Post on 08-Jul-2015
description
WELCOME
Nuclear Reactions
Fission and Fusion
Presented by KIRAN KUMAR. V.A
Code 13973011
State that in fission a nucleus of large mass splits into 2
nuclei of smaller mass numbers, usually with the release
of neutrons.
State that fission may be spontaneous or induced by
neutron bombardment.
Nuclear Fission
There are 2 types of fission that exist:
1. Spontaneous Fission
2. Induced Fission
Spontaneous Fission
Some radioisotopes contain nuclei which are highly
unstable and decay spontaneously by splitting into 2
smaller nuclei.
Such spontaneous decays are accompanied by the
release of neutrons.
Induced Fission
Nuclear fission can be induced by bombarding atoms
with neutrons.
Induced fission decays are also accompanied by the
release of neutrons.
The nuclei of the atoms then split into 2 equal parts.
U23592n
10
The Fission Process
A neutron travels at high speed towards a uranium-235
nucleus.
U23592n
10
The Fission Process
A neutron travels at high speed towards a uranium-235
nucleus.
U23592n
10
The Fission Process
A neutron travels at high speed towards a uranium-235
nucleus.
U23592n
10
The neutron strikes the nucleus which then captures the
neutron.
The Fission Process
U23692
The nucleus changes from being uranium-235 to
uranium-236 as it has captured a neutron.
The Fission Process
The uranium-236 nucleus formed is very unstable.
The Fission Process
It transforms into an elongated shape for a short time.
The uranium-236 nucleus formed is very unstable.
The Fission Process
It transforms into an elongated shape for a short time.
The uranium-236 nucleus formed is very unstable.
The Fission Process
It transforms into an elongated shape for a short time.
It then splits into 2 fission fragments and releases
neutrons.
The Fission Process
14156Ba
9236Kr
n10
n10
n10
It then splits into 2 fission fragments and releases
neutrons.
The Fission Process
14156Ba
9236Kr
n10
n10
n10
It then splits into 2 fission fragments and releases
neutrons.
The Fission Process
14156Ba
9236Kr
n10
n10
n10
It then splits into 2 fission fragments and releases
neutrons.
The Fission Process
14156Ba
9236Kr
n10
n10
n10
Nuclear Fission Examples
U235
92+Ba
141
56+ n
1
03n
1
0+Kr
92
36
U235
92+Cs
138
55+ n
1
02n
1
0+Rb
96
37
Energy from Fission
Both the fission fragments and neutrons travel at high
speed.
The kinetic energy of the products of fission are far
greater than that of the bombarding neutron and target
atom.
EK before fission << EK after fission
Energy is being released as a result of the fission reaction.
Energy from Fission
U235
92+Cs
138
55+ n
1
02n
1
0+Rb
96
37
Element Atomic Mass (kg)
23592U 3.9014 x 10-25
13855Cs 2.2895 x 10-25
9637Rb 1.5925 x 10-25
10n 1.6750 x 10-27
Nuclear Fusion
In nuclear fusion, two nuclei with low mass numbers
combine to produce a single nucleus with a higher mass
number.
H2
1+He
4
2+ n
1
0H
3
1 +Energy
The Fusion Process
H21
H31
The Fusion Process
H21
H31
The Fusion Process
H21
H31
The Fusion Process
H21
H31
The Fusion Process
The Fusion Process
The Fusion Process
The Fusion Process
The Fusion Process
He42
n10
The Fusion Process
He42
n10
The Fusion Process
He42
n10
The Fusion Process
He42
n10
Energy from Fusion
Element Atomic Mass (kg)
21H 3.345 x 10-27
31H 5.008 x 10-27
42He 6.647 x 10-27
10n 1.6750 x 10-27
H2
1+He
4
2+ n
1
0H
3
1 +Energy
THANKU