Status of the KLYPVE-EUSO detector for UHECR study on board the ISS Pavel Klimov Skobeltsyn Institute of Nuclear Physics For the JEM-EUSO Collaboration

Outline Scientific objectives of the project Initial KLYPVE design From KLYPVE to K-EUSO Current Schmidt telescope design Optical system Photodetector Conclusion

Scientific goals of the project UHECR measurements from space with uniform exposure over the celestial sphere. Various transient atmospheric phenomena in UV

SINP MSU space detectors of UV events in the atmosphere development Tatiana-1 Tatiana-2 Vernov 2005 2009 2014 KLYPVE TUS 2016 ≳ 2018

KLYPVE (2010-2013) This experiment is in the Federal Space Program Passed the stage of preliminary design (pre-phase A) The KLYPVE detector consists of: Supporting framework Mirror-concentrator (optics) Photo receiver Adjustment system Atmosphere control system LIDAR IR camera Information unit

Expected technical parameters of detectors KLYPVE TUS Orbit height, km ~400 550 Mirror area, m2 10 2 Focal distance 3 1.5 Pixel angular size, mrad 5 FOV, deg ±7,5 ±4,5 Number of pixels ~2500 256

Tilted K-EUSO location on board MRM-1 (RS of the ISS) KLYPVE -> K-EUSO Tilted K-EUSO location on board MRM-1 (RS of the ISS) Additional lens-corrector 1 mrad angular resolution

K-EUSO baseline optical system Figures by Y. Takisawa (RIKEN)

K-EUSO METS-3 option Figures by S. Sharakin and I. Gerasimov K-EUSO METS-3 optical performance K-EUSO METS-3 3D view Two main components of OS: aspheric Mirror (D = 240 cm) plane Fresnel Lens (D=120 cm) FOV1 = ± 10° FOVtotal = ± 17° K-EUSO MEST-3 mirror Figures by S. Sharakin and I. Gerasimov

Thunderstorm signal in TUS measurements “Slow” rising of signal Correlation with thunderstorm regions Large are of luminosity, stray light outside FOV.

Schmidt telescope design “Closed” optical system Wider FOV Spherical mirror

Schmidt camera K-EUSO design Mirror D = 4m Entrance aperture D = 2.5 m Focal surface 52 PDMs Spatial resolution 500-1000 m Temporal resolution 2.5 us “Progress” cargo

K-EUSO Optics Design: Schmidt camera Parameter Value FoV * 40° (maximum field angle 20˚) Entrance pupil diameter EPD = 2.5 m Effective focal length Fraction of vignetted rays Diameter of corrector 2.5 m < Dcorr < 2.6 m Diameter of the mirror Dmirr = 4 m Shape of the mirror Baseline: spherical mirror Advanced: spherical mirror in center with aspheric petals Polychromatic RMS spot dRMS < 3 mm for all the FoV Ground sampling distance Ω20° (K-EUSO)= 1/2 Ω30° (JEM-EUSO) About 85-90% ensquared energy on a 3 × 3 mm2

Baseline layout: Spherical Mirror

Advanced layout: Sperical + Aspherical petals F

Spot radius and ground resolution of baseline design. Schmidt design parameters P. Sandri, S. Sharakin, P. Mazzinghi, Y. Takizawa Spot radius and ground resolution of baseline design. Vignetting curve as a function of FoV

PDM. Network structure CPU PDM design is based om mini-EUSO PDM which is already developed and is being tested PD is based on system-on-chip XILINX ZYNQ. PDMs are united in a network 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 Inside the ISS 27 28 29 30 31 32 33 34 CPU 35 36 37 38 39 40 41 42 43 44 45 46 47 48 Storage dev. 49 50 51 52

Variant of telescope structure which can be transported with minimal separate parts The telescope contains the following parts: Mirror with folding edges Focal surface Corrector lens with external baffle Supporting mechanical structure Preliminary design by SINP MSU. Will be worked out by RSC “Energia” during conceptual design

Reflector Correction lens Focus adjustment Focal surface electronics PDM Laser unit IR Camera Focal surface electronics MAPMT Correction lens Fresnel surface Fresnel surface or Diffractive surface Focus adjustment mechanism Reflector BG3 filter

Thank you for your attention. 2022