The Chain Mechanism
Chain reactions are nature's amplifiers. A single initiation event — a photon breaking a bond, a spark igniting fuel — produces a reactive radical that enters a propagation cycle. Each cycle consumes and regenerates the radical while converting reactant to product. In branching chains, each cycle produces more than one radical, creating exponential growth that can lead to explosion.
Branching vs Termination
The fate of a chain reaction depends on the competition between chain branching (radical multiplication) and chain termination (radical removal by wall collisions, three-body recombination, or inhibitor reactions). When branching exceeds termination, the radical population grows exponentially — this is the mathematical condition for explosion. The simulation tracks this balance in real time.
Explosion Limits
The hydrogen-oxygen system beautifully illustrates chain reaction dynamics with its three explosion limits. The 'explosion peninsula' in pressure-temperature space reveals how wall termination, gas-phase branching, and three-body termination compete. This simulation models the net branching factor and shows the transition from steady burning to explosive behavior as parameters change.
Visualizing Radical Growth
The canvas shows individual radicals as particles, with propagation events creating new radicals (branching) or removing them (termination). In the steady regime, you see a constant population maintained by the balance of initiation and termination. In the explosion regime, the radical count grows visibly, filling the simulation space — a dramatic visual representation of exponential amplification.