The Earth is continiously exposed to high-energy particles from outher space.
A fraction of them are charged particles, fully ionized atomic nuclei,
traveling with almost the speed of light through the Galaxy - the cosmic rays.
They interact with the atomic nuclei in the atmosphere of the Earth.
The energy released in the collisions is transformed into a variety of
elementary particles, which form a cascade, the extensive air showers.
Such showers are explored with the KASCADE experiment in Karlsruhe.
A calculated air shower in a computer model.
The lines represent the tracks of individual particles.
The properties of cosmic rays are investigated with the experiment. Objective
is to increase the knowledge about these high-energy particles and therewith
about the processes in the cosmos. It is assumed that the atomic nuclei are
accelerated in exploding stars, the supernova explosions. Afterwards, the
particles propagate for several million years through the Galaxy until this
matter from far away accidentally hits the Earth.
Pictures from a detector of KASCADE are projected at the Kunstfassade. The
detector registers hadrons, among them are protons and neutrons, the building
blocks of atomic nuclei. Their measurement allows unique insights in the
processes during the development of the particle cascades in the atmosphere.
(Dr. Jörg R. Hörandel)