Reconstruction of the altitude of the shower maximum.

1
D.V.Skobeltsyn INP Moscow State University
TUS/KLYPVE Collaboration
V. Alexandrov, D. Bugrov, G. Garipov,
N.Kalmykov,B.Khrenov, M. Panasyuk, S.Sharakin, A.
Silaev, I. Yashin
JINR, Dubna, Russia
V. Grebenyuk,M. Finger, A. Zhuchkova, D. Naumov,
Nguen Man Sat, A. Olshevsky, B. Sabirov, L.
Tkatchev, N. Zaikin
UHECRs measurements from Space via detection of
fluorescent and Cherenkov light produced by EAS
Energia Korolev (Rocket Space Corporation)
Goal
O. Saprykin, V. Syromyatnikov
Luch Syzran SCTB, Russia
E. Bitkin, S. Eremin, A. Matyushkin, F. Urmantsev
1.5 m diameter Fresnel Mirror Background
measurement dozens events per year with Egt1020 eV
TUS
Mexico University, Mexico
A. Cordero, O. Martinez, E. Morena, C.
Robledo,H. Salazar, L. Villaseeor, A. Zepeda
Ewha Womans University Seoul, South Korea
TUS2
Double TUS
I. Park
3.5 m diameter Fresnel Mirror 103 events per
year 102 events with Egt1020 eV
NIO KOMPAS, Czech Republic
KLYPVE
M. Shonsky
Technical University, Prague, Czech Republic
J. Zicha
2
Ultra High Energy Cosmic Rays (UHECRs)
Modulated by solar activity
GROUND BASED DETECTOR DATA ON UHECR
1 particle per m2second
1st knee
1 particle per m2year
2nd knee
Ankle
1 particle per km2year
Energy, eV
Energy, eV
Energy, eV
aqqqq

• What is their origin?
• ?Top-down? Bottom-up? Source?
• What is the nature of UHECRs?
• ?p,Fe,?,?

• What is their spectrum?
• ?consistent with GZK
• (p?2.7 ? p ?0)?

3
Concept of TUS/TUS2 space free flyer
16x16 PMTs
Fresnel mirror 10 rings
Focal distance is 1.5 m Field of View is 7.3o
4
mm
Fresnel Mirror RD
Measured vs theory
mold production in JINR/Dubna Space qualified
carbon-plastic Fresnel mirror to be produced At
Luch (Syzran)
Mirror mold section
Measured - theory
Ring number
The light spread radius on the focal plane
90
80
70
5
Simulation

• SLAST package
• 3D Geometry
• Various Atmosphere profiles
• GIL parameterization of CORSIKA
• Hillas parameterization for the energy
  distribution
• First interaction of nuclei or neutrino from
  cross-section
• Fluorescence as a function of altitude in the
  atmosphere and the shower age
• Cherenkov light simulation
• LOWTRAN7.1 atmosphere response

Events per year
KLYPVE
TUS

• Electronics Simulation
• Analog Digital
• Multi-Level trigger system with two modes
  vertical horizontal showers

6
TUS relative resolution of Hmax as a function of
zenith angle for
Reconstruction
Golden Events

• Reconstruction (under way)
• Arrival direction
• Hmax and Xmax for
• Golden events
• Fluorescent events
• Energy

Cherenkov echo gives us a reference point to
reconstruct Hmax for golden events. Temporal
profile of (quasi) horizontal showers is
sensitive to Hmax. This makes possible to
reconstruct Hmax (and Xmax) for events
without Cherenkov echo. Both methods are
complementary to each other.
Fluorescent Events
7
Conclusions
TUS will measure in one year

• The real background ? need for all space based
  experiments
• dozens of events above 1020 eV ? more than the
  world current statistics (with overall sky
  coverage)

TUS as a space based experiment will

• Test the approach preparing for the next
  generation of experiments EUSO, KLYPVE,OWL and
  OTHERS!