|
GR8677 #85 |
|
|
Problem
|
|
 |
Advanced Topics }Nuclear Physics
Pair production only occurs above a certain energy on the order of MeV. Thus, all except choices (B) and (C) remain.
The photoelectric effect is dominant for low energies, so its cross-section must be line (1). Choose choice (B).
|
|
|
Alternate Solutions |
| There are no Alternate Solutions for this problem. Be the first to post one! |
|
|
Comments |
petr1243
2008-02-16 20:33:09 | pg.528 of Modern Physics(3rd edition) by Serway, has a good explanation of these 3 processes.
smokwzbroiplytowej
2008-10-26 19:49:11 |
For the common good:
"At low photon energies (less than about 0.5 MeV), the predominant process that removes photons from a beam is the photoelectric effect, in which a photon is absorbed and transfers all of its energy to an electron.
At intermediate photon energies, the predominant process is Compton scattering, in which the photon transfers some of its energy to an electron. Both the photoelectric effect and Compton scattering were discussed in Chapter 3.
At high energies, the predominant process is pair production, in which an electron-positron pair is created as a photon passes near a nucleus in the medium. Since the reset energy of the electron-positron pair is  (twice the rest energy of an electron), the gamma-ray photon must have at least this much energy to produce a pair. Pair production will be discussed further in Chapter 15."
That being said, you probably shouldn't be studying for the GRE without your trusty Serway!
|
GreenApple
2008-11-05 00:43:04 |
smokwzbroiplytowej, thanks for the "common good". :-) It's helpful.
|
|  | Hagus
2006-10-30 05:29:35 | Correction: It should read, only choices B and C remain, or all except choices B and C are eliminated. | |
|
| Post A Comment! |
|
|
Bare Basic LaTeX Rosetta Stone
|
LaTeX syntax supported through dollar sign wrappers $, ex., $\alpha^2_0$ produces  .
|
| type this... |
to get... |
| $\int_0^\infty$ |
 |
| $\partial$ |
 |
| $\Rightarrow$ |
|
| $\ddot{x},\dot{x}$ |
 |
| $\sqrt{z}$ |
 |
| $\langle my \rangle$ |
 |
| $\left( abacadabra \right)_{me}$ |
_{me}) |
| $\vec{E}$ |
 |
| $\frac{a}{b}$ |
 |
|
|
|
|
The Sidebar Chatbox...
Scroll to see it, or resize your browser to ignore it... |
|
|
|
