Value chain · CLM-0147
In plain terms
A major 2007 physics review gives a different mathematical formula, with different dependence on temperature and frequency and no dependence at all on plasma density, for a related but distinct instability than the one usually used to set space solar power's safety threshold.
The claim as recorded
Gurevich's (2007) review gives a critical field for the resonance instability that drives striation formation of Ec = ET x sqrt(delta x vT/c), numerically about 30-100 mV/m in the F-layer, produced by an ionospheric modification station of effective emission power about 10-100 MW; this formula has no explicit electron-density (Ne) dependence and scales roughly as frequency to the first power and temperature to the 3/4 power on field (f^2, Te^1.5 on power density) - structurally different from the Ne^-3, Te^4, f^3 scaling used in the microwave SPS self-focusing threshold formula.
Scope and limits
Does NOT confirm or contradict the numeric coefficient (0.43) in the widely used microwave self-focusing threshold formula, because the two describe structurally different scalings for what may be physically distinct mechanisms sharing only a common name ("self-focusing"). Whether the two are the same instability in different regimes is stated as an open physics question, not settled here.
What it assumes
This formula concerns HF ionospheric-heater physics at the F-layer reflection/resonance height, a different propagation regime from underdense GHz microwave transmission.
Where it comes from
Gurevich (2007), Physics-Uspekhi 50(11), PDF p.10-11 (printed pp.1100-1101): "Under conditions of the ionospheric F-layer, Ec ~ 30-100 mV/m. Such a field is created by an ionospheric modification station with the effective emission power PG ~ 10-100 MW." Formula Ec = ET(delta vT/c)^(1/2), verified by rendering the page to a 250-dpi image and reading it against the extracted text.
Basis: electric field, mV/m, F-layer, HF ionospheric-heater physics
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0147
CLM-0147, Energy Aperture, as of 2007.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-132
- CLM-0114The Russian treatment says self-focusing is triggered by lumpiness already present in the ionosphere, not by beam power crossing a line...CLM-0116The Russian formulas are a different shape from the 0.43 relation, so they cannot be used to check it either way.CLM-0158Neither of the two sources read at the page, a 2004 review by Robinson and others and Gurevich (2007), states the range of conditions under...