[1]
Mirzaei Mahmoud Abadi Vahid, Faculty of Physics, ShahidBahonar University, Kerman, Iran.
[2]
Askari Mohammad Bagher, Department of Physics, Payame Noor University, Tehran, Iran.
[3]
Mirhabibi Mohsen, Department of Physics, Payame Noor University, Tehran, Iran.
One such model is the Shell Model, which accounts for many features of the nuclear energy levels. According to this model, the motion of each nucleon is governed by the average attractive force of all the other nucleons. The resulting orbits form "shells", just as the orbits of electrons in atoms do. As nucleons are added to the nucleus, they drop into the lowest-energy shells permitted by the Pauli Principle which requires that each nucleon have a unique set of quantum numbers to describe its motion When a shell is full (that is, when the nucleons have used up all of the possible sets of quantum number assignments), a nucleus of unusual stability forms. This concept is similar to that found in an atom where a filled set of electron quantum numbers results in an atom with unusual stability–an inert gas. When all the protons or neutrons in a nucleus are in special filled shells, the number of protons or neutrons is called a "magic number." Some of the magic numbers are 2, 8, 20, 28, 50, 82, and 126. For example, 116Sn has a magic number of protons (50) and 54Fe has a magic number of neutrons (28). Some nuclei, for example 40Ca and 208Pb, have magic numbers of both protons and neutrons; these nuclei have exceptional stability and are called "doubly magic." Magic numbers are indicated on the chart of the nuclides. Filled shells have a total angular momentum, J, equal to zero. The next added nucleon (a valence nucleon) determines the J of the new ground state. When nucleons (singly or in pairs) are excited out of the ground state they change the angular momentum of the nucleus as well as its parity and are spin projection quantum numbers. The shell model describes how much energy is required to move nucleons from one orbit to another and how the quantum numbers change.
Shell Model, Energy Eigen Values, Eigen Functions, Spin Parity
[1]
Cf weizsacker z phys 96 (1935)431
[2]
P. Ring and P. Schuck, 1980, The Nuclear Many-Body Problem Springer – verlag (1980)
[3]
D. L. Hill, and J. A. Wheeler, Phys.Rev. 89 (1953)
[4]
R., Holinde K., Elster C.: Phys. Reports149 (1987)
[5]
G. Bertsch, and S. Das Gupta. Phys. Rev. C 35, 1666 (1987)
[6]
R. Woods, D. Saxon. Phys. Rev., 95 (1954), p. 577. [SD-008]
[7]
Maria Goeppert Mayer. Phys. Rev. 75, 1969 – Published 15 June 1949
[8]
O. Hazel, J. H. D. Jensen, and H. E. Suess,. Phys. Rev. 75 (1949)
[9]
S G NILssoN, Zs f Physik 141, 217 (1955)
[10]
Bohr A and Mottelson B R 1953 Mat. Fys. Med.
[11]
G. Vogel, et al. Phys. Lett., 40B (1972), p. 513.
[12]
D. R. Inglis. Phys. Rev. 96, 1059 – Published 15 November 1954.
[13]
Deck-Model Calculation for Doubly Charged Systems in Reactions. F. Bomse and E. J. Moses. Phys. Rev. 176, 2163 – Published 25 December 1968
[14]
T. H. R. Skyrme, "The effective nuclear potential" , Nucl. Phys. 9 51 (1959) 615-634.
[15]
J.Bartel et al., Nucl. Phys. A 386 (1982)
[16]
J. Dobaczewski, H. Flocard, J. Treiner,. Nucl. Phys. A422 (1984) 103.
[17]
D. Gogny. Nucl. Phys. A237 (1975) 399. 265
[18]
Nuclear physics since the nuclear shell model, complemented with the collective. Amsterdam, 1952; Physica 18, 1043 (1952).
[19]
Nordling C., Sokolowski E. and Siegbahn K., Phys. Rev. 105, 1676 (1957)
[20]
N. N. Bogoliubov, V. V. Tolmachev, D. V. Shirkov (1959)
[21]
h.felocard et al nucl phys a203 (1973) -433
[22]
H. J. Lipkin, Annals of Physics, 9, 332 (1960); Phys. Rev. B 52
