Physics HL

Chapter 25: Nuclear Fusion and Stars

Build Chapter 25 from fusion ignition conditions and stellar-core energy pathways to HR-diagram interpretation, mass-dependent stellar evolution, and nucleosynthesis limits.

1 simulation entries

Simulation: Fusion Threshold and Barrier Crossing

Switch reaction channels and tune plasma temperature, density, and confinement to inspect barrier-crossing estimates and ignition-regime transitions.

Appears in: 25.1 Nuclear Fusion and Ignition Conditions, 25.2 Stellar Properties and the Hertzsprung-Russell Diagram, 25.3 Hydrogen Burning Pathways and Main-Sequence Lifetimes, 25.4 Post-Main-Sequence Evolution and Stellar Remnants, 25.5 Nucleosynthesis and the Origin of the Elements

Map temperature, density, and confinement time into a fusion-threshold score and barrier-crossing estimate.

D + T -> He-4 + n

Thermal distribution vs Coulomb barrierbarriermost ionshigh-energy tailFusion gateway metricsThermal energy:1.55 keVTunneling estimate:1.51e-4Lawson-style score:0.03Ignition index:7.36e-3

Barrier

120.0 keV

Q-value

17.60 MeV

Barrier crossing

0.02 %

Regime

below fusion threshold