Neutron (elementary particle). Neutrons, isotopes and radioactivity
Neutron ( elementary particle)
This article was written by Vladimir Gorunovich for the site "Wikiknowledge", placed on this site in order to protect information from vandals, and then supplemented on this site.
The field theory of elementary particles, acting within the framework of SCIENCE, relies on a foundation proven by PHYSICS:
- classical electrodynamics,
- quantum mechanics,
- Conservation laws are the fundamental laws of physics.
This is the fundamental difference scientific approach, used by the field theory of elementary particles - a true theory must strictly operate within the laws of nature: this is what SCIENCE is all about.
To use elementary particles that do not exist in nature, to invent fundamental interactions that do not exist in nature, or to replace the interactions that exist in nature with fabulous interactions, to ignore the laws of nature, doing mathematical manipulations on them (creating the appearance of science) - this is the lot of FAIRY TALES masquerading as science. As a result, physics slipped into the world of mathematical fairy tales.
1 Neutron radius
2 Magnetic moment of the neutron
3 Neutron electric field
4 Neutron rest mass
5 Neutron lifetime
6 New Physics: Neutron (elementary particle) - result
Neutron - elementary particle quantum number L=3/2 (spin = 1/2) - baryon group, proton subgroup, electric charge +0 (systematization by field theory elementary particles).
According to the field theory of elementary particles (a theory built on a scientific foundation and the only one that received the correct spectrum of all elementary particles), the neutron consists of a rotating polarized variable electro magnetic field with a constant component. All the unsubstantiated assertions of the Standard Model that the neutron supposedly consists of quarks have nothing to do with reality. - Physics has experimentally proved that the neutron has electromagnetic fields (zero value of the total electric charge does not yet mean the absence of a dipole electric field, which even the Standard Model indirectly had to admit by introducing electric charges in the elements of the neutron structure), and also a gravitational field. The fact that elementary particles do not just possess - but consist of electromagnetic fields, physics brilliantly guessed 100 years ago, but it was not possible to build a theory until 2010. Now, in 2015, the theory of gravity of elementary particles also appeared, which established the electromagnetic nature of gravity and received the equations of the gravitational field of elementary particles, different from the equations of gravity, on the basis of which more than one mathematical fairy tale in physics.
The structure of the electromagnetic field of the neutron (E-constant electric field, H-constant magnetic field, yellow a variable electromagnetic field is noted).
Energy balance (percentage of total internal energy):
- constant electric field (E) - 0.18%,
- permanent magnetic field (H) - 4.04%,
- alternating electromagnetic field - 95.78%.
The presence of a powerful constant magnetic field explains the possession of a neutron by nuclear forces. The structure of the neutron is shown in the figure.
Despite the zero electric charge, the neutron has a dipole electric field.
1 Neutron radius
The field theory of elementary particles defines the radius (r) of an elementary particle as the distance from the center to the point where the maximum mass density is reached.
For a neutron, this will be 3.3518 ∙ 10 -16 m. To this we must add the thickness of the electromagnetic field layer 1.0978 ∙ 10 -16 m.
Then it will be 4.4496 ∙ 10 -16 m. Thus, the outer boundary of the neutron should be located at a distance of more than 4.4496 ∙ 10 -16 m from the center. The result is a value almost equal to the radius of the proton, and this is not surprising. The radius of an elementary particle is determined by the quantum number L and the magnitude of the rest mass. Both particles have the same set of quantum numbers L and M L , and the rest masses differ slightly.
2 Magnetic moment of the neutron
A counterweight quantum theory The field theory of elementary particles states that the magnetic fields of elementary particles are not created by the spin rotation of electric charges, but exist simultaneously with a constant electric field as a constant component of the electromagnetic field. Therefore, all elementary particles with quantum number L>0 have magnetic fields.
The field theory of elementary particles does not consider the magnetic moment of the neutron to be anomalous - its value is determined by a set of quantum numbers to the extent that quantum mechanics works in an elementary particle.
So the magnetic moment of the neutron is created by the current:
- (0) with magnetic moment -1 eħ/m 0n c
Next, we multiply it by the percentage of the energy of the alternating electromagnetic field of the neutron divided by 100 percent, and convert it into nuclear magnetons. At the same time, one should not forget that nuclear magnetons take into account the mass of the proton (m 0p), and not the mass of the neutron (m 0n), so the result obtained must be multiplied by the ratio m 0p /m 0n. As a result, we get 1.91304.
