The document discusses the Coulomb barrier, which is the barrier between two atomic nuclei due to coulomb repulsion that must be overcome for nuclear fusion to occur. The Coulomb barrier is given by the Coulomb potential, which depends on the atomic numbers and effective radii of the two nuclei. While it takes relatively little energy to simply collide two accelerated light nuclei, in practice most particles would be elastically scattered. Therefore, to achieve fusion, a confined mixture of nuclei must be heated to a temperature that supplies enough thermal energy to overcome the Coulomb barrier, accounting for quantum tunneling and a distribution of nuclear energies.

1. Experimental Nuclear physics
Course Instructor: Dr. Waseem Ahmad
Presentation On: Coulomb Barrier
presented by: Mehak Tariq
Ghazi University DG Khan

2. Coulomb Barrier
 The barrier between two atomic nuclei, due to coulomb repulsion that has to be overcome for
nuclear fusion to proceed
 This is given by coulomb potential
 Where
 Z & z` are atomic numbers of two nuclei

3. Coulomb Barrier
 R & R` are their effective radii
 The quantity ( R+R`) therefore classically the distance of closest approach.
 Previous study as we know that
R= 1.2 A⅓ fm

4. Coulomb Barrier
 This is relatively small amount of energy to supply by simply colliding two accelerated beams of
light nuclei but in practice nearly all the particles would be elastically scattered
 The only particle way is to heat a confined mixture of the nuclei to supply enough thermal
energy to overcome the coulomb barrier
 The temperature estimated from the relation
E= kT
Where Kb is Boltzmann’s constant given by kB = 8.6× 𝟏𝟎−𝟓
eVK`

5. Coulomb Barrier
 Fusion actually occurs at low temperature than this estimate due to a combination of two
reasons
 First & most important is the phenomenon of quantum tunneling, which means that the full
height of the coulomb barrier does not have to be overcome.
 Second reason that fusion occurs at low temperature then expected is that a collection of nuclei
at a given mean temperature.

6. Thanks for listening to me..