Cosmic Rays as an Object of Research

An educational study of the barometric effect of cosmic rays with a Geiger counter

“…The two main causes of variations in the cosmic ray flux at sea level originating from the Earth's atmosphere are the barometric effect and the temperature effect [1]. While the temperature effect is generally determined by the overall profile of the atmosphere from the level of origin to the detection level, and hence is the more difficult to interpret, the barometric effect is determined by only a single parameter, namely the pressure at sea level.…”

“…Several studies carried out in the past have provided a large quantity of data on the barometric coefficient [1,2]. Values around −(0.18-0.20) %/mbar were extracted for the total ionizing component in the first investigations.…”

“…The coefficient also depends upon the height of observation, the direction of incidence and the energy spectrum of the detected particles. Transport calculations [1] allow one to calculate the value of the barometric coefficient in a wide variety of situations. A strong dependence is observed on the amount of shielding provided around the detector, which determines the energy threshold of muons and the relative composition of the hard and soft components.…”

“…Extensive measurements on the variations in space and time of cosmic rays at sea level began more than 50 years ago. Thus a lot of experimental data have been collected at several observation stations around the world, with the result that the main causes of intensity variation are understood [1,2]. They are periodic effects (cycles with periods of 11 years, one year, 27 days, one solar day or semidiurnal variations) as well as exceptional events, such as magnetic storms and large solar flares.…”

“…However, the statistical analysis of such data is not trivial, since different factors contribute at the same time to the observed variations. Many statistical methods have been developed and used in this context, including averaging techniques, correlations between two or more variables, time series analysis, correlograms and harmonic analysis [1,2].…”