Value chain · CLM-0420
In plain terms
NASA's 1981 report says the experiments found nothing supporting the 23 milliwatt limit, that the measured heating was two or three times, not ten times, and that the theory was being rewritten. Its review panel called the basis obsolete and unsupported.
The claim as recorded
NASA's 1981 technical summary reports that experimental tests at Arecibo and Platteville showed no evidence to support 23 milliwatts per square centimetre as an upper limit, that measured electron temperature increases from underdense heating were a factor of two or three rather than the order of magnitude predicted by the early analyses, and that the theory was being revised toward a one-over-f-cubed rather than one-over-f-squared heating dependence; and its review panel appendix states separately that the number in use is based on an obsolete theoretical foundation and is without experimental support while remaining the constraining parameter in a number of design areas.
Scope and limits
The main-body sentence is a statement that the tests found NO SUPPORTING evidence, which is not the same as evidence that the limit is wrong. It is an absence of confirmation, and the corrected wording says only that. The panel appendix is a recommendation document, not a finding of the study proper.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
PDF p59, verbatim: "The results of the tests performed to date at Arecibo and Platteville show no evidence to support 23 mW/cm2 as an upper limit. The electron temperature increases due to underdense heating are a factor of two or three, rather than the order of magnitude predicted in the early analyses (ref. 15). The theory is now being revised, and initial results predict a l/f3 heating rather than l/f2, where f is frequency". SRC-107 PDF p266, verbatim: "The number being used, 23 mW/cm2, is based on an obsolete theoretical foundation and is without experimental support, and yet it is the constraining parameter in a number of the SPS design areas."
Related records
- Answers question
- QST-001 not published in this release
- Contradicts
- CLM-0073 not published in this release
- Supersedes
- CLM-0073 not published in this release
Cite this
energyaperture.com/c/clm-0420
CLM-0420, Energy Aperture, as of 1981.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-107
- CLM-0033 (low confidence)Apart from a 1981 NASA review that found no evidence for the number and suggested a higher one, nobody was found to have revisited it, and...CLM-0060In 1981 a NASA review panel said the 230 watts per square metre figure rested on an obsolete theory with no experimental support, and made...CLM-0061The experiments were done. They found heating two or three times stronger than normal, not the tenfold effect predicted, no irregularities...CLM-0062By 1981 the theory was being revised to a steeper frequency dependence, which would raise the permitted power density.CLM-0063NASA suggested in 1981 that 550 to 600 watts per square metre might be reasonable, roughly two and a half times the figure still in use...CLM-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0160A 1978-81 NASA design study calculated that simply pointing the satellite's structure accurately enough, without any electronic correction...CLM-0901Each antenna must hold its position along the line to the receiver within about three millimetres for a tenth of a decibel. The whole 1970s...More on the source page.