After the discovery of materials capable of spontaneous emission of elementary particles (radio emission as a result of the collapse), began the study of their properties.Active participation in the search for new and organize existing knowledge in physics took the famous Curies and Rutherford.That he managed to open the first gamma rays.Delivered them experiment was simple and, at the same time, a genius.
The radiation source was taken radium.The thick-lead capacitance is doing a narrow opening.At the bottom of the resulting channel hosted radium.At a small distance from the container axis perpendicular holes photosensitive member was located - plate.In the gap between it and a container with radioactive special apparatus could generate a magnetic field of high intensity, the lines of tension which were oriented parallel to the photosensitive plate.All the elements, except for the field generator, were in an airless environment to eliminate the impact of air atoms on the outcome of the experiment.If Rutherford ignored this point, the gamma rays could open someone else.
In the absence of magnetic influence on the plate arose a dark stain, indicating the straight propagation of radiation (all other directions are simply cut off by walls of lead capacity).But as soon as appear the magnetic field on the photosensitive element of the system occurred just three spots.This meant that some particles emitted by radium, deflecting field.Rutherford suggested that the beam consists of at least three components.Character deviation indicated that the particles of the two beams have an electric charge, and the third beam is electrically neutral.Moreover, the negative component of the source of the radiation deflected more pronounced than the positive.Electrically neutral component - this is the gamma-rays.Component with negative charge is called the beta-rays, and the latter, positive charge - alpha ray.
Furthermore, they behave differently in a magnetic field, the beams have different properties.Gamma rays are able to penetrate into the matter for quite a long distance.Thus, the lead plate 1 cm thick reduces their intensity only twice.Alpha-beam can be stopped even a thin sheet of paper.But beta radiation occupies an intermediate position: stop the flow of metal can be several millimeters thick.
later found that:
- beta ray is a stream of negatively charged particles (electrons) moving at high speed;
- alpha-ray - a helium nucleus, a very stable formation;
- gamma ray - one form of electromagnetic waves.The emission spectrum of a line entirely, as the emitting nucleus is characterized by discrete energy states.They represent a level distribution of the radiation energy quanta.The term "gamma-ray" is increasingly used not only to describe the process of radioactive decay, but also, in general, for all the hard radiation of electromagnetic nature which corresponds to each quantum of energy is not less than 10 keV.The source of this type of radiation are electrons in the structure of the excited atoms.Surplus energy transfers electrons to higher energy levels.From there, they go back to their previous state, releasing radiation in the form of X-rays or light (electromagnetic waves).The spectrum of electromagnetic radiation in the case of gamma rays is extremely small and does not exceed 5 * 0.001 nm because of what clearly manifest the properties of particles and not waves.
