The document provides an overview of the nuclear shell model. It discusses the historical development of the model from 1927 to 1935. It then presents three pieces of evidence from experiments that supported developing the shell model to describe nuclear properties, including excitation energies, neutron absorption cross-sections, and neutron separation energies. The rest of the document outlines how the shell model was developed theoretically by introducing a Woods-Saxon potential well and spin-orbit coupling to explain nuclear magic numbers and properties like ground and excited state configurations and nuclear magnetic moments. The model provides good predictions but has some limitations for deformed nuclei.
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BS-III
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BS-III
In 1909, Rutherford performed the Gold Foil Experiment and suggested the following characteristics of the atom:
It consists of a small core, or nucleus, that contains most of the mass of the atom
This nucleus is made up of particles called protons, which have a positive charge
The protons are surrounded by negatively charged electrons, but most of the atom is actually empty space.
In 1913, Bohor proposed the Atomic Model, which suggests that electrons travel around the nucleus of an atom in orbits or definite paths.
Atom consists of a tiny nucleus.
Each orbit has fixed energy that is quantatized.
The energy is emitted or absorb only when an electron jumps from one orbit to another.
Electron can revolve in orbits of fixed angular momentum mvr.
Liquid Drop Model
The nuclei of all elements are considered to be behave like a liquid drop of incompressible liquid of very high density.
In an equilibrium state the nuclei of atoms remain spherically symmetric under the action of strong attractive nuclear forces just like the drop of a liquid which is spherical due to surface tension.
The density of a nucleus is independent of its
size just like the density of liquid which is also
independent of its size.
The protons and neutrons of the nucleus move about
within a spherical enclosure called the nuclear
potential barrier just like the movement of the
molecules of a liquid within a spherical drop of liquid.
. The binding energy per nucleon of a nucleus is constant
Binding Energy
The binding energy, BE, of a nucleus is a measure of the strong force and represents the energy required to separate the nucleus into its constituents protons and neutrons;
Greater the binding energy, the more stable the nucleus.
Volume
The volume of the nucleus is directly proportional to the total number of nucleons present in it.
Density
The density of the nucleus is nearly constant.
In 1909, Rutherford performed the Gold Foil Experiment and suggested the following characteristics of the atom:
It consists of a small core, or nucleus, that contains most of the mass of the atom
This nucleus is made up of particles called protons, which have a positive charge
The protons are surrounded by negatively charged electrons, but most of the atom is actually empty space.
In 1913, Bohor proposed the Atomic Model, which suggests that electrons travel around the nucleus of an atom in orbits or definite paths.
Atom consists of a tiny nucleus.
Each orbit has fixed energy that is quantatized.
The energy is emitted or absorb only when an electron jumps from one orbit to another.
Electron can revolve in orbits of fixed angular momentum mvr.
Liquid Drop Model
The nuclei of all elements are considered to be behave like a liquid drop of incompressible liquid of very high density.
In an equilibrium state the nuclei of atoms remain spherically symmetric under the action of strong attractive nuclear forces just like the drop of a liquid which is spherical due to surface tension.
The density of a nucleus is independent of its
size just like the density of liquid which is also
independent of its size.
The protons and neutrons of the nucleus move about
within a spherical enclosure called the nuclear
potential barrier just like the movement of the
molecules of a liquid within a spherical drop of liquid.
. The binding energy per nucleon of a nucleus is constant
Binding Energy
The binding energy, BE, of a nucleus is a measure of the strong force and represents the energy required to separate the nucleus into its constituents protons and neutrons;
Greater the binding energy, the more stable the nucleus.
Volume
The volume of the nucleus is directly proportional to the total number of nucleons present in it.
Density
The density of the nucleus is nearly constant.
ESC Talk on the seminal paper from 1967 by Partidge & Peebles, where they predicted the visibilty of galaxies in the early universe by the virtue of their strong Lyman Alpha emission.
Nuclear physics is an essential part of our social life.We can not less the value of nuclear physics from our lives.If we ignore the value of nuclear physics from our lives then it as a great impact on our lives.
Cancer cell metabolism: special Reference to Lactate PathwayAADYARAJPANDEY1
Normal Cell Metabolism:
Cellular respiration describes the series of steps that cells use to break down sugar and other chemicals to get the energy we need to function.
Energy is stored in the bonds of glucose and when glucose is broken down, much of that energy is released.
Cell utilize energy in the form of ATP.
The first step of respiration is called glycolysis. In a series of steps, glycolysis breaks glucose into two smaller molecules - a chemical called pyruvate. A small amount of ATP is formed during this process.
Most healthy cells continue the breakdown in a second process, called the Kreb's cycle. The Kreb's cycle allows cells to “burn” the pyruvates made in glycolysis to get more ATP.
