V. M. Pankov

X-RAY SEMICONDUCTOR (CdTe) SPECTROMETER FOR SOLAR FLARE AND PREFLARE STUDIES

This paper describes the main parameters of an instrument for X-ray flux measurement and solar flare and preflare spectrum registration. The nontraditional CdTe semiconductor detector was space qualified and has sensitivity 0.5 cm2, energy region 3–30 keV, and energy resolutions ∼ 1.3 keV for 5.9 keV and ∼ 10% for 22.1 keV.

RPS-1 Experiment

This Chapter describes the physical characteristics of RPS-1 device and some of experimental results of observations onboard CORONAS-F satellite. Semiconductor spectrometer registered x-ray radiation in the range 3–31.5 Kev. Detailed spectral and time characteristics of weak solar flares were obtained for the first time under relatively low solar activity conditions and at the satellite passage outside the Earth Radiation Belts (ERB). It was established that the increase of solar activity was accompanied by the hardening of the background radiation spectra (without flares). Observations of the nighttime Earth atmosphere visualized the ERBs dynamics (disruption of the northern radiation belt in summer 2002) in the period following the cycle maximum. The energy of the nighttime X-ray emission of the upper atmosphere caused by precipitating magnetospheric electrons did not exceed 8 keV. The energy of GCR contribution to this emission did not exceed 5 keV

The GRIF-2 solar-geophysical experiment on board ALPHA

The main purpose of the GRIF-2 solar-geophysical experiment on board the ALPHA space vehicle is the comprehensive study of the temporal and spectral characteristics of the high-energy neutral radiations (gamma-quanta, neutrons, etc.) generated in solar flares. Another important part of the experiment is the study of the dynamics of energetic charged particles (electrons, protons, etc.) in the circumterrestrial space and its correlation with solar phenomena. The complex of instruments includes a high-sensitivity oriented spectrometer of gamma-quanta and neutrons, an oriented spectrometer of X-rays and electrons with a large geometrical factor, and a spectrometer of electrons and protons with a small geometrical factor. The spectrometer of gamma-quanta and neutrons measures particle fluxes and spectra in the gamma-quantum energy range 0.1– 10 MeV and the spectrometer of neutrons is used for energies over 10 MeV. The spectrometer of X-rays and electrons is intended for both the continuous control of magnetospheric electron precipitations and monitoring the X-ray solar activity in the range 10–100 keV. The spectrometer of charged particles with a small geometrical factor is intended for measurement of high-intensity charged particle fluxes in the trapped radiation zones in the Earth magnetosphere.

GRIF-1 experiment on board the SPEKTR/MIR orbital complex: Study of solar X-ray, gamma-ray, and neutron flares and correlation of magnetosphere-charged particle fluxes with solar activity

The SPEKTR module of the MIR orbital station was launched in May 1995. The multipurpose experiment was based on the GRIF-1 research complex consisting of an oriented X-ray spectrometer, a spectrometer of gamma-quanta and neutrons, a spectrometer of electrons and protons with a large geometrical factor, and a spectrometer of electrons, protons, and nuclei with a small geometrical factor. The solar geophysical aspects of the experiment included the measurements of spectral and temporal parameters of solar hard electromagnetic (0.01–50 MeV) and neutron (>20 MзB) radiation, the study of spectral, temporal, and spatial characteristics of energetic electrons (0.04–1.5 MeV), protons, and nuclei (1–200 MeV/nucleon) in the circumterrestrial space, as well as the correlations of these parameters with solar activity phenomena.