3 Neutron electric field
Despite the zero electric charge, according to the field theory of elementary particles, the neutron must have a constant electric field. The electromagnetic field that makes up the neutron has a constant component, and, therefore, the neutron must have a constant magnetic field and a constant electric field. Since the electric charge is zero, the constant electric field will be dipole. That is, the neutron must have a constant electric field similar to the field of two distributed parallel electric charges of equal magnitude and opposite sign. At large distances, the electric field of the neutron will be practically imperceptible due to the mutual compensation of the fields of both charge signs. But at distances of the order of the neutron radius, this field will have a significant effect on interactions with other elementary particles of similar sizes. This primarily concerns the interaction in atomic nuclei of a neutron with a proton and a neutron with a neutron. For neutron - neutron interaction, these will be repulsive forces with the same direction of spins and attractive forces with the opposite direction of spins. For the neutron - proton interaction, the sign of the force depends not only on the orientation of the spins, but also on the displacement between the planes of rotation of the electromagnetic fields of the neutron and proton.
So, the neutron must have a dipole electric field of two distributed parallel symmetric ring electric charges (+0.75e and -0.75e), of average radius located at a distance
The electric dipole moment of the neutron (according to the field theory of elementary particles) is equal to:
where ħ is Planck's constant, L is the main quantum number in the field theory of elementary particles, e is the elementary electric charge, m 0 is the rest mass of the neutron, m 0~ is the rest mass of the neutron enclosed in an alternating electromagnetic field, c is the speed of light, P - electric dipole moment vector (perpendicular to the neutron plane, passes through the center of the particle and is directed towards the positive electric charge), s - average distance between charges, r e - electric radius of the elementary particle.
As you can see, electric charges are close in magnitude to the charges of the supposed quarks (+2/3e=+0.666e and -2/3e=-0.666e) in the neutron, but unlike quarks, electromagnetic fields exist in nature, and a similar structure of constant any neutral elementary particle has an electric field, regardless of the size of the spin and... .
The potential of the neutron electric dipole field at point (A) (in the near zone 10s > r > s approximately), in the SI system is:
where θ is the angle between the dipole moment vector P and direction to the observation point A, r 0 - normalization parameter equal to r 0 =0.8568Lħ/(m 0~ c), ε 0 - electrical constant, r - distance from the axis (rotation of the alternating electromagnetic field) of the elementary particle to the observation point A, h is the distance from the plane of the particle (passing through its center) to the observation point A, h e is the average height of the electric charge in a neutral elementary particle (equal to 0.5s), |...| is the modulus of the number, P n is the magnitude of the vector P n. (There is no multiplier in the CGS system.)
The strength E of the neutron electric dipole field (in the near zone 10s > r > s approximately), in the SI system is:
where n=r/|r| - a unit vector from the center of the dipole in the direction of the observation point (A), the dot (∙) denotes the scalar product, the vectors are in bold. (There is no multiplier in the CGS system.)
The components of the electric dipole field strength of a neutron (in the near zone 10s>r>s approximately) are longitudinal (| |) (along the radius vector drawn from the dipole to a given point) and transverse (_|_) in the SI system:
where θ is the angle between the direction of the dipole moment vector P n and the radius vector to the point of observation (there is no multiplier in the CGS system).
The third component of the electric field strength is orthogonal to the plane in which the dipole moment vector lies P n of the neutron and the radius vector, - is always equal to zero.
