M. I. Fradkin

Secondary protons in the atmosphere at different latitudes

SummaryWe present a semiempirical method to study the production and propagation of atmospheric secondary protons with energy>100 Mev, moving in the vertical direction. The derived production functions are fitted by the least-square method for the only previously published splash (SP) and return (RE) albedos observed data using the same instrument and measurement sites. The closed agreements between the measurement data and the calculations over a wide range of atmospheric depths lead to a possible extension of the method for other latitudes. The spectra of SP and RE intensitiesversus the geomagnetic cut-off reveal similar behaviour as assumed earlier by the theory for those components in the Earths magnetic field.

Short-period variation of cosmic-ray intensity observed in the stratosphere

SummaryTo investigate the variation of the cosmic-ray intensity in the Earth atmosphere, stratospheric balloon soundings are performed weekly at Campinas (Brazil). During the flight of May 20th, 1988 short-period variations were detected. Through Fourier analysis it was identified a period of ∼2.5 min, with a confidence level of 99.6% between 23 g/cm2 and 173 g/cm2. Apparently these oscillations are not correlated either with the earth magnetic field or solar activity, suggesting their atmospheric origin, nevertheless it is difficult to explain the production mechanisms of these disturbances.RiassuntoPer studiare le variazioni dellintensità dei raggi cosmici nellatmosfera terrestre sono messi in funzione palloni sonda stratosferici settimanalmente a Campinas (Brasile). Durante il volo del 20 Maggio 1988 sono state registrate variazioni a breve periodo. Mediante lanalisi di Fourier è stato identificato un periodo di ≈2.5 min con un livello di confidenza di 99.6% tra 23 g/cm2 e 173 g/cm2. Apparentemente queste oscillazioni non sono correlate né con il campo magnetico terrestre né con lattività solare, il che suggerisce la loro origine atmosferica, nonostante sia difficile spiegare i meccanismi di produzione di queste perturbazioni.Резюмедля исследования изменения интенсивности комсических лучей в земной атмосфере еженелельно запускайтся стратосферные шарызонды в лаборатории Кампинас (Бразилия). Во время подыта 20 мая 1988 года, были зарегистрированы изменения с коротким периодом. С помощью фурье-анализа определен период 2.5 минуты, с уровнем достоверности 99.6%, в области между 23 г/см2 и 173 г/см2. По-видимому, эти осцилляции не связаны ни с магнитным полем Земли, ни с солнечной активностью. Предполагается их атмосферное происхождение, тем не менее трудно обБяснить механизм образования этих возмущений.

Atmospheric cosmic rays in the South Atlantic anomaly region

SummaryTo study the production and propagation of fast secondaries particles in the atmosphere, data collected during eleven quiet-time balloon flights are analysed. Comparisons of these data with those obtained in different geomagnetic rigidity regions permit to estimate the contributions of the proton and electron components in the measured intensities. Derivations of this last component in the «upward» and «downward» moving electrons fluxes indicate that in the anomaly region a fraction of these particles, produced by the primary protons, are leaving the atmosphere and will not return to the Earth.

Observations of high-energy electrons in the stratosphere

SummaryTo investigate the variation of the flux of cosmic radiation in the vicinity of the Earth, stratospheric balloon soundings are performed weekly at Campinas (Brazil). During some soundings, enhancements of the counting rates are detected. In this paper data from these excesses as well as their analysis are shown. It seems to indicate that possibly high-energy electrons are injected from the lower boundary of the radiation belt into the stratosphere.RiassuntoPer ricercare la variazione del flusso delle radiazioni cosmiche in prossimità della Terra, sono fatti funzionare settimanalmente palloni sonda a Campinas (Brasile). In alcune sonde si registrano aumenti delle frequenze di conteggio. In questo lavoro si mostrano dati da questi eccessi nonché le loro analisi. Ciò sembra indicare che gli elettroni ad alta energia sono probabilmente immessi dallo strato inferiore della fascia di radiazioni nella stratosfera.Резюмедля исследования изменения потока космического излучения в окрестности Земли еженедельно запускаются стратосферные шары-зонды в лаборатории Кампинас (Бразилия). Во время некоторых зондирований зарегистрированы увеличения интенсивности излучения. В этой статье приводятся данные измерений и их анализ. Проведенный анализ показывает, что эти случаи возможно связаны с электронами высоких энергий, инжектированными из нижней границы радиационного пояса в стратосферу.

Electron measurements in the lower atmosphere near the South-Atlantic magnetic anomaly

Abstract To investigate the variation of the flux of cosmic radiation in the vicinity of the earth, stratospheric balloon soundings are performed weekly at Campinas (Brazil). During some soundings, enhancements of the counting rates are detected. In this article data from these excesses as well as their analysis are shown. The integral flux, estimated from extrapolation of these data to the top of the atmosphere, is in good agreement with satellite measurements and seems to indicate that possibly high-energy electrons are injected from the lower boundary of the radiation belt into the stratosphere.