The NAVIgation DOsimetry System (NAVIDOS) comprises a complete readout system for a radiation detector, an air pressure sensor and a GPS receiver.The detector system DOSTEL uses silicon detectors which make NAVI-DOS light weighted and compact in size.Therefore, NAVI-DOS is well suited to be installed on board aircraft.The calibration of NAVIDOS in terms of ambient dose equivalent is done by an in-field comparison with the PTB reference instrument πDOS.We also show that the dependence of these results on the vertical cut-off rigidity can be explained by the low response of the silicon detectors for neutrons.Therefore, in-flight measurements have been performed together with the PTB reference instrument πDOS.The dose rates, calculated using the PTB code FDOScalc, were verified with these πDOS measurements.The calibration of NAVIDOS was done with FDOScalc and results in calibration factors between 3.4 in the polar and 2.4 in the equator region.
A method has been developed to correct in real- time the cosmic ray (CR) muon component, observed by the muon telescopes of different geometry, for temperature ef- fect.
. Spacecraft missions such as Wind and ACE can be used to determine magnetic correlation functions in the solar wind. From such data sets one can obtain spatial and temporal correlations of magnetic fields. Such correlations are fundamental in the theory of magnetic turbulence and are important to describe the statistics of magnetic field lines and the propagation of energetic particles such as cosmic rays. In the present article we compare analytical forms of correlation functions with measurements performed in the solar system. We obtain new values for the correlations length scales and we test our understanding of the turbulence dynamics.
In this study, first direct and circumstantial ev- idences of the effects of cosmic rays (CR) on biological systems are presented. A direct evidence of biological ef- fects of CR is demonstrated in experiments with three cellu- lar lines growing in culture during three events of Ground Level Enhancement (GLEs) in the neutron count rate de- tected by ground-based neutron monitor in October 1989. Various phenomena associated with DNA lesion on the cel- lular level demonstrate coherent dynamics of radiation ef- fects in all cellular lines coincident with the time of arrival of high-energy solar particles to the near-Earth space and with the main peak in GLE. These results were obtained in the course of six separate experiments, with partial overlapping of the time of previous and subsequent experiments, which started and finished in the quiet period of solar activity (SA). A significant difference between the values of multinuclear cells in all cellular lines in the quiet period and during GLE events indicates that the cause of radiation effects in the cell cultures is an exposure of cells to the secondary solar CR near the Earth's surface. The circumstantial evidence was obtained by statistical analysis of cases of congenital mal- formations (CM) at two sites in the Murmansk region. The number of cases of all classes of CM reveals a significant correlation with the number of GLE events. The number of cases of CM with pronounced chromosomal abnormalities clearly correlates with the GLE events that occurred a year before the birth of a child. We have found a significant corre- lation between modulations of the water properties and daily background variations of CR intensity. We believe that the effects of CR on biological systems can be also mediated by fluctuations in water properties, considered as one of possi- ble mechanisms controlling the effects of CRs on biological systems.
We report here on two proton energetic particle events observed by the Energetic and Relativistic Nuclei and Electron (ERNE) instrument on the Solar and Heliospheri- cal Observatory (SOHO). Both events were impulsive (SEP) events with intensities of > 10 3 cm 2 sr 1 s 1 MeV 1 at an energy range of tens of MeVs and were associated with CMEs of angular widths 800 kms 1 . In one of the events there was no associated solar flare, which indicates that the first injected protons were completely due to the associated CME and in the second event the associated solar flare was an impulsive M1.1 class flare and the calculated first injection time for protons of en- ergies 36 MeV and propagating along 1.2 AU path length, was close to the liftoff time of the CME. These observations are inconsistent with the view presented in some studies that narrow fast CME are not associated with SEP events.