The potential energy U of the interaction of the electric dipole field of the neutron (n) with the electric dipole field of another neutral elementary particle (2) at the point (A) in the far zone (r>>s), in the SI system is equal to:
where θ n2 is the angle between the vectors of electric dipole moments P n and P 2 , θ n - angle between the dipole electric moment vector P n and vector r, θ 2 - the angle between the vector of the dipole electric moment P 2 and vector r, r- a vector from the center of the dipole electric moment p n to the center of the dipole electric moment p 2 (to the observation point A). (There is no multiplier in the CGS system)
The normalization parameter r 0 is introduced in order to reduce the deviation of the value of E from that calculated using classical electrodynamics and integral calculus in the near zone. Normalization occurs at a point lying in a plane parallel to the plane of the neutron, remote from the center of the neutron at a distance (in the plane of the particle) and with a height shift of h=ħ/2m 0~ c, where m 0~ is the value of the mass enclosed in an alternating electromagnetic field resting neutron (for a neutron m 0~ = 0.95784 m. For each equation, the parameter r 0 is calculated independently. As an approximate value, you can take the field radius:
From the foregoing, it follows that the electric dipole field of the neutron (the existence of which in nature, the physics of the 20th century did not even know), according to the laws of classical electrodynamics, will interact with charged elementary particles.
4 Neutron rest mass
In accordance with classical electrodynamics and Einstein's formula, the rest mass of elementary particles with quantum number L>0, including the neutron, is defined as the energy equivalent of their electromagnetic fields:
where definite integral is taken over the entire electromagnetic field of an elementary particle, E is the electric field strength, H is the magnetic field strength. Here all components of the electromagnetic field are taken into account: a constant electric field (which the neutron has), a constant magnetic field, an alternating electromagnetic field. This small, but very capacious formula for physics, on the basis of which the equations of the gravitational field of elementary particles are obtained, will send to the scrap more than one fabulous "theory" - therefore, some of their authors will hate it.
As follows from the above formula, the value of the rest mass of the neutron depends on the conditions in which the neutron is. So by placing a neutron in a constant external electric field (for example, an atomic nucleus), we will affect E 2, which will affect the mass of the neutron and its stability. A similar situation will arise when a neutron is placed in a constant magnetic field. Therefore, some properties of a neutron inside an atomic nucleus differ from the same properties of a free neutron in vacuum, far from the fields.
5 Neutron lifetime
The lifetime of 880 seconds, established by physics, corresponds to a free neutron.
The field theory of elementary particles states that the lifetime of an elementary particle depends on the conditions in which it is located. By placing a neutron in an external field (for example, magnetic) we change the energy contained in its electromagnetic field. One can choose the direction of the external field so that the internal energy of the neutron decreases. As a result, less energy will be released during the decay of a neutron, which will complicate the decay and increase the lifetime of an elementary particle. It is possible to choose such a value of the external field strength that the decay of the neutron will require additional energy and, consequently, the neutron will become stable. This is exactly what is observed in atomic nuclei (for example, deuterium), in which the magnetic field of neighboring protons does not allow the decay of neutrons in the nucleus. On the other hand, when additional energy is introduced into the nucleus, neutron decays can again become possible.
6 New Physics: Neutron (elementary particle) - result
The Standard Model (omitted from this article, but claimed to be true in the 20th century) states that the neutron is a bound state of three quarks: one "up" (u) and two "down" (d) quarks (assumed quark structure of the neutron: udd ). Since the presence of quarks in nature has not been experimentally proven, an electric charge equal in magnitude to the charge of hypothetical quarks has not been found in nature, and there are only indirect evidence that can be interpreted as the presence of traces of quarks in some interactions of elementary particles, but can also be interpreted differently, then the statement The Standard Model that the neutron has a quark structure remains just an unproven assumption. Any model, including the Standard one, has the right to assume any structure of elementary particles, including the neutron, but until the corresponding particles that the neutron supposedly consists of are found in accelerators, the statement of the model should be considered unproven.
The Standard Model, describing the neutron, introduces quarks with gluons that are not found in nature (nobody has found gluons either), fields and interactions that do not exist in nature, and conflicts with the law of conservation of energy;
Field theory of elementary particles ( New physics) describes the neutron based on the fields and interactions existing in nature within the framework of laws operating in nature - this is SCIENCE.
Vladimir Gorunovich
What is a neutron? What are its structure, properties and functions? Neutrons are the largest of the particles that make up atoms, which are the building blocks of all matter.
Atom structure
Neutrons are located in the nucleus - a dense region of the atom, also filled with protons (positively charged particles). These two elements are held together by a force called nuclear. Neutrons have a neutral charge. The positive charge of the proton is matched with the negative charge of the electron to create a neutral atom. Although neutrons in the nucleus do not affect the charge of an atom, they do have many properties that affect an atom, including the level of radioactivity.
