positrons are positively charged beta particles and electrons - negatively charged.They are formed in the core of the conversion of proton into a neutron into a proton or a neutron.Beta-rays from different secondary and tertiary electrons that result from the ionization of air.
When beta decay electron produced a new kernel, which is the number of protons per unit more.When the positron decay of the nuclear charge increases by one.And in fact, in both cases the mass number does not change.
beta rays have a continuous energy spectrum, it is because the excess energy of the nucleus is distributed differently between the two emitted particles, for example, between a neutrino and a positron.For this reason, the neutrino
is also characteristic of the continuous spectrum.
Beta-rays - a type of ionizing radiation, they lose their energy while passing through matter, cause ionization and excitation of atoms and molecules of the medium.The absorption of this energy can result in secondary processes in the irradiated material - luminescence radiation-chemical reaction or change in the crystal structure.
Run beta particle is called the way that it goes.Typically, this value is expressed in grams per square centimeter.Beta radiation penetrates the body tissue to a depth of 0.1 mm to 2 cm. In order to protect him enough to have a screen of an organic glass of the same thickness.When the layer of any substance, the surface density exceeds 1 g / sq.cm, almost completely absorbs beta-particles with an energy of 1 MeV.
penetrating power of beta particles is evaluated by their maximum range, it is significantly less than that of gamma radiation, but an order of magnitude greater than that of alpha radiation.The electric and magnetic fields of the beta particles are deflected from their straight-line direction, while their velocity is close to the speed of light.
Beta radiation is used in medicine to the surface, intracavitary and interstitial radiation therapy.It is also used for experimental purposes and for radioisotope diagnosis - detection of diseases using the compounds labeled with radioactive isotopes.
therapeutic effect of beta-therapy is based on the biological action of beta particles that are absorbed by the diseased tissue.The radiation sources used various radioactive isotopes.
- Medical-Enc.ru, Beta radiation