L. Tkachev

The TUS Fesnel mirror production and optical parameters measurement

The TUS space experiment is aimed to study energy spectrum, composition, and angular distribution of the Ultra-High Energy Cosmic Ray (UHECR) at E ∼ 1020 eV. The TUS mission is planned for operation at the end of 2012 at the dedicated “Mikhail Lomonosov” satellite. The TUS detector will measure the fluorescence and Cherenkov light radiated by EAS of the UHECR using the optical system—Fresnel mirror-concentrator of 7 modules of ∼2 m2 area in total. Production of the flight model of the optical system is in progress. Status of the Fresnel mirror production, the method, and results of their optical parameters measurement are presented.

Separation of the electron component by the shower shape in an ionization calorimeter for the NUCLEON experiment

An ionization calorimeter introduced in the composition of the NUCLEON research equipment is described. The possibility of employing it to study the spectrum of the electromagnetic charged component of cosmic rays in the energy range of 100–2000 GeV is discussed on the basis of data from a simulation.

Testing a prototype of the charge-measuring system for the NUCLEON setup

While preparing for the NUCLEON experiment, a prototype of the experimental setup was tested on a beam of high-energy ions. The response of the charge-measuring system was investigated. The test experiment was simulated. The simulated charge distributions were compared to the experimental data.

Preliminary results from the TUS ultra-high energy cosmic ray orbital telescope: Registration of low-energy particles passing through the photodetector

The TUS telescope, part of the scientific equipment on board the Lomonosov satellite, is the world’s first orbital detector of ultra-high energy cosmic rays. Preliminary results from analyzing unexpected powerful signals that have been detected from the first days of the telescope’s operation are presented. These signals appear simultaneously in time intervals of around 1 μs in groups of adjacent pixels of the photodetector and form linear track-like sequences. The results from computer simulations using the GEANT4 software and the observed strong latitudinal dependence of the distribution of the events favor the hypothesis that the observed signals result from protons with energies of several hundred MeV to several GeV passing through the photodetector of the TUS telescope.

The KLYPVE ultrahigh energy cosmic ray detector on board the ISS

The current status of the KLYPVE orbital detector of ultrahigh energy cosmic rays, which is scheduled to be deployed on board the Russian module of the International Space Station, is discussed. The main focus is on describing possible optical systems for the instrument.

Testing the engineering sample of the NUCLEON setup on a pion beam

Results from testing the sample of the setup for the NUCLEON experiment aimed at studying the energy spectra and the charge composition of cosmic rays in the energy range of 1012–1015 eV are presented. The sample has been made approach the actual setup to the maximum degree. Charged particle beams with energies of 200–350 GeV have been used for testing. The problem of selecting high-energy events and the accuracy of energy measurements using the method being developed are discussed. This method is based on measuring the spatial flux density of secondary particles that are produced in the first act of inelastic nuclear interaction inside the target of the setup and pass through a thin converter layer in which the electromagnetic component is multiplied. The event selection efficiency is shown to be rather high. The precision in determining the energy (90–80%) using this method is in good agreement with simulation results (∼100-80%). The results of the study fully comply with the requirements of the NUCLEON experiment.

Testing the prototype of the NUCLEON setup on the pion beam of the SPS accelerator (CERN)

A technique for determining the energy of primary cosmic rays in the range of 1012–1015 eV has been developed. The idea behind this technique consists in measuring the spatial flux density of secondary particles produced in the first act of inelastic nuclear interaction inside a target and passed through a thin converter layer in which the electromagnetic component (photons from decays of neutral pions) is multiplied. This technique has been developed by generalizing the well-known Castagnoli method (for measuring the angular characteristics of tracks of secondary particles produced in the first act of inelastic nuclear interaction inside a target), and its application offers a chance to design instruments for scientific studies such that their mass is relatively low while their luminosity is high. It is proposed to use this technique in a satellite-based NUCLEON experiment. The technique has been tested on charged particle beams of the SPS accelerator at CERN. Results of these tests confirm that, using this method, it is possible to measure the particle energy and, therefore, perform an orbital scientific experiment with the proposed equipment.

The NUCLEON experiment: The current status

The main purpose of the NUCLEON experiment is direct measurements of the energy spectra of cosmic rays in the range 1011–1015 eV with the use of the lightweight facility during a prolonged orbital flight. The energy is determined using a technique based on the measurement of the spatial density of secondary particles produced in the initial event of inelastic interaction. The schematic diagram of the NUCLEON facility, the current status of the project, the results of testing the prototype, and plans are presented.

The TUS Detector of Extreme Energy Cosmic Rays on Board the Lomonosov Satellite

The origin and nature of extreme energy cosmic rays (EECRs), which have energies above the 5⋅1019eV

The TAIGA experiment: from cosmic ray to gamma-ray astronomy in the Tunka valley

5\cdot10^{19}~\mbox{eV}