Value chain · CLM-0085
In plain terms
The 1978 formula does not give a threshold. It relates threshold power to the width of the plasma structures produced, so getting a single number out of it requires deciding which width matters.
The claim as recorded
The 1978 underdense self-focusing relation is Pth in watts per square metre equals 1.2e23 times electron temperature in kelvin to the fifth power times wave frequency in hertz squared times plasma frequency in hertz to the power minus six times perpendicular striation scale in metres to the power minus four times sine squared of the angle, and the perpendicular striation scale is an output of the relation determined by ionospheric conditions and power density, not an input, so the relation is a locus relating threshold power to striation width rather than an expression yielding a threshold.
Scope and limits
Establishes the relation and its units, not the physical validity of the mechanism at 2.45 GHz, which CLM-0083 records as unbounded by any source.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
This is the project's own working, shown in full:
Relation transcribed from a rendered image of SRC-108 p3-10, captioned as the threshold for underdense heating. Units recovered by back-solving against the document's own worked case and cross-checked against a companion overdense relation on p3-15 that states W/m2 outright; failing conventions miss by 8 to 30 orders of magnitude. Implementation verified by reproducing the structure of the document's own Figure 3.2: solving for lambda_perp at Pth 200 W/m2, Te 1200 K and fe 8 MHz gives 2,418 m at 90 degrees falling to 452 m at 2 degrees, matching the figure's described two panels in kilometres over 0 to 90 degrees and metres over 0 to 10 degrees. The document states lambda_perp "is determined by the ionospheric conditions and the power density of the heating radiation" and uses only the term "striation width", never growth length or scale length.
Related records
- Answers question
- QST-009 not published in this releaseQST-010 not published in this release
Cite this
energyaperture.com/c/clm-0085
CLM-0085, Energy Aperture, as of 2026-09.
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-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0132A 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...More on the source page.