Neutrino astronomy

Decoding the information contained in the space of electromagnetic waves allows us to solve a number of important tasks of studying the universe. But such methods do not make it possible to look inside the star and find out the nature of the processes taking place there. The fact that the electromagnetic radiation that are born in the depths of the stars can not "break" through the thickness of its material to the surface and did not reach us. What happens in the central part of the star? What is the state of its substance? What nuclear reactions take place in its depths? All these questions could be answered neutrino astronomy.

Neutrino astronomy is related to the discovery and study of special nuclear particles - neutrinos

Neutrino astronomy is related to the discovery and study of special nuclear particles - neutrinos. This particle is very small, has a negligible mass and no electric charge. Thanks to its properties of neutrinos can quite freely pass through giant column material. The mean free path of the particles, ie the average distance that it is able to pass into the matter, without experiencing collisions with other particles in the millions of billions of kilometers, and for significant absorption of neutrinos substance is necessary that its density reached monstrous magnitude: 10121015 grams one cubic centimeter. Even superdense stars (such as white dwarfs, of which 108 grams of density per cubic centimeter), are "transparent" for the neutrino.

Neutrinos are the direct "participants" of nuclear transformations occurring in the interiors of stars. It is known, for example, that different types of nuclear reactions corresponds to the emission of neutrinos and antineutrinos different energies.

But how to record and investigate the neutrino fluxes from space? In neutrino astronomy of neutrinos can be detected indirectly. You just need to get them to start any interaction with other particles and record the result. But the method of detection of neutrino radiation allows to fix it only in those cases where every square centimeter of surface every second falls at least a billion billion particles.

Neutrino astronomy and decided this task. To help astrophysicists to come a nuclear reaction involving "elusive" particles. In interaction with neutrinos kernel one of isotopes of chlorine, the latter is converted under an argon isotope nucleus and, moreover, produces one electron. Unlike neutrinos, these particles can be recorded by conventional methods. At the same time, you can at regular intervals to determine the amount of generated by radioactive argon.

The reservoir containing several tens of tons of carbon tetrachloride may be used as a "lens" neutrino telescopes. Such a device would make it possible to record the intensity of neutrino fluxes up to 10 billion particles per square centimeter per second. This sensitivity also is not quite sufficient, but there is the possibility of purely technical improvements, can significantly increase it.

The second difficulty which will have to meet neutrino astronomy - is noise from other cosmic radiation. However, these interferences can be eliminated very original way. Unlike conventional optical and radio observations, the study of the Sun neutrino fluxes will obviously not be carried out during the daytime, but at night, when our day-star sinks below the horizon. This neutrino telescope should not look at the sky, but... into the Earth. Thus, the observation will be carried out through the entire thickness of the planet. By absorbing all other light except the neutrino, the Earth will be an excellent filter.

In recent years, in connection with the discovery of anti-particles is much talk about the possibility of the existence of cosmic worlds, built entirely of antimatter. But there are such worlds in reality? The only real way that allows you to get an answer to this question, indicating neutrino astronomy. When nuclear reactions that occur in the interior of ordinary stars, streams emitted antineutrinos. But if the star was composed of antimatter, it would emitting neutrinos. Therefore, if we can establish that any galaxy emits neutrinos, we can say with full confidence that this galaxy is composed of antimatter.

Tools