Nuclear fission and fushion

1. NUCLEAR
FISSION &
FUSION

2. PRESENTATION CONTEXT
History
Definition of fission & fusion
Process of These System
Energy Comes From Fission & Fusion
Chain Reaction
Usage
Differences
Quiz

3. History . . .
Hahn & Strassman
 InMeitner & Frisch
1939 They First Identified The
Nuclear Fission
Explained Hahn & Strassman results
Their Statement Was :
Instead of heavier Uranium, it had split
Bombarded Uranium-235 samples with neutrons
into smaller elements = Nuclear neutrons
expecting the Uranium-235 to capture Fission

4. A LITTLE BIT ON THE ATOM
Neutral neutrons
-
Nucleus
-
-
  

 

-
-
Negative electrons
Positive protons

5. NUCLEAR FISSION
A reaction in which an
atomic nucleus of a
radioactive element splits by
bombardment from an
external source, with
simultaneous release of
large amounts of energy,
used for electric power
generation

6. CHAIN REACTION
A chain reaction
occurs
• When a Critical Mass
of Uranium
Undergoes Fission.
• Releasing a Large
Amount of Heat and
Energy That
Produces an Atomic
Explosion.

8. Nuclear Fission Diagram
1n
0
+
235U
92
“236 U”
92
91Kr
36
+ 142Ba + 3 1n + Energy
56
0

9. The Fission Process
A neutron travels at high speed towards a uranium235 nucleus
1
0
n
235
92 U

10. The Fission Process
A neutron travels at high speed towards a uranium235 nucleus
1
0
n
235
92 U

11. The Fission Process
A neutron travels at high speed towards a uranium235 nucleus
1
0
n
235
92 U

12. The Fission Process
The neutron strikes the nucleus which then captures
the neutron
1
0
n
235
92 U

13. The Fission Process
The nucleus changes from being uranium-235 to
uranium-236 as it has captured a neutron
236
92 U

14. The Fission Process
 The uranium-236 nucleus formed is very unstable
 It transforms into an elongated shape for a short time

15. The Fission Process
 The uranium-236 nucleus formed is very unstable
 It transforms into an elongated shape for a short time

16. The Fission Process
 The uranium-236 nucleus formed is very unstable
 It transforms into an elongated shape for a short time

17. The Fission Process
It then splits into 2 fission fragments and releases
neutrons
1
0
n
1
0
n
1
0
n
141
56 Ba
92
36 Kr

18. The Fission Process
It then splits into 2 fission fragments and releases
neutrons
1
0
n
1
0
n
1
0
n
141
56 Ba
92
36 Kr

19. The Fission Process
It then splits into 2 fission fragments and releases
neutrons
1
0
n
1
0
n
1
0
n
141
56 Ba
92
36 Kr

20. The Fission Process
The mass that was “lost” became energy
141
56 Ba
1
0
n
1
0
92
36 Kr
1
0
n
n

21. Conservation of Energy/Mass
 E = MC ²
• Energy cannot be created
Einstein's Formula Above Tell Us How The
or Occurs
destroyed – it can only
Change
change form
 In The Equation Above
Energy
Mass
Light
Speed
E = Energy
M = Mass
C = Speed Of Light ( Universal Constant)

22. Energy from Fission
Each uranium-235 atom has a mass of 3.9014 x 10-25
kg.
The total number of atoms in 1 kg of uranium-235
can be found as follows:
No. of atoms in 1 kg of uranium-235 = 1/3.9014 x 10-25
No. of atoms in 1 kg of uranium-235 = 2.56 x 1024 atoms

23. Energy from Fission
If one uranium-235 atom undergoes a fission reaction
and releases 2.385 x 10-11 J of energy, then the amount
of energy released by 1 kg of uranium-235 can be
calculated as follows:
Total energy = energy per fission x number of
atoms
Total energy = 2.385 x 10-11 x 2.56 x 1024
Total energy = 6.1056 x 1013 J

24. NUCLEAR POWER PLANT
In nuclear power
plants:
 fission is used to
produce energy
 control rods in the
reactor absorb neutrons
to slow and control the
chain reactions of fission

25. FISSION CAN BE USED
• GOOD
– A controlled chain reaction in a reactor used
in nuclear power plants to produce
electricity.
• EVIL
– An uncontrolled chain reaction is used to
create incredibly powerful weapons – the
atomic bombs dropped on Japan.

