In 2018, Butyrin, Shakirzianov, and Mikheev hypothesized that electromagnetic irradiation of cold plasma — including plasma produced by irradiation-induced ionization of gas — can create a state of "plasma hyperconductivity": a dense layer of emitted electrons at the vacuum–plasma boundary whose electrons have a very long mean free time τ\tau, so that the surface conductivity σ=ne2τ/m\sigma = ne^2\tau/m rises dramatically. The authors state the hypothesis can be easily verified experimentally, for instance by resistance measurements of gas-discharge tubes in microwave fields. The open problem is to determine whether the hypothesized state exists — or to refute the mechanism.

Background

An ionized gas (plasma) conducts electricity because mobile charge carriers — in cold, weakly ionized plasma mainly electrons — are accelerated by an electric field between collisions. The standard Drude expression for the electrical conductivity is σ=ne2τ/m\sigma = ne^2\tau/m, where nn is the electron concentration, ee the electron charge, mm the electron mass, and τ\tau the mean free time between collisions; in a collisional cold plasma, τ\tau is short and the conductivity correspondingly modest. At the boundary between a plasma and a wall or vacuum region, a space-charge layer called the plasma sheath forms, in which quasineutrality (the near-equality of positive-ion and electron densities that holds in the bulk plasma) breaks down and strong electric fields appear; electron emission from surfaces into this sheath (thermionic, secondary, or photoemission) is a classical topic of sheath theory, and emitted current is bounded by space-charge limits such as the Child–Langmuir law, the classical constraint on how much current an emitted-electron cloud can carry before its own space charge suppresses further emission.

Against this backdrop, Butyrin, Shakirzianov, and Mikheev proposed in a two-page 2018 letter the hypothesis of "plasma hyperconductivity": that electromagnetic irradiation of cold plasma — including plasma created by irradiation-induced ionization of a gas — can drive it into a state of dramatically enhanced ("hyper-") conductivity. The proposed mechanism is a dense layer of emitted electrons at the vacuum–plasma boundary: because collisions are rare near the boundary, the layer's electrons can have a very long mean free time τ\tau, and under irradiation the layer can reach an enhanced concentration nn, so that the surface conductivity σ=ne2τ/m\sigma = ne^2\tau/m rises dramatically. The authors state that the hypothesis "can be easily verified experimentally", suggesting measurements such as the resistance of gas-discharge tubes in microwave fields, and they situate it in a lineage of speculative work on concentrated electromagnetic energy — their earlier "Photonic domains" (2017) and Zelikin's mathematical survey "Superconductivity of plasma and fireballs" (2008), which explored related ideas about plasma superconductivity and ball lightning. The conjectured extrapolations (ball lightning as a hyperconducting resonator; self-termination of stellar thermonuclear burning, later developed in the authors' "Model of a Hot-Core Sun", 2021) are presented by the source itself as separate, conditional speculations.

What has never been done — and what the adjacent literature does not settle — is the core question. The sheath-with-emission literature (e.g., Hantzsche's 1998 review of active plasma boundary sheaths) treats sheath structure and emitted-current limits but not a tangential surface-conductivity enhancement sustained by irradiation, and gas-discharge tubes under high-power microwave irradiation have been studied as switching and breakdown devices without testing this hypothesis. Whether an irradiated vacuum–plasma boundary can in fact sustain a dense, long-τ\tau emitted-electron layer with dramatically enhanced surface conductivity — or whether standard sheath fields, space-charge limits, collisions, and plasma instabilities forbid it — is open.

Problem Statement

Determine whether the hypothesized irradiation-induced hyperconducting state of cold plasma exists. The hypothesis raises three linked scientific questions:

(1) Experimental test. Whether a vacuum–plasma boundary configuration — for example, a gas-discharge tube — shows the predicted dramatic, sustained increase of its effective electrical resistance (equivalently, its surface/boundary conductivity) under external electromagnetic irradiation (e.g., microwave) relative to the unirradiated case, and whether such an increase is distinguishable from mundane mechanisms: radio-frequency sheath rectification (rectification of an oscillating field into a steady sheath bias by the nonlinear sheath impedance), photoemission and secondary-emission currents, bulk-plasma heating, and irradiation-induced change of the overall ionization balance.

