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12 Cards in this Set
- Front
- Back
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1. Align in ascending order the following components of the
electromagnetic spectrum according to their energy: microwaves, gamma, ultraviolet, visible light, x ray, infrared, radiowaves! |
radiowaves < microwaves < infrared < visible light <
ultraviolet < x ray < gamma |
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2. Define the limiting frequency (νmax) of braking radiation
at V accelerating voltage! |
Vmax=eV/h
where h is Planck's constant and e is the charge of an electron. |
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3. Is it the photoelectric or the Compton-effect during which the total energy of the X-ray photon is given to the
electron? |
Photoelectric effect.
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4. Align in ascending order the following transitions
according to their energy difference: vibrational, rotational and electronic! |
rotational < vibrational < electronic
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5. How can the momentum of a photon be calculated?
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p=h/λ; where h is Planck's constant, λ is the wavelength
of the photon. |
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6. What is the difference between the orbital and spin
angular momenta of an electron? |
- the orbital angular momentum originates from the orbital motion of an electron; its magnitude depends on
the shape of the orbital and the interactions of the electron with the surrounding particles. - the spin angular momentum is an inherent property of the electron, its magnitude is independent of the surroundings. |
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7. What is the minimal energy of a γ-photon needed for
pair-production? (Not numerically.) |
E=mc2, the energy equivalent to the rest mass of an
electron and a positron. |
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8. Why is a heavy nucleus necessary for pair-production?
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The presence of a heavy nucleus is required by the law
of conservation of momentum |
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9. What is annihilation?
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When a positron and an electron interact with each
other, the total mass-energy of this particle system is converted to the energy of two gamma photons. |
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10. Give the three most important mechanisms responsible
for the absorption of X-rays ! |
- photoelectric effect
- Compton-effect - pair-production |
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11. Which mechanisms are responsible for the attenuation
of X-ray passing through a material? |
- absorption
- scattering. |
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12. What is the unit of the attenuation coefficient of
radiation? |
[μ]=1/m.
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