Thermionic emission
Electrons boil off a hot surface when their thermal energy exceeds the work function. Collected at a cooler electrode across a vacuum gap they carry current at a potential difference.
Atlas record: 6 claims reference this phenomenon — 5 established and 1 demonstrated.
Explorerelations · matrix context · routes · sources · cite
Relations
- cathode hot enough that kT is a useful fraction of the work function (typically > 1500 K for metals, lower for low-work-function coatings)
- a cooler anode across a vacuum or caesium-vapour gap
- emitted electrons collected at the anode at a potential difference set by the work-function difference
Matrix context
D = disequilibrium row · C = coupling family column. A cell reads the state of the atlas for that pair.
Enumerated routes through this · 10
- Thermionic converter3/3 est · demonstrated
- Chemical potential difference → Combustion → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Electric potential difference → Peltier effect → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · same energy form
- Electric potential difference → Ettingshausen effect → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · same energy form
- Incident radiation flux → Photothermal absorption → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Radiative imbalance with the sky → Radiative sky cooling → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Nuclear binding-energy difference → Nuclear fission → Temperature gradient → Thermionic emission → Charge carriers → Electrical work5/5 est · extends a recorded pathway
- Nuclear binding-energy difference → Nuclear fusion → Temperature gradient → Thermionic emission → Charge carriers → Electrical work3/5 est · extends a recorded pathway
- Nuclear binding-energy difference → Radioactive decay → Beta particles → Radioisotope heating → Temperature gradient → Thermionic emission → Charge carriers → Electrical work7/7 est · extends a recorded pathway
- Nuclear binding-energy difference → Radioactive decay → Alpha particles → Radioisotope heating → Temperature gradient → Thermionic emission → Charge carriers → Electrical work7/7 est · extends a recorded pathway
Cited sources · 2
- [1]G. N. Hatsopoulos, E. P. Gyftopoulos. Thermionic Energy Conversion, Vol. 1: Processes and Devices (1973)
- [2]O. W. Richardson. On the negative radiation from hot platinum (1901)
Cite this entity
Physical Transformation Atlas (2026). entity phenomenon:thermionic-emission: Thermionic emission. Dataset revision rbfbfcbb70e57 (hash of the canonical data). https://physical-transformation-atlas.wldud5192.workers.dev/phenomenon/thermionic-emission
Ids and matrix addresses are stable across revisions; the revision hash identifies the exact canonical files the record was compiled from and is meta.data_hash in every /api export. Reuse terms: see the license field in any export.