Does tunneling affect the energy of a particle in a finite box?

In summary, the energy of an alpha particle both inside and outside the nucleus is usually between 4-9 MeV, indicating that there is no significant difference in energy levels between the two. However, when considering tunnelling, the potential inside and outside the barrier may not match, leading to a change in kinetic energy for the tunnelled particle. The tunnelling probability formula does not provide information on the energy of the particle, so it is necessary to calculate the energy/frequency of the wave function for the tunnelled particle. This concept also applies to gamma emissions, where the total energy is conserved, but the kinetic energy of the alpha particle may be affected by the emitted gamma.
  • #1
houlahound
908
223
using alpha decay as a concrete example is the energy of the alpha inside and outside the nucleus the same. it appears so from what I can see but alphas do have a range of energies usually up to between 4 - 9Mev. which is the same range as inside the nucleus.

my question really is does tunnelling for say a particle in a finite box to out of the finite box change the kinetic energy of the particle in any situation, always or never?

the formula for tunnelling probability does not supply info on the energy of the tunnelled particle ie from hyperphysics (simple solution);

upload_2016-10-25_8-17-51.png


how would one calculate the energy/frequency of the wave function for the tunnelled particle?
 
Physics news on Phys.org
  • #2
Energy is conserved, but the potential inside in general won't match the potential outside.

"The energy of the alpha nucleus inside the nucleus" is not really a well-defined concept. You can use this as heuristics, but there are not physically two protons and two neutrons together bouncing around.
 
  • #3
thanks mfb, so if energy is conserved the particle does have the same energy on the outside implying there is no loss of energy passing through the barrier?

if as mostly does a gamma is also emitted will the gamma energy reduce the alpha particle kinetic energy?
 
  • #4
houlahound said:
thanks mfb, so if energy is conserved the particle does have the same energy on the outside implying there is no loss of energy passing through the barrier?
Sure.
Its kinetic energy will be different if the potential is different, the total energy is conserved.
houlahound said:
if as mostly does a gamma is also emitted will the gamma energy reduce the alpha particle kinetic energy?
Sure. Same concept: total energy is conserved.
 

1. What is the energy of a tunnelled particle?

The energy of a tunnelled particle refers to the amount of energy required for a particle to pass through a potential barrier, which is typically higher than the particle's kinetic energy. This energy is proportional to the particle's wavelength and the height and width of the barrier.

2. How does the energy of a tunnelled particle compare to its kinetic energy?

The energy of a tunnelled particle is typically lower than its kinetic energy due to the potential barrier it must overcome. However, as the barrier becomes thinner, the difference between the two energies decreases.

3. Can the energy of a tunnelled particle be measured?

Yes, the energy of a tunnelled particle can be measured using various experimental techniques such as electron tunneling spectroscopy or scanning tunneling microscopy. These methods allow for the determination of the particle's energy as it passes through a potential barrier.

4. How does the energy of a tunnelled particle affect its probability of tunneling?

The higher the energy of a tunnelled particle, the greater its probability of tunneling through a potential barrier. This is because a higher energy allows the particle to overcome the barrier more easily, increasing its chances of passing through it.

5. What factors can influence the energy of a tunnelled particle?

The energy of a tunnelled particle can be influenced by various factors such as the thickness and shape of the potential barrier, the particle's mass and charge, and the potential energy difference on either side of the barrier. Other factors may include temperature, magnetic fields, and electric fields.

Similar threads

  • Quantum Physics
Replies
12
Views
1K
Replies
27
Views
2K
Replies
4
Views
946
Replies
3
Views
1K
Replies
41
Views
3K
Replies
4
Views
875
Replies
7
Views
1K
Replies
13
Views
350
Replies
4
Views
5K
Replies
4
Views
1K
Back
Top