Barrier Tunneling and Kinetic Energy

AI Thread Summary
The discussion focuses on calculating the kinetic energy of a proton when it either tunnels through or reflects from a potential barrier. The transmission coefficient (T) was determined to be approximately 9.011*10^-6 using the given variables and equations. It is noted that the kinetic energy remains unchanged in both scenarios due to the conservation of energy principle, meaning the proton retains its energy regardless of whether it tunnels or reflects. The relationship between the kinetic energy and the tunneling parameter 'b' is acknowledged, but the main takeaway is that energy conservation applies to both cases. Understanding these principles is crucial for solving problems related to quantum mechanics and barrier tunneling.
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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.
 
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In both cases (reflection and tunneling) the energy remains unchanged. By conservation of energy the energy cannot change because it is not going anywhere. This holds for electrons and other particles as well.
 
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