The last step in the breakdown of glucose is called oxidative phosphorylation (Ox-Phos).
It takes place in specialized cell structures called mitochondria. This process produces a large amount of ATP. Importantly, cells need oxygen to complete oxidative phosphorylation.
If a cell completes only glycolysis, only 2 molecules of ATP are made per glucose. However, if the cell completes the entire respiration process (glycolysis - Kreb's - oxidative phosphorylation), about 36 molecules of ATP are created, giving it much more energy to use.
IN CANCER CELL:
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
Unlike healthy cells that "burn" the entire molecule of sugar to capture a large amount of energy as ATP, cancer cells are wasteful.
Cancer cells only partially break down sugar molecules. They overuse the first step of respiration, glycolysis. They frequently do not complete the second step, oxidative phosphorylation.
This results in only 2 molecules of ATP per each glucose molecule instead of the 36 or so ATPs healthy cells gain. As a result, cancer cells need to use a lot more sugar molecules to get enough energy to survive.
introduction to WARBERG PHENOMENA:
WARBURG EFFECT Usually, cancer cells are highly glycolytic (glucose addiction) and take up more glucose than do normal cells from outside.
Otto Heinrich Warburg (; 8 October 1883 – 1 August 1970) In 1931 was awarded the Nobel Prize in Physiology for his "discovery of the nature and mode of action of the respiratory enzyme.
WARNBURG EFFECT : cancer cells under aerobic (well-oxygenated) conditions to metabolize glucose to lactate (aerobic glycolysis) is known as the Warburg effect. Warburg made the observation that tumor slices consume glucose and secrete lactate at a higher rate than normal tissues.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
2. Why We Need the Model?
To describe and predict nuclear
properties associated with the
structure.
This Review will focus on:
Angular Momentum & parity, J
Ground and excited state configuration
Magnetic moment,
3. Presentation Overview
1. Historical development
2. Why Shell Model: The Evidences
3. How to develop the model
4. How to explain the ground and excited
state configuration of an nucleus
5. How to determine the magnetic
moment of the nucleus
4. Historical Development
1927-28: Statistical Law of Fermions developed
by Fermi
1932-33: Magic Number 2, 8, 20, 28, 50, 82,
126 pointed out by Barlett & Elsasser
1934: The nuclear structure model begun to
discuss. Fermi Gas Model developed, then
applied to nuclear structure.
1935: Liquid Drop Model by Weizsäcker
1936: Bohr applied LDM to nuclear structure
The magic number remained mystery…
5. Binding Energy per Nuclear
Particle
4He and 12C -cluster
Solid Red Experimental
Dash Black Semi-empirical
6. Why Shell Model?
Old-fashioned thought:
nucleons collide with each
other. No way for shell model.
Nuclear scattering result:
that thought doesn’t fit the
data!
Magic number even doesn’t
look to support shell model!
BUT
Indication that nuclear potential
can be approached by a
Potential-Well
Experiment evidence
Atomic physics electron orbits
around the core
?
But, how is inside the core???
7. The Evidence #1:
Excitation Energy of First 2+State
N/Z=20/20
Review Physics Letter 28 (1950) page 432
N/Z=50/40 N/Z=82/60
Z=50
N/Z=126/82
Z=70
Z=30
8. The Evidence #2:
Neutron Absorption X-section
E. B. Paul, “Nuclear & Particle Physics”, North Holland Pub. Comp., 1969, page 259
(Logarithmic)
9. The Evidence #3:
Neutron Separation Energy
Frauenfelder & Henley, “Subatomic Physics”, Prentice Hall, 1991, page 488
10. Conclusion so far…
Nuclear structure BEHAVES alike
electron structure
Magic number a Closed Shell
Properties:
1. Spherical symmetric
2. Total angular momentum = 0
3. Specially stable
11. Presentation Overview
1. Historical development
2. Why Shell Model: The Evidences
3. How to develop the model
4. How to explain the ground and excited
state configuration of an nuclei
5. How the determine the magnetic
moment of the nuclei
to
12. Let’s Develop the Theory!
Keyword:
Explain the magic number
Steps:
1. Find the potential well that
resembles the nuclear density
2. Consider the spin-orbit coupling
13. Shell Model Theory:
The Fundamental Assumption
The Single Particle Model
1. Interactions between nucleons are
neglected
2. Each nucleon can move
independently in the nuclear
potential
14. Various forms of the
Potential Well
1. Square Well
2. Harmonic Oscillation
3. Woods - Saxon
Potential
R
r
V(r)
V0
a
i
i
ij
i
i
i r
V
r
v
r
V
T
H )
(
)
(
)
(
'
Residual potential
Central potential
Cent. Pot >> Resd. Pot,
then we can set 0.
