ALPHA STEP and ALPHA STEP+2
Three nuclear growth patterns that made it possible to decipher nuclear structure.
Understanding these patterns are the key to understanding nuclear structure.
THE ALPHA STEP (light elements - oxygen to argon) is the second primary method used to builds the stable nucleus for elements. The alpha step is: Add two neutrons to form the next two stable isotopes, followed by adding two protons which forms the next two stable elements. The two types of alpha steps are the dominant method for incrementing from one stable nucleus to the next. See the figure below.
The alpha step can be demonstrated by following the first alpha step which starts with oxygen16.
The second alpha step series starts with neon20.
Argon consist of nine alpha particles. These nine alpha particles are used to create three rings of three alpha particles each, which forms the primary core of the nucleus. This core is used as a foundation that the subsequent elements and isotopes are built on.
The description given here is very abbreviated. To follow the complete building of the nucleus, the reader should follow the detailed line presented in the section on the Nuclear Valley of Stability.
THE ALPHA STEP + 2 (elements heavier than argon) is the third primary method used to builds the stable nucleus for elements heaver than zinc. Titanium is an exception. On the heavy end of the Valley of Stability The Alpha Step is modified so the 2 neutrons can be 4 neutrons. The important point is that after the Deuteron Step the number of protons and neutron added are always an even number of nucleons.
The alpha steps between oxygen and argon are building alpha particles that form the central core of the nucleus. Between argon and zinc the alpha step + 2 progression represents symmetrical building of deuterons on the outside of the nuclear core. This creates a star like nuclear structure that which resembles alpha particles radiating out from the center. The star phase culminates with the nucleus of zinc.
Nickel 62 the last element to give up energy when it is formed the full star structure is almost complete. The binding energy of zinc is 0.4 percent less than the binding energy of nickel. Progressing along the path of stability the closure of phases requires a little extra energy. Progressing along the path of stability the closure for phase requires a little extra energy. It takes energy to complete or fit in these last nucleons as the final parts of this star like structure.
The next process of this progression in nuclear building is the closing of the star point to form six outside six sided loops that are like the core structure. The closing of each of the loops is achieved with alpha particles.
The CONCLUSION is that the structure of a stable nucleus is BALANCED. This will become more evident with the progression through and along this model.
During the building of the first carbon ring the alternating of neutron and proton balances the electrical charges and also endeavors to balance the lattice structure.
The shift at Oxygen from one neutron and then one proton too two neutrons and then two protons represent the maintenance of nuclear lattice balance because it is necessary to add two neutrons and then two protons to both sides of the nucleus radially through the nuclear center. This maintains balance by placing these nucleons both above and below the core as well as on the left and right side of the core. This type of balancing becomes apparent because in several places it is necessary to add two nucleons for the next stable element’s or isotope’s nucleus to form.
An interesting requirement for the addition of double neutrons to the nucleus is important in understanding the final nuclear structure. The key is, double nucleons, not just double neutrons. There are two places where double protons are also needed, technetium (Tc) and promethium (Pm).
For protons this imbalance is expressed at Tc and Pm, because both Tc and Pm have odd numbers of protons making balance difficult. The imbalance enigma is also obvious for nuclei having odd neutron counts at the following number of neutrons of 19, 21, 35, 39, 45, 61, 71, 89, 115, and 123. This balance phenomenon also explains the dominance of even-even stable nuclei over odd-even and even-odd stable nuclei plus the fact that the only odd-odd stable nuclei are for elements lighter than oxygen. This lighter than oxygen effects for odd-odd nucleus is also a phenomena related to the balance that is required during the building of the first carbon ring.