Level 4 · Advanced undergraduate teaching kit · Third- and fourth-year university
Plasma and fusion systems
Use the learner record during the live investigation, then use the instructor guide to facilitate comparison, address misconceptions, and assess evidence-bounded reasoning.
Learner lab record
Plasma regime and gain-chain map
Which dimensionless and length-scale comparisons determine the valid plasma model, and where does fusion gain enter the full facility ledger?
Setup
Use the plasma-regime laboratory. Establish density, temperature, field, and device size, compare characteristic scales, then trace fusion power through plasma, engineering, and electric gain definitions.
Predict first
- 1. Predict how increasing density changes Debye length and plasma frequency.
- 2. Predict whether plasma gain above one guarantees net electric output.
| Variable | Role | Unit |
|---|---|---|
| Density and temperature | plasma inputs | m⁻³ and eV |
| Magnetic field and device size | confinement inputs | T and m |
| Debye length, gyroradius, plasma frequency | dependent scales | m and Hz |
| Plasma/engineering/electric gain | system diagnostics | dimensionless |
Observation columns
Analyze
- 1. Which scale comparison supports a fluid description?
- 2. Is the plasma magnetized for the selected species?
- 3. Which gain definition excludes recirculating plant power?
- 4. What instability or transport effect is outside this zero-dimensional model?
Conclusion frame
For n=___, T=___, and B=___, the regime is ___ because ___; Qplasma=___ corresponds to net-electric status ___ after ___.
Instructor guide · 60–80 minutes
Teach the investigation, not the interface
Learning target: Learners classify a plasma using characteristic scales and keep nuclear, plasma, engineering, and net-electric gain definitions distinct.
Prepare
- • Review species-dependent thermal speed and gyroradius.
- • Define every gain boundary.
- • Prepare one case where Qplasma>1 but net electric output is negative.
Facilitation moves
- • Require species labels on kinetic scales.
- • Compare scales with device size before choosing a model.
- • Trace every auxiliary and conversion loss through the gain chain.
Accessibility and participation
- • Use ratio statements alongside logarithmic scales.
- • Provide a gain-boundary flow diagram.
- • Spell out species and units in every table heading.
Evidence of learning
- • A characteristic-scale table
- • A justified regime classification
- • A complete gain-chain distinction
Misconception checks
Hot ionized gas is automatically an ideal plasma.
Collective behavior and model validity depend on Debye shielding, collision, magnetization, and scale separation.
Scientific breakeven means a power station is ready.
Plasma gain excludes many driver, thermal-conversion, recirculation, and facility losses.
Extension
Compare electron and ion magnetization and identify the transport model each ordering supports.