ИСТИНА

• Scien'fic objec'ves of the project K-EUSO (KLPVE) and K-­‐EUSO pre-­‐history SINP MSU and K-EUSO for neutrino measurements 1. For measurements of neutrino from space by Cherenkov or fluorescent radiation it is very important to learn the UV background of the atmosphere to know the conditions of measurements. The most attention should be payed to transient atmospheric events (TAEs) which mostly influence trigger system operation and produce a majority of fake events. SINP MSU realize a program of such measurements. First measurements were done by small UV detector on board Tatiana-1, Tatiana-2 and Vernoiv satellites [Garipov2005, AstVest2011, ASR 2015]. These measurements gave interesting information concerning temporal structure of UV flashes with millisecond resolution, their intensity and geographical distribution [JGR 2013, JAMC 2017]. 2. The next step was an attempt to measure TAEs and fast EAS tracks by the TUS detector launched on boards the Lomonosov satellite [SSR2017-TUS]. This detector is much more sensitive (due to large area mirror) and has a spatial resolution (5 km on the see level). This allows us to measure the fastest and faint TAEs, like ELVES [TEPA-2016 proc] and tracks of relativistic objects in the atmosphere [ICRC-2017-TUS, BRAS2017]. 3. Full size UHECR detector aimed to measure spectrum and anisotropy of particles beyond the GZK cut-off is KLYPVE-EUSO (K-EUSO) - a joint project of SINP MSU and the JEM-EUSO collaboration. It is a wide field of view Schmidt camera with a large area mirror (>10 m2) and large entrance pupil (~5m2) [PTEP2017, ICRC2017-KLYPVE]. It is planned to be installed on board the ISS in 2022. 4. The K-EUSO project is mostly designed for UHECR measurements it can be used for testing the technique of measurements of astrophysical neutrino (skimming the Earth). It is possible if we tilt the detector to the horizon and look to the border of atmosphere and the Earth. The only change in hardware is the usage of fast read-out electronics in the part that is looking to the edge (similar to electronics developed in POEMMA project, see the section devoted to POEMMA experiment). • K-­‐EUSO design (Schmidt telescope): The telescope contains the following parts: Mirror with folding edges; Focal surface; Corrector lens with external baffle; Supporting mechanical structure; and Optical system with Photodetector This is just preliminary design by SINP MSU, which will be further worked out by RSC “Energia” during conceptual design stage of the project.