(2) Parameter thresholds. The minimum conditions under which the dense emitted-electron surface layer forms and persists: incident electromagnetic flux and spectral content, plasma temperature, gas species, and ionization conditions.

(3) Kinetic-theory basis. Whether the emitted-electron layer at the vacuum–plasma boundary can simultaneously attain the assumed enhanced concentration nn and large mean free time τ\tau under sustained irradiation — accounting for collisions, the self-consistent sheath fields, space-charge-limited emission, and plasma instabilities — or whether it cannot, which would refute the hypothesis.

The goal is to settle the existence of the hypothesized state: whether electromagnetic irradiation of cold plasma — including plasma produced by irradiation-induced ionization of gas — creates the dense, long-τ\tau emitted-electron boundary layer with dramatically enhanced surface conductivity that the hypothesis predicts, or whether the mechanism is refuted. The authors state that the hypothesis "can be easily verified experimentally" and suggest resistance measurements of gas-discharge tubes in microwave fields. The existence question is settled by the conditions under which the layer forms and persists (incident flux, spectral content, plasma temperature, gas species, ionization conditions) and by the kinetic consistency of the assumed large τ\tau and enhanced nn against collisions, sheath fields, space-charge limits, and instabilities. The characterization of the enhancement remains qualitative, as in the source, which poses the hypothesis qualitatively ("hyper-" conductivity arising "as a result of irradiation"); no fixed magnitude threshold is imposed. The conjectured applications (ball lightning as a hyperconducting resonator; self-termination of stellar thermonuclear burning) are downstream speculations that the source itself marks as requiring separate modeling and observational tests; they are not part of this problem.

References

  1. Butyrin, P. A., Shakirzianov, F. N., and Mikheev, D. V., "Plasma Hyperconductivity", Bulletin of the Russian Academy of Sciences: Physics 82(8), 922–923 (2018). DOI: 10.3103/S1062873818080129, https://doi.org/10.3103/S1062873818080129
  2. Zelikin, M. I., "Superconductivity of plasma and fireballs", Journal of Mathematical Sciences 151(6), 3473–3496 (2008). DOI: 10.1007/s10958-008-9047-x, https://doi.org/10.1007/s10958-008-9047-x
  3. Butyrin, P. A. and Shakirzianov, F. N., "Photonic domains", Bulletin of the Russian Academy of Sciences: Physics 81(8), 1016–1018 (2017). DOI: 10.3103/S1062873817080081, https://doi.org/10.3103/S1062873817080081
  4. Shakirzianov, F. N., Butyrin, P. A., Abdulkerimov, S. A., and Mikheev, D. V., "Model of a Hot-Core Sun", Bulletin of the Russian Academy of Sciences: Physics 85(11), 1198–1200 (2021). DOI: 10.3103/S1062873821110332, https://doi.org/10.3103/S1062873821110332
  5. Shakirzianov, F. N., Butyrin, P. A., Abdulkerimov, S. A., and Mikheev, D. V., "What Does the Next Century Have in Store for Us?", Bulletin of the Russian Academy of Sciences: Physics 86(9), 1015–1018 (2022). DOI: 10.3103/S106287382209026x, https://doi.org/10.3103/S106287382209026x
  6. Hantzsche, E., "Active Plasma Boundary Sheath with Electron Emission", Contributions to Plasma Physics 38(4), 467–487 (1998). DOI: 10.1002/ctpp.2150380402, https://doi.org/10.1002/ctpp.2150380402
  7. Van Benschoten, W. Z., Petras, H. R., and Shepherd, J. J., "Electronic Free Energy Surface of the Nitrogen Dimer Using First-Principles Finite Temperature Electronic Structure Methods", The Journal of Physical Chemistry A 127(32), 6842–6856 (2023). DOI: 10.1021/acs.jpca.3c01741, https://doi.org/10.1021/acs.jpca.3c01741