Neutrons, isotopes and radioactivity
A particle that is in the nucleus of an atom - a neutron is 0.2% larger than a proton. Together they make up 99.99% of the total mass of the same element and can have a different number of neutrons. When scientists refer to atomic mass, they mean the average atomic mass. For example, carbon usually has 6 neutrons and 6 protons with an atomic mass of 12, but sometimes it occurs with an atomic mass of 13 (6 protons and 7 neutrons). Carbon with atomic number 14 also exists, but is rare. So the atomic mass for carbon averages out to 12.011.
When atoms have different numbers of neutrons, they are called isotopes. Scientists have found ways to add these particles to the nucleus to create large isotopes. Now adding neutrons does not affect the charge of the atom, since they have no charge. However, they increase the radioactivity of the atom. This can lead to very unstable atoms that can discharge high levels energy.
What is a core?
In chemistry, the nucleus is the positively charged center of an atom, which is made up of protons and neutrons. The word "core" comes from the Latin nucleus, which is a form of the word meaning "nut" or "core". The term was coined in 1844 by Michael Faraday to describe the center of an atom. The sciences involved in the study of the nucleus, the study of its composition and characteristics, are called nuclear physics and nuclear chemistry.
Protons and neutrons are held together by the strong nuclear force. Electrons are attracted to the nucleus, but move so fast that their rotation is carried out at some distance from the center of the atom. The positive nuclear charge comes from protons, but what is a neutron? It is a particle that has no electrical charge. Almost all of the weight of an atom is contained in the nucleus, since protons and neutrons have much more mass than electrons. Number of protons in atomic nucleus defines its identity as an element. The number of neutrons indicates which isotope of an element is an atom.
Atomic nucleus size
The nucleus is much smaller than the overall diameter of the atom because the electrons can be further away from the center. A hydrogen atom is 145,000 times larger than its nucleus, and a uranium atom is 23,000 times larger than its center. The hydrogen nucleus is the smallest because it consists of a single proton.
Location of protons and neutrons in the nucleus
The proton and neutrons are usually depicted as packed together and uniformly distributed over spheres. However, this is a simplification of the actual structure. Each nucleon (proton or neutron) can occupy a certain energy level and range of locations. While the nucleus may be spherical, it may also be pear-shaped, globular, or disc-shaped.
The nuclei of protons and neutrons are baryons, consisting of the smallest, called quarks. The attractive force has a very short range, so protons and neutrons must be very close to each other in order to be bound. This strong attraction overcomes the natural repulsion of charged protons.
Proton, neutron and electron
A powerful impetus in the development of such a science as nuclear physics was the discovery of the neutron (1932). You should be thankful for this English physics who was a student of Rutherford. What is a neutron? This is an unstable particle, which in a free state in just 15 minutes is able to decay into a proton, an electron and a neutrino, the so-called massless neutral particle.
The particle got its name due to the fact that it has no electric charge, it is neutral. Neutrons are extremely dense. In an isolated state, one neutron will have a mass of only 1.67·10 - 27, and if you take a teaspoon densely packed with neutrons, then the resulting piece of matter will weigh millions of tons.
The number of protons in the nucleus of an element is called the atomic number. This number gives each element its own unique identity. In the atoms of some elements, such as carbon, the number of protons in the nuclei is always the same, but the number of neutrons may vary. An atom of a given element with a certain number of neutrons in the nucleus is called an isotope.
Are single neutrons dangerous?
What is a neutron? This is a particle that, along with the proton, is included in However, sometimes they can exist on their own. When neutrons are outside the nuclei of atoms, they acquire potentially dangerous properties. When they move at high speed, they produce lethal radiation. Known for their ability to kill humans and animals, so-called neutron bombs have minimal impact on non-living physical structures.
Neutrons are a very important part of an atom. The high density of these particles, combined with their speed, gives them extraordinary destructive power and energy. As a consequence, they can alter or even tear apart the nuclei of atoms that strike. Although the neutron has a net neutral electrical charge, it is made up of charged components that cancel each other out with respect to charge.
