Configuration Parameters Reference

This document describes all configuration parameters used by the Quantum Collider Sandbox simulation and visualization. Parameters are defined in quantum_collider_sandbox.config and can be adjusted for different use cases.

Physics Integration

DT

Type: float Default: 0.001 Range: 0.00001 – 0.02 (via GUI)

Base simulation timestep in arbitrary units. Smaller values yield smoother, more accurate motion but increase CPU/GPU load. Use 0.001 for realistic visualization; 0.002 for faster but slightly less smooth playback.

SUBSTEPS

Type: int Default: 4 Range: 1 – 10 (via GUI)

Number of physics integration steps per frame. Higher values improve numerical stability and reduce jitter, especially for fast particles or strong forces. Recommended: 4–5 for smooth visualization.

INTEGRATOR

Type: str Default: "leapfrog" Options: "euler", "leapfrog"

Integration scheme for particle motion.

  • euler — Simple first-order Euler; faster but less accurate, energy drift.

  • leapfrog — Symplectic integrator; preserves energy better, recommended for realistic long-running simulations.

Forces and Fields

COULOMB_K

Type: float Default: 40.0 Range: 0.0 – 200.0 (via GUI)

Coulomb constant scaling for electromagnetic repulsion/attraction between charged particles. Set to 0 to disable Coulomb force.

GRAVITY_G

Type: float Default: 6.0 Range: 0.0 – 80.0 (via GUI)

Gravitational constant scaling. Affects all massive particles. Set to 0 for collision-only or beam experiments without gravity.

SOFTENING

Type: float Default: 0.05

Softening length for force calculations. Prevents singularities when particles get very close; larger values smooth forces but reduce accuracy at short range.

CUTOFF_RADIUS

Type: float Default: 15.0

Maximum distance for force computations. Particles beyond this distance do not interact. Reduces computational cost for large systems.

MAGNETIC_FIELD

Type: tuple of (float, float, float) Default: (0.0, 0.0, 2.0)

Uniform magnetic field (B_x, B_y, B_z). Charged particles follow curved trajectories (Lorentz force). Used in cyclotron and synchrotron presets.

E_FIELD

Type: tuple of (float, float, float) Default: (0.0, 1.0, 0.0)

Uniform electric field (E_x, E_y, E_z). Accelerates charged particles along the field direction.

STRONG_FORCE_K

Type: float Default: 0.0 Range: 0.0 – 100.0 (via GUI)

Strong nuclear force strength. Attractive at short range; used for LHC-style proton-proton collisions. Set to 0 for electromagnetic-only physics.

STRONG_FORCE_RANGE

Type: float Default: 0.5 Range: 0.1 – 3.0 (via GUI)

Effective range of the strong force. Particles within this distance feel the strong interaction.

Relativity and Speed Limits

SPEED_OF_LIGHT

Type: float Default: 30.0

Speed of light in simulation units. Used for relativistic kinematics when USE_RELATIVITY is enabled. Particles are capped below this speed.

USE_RELATIVITY

Type: bool Default: True

Enable relativistic dynamics (Lorentz factor, mass increase at high speed). Recommended for high-energy collision presets (LHC, e⁺e⁻ annihilation).

SYNCHROTRON_COEFF

Type: float Default: 0.0 Range: 0.0 – 1.0 (via GUI)

Synchrotron radiation coefficient. Simulates energy loss when charged particles accelerate in magnetic fields. Nonzero values add radiative damping for more realistic cyclotron/synchrotron behavior.

MAX_VELOCITY

Type: float Default: 29.9

Hard cap on particle speed (must be < SPEED_OF_LIGHT). Prevents numerical overflow.

MIN_VELOCITY

Type: float Default: 0.01

Minimum velocity floor. Avoids numerical traps when particles come to rest (e.g., at boundaries).

Collisions and Pair Creation

COLLISION_RESTITUTION

Type: float Default: 0.85

Coefficient of restitution for elastic collisions (0 = fully inelastic, 1 = fully elastic). Affects bounce behavior when particles collide.

PAIR_CREATION_THRESHOLD

Type: float Default: 15.0 Range: 1.0 – 50.0 (via GUI)

Kinetic energy threshold (in simulation units) above which high-energy collisions can create particle-antiparticle pairs (e.g., e⁺e⁻ from photons).

SPAWN_VELOCITY_SPREAD

Type: float Default: 2.5

Velocity spread when spawning random particles. Used for preset setups.

Boundary Conditions

BOUNDARY_MODE

Type: str Default: "reflect" Options: "reflect", "periodic", "none"

  • reflect — Particles bounce off boundaries (elastic reflection).

  • periodic — Particles wrap around (toroidal space).

  • none — No boundary; particles can leave the simulation volume.

BOUNDARY_SIZE

Type: float Default: 12.0 Range: 3.0 – 30.0 (via GUI)

Half-extent of the simulation box. The domain is a cube from (-BOUNDARY_SIZE, -BOUNDARY_SIZE, -BOUNDARY_SIZE) to (BOUNDARY_SIZE, BOUNDARY_SIZE, BOUNDARY_SIZE).

Visualization

WINDOW_WIDTH

Type: int Default: 2560

Window width in pixels. Adjust for your display; smaller values improve performance on low-end GPUs.

WINDOW_HEIGHT

Type: int Default: 1600

Window height in pixels.

WINDOW_TITLE

Type: str Default: "Quantum Collider Sandbox"

Title of the application window.

CAMERA_POS

Type: tuple of (float, float, float) Default: (0.0, 2.0, 22.0)

Initial camera position (x, y, z). Use RMB+drag to orbit, scroll to zoom.

CAMERA_LOOKAT

Type: tuple of (float, float, float) Default: (0.0, 0.0, 0.0)

Point the camera looks at (usually the simulation center).

CAMERA_FOV

Type: float Default: 55

Camera field of view in degrees. Larger values = wider view, more distortion.

BACKGROUND_COLOR

Type: tuple of (float, float, float) Default: (0.01, 0.01, 0.03)

Background color (R, G, B) in [0, 1]. Dark blue-black for space-like feel.

BASE_PARTICLE_RADIUS

Type: float Default: 0.12 Range: 0.02 – 0.3 (via GUI “P.Size”)

Base radius for rendering particles. Combined with per-type radius from the PDG table for final size.

PARTICLE_RADIUS_SCALE

Type: float Default: 0.45

Scale factor applied to particle radii from the PDG table. Tunes relative sizes of different particle types.

TRAIL_LENGTH

Type: int Default: 1000

Maximum number of trail segments per particle. Longer trails show more history but use more memory and GPU.

TRAIL_WIDTH

Type: float Default: 2.0 Range: 0.5 – 5.0 (via GUI “Trail W”)

Line width for particle trails in pixels.

FLASH_OPACITY

Type: float Default: 0.1

Alpha (0–1) for collision flash particles. Lower = more transparent; particles remain visible through flashes.

Black Hole

BH_MASS

Type: float Default: 200.0 Range: 10.0 – 2000.0 (via GUI)

Black hole mass in simulation units. Schwarzschild radius r_s = 2·M/c². Affects gravitational pull and accretion disk.

Internal / Limits

MAX_PARTICLES

Type: int Default: 100

Maximum number of particles in the simulation. Decays and collisions can create new particles; excess are culled.

NUM_TYPES

Type: int Default: 48

Number of particle type slots (40 PDG + 8 reserved for user-defined).