Finally we have 3 well
potential candidates!
Full math. Treatment:
Kris L. G. Heyde, Basic Ideas and Concepts in Nuclear Physics, IoP, 1994, Chapter 9
15. The Closed Shell:
Square Well Potential
The closed shell magic
number
0
2
1
)
(
2
2
2
2
2
2
nl
nl
nl R
Mr
l
l
r
V
E
r
M
R
dr
d
17. The Closed Shell:
Woods - Saxon Potential
The closed shell
magic number
a
R
r
Vo
r
V
exp
1
)
(
But…
This potential
resembles with
nuclear density from
nuclear scattering
18. The Closed Shell:
Spin-Orbit Coupling Contribution
Maria Mayer (Physical Review 78 (1950),
p16) suggested:,
1.There should be a non-central
potential component
2.And it should have a magnitude
which depends on the S & L
Hazel, Jensen, and Suess also came to the
same conclusion.
19. The Closed Shell:
Spin-Orbit Coupling Calculation
The non-central Pot.
2
)
(
)
(
'
ls
V
r
V
r
V ls
2
1
2
1
2
2
1
2
2
1
1
1
l
j
l
l
j
l
s
s
l
l
j
j
ls
)
(
2
1
2
r
V
l
E ls
ls
Energy splitting
Experiment: Vls = negative
Energy for spin up < spin down
j = l +/- ½
j = l - ½
j = l + ½
Delta Els
Full math. Treatment:
Kris L. G. Heyde, Basic Ideas and
Concepts in Nuclear Physics, IoP, 1994,
Chapter 9
21. SMT: The Ground State
How to determine the Quantum Number J ?[1]
1. J (Double Magic number or double closed
shell) = 0+. If only 1 magic number, then J
determined by the non-magic number
configuration.
2. J determined from the nucleon in outermost
shell (i.e., the highest energy) or hole if
exist.
3. determined by (-1)l, where l(s,p,d,f,g,…) =
(0, 1, 2, 3, 4, …). To choose l: consider
hole first, then if no hole nucleon in
outermost shell.
23. SMT: Excited State
Some conditions must be known: energy
available, gap, the magic number exists,
the outermost shell (pair, hole, single
nucleon).
Otherwise, it is quite difficult to predict
precisely what is the next state.
24. SMT: Excited State (example)
Let’s take an example 18O with ground state
configuration:
– Z= 8 – the magic number
– N=10 – (1s1/2)2 (1p3/2)4 (1p1/2)2 (1d5/2)2 or (d5/2)2
If with E ~ 2 [MeV], one can excite neutron to (d5/2)
(d3/2), then with E ~ 4 [MeV], some possible excite
states are:
– Bring 2 neutron from 1p1/2 to 2d5/2 (d5/2)4 0 J 5
– Bring 2 neutron from 2d5/2 to 2d3/2 (d3/2)2 0 J 3
– Bring 1 neutron from 2d5/2 to 1f7/2 (f7/2)1 1 J 6
– Some other probabilities still also exist
25. SMT: Mirror & Discrepancy
Mirror Nuclei
15NZ=7 15OZ=8
If we swap protons &
neutrons, the strong
force essentially does
not notice it
Discrepancy
The prediction of SMT
fail when dealing with
deformed nuclei.
Example: 167Er
Theory 7/2 -
Exprm 7/2 +
Collective Model!
27. SMT: The Magnetic Moment
Since L-S
Coupling
associated to
each individual
nucleon
SO sum over
the nucleonic
magnetic moment
A
i
s
l
N
nucleus g
s
g
l
1
1
1
1
1
2
1
l
g
g
g
g
J
g
Jg
s
g
l
g
l
s
l
nucleus
N
nucleus
j
s
l
N
nucleus
values of gl and gs
proton Neutron
gl 5.586 -3.826
gs 1 0
Full math. Treatment:
A. Shalit & I. Talmi, Nuclear Shell Model, page 53-59
28. Conclusions
1. How to develop the model
- Explain the magic number
- Single particle model
- Woods – Saxon Potential
- LS Coupling Contribution
2. Theory for Ground & Excited State
- Treat like in electron configuration
- J can be determined by using the guide
3. Theory for Magnetic Moment
- is sum over the nucleonic magnetic moment
29. Some More Left…
Some aspects in shell Model Theory that are
not treated in this discussion are:
1. Quadruple Moment – the bridge of Shell
Model Theory and Collective Model Theory.
2. Generalization of the Shell Model Theory –
what happen when we remove the
fundamental assumption “the nucleons
move in a spherical fixed potential,
interactions among the particles are
negligible, and only the last odd particle
contributes to the level properties”.