What is shell model: Definition and 34 Discussions

The SHELL model is a conceptual model of human factors that clarifies the scope of aviation human factors and assists in understanding the human factor relationships between aviation system resources/environment (the flying subsystem) and the human component in the aviation system (the human subsystem).The SHELL model was first developed by Elwyn Edwards (1972) and later modified into a 'building block' structure by Frank Hawkins(1984). The model is named after the initial letters of its components (software, hardware, environment, liveware) and places emphasis on the human being and human interfaces with other components of the aviation system.The SHELL model adopts a systems perspective that suggests the human is rarely, if ever, the sole cause of an accident. The systems perspective considers a variety of contextual and task-related factors that interact with the human operator within the aviation system to affect operator performance. As a result, the SHELL model considers both active and latent failures in the aviation system.

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  1. M

    A When to use collective and when shell model?

    I am sorry if this is a silly question, but I am confused about it. When do I use a model over the other? I understand how they work separately, but I didn't understand from my readings when I should use one over the other and why. And when I look at an actual level scheme of a nucleus (for...
  2. amyy

    A Does 15F Qualify as an sd Shell Nucleus?

    If we call a nucleus a sd shell nucleus, should its last proton and last neutron both lie in the sd shell or just one lies in the sd shell? For example, 15F, whose proton number is 9 and neutron number is 6. Then the last proton lies in the 1d5/2 orbit and the last neutron lies in the 1p3/2...
  3. Marioweee

    Nuclear shell model of double magic nucleus 132Sn

    The independent particle energies for protons and neutrons around the exotic doubly magic core 132Sn are shown in the figure below, where π refers to protons and ν to neutrons. Using the nuclear shell model and using this figure as a guide, answer to the following questions: a)Estimate Jπ...
  4. I

    Nuclear shell model, spin and parity predictions

    Homework Statement Not exactly a homework problem but I tried to predict the spin and parity of (the ground states of) ##^{89}Sr##,##^{97}Zr## and ##^{137}Ba## using the shell model and my results seem to differ from the tables. Homework Equations Parity ##\pi = (-1)^l## Figure 4 seems to...
  5. P

    I Shell Model: Filling Up Nuclei

    I'm a bit confused about how things fill up in the shell model. Here is my understanding: the potential we are working with is the net potential due to the other nucleons that a proton or neutron feels throughout the nucleus; it is a combination of a square and harmonic oscillator potential...
  6. F

    Using nuclear shell model to determine parity and spin

    Homework Statement Use the shell model to determine the parity and spin assignments for all the stable isotopes of calcium. Homework Equations n/a The Attempt at a Solution The stable isotopes seem to be 40Ca, 42Ca, 43Ca, 44Ca, 46Ca, and 48Ca I believe all of those isotopes except 43Ca are...
  7. sk1105

    Nuclear Shell Model - pp bound states?

    I have looked around for help with this, including on existing threads, but I can't quite find what I'm looking for. I know that in the nuclear shell model we fill the shells in the same way as with electrons, so 2 protons in the first and 6 in the second etc, with the same being true for...
  8. B

    Problem with shell model and magnetic moment of Lithium-6

    I have a problem with the calculus of magnetic moment of Li-6. The configuration of protons is 1p_{3/2}, and the neutrons' one is the same. I have to add the magnetic moment of uncoupled proton and uncoupled neutron. I use the following formula for J=l+\frac{1}{2} (J is the particle...
  9. B

    Single particle shell model for nucleus

    Homework Statement Predict the ground state spin and parity for ^{7}_{3}Li, ^{15}_{7}N. ^{31}_{15}P. Homework Equations Fill up shells for neutrons and protons separately. Shells in increasing energy are: 1S_{1/2}, 1P_{3/2}, 1P_{1/2}, 1S_{1/2}, 1D_{5/2}, 1D_{3/2} and have...
  10. B

    Orbital quantum number in the shell model

    Why isn't the Orbital angular momentum quantum number in the nuclear shell model restricted by the principal quantum number like it is in the atomic shell model? Also, does the principal quantum number even correspond to energy in the shell model?
  11. R

    Understanding the Shell Model in Nuclear Physics

    Hi Just a quick question that I have been wondering about ... how do nucleons fill energy levels, and what is the maximum number of nucleons that can occupy each level? The given pattern is: 1s, 1p, 1d, 2s, 1f, 2p, 1g, etc I can see no obvious pattern here. Can anyone explain? I...
  12. E

    What would be a good Book on Nuclear Shell Model?

    I'm in undergrad doing research with a professor. He's leaving for vacation for a few weeks, and has tasked me with a project. I've been analyzing some spectra for some Carbon reactions, and he posed a question to me on why we don't see other higher-energy states, even if the experiment is ran...
  13. D

    Spin and parity for nuclear shell model

    Homework Statement I have an element: {}^{207}Pb, with Z=82, and A=125, and I need to find spin and parity of it.Homework Equations The angular momentum is determined by the angular momentum of the last nucleon that is odd, in this case it will be one unpaired neutron. Now what confuses me is...
  14. M

    Total Angular Momentum in Nuclear Shell Model

    Homework Statement Calculate the allowed total angular momentum quantum numbers J for 2 protons in a nuclear shell model state j = 3/2. Homework Equations J = j1 + j2 where j are the total angular momenta of each proton. Protons are spin 1/2, orbital angular momentum L is not given...
  15. H

    Nuclear shell model spin and parity?

