I. Kovalev

NUCLEON ASIC and ladder electronics for cosmic ray experiments

The 32-channels ASIC with a unique dynamic range from 1 to 40000 mips, signal to noise ratio not less than 2.5 at a shaper peaking time of 2 μ s and a low power consumption of 1.5 mW/channel has been designed. The transfer function of the charge sensitive amplifier (CSA), having two subranges of various gains, allowed to reach high dynamic range of the readout electronics. The subranges are automatically switched. Two ASICs were installed on a ladder construction which also contains an ADC, a microprocessor and a power supply. The ASIC and the ladder were created for the minicalorimeter of the NUCLEON experiment. The goal of the NUCLEON satellite mission is to measure the elemental (Z from 1 to 30) energy spectra of high-energy (1011-1015 eV) cosmic rays. The ladder has been tested at the SPS. The ladder can also be used for other future HEP and space cosmic ray experiments.

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.

The Organizational Features of Control, Reception, and Monitoring of Scientific Information in the Nucleon Space Experiment

The NUCLEON experiment is conducted via collaboration of Russian research organizations under the leadership of the Skobel’tsyn Institute of Nuclear Physics. The experiment is aimed at studying the elemental composition and energy spectra of galactic cosmic rays in the ranges of nuclear charges Z = 1–30 and energies of 1011–1015 eV. The research facilities of the experiment were installed on the Resurs-P No. 2 Russian spacecraft as an additional payload. The features of control of the scientific equipment and construction of the computer system responsible for the reception, storage, and quality control of scientific information of the experiment are presented.

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.

ASIC for calorimetric measurements in the astrophysical experiment NUCLEON

A satellite with the NUCLEON apparatus was launched in Dec. 2014. The space NUCLEON project of ROSCOSMOS is designed to investigate cosmic ray nuclei energy spectra from 100 GeV to 1000 TeV as well as cosmic ray electron spectra from 20 GeV to 3 TeV. The method of energy determination by means of a silicon instrument for measuring the particle charge of cosmic rays and the calorimetric system were developed. The main parameters, that determine the quality of calorimetric systems are linearity of transfer characteristic and the dynamic range of input signals, which should reach 30 000 MIPs (minimum ionizing particles). The ASIC, satisfying these requirements, consisting of 32 channels with a unique dynamic range from 1 to 40000 MIPs, signal to noise ratio not less than 2.5 at a shaper peaking time of 2 μs and a low power consumption of 1.5 mW/channel has been designed. The first results of the ASIC functionality in space are presented.