Value chain · CLM-0157
In plain terms
The published abstract of a 1981 physics paper on self-focusing gives its threshold formulas scaled to 15 MHz, about 160 times lower than the 2.45 GHz often planned for space solar power, and shows no example at gigahertz frequencies.
The claim as recorded
Perkins and Goldman's (1981) own abstract normalises both its F-region and E-region threshold power-flux formulas explicitly to a 15 MHz reference frequency (Pc,F ~ 1.5 uW/m2 x (f/15 MHz)^3 x ...; Pc,E ~ 1 mW/m2 x (f/15 MHz)^3 x ...), with no GHz-specific numeric worked example appearing anywhere in the abstract - 15 MHz is roughly 163 times lower than the 2.45 GHz commonly used for SPS microwave power beaming.
Scope and limits
Does NOT establish that the formula is invalid at GHz - only that the paper's own published worked examples are anchored to HF (15 MHz). Whether the underlying physics generalises to f/f_p ~200 (the 2.45 GHz case) as validly as to f/f_p ~1-3 (the 15 MHz case) is an open question no source resolves (see CLM-0158). The E-region form's cube was dropped in this record's first transcription and the F-region prefix was read as milliwatts from the OSTI transcription; both are restored from the publisher's abstract, held since 2026-09-20 - the abstract, not the paper, is the held text.
What it assumes
The publisher's abstract page, as supplied and held, is the abstract as published (the OSTI transcription is not relied on for the prefix); the full paper (closed access, not obtained) might contain a separate GHz-specific worked example not visible in the abstract.
Where it comes from
The published abstract as printed on the publisher's page (held with SRC-116 since 2026-09-20): "In the F region, the threshold power flux Pc is Pc,F ≈ (1.5 µW/m²) (f/15 MHz)³ (Te/1000 °K)4 × (106 cm−3/ne)³CF" and "In the E region, the result is Pc,E ≈ (1 mW/m²) (f/15 MHz)³ (105 cm−3/ne)CE" (the superscripts 4 and 6 flattened in the held text; read as powers). The OSTI bibliographic record (osti.gov/biblio/6536431) transcribes the F-region coefficient as 1.5 mW/m^2, a lost prefix; its E-region form agrees. No GHz worked example appears in either text.
Basis: threshold power flux, mW/m2, normalised to f=15 MHz reference frequency
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0157
CLM-0157, Energy Aperture, as of 1981.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-116
- CLM-0088The published abstract of the original paper states a testable condition for whether self-focusing can happen at all, and gives the growth...CLM-0093The thousand-fold disagreement between the two published versions was a lost micro prefix in the abstract I was working from. The papers...