NM Physics Test 1 Flashcards
What energy of positron-electron annihilation photons?
A) equal to the rest mass equivalent of the positron and electron
B) equal to the kinetic energy of the positron
C) equal to the electron binding energy
D) equal to the gravitational energy of the positronium ‘atom’
E) equal to 140 keV
equal to the rest mass equivalent of the positron and electron
Which of the following is not a possible interaction of the photons with matter? A) photoelectric effect B) Compton scatter C) Electron capture D) Coherent scatter
C) electron capture
In what direction, relative to a high-energy incoming photon, will a Compton scatter photon go?
A) it will most likely travel backwards
B) it will most likely travel laterally i.e. out to the sides
C) it will most likely travel in a forward direction
D) it will travel in exactly the same path as the recoil electron
E) it will travel in a circular orbit around the nucleus
C) it will most likely travel in a forward direction
Thermal neutrons:
A) have been heated to the average temperature of air molecules
B) make good insulators
C) have been slowed to the average velocity of air molecules
D) decay to thermal protons
E) None of the above
C) have been slowed to the average velocity of air molecules
Name the electron emitted during a Compton interaction. A) Auger electron B) conversion electron C) Gamma electron D) Recoil electron E) Positron
D) Recoil electron
Name the possible outcome of coherent scattering.
A) Ejection of an electron
B) Change of photon direction
C) change of photon energy
D) Total absorption and disappearance of the incident photon
E) Nuclear photodisinegration
B) Change of photon direction
Name the possible outcomes of Compton scatter A) ejection of an electron B) Change of photon direction C) Change of photon energy D) Change of photon wavelength E) All of the above
E) All of the above
Name the possible outcomes of the photoelectric effect: (2)
A) ejection of an electron
B) change of photon direction
C) Change of photon energy
D) Total absorption and disappearance of the incident photon
E) There will be no scattered photon
A) ejection of an electron
D) Total absorption and disappearance of the incident photon
After a Compton scattering event, a scattered photon will have which of the following:
A) increased energy compared to the incident photon
B) decreased energy compared to the incident photon
C) A longer wavelength than the incident photon
D) A shorter wavelength than the incident photon
E) There will be no scattered photon
C) A longer wavelength than the incident photon
T/F
Probability of Compton Scatter (CS) is strongly dependent upon Z
True
T/F Photoelectric effect (PE) involves interaction with the atomic nucleus
False
T/F
PE is more likely than CS at a photon energy of 140 keV
False
T/F
Photoelectron emission is usually followed by characteristic xrays
True
T/F
Pair production is the emission of 2 annihilation photons from the nucleus
False
T/F
The minimum required incoming photon energy for pair production is 1022 keV
True
