Question
The magnitude of this process’s amplitude squared equals the differential cross section. For 10 points each:
[10e] Name this general process that can involve an electron diverting a photon in a low-energy type named for J. J. Thomson.
ANSWER: scattering [or word forms like scattered; accept Thomson scattering; accept scattering amplitude]
[10m] For Thomson scattering, the differential cross section is proportional to: “one plus this function of the scattering angle theta.” By Malus’s (“mah-LOOSE’s”) law, the proportion of polarized light that gets through a polarizer is this function of the angle between the polarizer and the initial polarization.
ANSWER: cosine squared theta [or cosine of theta all squared; accept power two or to the power two in place of “squared”; reject “cosine” or “squared”]
[10h] To extend Thomson scattering to a full atom, the differential cross section is multiplied by the square of this quantity, which is sometimes called the scattering factor and is the Fourier (“foor-YAY”) transform of spatial density into momentum space.
ANSWER: atomic form factor [prompt on form]
<Physics>
Summary
| 2024 ACF Nationals | 2024-04-21 | Y | 3 | 16.67 | 100% | 67% | 0% |
Data
| Cornell A | Chicago A | 10 | 10 | 0 | 20 |
| Minnesota A | Stanford | 10 | 10 | 0 | 20 |
| Chicago B | Waterloo | 10 | 0 | 0 | 10 |