Barrier Tunneling and Kinetic Energy

Click For Summary
SUMMARY

The discussion focuses on calculating the kinetic energy of a proton in two scenarios: tunneling through a potential barrier and reflecting from it. The transmission coefficient (T) is determined using the formula T = e^-2bL, where L is the barrier length (10 fm) and b is calculated from the given parameters. The kinetic energy after tunneling (Kt) and reflecting (Kr) can be derived using the equation K = (1/2)mv2, where m is the proton mass (1.673 x 10-27 kg) and v is its velocity.

PREREQUISITES
  • Understanding of quantum mechanics concepts, specifically barrier tunneling
  • Familiarity with kinetic energy calculations in physics
  • Knowledge of the transmission coefficient and its significance in quantum physics
  • Basic proficiency in using constants such as Planck's constant (h = 6.62 x 10-34) and energy units (MeV)
NEXT STEPS
  • Study the implications of the transmission coefficient in quantum mechanics
  • Explore the relationship between kinetic energy and potential energy in quantum tunneling
  • Learn about the derivation and applications of the Schrödinger equation in barrier problems
  • Investigate real-world applications of quantum tunneling in fields such as semiconductor physics
USEFUL FOR

Students and professionals in physics, particularly those studying quantum mechanics, as well as educators looking to enhance their understanding of barrier tunneling and kinetic energy concepts.

nickm4
Messages
4
Reaction score
0


1. Homework Statement


b). Find the kinetic energy K (sub t), the proton will have on the other side of the barrier if it tunnels through the barrier.

c) Find the kinetic energy K (sub r), it will have if it reflects from the barrier.

Variables:

Transmission Coefficient (T)

T= e^-2bL
T was found to be T= e^-11.617 or (9.011*10^-6)
e= 2.718...
L= length of the barrier which is given as 10fm or (10.0*10^-15m)

b= sqrt(((8pie^2)(m)(U(sub b)-E))/(h^2))

m= mass of proton(1.673*10^-27kg)
Ub= height of the potential barrier(given= 10MeV)
E= energy of the proton (given= 3MeV)
h= plank's constant (6.62*10^-34)

2.


Homework Equations



T= e^-2bL
b= sqrt(((8pie^2)(m)(U(sub b)-E))/(h^2))

The Attempt at a Solution



I solved the first part of the question to find the transmission coefficient, T. But I'm not sure how Kinetic energy is related. Other than through b.

This question is taken from " Fundementals of Physics" Halliday/Resnick 7th ED. Question: 38-63

Thanks Tons.
 
Physics news on Phys.org
Kinetic energy is the energy that an object has due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes. The same amount of work is done by the body in decelerating from its current speed to a state of rest.For a proton, the kinetic energy K (sub t) it will have on the other side of the barrier if it tunnels through the barrier can be calculated using the following equation:K (sub t) = (1/2)mv^2where m is the mass of the proton and v is the velocity of the proton.Similarly, the kinetic energy K (sub r) it will have if it reflects from the barrier can be calculated using the same equation.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
  • · Replies 1 ·
Replies
1
Views
4K
Replies
2
Views
1K
  • · Replies 3 ·
Replies
3
Views
1K
  • · Replies 20 ·
Replies
20
Views
6K
Replies
9
Views
3K
  • · Replies 19 ·
Replies
19
Views
2K
Replies
6
Views
1K
  • · Replies 54 ·
2
Replies
54
Views
11K
  • · Replies 1 ·
Replies
1
Views
1K