in MeV equal to 197.3 MeV [10—12]. These units boil down to the fact that equality (3) is true and clearly a simplification of the entire expression.
The radius of the core can be chosen as a constant, but the ratio (4) is most often used.
Expression (4) is calculated in fermi, equal to a femtometer or 10—15 m. Now, when the kinetic energy and the Coulomb barrier have been determined, as well as the particle has already passed through it, having spent a certain part of its energy and entered the reaction, having overcome a distance of 10—15 from the nucleus – the radius of the Coulomb barrier, it is possible to determine the value of the new kinetic energy (5), indicating some note that the initial kinetic energy indicated here is determined after the passage of a particle through the atomic structure of a particular material, which includes the target nucleus, however, such an algorithm most often refers to the atomic, molecular scale and spending on these phenomena are not so significant, most often appearing in the form of some kind of scattering on the present material.
Further, after these expressions, first of all it is necessary to determine the type of nuclear reaction – calculate the energy yield of the nuclear reaction (6).
A simpler calculation of the present expression can be provided due to the fact that the mass of each of the components of a nuclear reaction is calculated in atomic units of mass and after performing elementary arithmetic operations is multiplied by the square of the speed of light, also represented in MeV, which for 1 a. u. m. is equal to 931.5 MeV. As a result, a positive or negative output of the nuclear reaction is obtained, from which it is possible to determine the exa- or endo-energy of the nuclear reaction.
It was stated above that a particle can expend a certain amount of energy, which will be spent not only on Coulomb, but also on other barriers. In order to determine their approximate sum, the concept of the energy threshold of nuclear reactions (7) is used.
In this case, all the necessary indicators are known and give the general state of the reaction. Further, it is desirable to present the general energy equation of such a nuclear reaction (8), after which it is possible to proceed to the determination of the kinetic energy of the results of a nuclear reaction.
In order to determine the kinetic energy of the nuclear reaction products, it should be noted that each of the particles receives an initial energy additional balance equal to the sum of the reaction output and the second kinetic energy of the directed particle after the Coulomb barrier, in an inversely proportional to its own mass ratio (9—10).
The representation of these expressions becomes more pronounced already for three reaction products. Most often, in this case, a moment is obtained when the particles are divided into two groups – light and heavy groups. For the above reasons, the light group receives most of the total energy and such an algorithm is stored in the appropriate way.
So, if the amount of the outgoing particle tends to a certain large number (11), then their energies will be distributed in an inversely proportional manner to their mass (12), taking into account the yield of the reaction (13) for such (11).
After the kinetic energy of each of the reaction results is determined, it becomes necessary to define such a concept as the nuclear effective cross section of a nuclear reaction (14).
This concept finds its origin in quantum physics, according to the laws of which, even if a particle does not fall into the physical corpuscular area of the nucleus, it can be captured by it as a result of its low velocity, due to which the de Broglie wave of the directed beam grows (15).
In this case, according to the theory of relativity, (16) is used to calculate the momentum of a directed particle, taking into account the fact that the nuclear effective cross section, as well as all the functions following it, are determined on a time scale after the beam overcomes the Coulomb barrier, from where both the momentum and the velocities are taken directly second, given the factor that due to an increase in the nuclear effective cross-section, for a short time, the nuclear forces together with the Coulomb barrier increase in size.
Where the velocity of the directed particle from the kinetic energy is calculated by deducing through (17).
As a result of the calculations carried out, it was possible to determine the nuclear effective cross-section, which varies in square meters, but a special unit was introduced for it – barn, equal to 10—28 m2. But it is worth pointing out some peculiarity in the definition that the value (14) is the reduced nuclear effective cross-section, which for practical value is translated by (19), where the constant (18) is used, which is a dimensionless quantity, which is expressed through the ratio of the practical experimentally determined value of the nuclear effective cross-section of the most commonly used nuclear reaction – the decay reaction uranium equal to 584 barns to the theoretical basis, equal to 3 396 747 21529 barns.
Further, when this value is determined, it is necessary in order to determine which part of all directed particles will actually pass through a nuclear reaction and be able to give a result, the following algorithm is used for this. Let N (x) particles hit the target, and after overcoming the target, the number of particles is N (x) -dN, from where dN is the number of all interactions that occurred in the target. Now, let’s determine that the coordinate at the beginning of the target is x, and at the moment of exit is x+dx, hence dx is the thickness of the target. Then the definition of the concept of the density of the target nuclei is introduced, in order to calculate it, it is necessary to use (20).
This is the number of nuclei present in one cubic meter of the substance used, therefore, based on the definitions and designations introduced, it can be concluded that there are (21) nuclei in the entire target, and if we take into account that the area where the particles enter into interaction, counting as the area of a single case, where it is enough to get one directed particle in order for the reaction to occur, take (14), then for the entire target, these values can be determined according to (22).
Now it is possible to determine the ratio of the entire area, getting to which, it is possible to cause the beginning of the reaction to the entire area of the target, which will be equal to the