Lecture 9 Flashcards
What does ‘Laser’ stand for?
Light Amplification by Stimulated Emission of Radiation
What are coherent photons?
When a photon stimulates an atom, transferring energy, causing the atom to release another photon.
These photons are identical
If more atoms are in the upper state than the lower, what occurs?
Population Inversion
What is needed for coberent light intensity amplification to occur?
Population inversion must be continuously maintained
causing a release of a spontanously emitted photon
Give the four types of laser.
Solid State
Gas
Dye
Semiconductor
Give the wavelenght of a ruby laser
0.694 μm
Give the wavelength of the Nd-Yag laser Type
1.064 μm
Give the wavelength of the CO2 laser type
9.6-10.6 μm
Give the wavelength of the Kumarin laser type
0.4-0.5 μm
How can x-rays be compared with light?
Larger penetrating power
Penetrating power of x rays increase as…
Wavelength becomes shorter
A high penetrating power is know as…
‘Hard’
Where is the focus for an x-ray
The spot on the anode
What is used to produce more energetic x-rays?
Electron Accelerators
Give the 5 effects of x-rays
Ionisation
Luminescence
Photographic effect
Chemical effects
Biological effects
Formula to calculate minimum wavelength with the accelerating potential difference.
U = Accelerating potential difference
Formula to calculate the efficentcy of an x-ray tube
Formula showing the exponential decrease of light intensity with distance covered.
x = passed thickness
μ = Attenuation coefficient
Calculate photoeffect
A = Binding energy of the electron
