- sim/coilgun.py: chains StageConfig results through a global coordinate,
stops honestly on the first infeasible stage (with which stage and why),
and computes overall efficiency = exit KE / total capacitor energy in
- Discovered while wiring up the chain: a high-capacitance single-stage test
configuration let current stay high past the coil center, decelerating and
reversing the slug (exit velocity negative). This is a real coilgun tuning
failure mode (not a bug) since KE ~ v^2 doesn't care about direction and
the energy balance still holds to ~1%. Kept it as an explicit regression
test (test_overpowered_discharge_can_fling_slug_backward) instead of
quietly picking parameters that hide it, and tightened the "kinetic energy
increases" test to also require forward (exit_v > 0) motion.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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