Physics SL
Physics SL
5
Chapters
329
Notes
Theme A - Space, Time & Motion
Theme A - Space, Time & Motion
Theme B - The Particulate Nature Of Matter
Theme B - The Particulate Nature Of Matter
Theme C - Wave Behaviour
Theme C - Wave Behaviour
Theme D - Fields
Theme D - Fields
Theme E - Nuclear & Quantum Physics
Theme E - Nuclear & Quantum Physics
IB Resources
Theme E - Nuclear & Quantum Physics
Physics SL
Physics SL

Theme E - Nuclear & Quantum Physics

Unraveling Compton's Pioneering X-ray Experiments

Word Count Emoji
672 words
Reading Time Emoji
4 mins read
Updated at Emoji
Last edited on 5th Nov 2024

Table of content

Hey there, budding physicist! 🌌✨ Ready to dive into the fascinating world of the Compton effect? Let's do it!

The Story Behind The Compton Effect 🚀

  • Setting the Stage: It's the 1920s. Einstein's ideas about photoelectricity are buzzing in the minds of physicists.
  • The Main Actor: Arthur H Compton. This cool American scientist decided to take a deeper look at high-energy, short-wavelength X-radiation.
  • His Discovery: When these X-rays bounced off elements with small proton numbers, their wavelengths increased!

How Compton Did It 🎬

  • He used a carbon target.
  • To produce the X-radiation, he zapped electrons onto a molybdenum target using a potential difference of 17kV.
  • These X-rays were then focused onto the carbon block.
  • A special detector picked up the scattered X-ray photons.
  • He noticed
    • Two peaks in the spectrum at every scattering angle (except straight-on).
    • One from atom scattering (small peak) and another from free-electron scattering (big peak).
    • The wavelength shift increased with the scattering angle.

Some Fancy Math (But Make It Simple) 📏

  • Energy of an X-ray photon is given by E =\(\frac {hc}{ λ}\).
  • Compton proved that the difference in wavelengths before and after scattering is - Δλ = \(\frac {h}{me × c}\) (1− cosθ), where θ is the scattering angle and me is the mass of the electron.

The Deeper Dive 🤓

  • Why do X-rays scatter? They bump into free electrons in carbon. A teeny bit of their energy ionizes the carbon atoms. The rest? Interacts with a free electron, making the electron scoot and the X-ray scatter.
  • The scattering is like a two-dimensional collision (imagine two balls colliding in mid-air!).
  • Photon-Electron Interaction is a tango dance! The electron "recoils" and the X-ray photon is left with lesser energy, dancing away with a longer wavelength!

Bonus Round: Compton's results tossed wave models of light out the window. Why? Classical explanations didn't predict a wavelength shift with small radiation intensity, but Compton's experiments did!

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IB Resources
Theme E - Nuclear & Quantum Physics
Physics SL
Physics SL

Theme E - Nuclear & Quantum Physics

Unraveling Compton's Pioneering X-ray Experiments

Word Count Emoji
672 words
Reading Time Emoji
4 mins read
Updated at Emoji
Last edited on 5th Nov 2024

Table of content

Hey there, budding physicist! 🌌✨ Ready to dive into the fascinating world of the Compton effect? Let's do it!

The Story Behind The Compton Effect 🚀

  • Setting the Stage: It's the 1920s. Einstein's ideas about photoelectricity are buzzing in the minds of physicists.
  • The Main Actor: Arthur H Compton. This cool American scientist decided to take a deeper look at high-energy, short-wavelength X-radiation.
  • His Discovery: When these X-rays bounced off elements with small proton numbers, their wavelengths increased!

How Compton Did It 🎬

  • He used a carbon target.
  • To produce the X-radiation, he zapped electrons onto a molybdenum target using a potential difference of 17kV.
  • These X-rays were then focused onto the carbon block.
  • A special detector picked up the scattered X-ray photons.
  • He noticed
    • Two peaks in the spectrum at every scattering angle (except straight-on).
    • One from atom scattering (small peak) and another from free-electron scattering (big peak).
    • The wavelength shift increased with the scattering angle.

Some Fancy Math (But Make It Simple) 📏

  • Energy of an X-ray photon is given by E =\(\frac {hc}{ λ}\).
  • Compton proved that the difference in wavelengths before and after scattering is - Δλ = \(\frac {h}{me × c}\) (1− cosθ), where θ is the scattering angle and me is the mass of the electron.

The Deeper Dive 🤓

  • Why do X-rays scatter? They bump into free electrons in carbon. A teeny bit of their energy ionizes the carbon atoms. The rest? Interacts with a free electron, making the electron scoot and the X-ray scatter.
  • The scattering is like a two-dimensional collision (imagine two balls colliding in mid-air!).
  • Photon-Electron Interaction is a tango dance! The electron "recoils" and the X-ray photon is left with lesser energy, dancing away with a longer wavelength!

Bonus Round: Compton's results tossed wave models of light out the window. Why? Classical explanations didn't predict a wavelength shift with small radiation intensity, but Compton's experiments did!

Unlock the Full Content! File Is Locked Emoji

Dive deeper and gain exclusive access to premium files of Physics SL. Subscribe now and get closer to that 45 🌟

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