FIELD NOTES / SUBATOMIC INSTRUMENTATION

Inside the particle detector.

Explore the engineering that translates charged-particle traces into measurements.

ILLUSTRATIVE MODEL

FIG 01 / LAYERED DETECTOR GEOMETRY

INITIALIZING

NOT TO SCALE • SCHEMATIC PROPORTIONS

DRAG TO ORBIT · SCROLL TO ZOOM

PRINCIPLECURVATURE IN A SOLENOIDAL FIELD

The illustrated magnetic field runs parallel to the beam axis. A charged particle’s transverse momentum controls the radius of its helical track.

TRACK RADIUS

r = p_T / (0.299792458 · |q/e| · B)

p_T in GeV/c · B in T · r in m

For a charge magnitude |q| = e, a uniform solenoidal field produces a circular transverse projection with radius r = p_T/(|q|B). With p_T in GeV/c and B in tesla, r = p_T/(0.299792458 B) metres.

The sagitta uses an illustrative transverse chord L = 0.8 m: s = r − √(r² − (L/2)²). The time of flight is t = 7 m/(βc), with β = p/√(p² + m²), p = p_T/sin θ and textbook charged-pion rest mass m = 0.13957039 GeV/c². Pseudorapidity is η = −ln tan(θ/2).

Readouts are equation-based idealizations, not detector reconstruction. Track particles are visual traces without energy loss, secondary shower transport, multiple scattering, detailed field maps or collision-event reconstruction. Geometry is scaled; hardware and animations are engineering-inspired reconstructions, not certified designs.

Labels: physical constants and formulas are textbook; slider values and travel paths are illustrative; geometry is scaled. No component in the exhibit is speculative hardware.

Illustrative design, not affiliated with any real institution or manufacturer.