Value chain · CLM-0104
In plain terms
A separate Japanese review worked out the same threshold from the original paper and got 32 and 425 watts per square metre. My own calculation gives 32.01 and 424.73. That is an independent check on the coefficient everything here depends on.
The claim as recorded
An independent 2008 review citing Perkins and Goldman directly rather than through Duncan states that for an electron density of 1e12 per cubic metre and an electron temperature of 1500 K the thermal self-focusing threshold is 32 watts per square metre at 2.45 GHz and 425 watts per square metre at 5.8 GHz, and the implementation at CALC-015 using Duncan's 0.43 coefficient reproduces both figures to better than 0.1 per cent, at 32.01 and 424.73 watts per square metre.
Scope and limits
SRC-124 is a review article in Japanese, so this is a secondary application of the relation and not the original derivation. It does not quote the coefficient itself, so the confirmation is by reproduction of two worked values rather than by reading 0.43 in a second place. Two independent values matching to better than 0.1 per cent is nevertheless a strong test, and it is a test the earlier route could not provide.
What it assumes
that SRC-124's reference 6 is Perkins and Goldman 1981, which its own reference list confirms
Where it comes from
This is the project's own working, shown in full:
page 2, translated from the Japanese: the threshold for beam thermal self-focusing is expressed as a function of electron density, electron temperature and microwave frequency; calculating with an electron density of 1e12 per cubic metre and an electron temperature of 1500 K, for the SPS model at 2.45 GHz the threshold is 32 W/m2, and for the SPS model at 5.8 GHz the threshold is 425 W/m2. Own arithmetic: 0.43 x (1e12/1e12)^3 x (1500/1000)^4 x 2.45^3 = 32.01, and 0.43 x 1 x 5.0625 x 5.8^3 = 424.73.
Related records
- Answers question
- QST-001 not published in this release
Cite this
energyaperture.com/c/clm-0104
CLM-0104, Energy Aperture, as of 2008.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-124
- CLM-0105A third party looked at the 230 watt per square metre design figure and said self-focusing may happen at 2.45 gigahertz but not at 5.8...CLM-0168In this 2008 Japanese review, the absorption figures of under 1% normally and up to about 10% at increased solar activity are not tied to...CLM-0169The 2008 Japanese review that gives the well-known 32 and 425 watts-per-square-metre self-focusing thresholds only ever says self-focusing...CLM-0500The same formula for how much microwave power a beam can carry before it destabilises the upper atmosphere gives 425 watts per square metre...