Nucleons and Nuclei
Selections From Chapters 3 and 5
Under this rotating photon model of matter, nucleons are not little hard objects like billiard balls with quarks whizzing around inside them. They are totally electromagnetic in nature. The best illustration of that comes from particle/anti-particle annihilation. All that is left is photons, as discussed in chapter 2. There is nothing else left because there is nothing else! This section shows how the electric and magnetic fields combine to give the nucleons. Firstly, the electric fields. The illustrations below show an oblique view of the circular disks that make up the charge distribution of protons and neutrons.
Figure 3.6 A Charge distribution density of a proton
Figure 3.9 A Charge distribution density of a neutron
Figure 5.3 G Schematic illustration of the structure of a proton
Figure 5.3 H Schematic illustration of the structure of a neutron
Protons and neutrons, like all other particles, are not “solids” equivalent to billiard balls or any other shape. They are entirely electromagnetic fields. They include structures that have the properties of muons and pions. They have structures that could be interpreted as quarks, but are not quarks. It is the spread of charge that gives all nuclei the “skin effect”. These nucleons are held together in layers by a strong force.
The layers are held together by a weaker force. Within those layers protons can only combine with neutrons. Like nucleons repel each other. The following gives some examples of the structure of some nuclei. Red marks proton centers, blue marks neutron centers. Dots and crosses mark spin up and spin down.
Illustrations of the centres of 4He, 6Li and 7Li nuclei. They form in a plane.
Illustrations of the positive charge distribution associated with the protons in 4He and 6Li nuclei.
To save space the following figures show the nucleon centers in isometric view. The vertical groups indicate layers stacked upon each other.
Figure 5.18 The structure of different O8 isotopes. Note the most abundant isotope has all protons joined to two neutrons and all looped neutron lattice positions vacant. It shows 3 with the largest layers containing 3 nucleons in both directions. The A = 24 and 26 isotopes show the additional neutrons attached to only one proton each. They have very short half lives.
Figure 5.28 The structure of Pb82 isotopes as determined from the rules for forming nuclei. They show 8 layers of nucleons, with the widest having 8 nucleons by 7 nucleons. Other structures are possible.
Note that all neutron lattice vacancy positions are filled for the most abundant Pb isotope. 209Bi, has a very long half life. There will be no stable isotopes beyond 208Pb because there are no nucleons available to fulfill the binding requirements. Note that protons and neutrons are uniformly distributed throughout the nucleus in the lattice structure indicated. They all form alpha particle structures. That explains why alpha particles are so easily generated when nuclei are hit by other particles.
Under the binding requirements, there are a maximum and minimum number of neutrons for each atomic number Z for the isotopes to have some stability. This is illustrated in figure 5.25. Isotopes outside the red and blue lines will have short half lives, usually measured in fractions of a second. For even Z ≤ 20, all inner neutron lattice positions are vacant for the most abundant isotope. At Z = 82, they are all full for the most abundant isotope. Mid range nuclei, Z ≈ 50, have the greatest opportunity for stable isotopes. They can form either side of the most abundant isotope.
The following shows how this model has matched some of the known properties of nuclei.
1 Nuclei will be automatically subjected to the special relativity corrections of mass, length and time when they move.
2 The spin of a nucleus. It is the sum of the spins of the individual nucleons, the spin of each being the angular momentum of the rotating photon that comprises the nucleon.
3 The magnetic moment of a nucleus. It is the sum of the magnetic moments from the spin orientation of the individual nucleons, with a slight correction that is postulated to be due to the distortion of the rotating photons as they overlap those of neighbouring nucleons.
4 The nucleons within a nucleus orient their spins to give maximum magnetic attraction with neighboring nucleons and minimum external magnetic moment.
5 This strong nuclear force has a range of less than ≈ 5.5 fm, being very weak at that distance and increasing at shorter separation distances, particularly between 1.9 fm and 1.2 fm.
6 Layers of strongly bound nuclei are held together by a weaker force.
7 Proton to proton and neutron-to-neutron binding is only possible when the nucleons are in separate layers and by the magnetic force.
8 Short term isotopes with weakly bound nucleons can be formed by either a proton or neutron being bound at distances of < 3 fm from the surface of the nucleus. It is caused by the nucleon being bound to just one opposite nucleon.
