Value chain · CLM-0039
In plain terms
The 1978 report set the figure to protect radio and navigation systems from a disturbed ionosphere, called the number theoretical and untested, and said experiments were underway.
The claim as recorded
The 1978 Reference System states that non-linear thermal self-focusing in the ionospheric F-region at 200 to 300 km and thermal runaway in the D-region at 100 km may limit maximum beam centre power density to approximately 23 mW/cm2 at 2450 MHz, calls that threshold a theoretical number not yet verified by experiments, cites four references for it, gives the reason for concern as possible degradation of HF, VHF and VLF communication and navigation systems rather than health, and states in the same paragraph that the interactions were then being studied both theoretically and experimentally.
Scope and limits
A 1978 self-assessment. Its statement that experiments were underway is evidence of intent in 1978, not evidence that any experiment was completed. Whether one was is established separately by CLM-0030 and CLM-0033 (low confidence), which found none at 2.45 GHz. A CONTEMPORANEOUS FEDERAL SOURCE IS STRONGER THAN THIS RECORD'S CAUTION AND IS NOW HELD, ADDED 2026-09-15. This record's limits reads the Reference System's "now being studied, both theoretically and experimentally" as evidence of intent rather than completion. SRC-439, one month later, states the experimental position directly, machine-confirmed in its text layer with whitespace removed because the document letterspaces: "only a small effort has been devoted to date to studies of the instabilities that may be produced by microwave transmissions", and "Other effects, presently unpredicted, may also occur". It also carries a costed proposal to build a 25 MHz heating capability at Platteville - antenna, transmitter modifications and amplifiers, with an annual operating figure. THOSE COST FIGURES ARE RENDER-ONLY: they do not appear in the text layer and are NOT recorded here as quotations. The point that stands without them is the one that matters: in March 1978 a federal agency was pricing the experimental capability rather than reporting its results, which is not "studies underway". Its calculated effects at 20 mW/cm2 are confirmed - electron temperature reaching "a steady-state value about twice their undisturbed value in about 30 sec" and densities "45 percent below ambient" - so the CALCULATION was not in doubt and the EXPERIMENT did not exist.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
p41 verbatim, full paragraph: "... non-linear thermal self-focusing instabilities in the F-region ... thermal runaway conditions in the D-region ... may limit the maximum power density at the center of the beam to approximately 23 mW/cm2 at the 2450 MHz operating frequency (references 26, 29, 30 and 31) ... (which is a theoretical number, not yet verified by experiments) ... possible degradations to existing HF and VHF communication and VLF navigation systems ... now being studied, both theoretically and experimentally ..."
Related records
- Answers question
- QST-009 not published in this releaseQST-010 not published in this release
- Contradicts
- CLM-0056 not published in this release
- Supersedes
- CLM-0022 not published in this release
Cite this
energyaperture.com/c/clm-0039
CLM-0039, Energy Aperture, as of 1978.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-085
- CLM-0013The paper that modern UK studies rely on for the beam figure calls anything below 1 kilowatt per square metre safe, with 230 watts per...CLM-0020The original 1978 design set the beam at 230 watts per square metre in the middle of the receiving site, about one twenty-third of that at...CLM-0023In the 1978 reference design, two limits set the size of the transmitter and the receiving site: how much heat the transmitter can shed...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-0101The 1978 contract required the researchers to report fixes if ionospheric disturbance pushed the pilot-beam phase error past 2 to 3...CLM-0137In four major space solar power studies from 1978 to 2007, none put a number on how much of the beam's energy would be lost if the beam...CLM-0138The original 1978 government design for beaming power down from space adds up all the expected energy losses to get 63% overall efficiency...CLM-0182When two different research teams assessed the exact same 1978 space solar power design, the older accounting method (which spreads...More on the source page.