The Wilson Cloud Chamber: Subatomic Tracks & Cosmic Muons

🌌 Cosmic Ray Shower

T: -78.5°C

B: +1.20 T

Click / Tap to Spawn Probe Track · Drag to deflect

⚠️

Vapor Layer Collapsed

Temperature has risen above -50°C. Supersaturation ratio S < 3.0. Condensation nucleation suspended.

TOTAL TRACKS 0

ALPHA (α) 0

BETA / e⁺ 0

MUONS (μ) 0

☢️ Radiation Source Natural Ambient

🧲 Magnetic Solenoid (Bz) +1.20 Tesla

Lorentz force F = q(v × B) curves charged trajectories into radii R = p / (|q|B).

🧊 Thermal & Electrostatic S = 4.8 (Super)

Cryogenic Baseplate -78.5°C

Laser Sheet

📐

Subatomic Particle Telemetry

Muon (μ⁻) Cosmic Ray

Measured Kinematics

Radius of Curvature (R): 38.4 cm

Relativistic Momentum (p = qBR): 1,382 MeV/c

Rest Mass (m₀): 105.66 MeV/c²

Specific Ionization (dE/dx): 28 droplets / cm

Velocity (β = v/c): 0.997 c (Relativistic)

Lorentz Force Mechanics

Because the magnetic field B is perpendicular to the particle velocity v, the magnetic force acts solely as a centripetal accelerator:

F = q · v · B = m · v² / R ⟹ R = p / (|q| · B)

- Positive ions (α, e⁺) curl clockwise with field pointing into chamber.
- Negative leptons (e⁻, μ⁻) curl counter-clockwise.
- High-energy muons have vast momentum p > 1 GeV/c, resulting in barely perceptible deflection.

Detected Energy Spectrum Histogram

Counts vs Log Energy (MeV)

0.1 MeV (Beta) 5.5 MeV (Alpha) 100 MeV (Pion) > 2,000 MeV (Muon)

Live Particle Feed ● LOGGING

🏛️ The Cloud Chamber: Cradle of Modern Particle Physics

Before electronic scintillation counters and silicon pixel trackers, the cloud chamber was the sole window through which humanity could observe individual subatomic particles in flight.

1911 · CAMBRIDGE C.T.R. Wilson

The Expansion Vapor Chamber

Inspired by the meteorological glory halos he observed while working at the Ben Nevis weather observatory in Scotland, Wilson set out to create artificial clouds in a glass cylinder. By dropping a piston to expand moist air adiabatically, he realized ionizing alpha particles left trails of liquid mist—winning him the 1927 Nobel Prize in Physics.

First Visual Track Nobel 1927

1932 · CALTECH / PIKES PEAK Carl D. Anderson

Discovery of Antimatter (Positron)

Anderson fitted a cloud chamber with a 6mm lead plate and a 1.5 Tesla electromagnet, carrying it up Pikes Peak (14,115 ft) to study cosmic rays. On August 2, 1932, he photographed a track with the exact mass of an electron that curved in the *opposite* direction after losing energy through the lead—confirming Paul Dirac's theoretical anti-electron.

First Antimatter Observation Nobel 1936

1936 · PASADENA Anderson & Neddermeyer

The Muon: "Who Ordered That?"

While studying cosmic ray cascades, Anderson and Seth Neddermeyer found particles that penetrated deep into matter without showering like electrons, yet deflected more than protons. They had discovered the muon—a 207-times heavier replica of the electron whose unexpected existence baffled physicists for decades.

Second-Generation Lepton m = 105.7 MeV/c²

1947 · MANCHESTER Rochester & Butler

Strange Particles & Kaon V-Tracks

George Rochester and Clifford Butler photographed neutral cosmic ray particles decaying spontaneously in mid-air into characteristic "V-shaped" tracks of two charged pions. These "V-particles" (neutral and charged kaons) possessed a mysterious long lifetime, leading Murray Gell-Mann to propose the "Strange" quark quantum number.

Birth of Strange Quark Physics V-Shaped Decay

Evolution of Particle Trackers

1911 Cloud Chamber Gas vapor droplets (Wilson)

1952 Bubble Chamber Superheated liquid hydrogen (Glaser)

1968 Wire Chamber Electronic ion drift wires (Charpak)

2026 CMS & ATLAS Gigapixel silicon microstrip trackers

Emulsion Plate Developer Latent Image Ready

Silver Halide AgBr Developer Bath: 100% (Fixed)

Cavendish Observer Notebook

September 22, 2026 Archive Series

Observer Name / Station

Field Remarks & Particle Notes

DATE: 2026-09-22

SOLENOID B: +1.20 T

BASE TEMP: -78.5°C

PLATE ID: WCC-2026-0922-P01