Earth’s atmosphere. Integral field spectroscopy combined with polarimetry is key for the study of the Sun, but the current EUV technology is limiting: the transmission of optical fibers IFUs (integral field units) is low and in-flight effects affect polarisation measurements. The best solution seems to be image slicers. However, this technology has not yet been developed for the EUV spectral range. This communication explores a new highly efficient and compact integral field spectrograph layout based on the application of image slicers combining the surfaces of the IFU with those of the spectrograph, suitable for space applications.