The neutron in an atom is a tiny particle. Like protons, they are too small to see even with an electron microscope, but they are there because they are the only way explaining the behavior of atoms. Neutrons are very important for the stability of an atom, but outside of its atomic center they cannot exist for a long time and decay on average in only 885 seconds (about 15 minutes).
"The first five fuel assemblies of fuel assemblies of MOX fuel for the BN-800 reactor of the Beloyarsk NPP have been produced. Thus, the stage of mastering the production of the MOX MOX technological complex has been completed," the press service of the MCC said.
Currently, measures are being implemented, developed by the Mining and Chemical Combine together with a number of Rosatom enterprises, and aimed at increasing production productivity in order to fulfill the annual plan - 40 fuel assemblies.
Power unit No. 4 of the Beloyarsk NPP is needed to develop a number of technologies for closing the nuclear fuel cycle based on "fast" reactors. In such a closed cycle, due to the expanded reproduction of nuclear "fuel", it is believed that the fuel base of nuclear energy will significantly expand, and it will also be possible to reduce the volume of radioactive waste due to the "burning" of dangerous radionuclides. Russia, according to experts, ranks first in the world in the technology of building fast neutron reactors.
Block No. 4 of the BNPP with the BN-800 reactor became the prototype of more powerful commercial "fast" power units BN-1200. Earlier it was reported that the decision to build a BN-1200 pilot unit also at the Beloyarsk NPP could be made in the early 2020s.
The BN-800 reactor is designed to use MOX fuel, which can use plutonium separated during the reprocessing of spent nuclear fuel from thermal neutron reactors, which form the basis of modern nuclear energy. industrial production MOX fuel for BN-800 was built at the MCC with the participation of more than 20 organizations of the Russian nuclear industry.
The initial fuel load of the BN-800 reactor was formed mainly from traditional uranium oxide fuel. At the same time, part of the fuel assemblies contains MOX fuel manufactured at the pilot plants of other Rosatom enterprises - RIAR (Dimitrovgrad, Ulyanovsk Region) and the Mayak Production Association (ZATO Ozersk, Chelyabinsk region). Over time, the BN-800 reactor should be switched to MOX fuel produced by the MCC.
The Federal State Unitary Enterprise "Mining and Chemical Plant" (part of the division of the final stage of the life cycle of nuclear facilities of Rosatom) has the status of a federal nuclear organization. MCC is the key enterprise of Rosatom for the creation of a technological complex for a closed nuclear fuel cycle based on innovative technologies new generation. For the first time in the world, the Mining and Chemical Combine concentrates three high-tech processing units at once - the storage of spent nuclear fuel from nuclear power plant reactors, its processing and the production of new nuclear MOX fuel for fast neutron reactors.
Neutron (Latin neuter - neither one nor the other) is an elementary particle with zero electric charge and a mass slightly greater than the mass of a proton. Neutron mass m n=939,5731(27) MeV/s 2 =1,008664967 a.u.m. =1,675 10 -27kg. Electric charge =0. Spin = 1/2, the neutron obeys Fermi statistics. The internal parity is positive. Isotopic spin T=1/2. Third projection of isospin T 3 = -1/2. Magnetic moment = -1.9130. Binding energy in the nucleus rest energy E 0 =m n c 2 = 939,5 mev. A free neutron decays with a half-life T 1/2= 11 min through the channel due to the weak interaction. AT bound state(in the nucleus) the neutron lives forever. "The exclusive position of the neutron in nuclear physics is similar to the position of the electron in electronics." Due to the absence of an electric charge, a neutron of any energy easily penetrates into the nucleus, and causes a variety of nuclear transformations.
