SRC-117

LA-UR-80-1562 / CONF-800672-1, SPS Environmental Effects on the Upper Atmosphere, Intl Symposium on Solar Power Satellites, Toulouse, 25-27 June 1980.

Commissioned by US DOE. Who paid for a study is recorded because it bears on how its conclusions should be read, not because it makes them wrong.

Published claims resting on this source

• CLM-0092 Duncan's own 1980 paper says the flawed earlier calculation was Holway and Meltz's, and praises Perkins and Roble's as the first thorough one. It does not say Perkins and Roble were wrong.
• CLM-0093 The thousand-fold disagreement between the two published versions was a lost micro prefix in the abstract I was working from. The papers agree.
• CLM-0693 The formula used here for when a microwave beam starts to focus itself in the ionosphere has now been checked against the original 1980 paper that first published it. Every part matches: the constant, the way it scales with frequency, density and temperature, and the assumption that one correction factor is about one.
• CLM-0694 The scientist who published the threshold formula says a single threshold number does not really exist. Whether the beam becomes unstable depends on the size of the ripples it is making, and as the beam gets stronger, smaller ripples start to grow too. He also warns the threshold drops very low when the beam happens to run almost along the Earth's magnetic field.
• CLM-0695 The 1980 paper says the SPS beam is expected to cause the ionosphere to focus it. It backs this with radar measurements from Arecibo, made in a different heating regime from the one an SPS beam would create, showing the predicted ripple sizes actually appear, roughly a kilometre across, and that they change the local electron density by about 5 per cent. The ripples form in seconds and fade in minutes.

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