Question B2 Consider a potential barrier with V (x) = Vo cos² (2) for - 1/4 < x < and which is zero everwhere else, as illustrated below. V(x) Vo -L/2 L/2 0 Figure 2: A potential barrier with V(x) = V₁ cos² (7). a) Identify expressions for the values of x at the edges of the "classically forbidden region" (i.e. the region that needs to be tunnelled through), for a particle with energy E < Vo. b) [4 marks] Calculate the leading-order contribution to the Gamow factor for a particle with energy E to tunnel through this barrier, under the assumption that E <<< Vo. N.B. You may wish to refer to the Appendix when answering this question. [8 marks] c) The barrier has height V and width L. Using your result from part b), determine how the transmission rate of particles that tunnel through this barrier would change if (i) the height of the barrier is doubled. (ii) the width of the barrier is doubled. (iii) the barrier is altered so that V = 0 when x > 0. [6 marks] d) Assume that two barriers like the one in Figure 2 are placed back-to-back, and that particles with energy EV are trapped between them. Calculate the half-life 1/2 of a population of such particles. [7 marks]

College Physics
11th Edition
ISBN:9781305952300
Author:Raymond A. Serway, Chris Vuille
Publisher:Raymond A. Serway, Chris Vuille
Chapter1: Units, Trigonometry. And Vectors
Section: Chapter Questions
Problem 1CQ: Estimate the order of magnitude of the length, in meters, of each of the following; (a) a mouse, (b)...
icon
Related questions
Question
Question B2
Consider a potential barrier with V (x) = Vo cos² (2) for - 1/4 < x < and which is zero everwhere
else, as illustrated below.
V(x)
Vo
-L/2
L/2
0
Figure 2: A potential barrier with V(x) = V₁ cos² (7).
a) Identify expressions for the values of x at the edges of the "classically forbidden region"
(i.e. the region that needs to be tunnelled through), for a particle with energy E < Vo.
b)
[4 marks]
Calculate the leading-order contribution to the Gamow factor for a particle with energy E to
tunnel through this barrier, under the assumption that E <<< Vo.
N.B. You may wish to refer to the Appendix when answering this question.
[8 marks]
c) The barrier has height V and width L. Using your result from part b), determine how the
transmission rate of particles that tunnel through this barrier would change if
(i) the height of the barrier is doubled.
(ii) the width of the barrier is doubled.
(iii) the barrier is altered so that V = 0 when x > 0.
[6 marks]
d) Assume that two barriers like the one in Figure 2 are placed back-to-back, and that particles
with energy EV are trapped between them. Calculate the half-life 1/2 of a population
of such particles.
[7 marks]
Transcribed Image Text:Question B2 Consider a potential barrier with V (x) = Vo cos² (2) for - 1/4 < x < and which is zero everwhere else, as illustrated below. V(x) Vo -L/2 L/2 0 Figure 2: A potential barrier with V(x) = V₁ cos² (7). a) Identify expressions for the values of x at the edges of the "classically forbidden region" (i.e. the region that needs to be tunnelled through), for a particle with energy E < Vo. b) [4 marks] Calculate the leading-order contribution to the Gamow factor for a particle with energy E to tunnel through this barrier, under the assumption that E <<< Vo. N.B. You may wish to refer to the Appendix when answering this question. [8 marks] c) The barrier has height V and width L. Using your result from part b), determine how the transmission rate of particles that tunnel through this barrier would change if (i) the height of the barrier is doubled. (ii) the width of the barrier is doubled. (iii) the barrier is altered so that V = 0 when x > 0. [6 marks] d) Assume that two barriers like the one in Figure 2 are placed back-to-back, and that particles with energy EV are trapped between them. Calculate the half-life 1/2 of a population of such particles. [7 marks]
Expert Solution
steps

Step by step

Solved in 2 steps with 4 images

Blurred answer
Similar questions
Recommended textbooks for you
College Physics
College Physics
Physics
ISBN:
9781305952300
Author:
Raymond A. Serway, Chris Vuille
Publisher:
Cengage Learning
University Physics (14th Edition)
University Physics (14th Edition)
Physics
ISBN:
9780133969290
Author:
Hugh D. Young, Roger A. Freedman
Publisher:
PEARSON
Introduction To Quantum Mechanics
Introduction To Quantum Mechanics
Physics
ISBN:
9781107189638
Author:
Griffiths, David J., Schroeter, Darrell F.
Publisher:
Cambridge University Press
Physics for Scientists and Engineers
Physics for Scientists and Engineers
Physics
ISBN:
9781337553278
Author:
Raymond A. Serway, John W. Jewett
Publisher:
Cengage Learning
Lecture- Tutorials for Introductory Astronomy
Lecture- Tutorials for Introductory Astronomy
Physics
ISBN:
9780321820464
Author:
Edward E. Prather, Tim P. Slater, Jeff P. Adams, Gina Brissenden
Publisher:
Addison-Wesley
College Physics: A Strategic Approach (4th Editio…
College Physics: A Strategic Approach (4th Editio…
Physics
ISBN:
9780134609034
Author:
Randall D. Knight (Professor Emeritus), Brian Jones, Stuart Field
Publisher:
PEARSON