D. Karmanov

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 32-channel integrated circuit for recording signals of silicon detectors

A 32-channel integrated microcircuit for microstrip silicon detectors of the “Nuklon” project for studying ionizing radiation in space conditions is tested. The microcircuit allows one to record signals of relativistic particles and nuclei with a charge from Z = 1 up to Z > 50 from silicon detectors. A structural diagram of the microcircuit and its main experimental characteristics are given. The power consumption does not exceed 1.5 mW/channel, and the dynamic range of recorded signals is not smaller than 100 pC.

First results in studying the readout electronics of the silicon tracking system for upgrading the CLAS12 experiment

Investigations of the readout electronics for the tracking system of the CLAS12 experiment have been performed for the last 2 years. The setup and physical problems of the CLAS12 experiment are described. The silicon detectors designed by the authors for the tracking system of the experiment are considered in brief. The electronic system contains the silicon microstrip detector and FSSR2 integrated circuit, which reads signals from the detector. The FSSR2 chip is described and the principles of the chip architecture intended for processing a time-variable data flow and experimental characteristics obtained on trials of the chip are set forth in brief. Results of simulating the chip throughput under loads expected for the physical experiment and experimental characteristics obtained on trials of this chip are described.

A silicon tracking detector module for the CLAS12 experiment

Results of testing the detecting module prototype for the barrel part of the tracking system of the CLAS12 experiment are presented. The module consists of four series-connected silicon microstrip sensors with a 30-cm total length and FSSR2 readout chip. The measurement results of the signal along the module and noise level for different lengths of strips in the module are given. It is possible to conclude from the obtained results that, at a strip length of <30 cm, the signal-to-noise ratio is 6: 1 or higher when minimum ionizing relativistic particles are detected.

New Universal Cosmic-Ray Knee near a Magnetic Rigidity of 10 TV with the NUCLEON Space Observatory

Data from the NUCLEON space observatory give a strong indication of the existence of a new universal cosmic ray “knee”, which is observed in all groups of nuclei, including heavy nuclei, near a magnetic rigidity of about 10 TV. Universality means the same position of the knee in the magnetic rigidity scale for all groups of nuclei. The knee is observed by both methods of measurement of particles energy implemented in the NUCLEON observatory—the calorimetric method and the kinematic method Kinematic Lightweight Energy Meter. This new cosmic ray knee is probably connected with the limit of acceleration of cosmic rays by some generic or nearby source of cosmic rays.

Heavy isotopes cosmic ray spectrometer (HICRS) for the NUCLEON-2 mission

The NUCLEON-2 experiment is aimed at the investigation of isotope and charge composition of medium, heavy and ultra-heavy ions (Z < 82) in the 300 MeV/N — 1 GeV/N energy range. The concept design of HICRS for the NUCLEON-2 satellite cosmic ray experiment is presented. The performed simulation confirms the isotope resolution algorithms and techniques.

The NUCLEON Space Experiment - Preliminary Results

The NUCLEON satellite experiment is designed to investigate directly the energy spectra of cosmic-ray nuclei and the chemical composition (Z=1−30) at energy range 100 GeV–1000 TeV. nThe satellite has been launched in 26 December 2014. The planned exposition time is more than 5 years. The first preliminary results are presented including charge distributions and all particles energy spectra

The HERO (High-Energy Ray Observatory) simulation

The main goal of the High-Energy Ray Observatory (HERO) mission is to perform direct measurements of very high energy cosmic ray. Measurements will concern the following scientific goals: detailed study of charge composition of CR in knee region, studies of the energy spectra of Galactic and extragalactic CR, search for signatures of dark matter particles. HERO is planned to be launched onboard a heavy satellite. This experiment is based on the application of a wide aperture (>2π) deep (~5λ) ionization calorimeter. The effective geometrical factor of the apparatus is not less than 8-16 m2sr depending on the type of particles. Under the long exposure (~10 years), this mission will make it possible to precisely measure cosmic rays up to 1017eV. Wide Monte-Carlo simulations were performed to obtain instrument response for different species of cosmic rays, including charged particles and gammas.

Energy spectra of cosmic ray heavy nuclei in the NUCLEON space experiment after two years of data acquisition

The energy spectra of abundant heavy nuclei from carbon to iron collected by the NUCLEON space experiment after two years of operation are presented. The spectra were measured with use of both calorimeter and KLEM methods. The complex behavior of the spectra from carbon to silicon in the energy range from a few TeV to hundreds of TeV per particle is presented and discussed. The difference between the spectrum of iron and the spectra of other heavy nuclei from carbon to silicon and a signature of a universal break in the spectra of all nuclei near the magnetic rigidity 10 TV are emphasized. Some new features in the spectra of heavy nuclei are discussed.

Primary and secondary cosmic rays in the NUCLEON space experiment after two years of data acquisition

The NUCLEON space experiment was designed to measure energy spectra of cosmic ray nuclei from protons to iron in the energy range approximately from 1 TeV per particle to 1 PeV per particle with good individual charge resolution. The apparatus started the collection of data at the beginning of 2015 and it is in operation up to now. The duration of the mission is expected to be no less than five years. One of the main feature of the experiment is an implementation of two different methods of energy measurement on board of the apparatus -- the calorimetric method and the new kinematic KLEM method (Kinematic Lightweight Energy Meter). The data obtained after two years of operation are presented. A multiple signs of complex behavior of the nuclei spectra and the ratios of spectra violating of a simple universal power-law behavior of the spectra will be presented in the report.