Which magic number was explained by Woods Saxon potential?
Typical values for the parameters are: V0 ≈ 50 MeV, a ≈ 0.5 fm. It is monotonically increasing with distance, i.e. attracting. For large A, it is approximately flat in the center. Nucleons near the surface of the nucleus (i.e. having r ≈ R within a distance of order a) experience a large force towards the center.
How do you calculate spin parity from the shell model in nuclear physics?
The total spin of the nucleus is the (vector) sum of these angular momenta and can take val- ues between |j1 − j2| and |j1 + j2| (in unit steps). The parity is given by (−1)(l1+l2), where l1 and l2 are the orbital angular momenta of the unpaired proton and neutron respectively.
Why neutron has no excited state?
The deuteron is the nucleus that contains 1 proton and 1 neutron. The spin and isospin of proton and neutron are the same, both are equal to half. Deuteron has no excited state. It is because any excitation will easily to make the system break apart.
Why do even even nuclei have 0 spin?
Even proton, even neutron All even–even nuclides have spin 0 in their ground state, due to the Pauli exclusion principle (See Pairing Effects for more details).
What is the difference between shell and nucleus?
The shell which is closest to the nucleus is the first shell….Difference Between Shell Structure of Nuclei and Shell Structure of Atom.
| Shell Structure of Nuclei | Shell Structure of Atom |
|---|---|
| Particles of the shell structure of nuclei are neutrons and protons | Particles of the shell structure of an atom are electrons |
How is nuclear spin determined?
The rules for determining the net spin of a nucleus are as follows; If the number of neutrons plus the number of protons is odd, then the nucleus has a half-integer spin (i.e. 1/2, 3/2, 5/2) If the number of neutrons and the number of protons are both odd, then the nucleus has an integer spin (i.e. 1, 2, 3)
Why is there no bound NN or PP state?
As we know, there is no stable bound state for pp(proton-proton) and nn(neutron-neutron). okay, Why? the negative scattering length for diproton or dineutron shows that the two proton or two neutron do not form a stable bound state. but the two proton have the same spin direction and so on for dineutron.
What is deuteron problem?
The problem is a many body one which only becomes tractable through simplification. This has led to the devising of quite different nuclear models to deal with different nuclear properties. Also the simplest nucleus, the deuteron, has only one bound state and so is rather limited as a test ground for theories.
How many isotopes have even atomic number?
For mass numbers of 147, 151, and 209+, the beta-stable isobar of that mass number has been observed to undergo alpha decay. (In theory, mass number 143 to 155, 160 to 162, and 165+ can also alpha decay.)…Even proton, odd neutron.
| Decay | Half-life | |
|---|---|---|
| 147 62Sm | alpha | 1.06×1011 a |
| 235 92U | alpha | 7.04×108 a |
Why is c12 NMR inactive?
There is no NMR spin capability with 12C (6 protons and 6 neutrons). There must be an odd number of a) protons, b) neutrons, or c) both in order for there to be spin activity and thus NMR detectability.