26. NUCLEAR FUSION
• Nuclear Fusion Is The Process By
Which Multiple Nuclei Join Together
To Form a Heavier Nucleus.
• It Is Accompanied By The Release Or
Absorption Of Energy Depending On
The Masses Of The Nuclei Involved..
2
1
3
H+ H
1
4
1
He+ n + Energy
2
0

27. Fusion: Small Nuclei Form Larger
Nuclide, Release Energy
Small nuclei come together to form larger
nuclide, releasing energy
This type of
Fusion is being
Examined as
An alternative
Energy source
On Earth.

28. Complete the Reaction
1H
element
atomic number
(protons)
4Be
1H
6C
2He
1H
2He
1H
2He
6C
4Be
2He
8
2He
O

29. THE FUSION PROCESS
2
1H
3
1H

30. THE FUSION PROCESS
2
1H
3
1H

31. THE FUSION PROCESS
2
1H
3
1H

32. THE FUSION PROCESS
2
1H
3
1H

33. THE FUSION PROCESS

34. THE FUSION PROCESS

35. THE FUSION PROCESS

36. THE FUSION PROCESS

37. THE FUSION PROCESS
1
0
4
2 He
n

38. THE FUSION PROCESS
1
0
4
2 He
n

39. THE FUSION PROCESS
1
0
4
2 He
n

40. THE FUSION PROCESS
1
0
4
2 He
n

41. ENERGY FROM FUSION
2
3
H + 1H
1
m = 3.1 x 10-29 kg
c = 3 x 108 ms-1
E=E
4
1
He + 0 n + Energy
2
E = mc2
E = 3.1 x 10-29 x (3 x 108)2
E = 2.79 x 10-12 J
The energy released per fusion is 2.79 x 10-12 J.

42. THE SUN
Every second, the sun converts 500
million metric tons of hydrogen to
helium. Due to the process of fusion,
5 million metric tons of excess
material is converted into energy in
each second. This means that every
year, 157,680,000,000,000 metric
tons are converted into energy

43. A-BOMB vs. H-BOMB
• ATOMIC BOMB (Hiroshima)
– Killed over 66,000 people instantly
– 13 kilotons of TNT-equivalent
– 2 exploded in warfare
• HYDROGEN BOMB
– 10 megatons (million-tons) of TNTequivalent
– NEVER exploded in warfare
– Is it the bomb too big to ever be
used???

44. FUSION CAN BE USED
• GOOD
– A controlled reaction in a reactor used to
produce cleaner, inexpensive electricity
• EVIL
– A fission bomb starts a fusion chain reaction
to create an incredibly powerful weapon –
thermonuclear weapons (H-bombs), MUCH
more destructive than atomic bombs.

45. FISSION VS FUSION
One energymass of One energyof
Fissionlittlereleased Few radioactive
Takes produces
Extremely released
Fission is energy Fusiondensity,
The class of
The class high
Critical the
High occurs
Fission is a atoms nuclear isis three to
Fusionweapon
is the
many highly
to fission does in stars, such
nuclear two million particles are
by split weapon energy required
by fusion
reaction of a
the substance fusing of two
high
splitting than isfour times by or or
radioactive
in a fission
producedtwo
to bring greater
istimes greater
a fission
the hydrogen
and atom into fusion reaction,
temperature
not normally as the sun.
that released in
than thelighter
largehigh-speed bomb,protons
morewhich
particles
reaction.
more energy
bomb, also are
neutrons
environment
chemical more
released by fission.
occuror reactions; but if a fissiona is
two in an
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repulsion.

46. REVIEW
NUCLEAR FISSION:
A large nucleus splits into several
small nuclei when impacted by a
neutron, and energy is released in
this process
NUCLEAR FUSION :
Several small nuclei fuse
together and release
energy.

47. SOURCES
• Fission and Fusion Animations:
http://reactor.engr.wisc.edu/fission.htm
• Fission graphic: http://hyperphysics.phyastr.gsu.edu/hbase/nucene/u235chn.html
• Data:
http://www.w3.org/TR/xhtml1/DTD/html”
http://en.wikipedia.org/wiki/Nuclear_force

48. Quiz
• Which nuclear process produces large
amounts of energy?
A. Fission
B. Fusion
C. Both fission & fusion
D. Neither fission nor fusion

49. • Contact: 01672-462007
• Country : Bangladesh
• Email: aliv_jauad@yahoo.com