Electron mass - small spool and roads

If you ask 100 people to say at least three known elementary particles, then maybe not everyone will name all three, but nobody will forget to call the champion of popularity - the electron. The smallest, lightest among the particles carrying the charge, omnipresent and ... unfortunately "negative", it is a part of any substance on Earth and this already deserves a special relation to it. The name of the particle originated in ancient Greece from the Greek word "amber" - a material that the ancients loved because of its ability to attract small objects. Then, when the study of electricity got a larger scale, the term "electron" began to mean an indivisible, and therefore, the smallest unit of charge.

The eternal life of an electron, as an integral part of matter, was presented by a group of physicists, led by JJ Thomson. In 1897, investigating the cathode rays, they determined how the electron mass relates to its charge, and found that this ratio does not depend on the cathode material. The next step in understanding the nature of the electron was made by Becquerel in 1900. In his experiment it was proved that the beta rays of radium also deviate in the electric field, and their mass-to-charge ratio is the same as the cathode rays. This became indisputable proof that the electron is an "independent piece" of the atom of any substance. And then, in 1909, Robert Milliken, in an experiment with droplets of oil that fell in the electric field, was able to measure the electrical force balancing the force of gravity. At the same time, the value of the elementary one became known. Least, charge:

Eo = - 1.602176487 (49) * 10-19 Cl.

This was enough to calculate the mass of the electron:

Me = 9,109,38215 (15) * 10-31kg.

It would seem that now there is order, everything is behind, but this was only the beginning of a long way of knowing the nature of the electron.

For a long time, the two-faced essence of the electron was a deadlock in physics: its quantum-mechanical properties pointed to a particle, and in experiments on the interference of electron beams on parallel slits, the wave nature was manifested. The moment of truth came in 1924 when, first, Louis de Broglie endowed all material, and electron also, with waves named by his name, and three years later Pauli completed the formation of the initial concepts of quantum mechanics describing the quantum nature of particles. Then came the turn of Erwin Schrodinger and Paul Dirac - complementing each other, they found equations for describing the essence of the electron, in which the electron mass and the Planck constant, quantum quantities, were reflected through the wave characteristics - frequency and wavelength.

Certainly, such duplicity of an elementary particle had far-reaching consequences. Over time, it became clear that the characteristics of a free electron outside matter (as an example - cathode rays) - this is not the same thing as an electron in the form of an electric current in a crystal. For a free electron, its mass is known as the "rest mass of an electron". The physical nature of the difference in the masses of an electron under different conditions follows from the fact that its energy depends on the saturation of the magnetic field of the space in which it moves. Deeper "disassemblies" show that the magnitude of the magnetic field of electrons moving in a conductor, more accurately the flow of current in matter, depends not on the magnitude of the charge of the current carriers, but on their mass. But, on the other hand, the specific energy of the magnetic field is equal to the kinetic energy density of the moving charges, and the growth of this energy is actually equivalent to the increased mass of charge carriers, which was called the "effective mass of the electron." It was analytically determined that it is greater than the mass of a free electron in a / 2λ times, where a is the distance between the planes bounding the conductor, and λ is the depth of the skin layer of the magnetic field.

In elementary particle physics, the mass of an electron is one of the reference constants. The biography of the electron did not end - studies are always relevant and in demand, where he is an indispensable participant. It has long been clear that although small, elementary, and the universe without it - not a step.