Figure 5.25 Plot of mass number A versus atomic number Z
9 Nuclei bombarded by energetic charged particles have a high probability of alpha particles being knocked out of them because those structures are present everywhere within almost all compound nuclei.
10 The greater the number of protons in a nucleus, the more neutrons that are required to bind them together.
11 Low Z nuclei have more isotopes above their most abundant isotope, while high Z nuclei have more isotopes below their most abundant state. This is because low Z nuclei have many vacant neutron sites within the lattice array for the most abundant isotope, while high Z nuclei have almost all their lattice neutron lattice sites full for their most abundant isotope.
12 When a 235U nucleus fissions, it generates an array of different nuclear fragments which will have maxima near A = 90 and A = 142, with a lesser probability of getting equal mass fraction at A ≈ 116. The maximum and minimum fractions will be near A = 170 and A = 62 respectively. These values come about from the splitting of one of the two central layers of the 235U nucleus shown in figure 5.28.
13 The charge density of the 4He nucleus will be much higher than that of all other nuclei.
14 The dimensions of nuclei are automatically determined by the structure of the individual nucleons, the lattice structure and the binding energy of the nucleus.
15 The charge density of Z ≈ 82 nuclei will be less than the charge density of Z < 10 nuclei.
16 The charge density of all nuclei will diminish from its maximum to zero over a distance of ≈ 2 – 2.5 fm, that being the extent of the charge distribution of the proton with an allowance for the non-circular distribution of nucleons within the nucleus.
17 Measurements of the dimensions of nuclei will yield a slightly larger diameter when they are measured using neutron scattering than when using charged particle scattering.
18 Protons are held in place by neutrons and will not migrate to the outer regions despite their high positive charge exerting a significant repulsive force on neighbouring protons.
19 Protons and neutrons are uniformly distributed throughout the nucleus.
20 A = 5 nuclei can’t exist (because the 4He nucleus has only one nucleon of any type available for another nucleon to attach to it).
21 8Be nuclei can’t exist (because they will rapidly become 2 x 4He nuclei).
As well as the above, this model makes the following predictions about nuclei that were unknown (to the author) at the time of writing.
22 Nucleons combine within a nucleus as individual particles, largely retaining their individual particle properties.
23 Nucleons unite into a nucleus by forming into layers in a hexagonal close packed lattice structure in which binding is between protons and neutrons only, A < 8 excluded.
24 The strong nuclear force is due to the two dimensional nature of the charge distribution of the nucleons It is caused by parts of the proton’s positive charge directly overlapping parts of the neutron’s negative charge segments at very small distances, giving rise to what can be called “division by zero” attraction.
25 Individual nucleons within a layer are arranged in a lattice structure within the nucleus, with specific sites for each of the proton and neutron. A proton cannot change its lattice position with a neutron.
26 With high Z nuclei, inner protons are bound by up to 6 neutrons, while outer protons in stable nuclei are bound to 3 neutrons.
27 Stable nuclei with Z > 3 are composed of multiple layers of nucleons, with nucleons within an individual layer held together by the strong “division by zero” electric attraction and the layers held together by the weaker magnetic attraction.
28 The 6Li and 7Li nuclei have a dimension somewhat larger than predicted from their Z and A because they form in a single layer.
29 In “quasi-stable” nuclei (half life > ≈ 1 sec), all protons must be bound to at least three neutrons (H, He, 6Li and some other low Z isotopes excluded).
30 In “quasi-stable” nuclei, all neutrons must be bound to at least two protons (2H excluded).
31 Nuclei in which one or more nucleons are bound to just one opposing nucleon will form very short-life isotopes.
32 Nucleons combine as whole entities in a lattice structure. For low Z nuclei, the minimum number of neutrons for a given Z is determined by the minimum number for each proton to be held by two neutrons (2H and 3He excluded).
33 Nucleons are bound in layers within the nucleus by the electromagnetic force. Because charge is only distributed in the two dimensions of the rotating photons that constitute the nucleons, overlapping charge segments can occur at effective distances of less than 0.1 fm. This allows small overlapping opposite charge segments to overcome the repulsion of much larger proton charges at distances of ≈ 2.5 fm.
34 Individual nucleons are bound in the lattice structure and are not free to migrate around within the nucleus.
35 There is no contribution to a nucleus’s spin from the nucleons in the nucleus rotating about its common centre of mass.
36 Within a given layer, like nucleons cannot bind to each other.