    Homework Statement What is the shell model spin and parity of _{38}^{89}Sr? 2. The attempt at a solution If i fill the levels as we usually do, Protons will end up in the level 1f_{5/2} with 6protons,ie the level is completely filled If the neutron number is considered,1g_{7/2}...
  16. O

    Question About Bohr's Quantified Shell Model

    I'm sure this has a straightforward explanation and am hoping someone can answer it for me. Looking at this diagram of Bohr's quantified shell model of the atom: http://library.thinkquest.org/C005775/Theory/oldtheory_section3.html ...I don't understand what is preventing the electron...
  17. W

    Understanding the Nucleus Shell Model

    hi please explain what is nucleus shell model?
  18. W

    Why is the nuclear shell model build around single particle motion?

    Hi everyone For the past few months I have been learning about the nucleus and the nuclear shell model. The experimental evidence for a shell structure is overwhelming and easy to understand. It is also quite straight forward to obtain the correct shell closures (magic numbers) using a 3d...
  19. S

    Proton and neutron configurations (shell model)

    Question is: Determine the neutron and proton configurations of the first and second excited states of: _{20}^{41}Ca which have spin-parities of 3/2^{-} and 3/2^{+} respectively.My attempt at solution: (I haven't encountered a problem quite of this type before so am a little unsure as to how...
  20. U

    Nuclear Shell model, how do we know energy levels?

    One of my 'course aims' is to be able to classify the shell model energy levels in terms of quantum numbers l and n and explain how magic numbers arise. I'm using this to help to understand it as well as lecture notes. http://hyperphysics.phy-astr.gsu.edu/hbase/nuclear/shell.html I know...
  21. U

    Nuclear Shell Model, spin and parity

    Homework Statement What is the parity and possible spins predicted by the single particle shell model for the ground state of the 19K40 nucleus (I'm most unsure about the spins) Homework Equations The Attempt at a Solution This has 19 protons and 21 neutrons. Odd-odd...
  22. A

    Answer: 39Ca, 40Ca, 41Ca, 41Sc: Ground & Excited State Spins & Parities

    The question: Use the shell-model diagram provided to justify the spins and parities of the ground-state of 39Ca, 40Ca, 41Ca and 41Sc. Give the spins and parities of the first excited state of 39Ca,41Ca and 41Sc (Z=20 for CA and Z=21 for Sc) My problem: Although I'm fairly certain I've got the...
  23. R

    Exploring Nuclear Energy Levels: Shell Model

    I am trying to explain nuclear energy levels in terms of Shell model and I hope that you guys would assist me through this- 1. The potential which exists inside the nucleus is assumed to be harmonic oscillator potential and it's value is obviously given by V(r)=\frac{1}{2}m\omega ^2r^2 However...
  24. E

    Shell Model: Filling g9/2 Shell w/ 5 Protons

    Homework Statement How do 5 protons fill a g9/2 shell in the shell model? There are 10 spots in the g9/2 shell. Homework Equations The Attempt at a Solution Pauli principle dictates the first four to be in anti-parallel pairs. But the last can be either up or down. Am I missing...
  25. J

    Two questions about angular momentum in the nuclear shell model?

    Hi, I have a couple of questions about the spin of an atomic nucleus. Say I had a carbon-12 nucleus, which is 6 protons and 6 neutrons. The Pauli exclusion principle tells us that these should be arranged in shells determined by their orbital angular momenta and spins. So, the shell...
  26. M

    Nuclear Shell Model - Spin-parity of excited states

    Homework Statement The ground state of _{6}Cl^{13} has spin-parity 1/2- and the next three excited states have values of 1/2+, 3/2- and 5/2+. Explain these values in terms of the shell model.The Attempt at a Solution The problem is that i don't know what is being asked of me...i initially...
  27. P

    Uclear shell model is based on the shell model for electrons

    The nuclear shell model is based on the shell model for electrons, and in the electron shell model, lasing is possible under the right conditions. Does this mean that if the nuclear shell model is correct, a nucleus will be able to undergo lasing. And does anyone know if this has ever been...
  28. Z

    What is the spin and parity of the nucleus 15N in the shell model?

    Hi all, Homework Statement In this question consider the nucleus 15N (The 15 is the atomic mass, so superscript top left of N), and refer to the shell model diagram. (a) Predict the ground state spin and parity, Jpi. (b) Write out the relevant odd particle configuration in the form: p (or n)...
  29. C

    Shell model determining spin and parity

    shell model determining spin and parity - urgent Homework Statement Find the spin and parity of _{20}^{41}Ca and _{20}^{40}Ca Homework Equations http://hyperphysics.phy-astr.gsu.edu/hbase/Nuclear/shell.html The Attempt at a Solution For _{20}^{41}Ca we've an odd number...
  30. B

    Who Introduced NCSM and When Was It Introduced?

    Can anyone tell me who introduced the NCSM and what year was it introduced?
  31. W

    Possible Configurations for the First Excited State in 17-F-9

    I am confused how to determine the spin / parity of excited states. In my textbook, one of the questions states: ------------------------------ The ground state of the radioisotope 17-F-9 has spin-parity j_P = (5/2)+ and the first excited state has j_P=(1/2)-. Suggest two possible...
  32. W

    Nuclear Shell Model - Spin-parity

    I am confused how to determine the spin / parity of excited states. In my textbook, one of the questions states: ------------------------------ The ground state of the radioisotope 17-F-9 has spin-parity j_P = (5/2)+ and the first excited state has j_P=(1/2)-. Suggest two possible...
  33. W

    Nuclear Shell Model: Explaining Nucleon Occupancy

    I don't know how nucleons occupy each energy level, especially the one with multiple states. For example, 1p3/2, there are 4 states in this level, that can be occupied 4 nucleons. If there are 2 nucleons in this level, do they must be paired-up? Why? And if there are 3 nucleons in this...
  34. T

    Predicting Nuclear Spin with Shell Model: How is it Calculated and Validated?

    How would one predict the total spin of a nucleus given Z, N and the shell model? Does it have to to do with even-even, even-odd, odd-odd nuclei?