Visualizing the Traversal of Charged Particles in a Diffusion Cloud Chamber

1. Visualizing the Traversal of Charged Particles in a Diffusion Cloud Chamber

2. Liquid Vs. Gases Intermolecular Forces Vapor Pressure The Basics • Ionization Energy • Temperature • Condensation • Ideal Gas Law

3. The Cloud Chamber? • A sealed environment that contains supersaturated vapor in a non-condensing gas. • The condensation induced by the temperature gradient can mark the paths traveled by charged particles. • Two types: Expansion and Diffusion-Continuous

4. Expansion Cloud Chamber • Invented by Charles T. Wilson (1900) • Used in some weather balloons

5. Expansion Cloud Chamber Workings • Vapor Compression • Charged Particle Detection • Vapor Expansion • Track production • Recording of produced tracks • Replenishing of Vapor

6. Diffusion Cloud Chamber • Invented by Alexander Langsdorf Jr. (1936) • Provides a continuous supply of vapor for the detection of ions tracks.

7. Diffusion Cloud Chamber Workings • Vapor/Gas Selection • Creation of temperature gradient • Diffusion of Vapor • Continuous light supply

8. System in Use • Continuous-Diffusion Cloud Chamber • Chamber Diameter/Height: 11cm/8cm • Alpha & Beta Particles Used • Cooling Method: Ice Water

9. System in Use (Cont.) • Vapor/Gas Selection: 90% Ethanol (by volume), Air • Light Source: Orange LEDs (590 nm) • Floor Temp: -12 Degrees Celsius • Ceiling Temp: 23.1C

10. Show Movie Cloud Movie-Alpha

11. Cloud Movie-Beta Show Movie

12. Similarities/Differences • Path Widths • Path Lengths • Path Definition • Color

13. What's Happening? • “Charged” Elastic Collisions • Ionization of Ethanol Particles • Ion-Initiated Droplet Formation • Gradient-Continued Droplet Formation • Cloud “Falling”

14. Blue Skies and Clouds • “Floating” Clouds • Rayleigh Scattering • Mie Scattering • Sunny Day Clouds (White) • Rainy Day Clouds (Grey)

15. Another Attempt at Visualization • The Problem: How do Charge particles move to produce clouds? • Elastic “Charged” Collisions • Minimum distance of “Action” • Application of Measured Temperature Gradient • Simplify problem(Model Assumptions) • Solve Collision problems for a given path

16. Setting the Stage • Data portability and method of visualization • What's the Minimum distance of “Action”? (Derivation) • 3D field shape and “grid-definition

17. Selecting the Proper Actors • Particle distribution (pseudo-random) • Application of a Temp. Gradient

19. Casting of Main Character • Initial position • Iterative collison formula (Derivation) • Choose an Interesting path (Trial and Error)

20. “Special Effects” • Collision Simulation (Iterative Calculation) • Path Tracing

21. What We Did... • Sat realistic goals for the visualization of physical events. • Recognized a problem and made reasonable simplifications • Picked a method for visualizing our chosen physical events • Constructed models based on “real” physical data • Added parts to demonstrate key physical events

22. Third Attempt at Visualization • Orientation of magnet and field lines direction • Creation of charged particles (Electric Discharge) • Direction of particles produced in field

23. Thanks!!

24. Dr. Douglas Durig Dr. Randolph Peterson Comic Ray Theory. Bruno Rossi. 1941. A Continuously Sensitive Diffusion Cloud Chamber. Alexander Langsdorf, Jr. 1938 A Theory of Diffusion Cloud Chambers. R. P. Shutt. 1951. Acknowledgments/Sources