Value chain · CLM-0132
In plain terms
A 1978 NASA-funded study calculated that a beam of about 12 milliwatts per square centimetre at 2.45 GHz would be the point where the ionosphere starts heating itself out of control.
The claim as recorded
Duncan and Gordon (1978) give a modelled thermal-runaway power-flux threshold of 12 mW/cm2 at 2.45 GHz.
Scope and limits
This is a distinct threshold concept (thermal runaway) from both the self-focusing threshold and the human-exposure/interference limits recorded elsewhere; should not be conflated with either. It is a 1978 modelled figure, not measured.
What it assumes
The modelled ionospheric parameters used by Duncan and Gordon for this calculation are not detailed in the reviewing report; treat as their stated reference case.
Where it comes from
Duncan and Gordon (1978), NASA-CR-151821, p.19: thermal-runaway threshold of 12 mW/cm^2 at 2.45 GHz.
Basis: power flux density, mW/cm2, at 2.45 GHz
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0132
CLM-0132, Energy Aperture, as of 1978.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-108
- CLM-0043The study the 1978 reference system cites put the level where the beam may start to disturb the ionosphere at about 20 milliwatts per...CLM-0045The apparent conflict between 12 and 23 was not an error. The underlying study gave a range, and the figure adopted sits near the top of it.CLM-0066The figure adopted in 1978 was higher than each of the lower figures in the studies it cited, though those figures were themselves...CLM-0072The 1978 study gives 12 milliwatts per square centimetre for runaway, give or take a factor of two, and says no threshold can be set in the...CLM-0082The formula is the right one for the conditions space solar power would create. It was written for this case, not borrowed from a different...CLM-0083The formula is the right type but nobody has said how far it can be pushed, and at space solar power frequencies the wave is about 200...CLM-0085The 1978 formula does not give a threshold. It relates threshold power to the width of the plasma structures produced, so getting a single...CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...More on the source page.