V. Grebenyuk

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.

3He detectors in experiments at the powerful pulsed accelerators

Abstract A possibility of using a thermal neutron detector in the high γ-quantum and bremsstrahlung fields is considered in the paper. The design of the thermal neutron detector consisting of 10 counters filled with 3 He under the pressure of 2 atm and enclosed in the polyethylene moderator is described. The results of measuring the neutron recording efficiency and neutron lifetimes by this detector exposed to a neutron flux from the dt-reaction and from the 252 Cf and Pu–Be sources are reported. The thicknesses of the polyethylene moderator and the Pb layer used for suppression of the background in the fields of powerful electromagnetic radiation are optimized.

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.

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.

Self-shunted streamer chamber spectrometer with CCD video cameras for studying pion interactions with light nuclei at energies below the Δ-resonance

A description is presented of the detector system (a self-shunted streamer chamber in a magnetic field, equipped with two CCD video cameras) developed by the DUBTO collaboration for studying pion interactions with light nuclei at the JINR phasotron.

PREPARATION OF THE TUS SPACE EXPERIMENT FOR UHECR STUDY

We report on the current status of the TUS space mission project: its goals and the progress achieved so far. The Fresnel mirrors design, performed checks and their production are discussed. Also we discuss our future plans including auxiliary analysis of the fluorescence light yield measured this year by LAPP (Annecy), JINR (Dubna) and LIP (Lisbon) MACFLY Collaboration.

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}