Approximate neutron classification energy is given in Table 1.3
Name | Energy region ( ev) | Average energy E( ev) | Speed cm/sec | Wavelength λ ( cm) | Temperature T( To about) | |
ultracold | <3 10 - 7 | 10 - 7 | 5 10 2 | 5 10 -6 | 10 -3 | |
cold | 5 10 -3 ÷10 -7 | 10 -3 | 4,37 10 4 | 9,04 10 -8 | 11,6 | |
thermal | 5 10 -3 ÷0.5 | 0,0252 | 2,198 10 5 | 1,8 10 -8 | ||
resonant | 0.5÷50 | 1,0 | 1,38 10 6 | 2,86 10 -9 | 1,16 10 4 | |
slow | 50÷500 | 1,38 10 7 | 2,86 10 -10 | 1,16 10 6 | ||
intermediate | 500÷10 5 | 10 4 | 1,38 10 8 | 2,86 10 -11 | 1,16 10 8 | |
fast | 10 5 ÷10 7 | 10 6 =1mev | 1,38 10 9 | 2,86 10 -12 | 1,16 10 10 | |
High energy. | 10 7 ÷10 9 | 10 8 | 1,28 10 10 | 2,79 10 -13 | 1,16 10 12 | |
relativistic | >10 9 =1 gav | 10 10 | 2,9910 10 | 1,14 10 -14 | 1,16 10 14 |
Reactions under the action of neutrons are numerous: ( n, γ), (n,p), (n,n'), (n,α), ( n,2n), (n,f).
Radiative capture reactions( n, γ) of a neutron followed by the emission of a γ-quantum go on slow neutrons with energies from 0÷500 kev.
Example: mev.
Elastic scattering of neutrons ( n, n) is widely used for detection of fast neutrons by the method of recoil nuclei in track methods and for moderating neutrons.
For inelastic neutron scattering ( n,n') a neutron is captured with the formation of a compound nucleus, which decays, ejecting a neutron with an energy less than that of the original neutron. Inelastic scattering of neutrons is possible if the neutron energy is several times higher than the energy of the first excited state of the target nucleus. Inelastic scattering is a threshold process.
Neutron reaction with the formation of protons ( n,p) occurs under the action of fast neutrons with energies of 0.5÷10 meV. The most important are the reactions of obtaining the isotope of tritium from helium-3:
mev with cross section σ warm = 5400 barn,
and registration of neutrons by the method of photographic emulsions:
0,63 mev with cross section σ warm = 1.75 barn.
Neutron reactions ( n,α) with the formation of α-particles effectively proceed on neutrons with an energy of 0.5÷10 MeV. Sometimes reactions take place on thermal neutrons: the reaction of tritium production in thermonuclear devices.
§one. Meet the Electron, Proton, Neutron
Atoms are the smallest particles of matter.
If enlarged to globe Apple medium size, then the atoms will become only the size of an apple. Despite such a small size, the atom consists of even smaller physical particles.
You should already be familiar with the structure of the atom from school course physics. And yet we recall that the atom contains a nucleus and electrons that rotate around the nucleus so quickly that they become indistinguishable - they form an "electron cloud", or the electron shell of the atom.
Electrons is usually denoted as follows: e − . Electrons e- very light, almost weightless, but they have negative electric charge. It is equal to -1. Electricity, which we all use is a stream of electrons running in wires.
atom nucleus, in which almost all of its mass is concentrated, consists of particles of two types - neutrons and protons.
Neutrons denoted as follows: n 0
, a protons So: p +
.
By mass, neutrons and protons are almost the same - 1.675 10 −24 g and 1.673 10 −24 g.
True, it is very inconvenient to count the mass of such small particles in grams, so it is expressed in carbon units, each of which is equal to 1.673 10 −24 g.
For each particle get relative atomic mass, equal to the quotient of dividing the mass of an atom (in grams) by the mass of a carbon unit. relative atomic masses proton and neutron are equal to 1, but the charge of protons is positive and equal to +1, while neutrons have no charge.
. Riddles about the atom
An atom can be assembled "in the mind" from particles, like a toy or a car from parts of a children's designer. It is only necessary to observe two important conditions.
- First condition: each type of atom has its own own set"details" - elementary particles. For example, a hydrogen atom will necessarily have a nucleus with a positive charge of +1, which means that it must certainly have one proton (and no more).
A hydrogen atom can also contain neutrons. More on this in the next paragraph.
Oxygen atom (serial number in Periodic system equal to 8) will have a nucleus charged eight positive charges (+8), which means there are eight protons. Since the mass of an oxygen atom is 16 relative units, in order to obtain an oxygen nucleus, we add 8 more neutrons. - Second condition is that each atom is electrically neutral. To do this, it must have enough electrons to balance the charge of the nucleus. In other words, the number of electrons in an atom is equal to the number of protons at its core, and the serial number of this element in the Periodic system.