The helpful press office at JPL was able to point me to the paper
THE MODULATION OF GALACTIC COSMIC-RAY ELECTRONS IN THE HELIOSHEATHwhich was the primary reference for the press release NASA's Voyager Hits New Region at Solar System Edge.
R. A. Caballero-Lopez, H. Moraal and F. B. McDonald
This was the press release used by Dr. Scott for an 'update' to his electric Sun model (Thunderbolts: Voyager 1 Updates Solar Electron Flux. Since EU has a multitude of contradictory "electric sun" models, I call Scott's version as the Solar Capacitor Model to distinguish it among those that I have analyzed.
The press release and the actual paper describes in-situ Voyager 1 & Voyager 2 measurements of the electron flux at the heliopause, about 100AU from the Sun. Voyager is reporting an increase in the flux of high energy electrons as the spacecraft moves towards the outer edge of the heliopause (wikipedia). What the spacecraft is detecting is the higher energy galactic electron population that has penetrated into the outflowing region of the solar wind which is dominated by lower energy electrons (and spiced up with some higher energy electrons from Jupiter's magnetosphere).
There were a couple of items reported in the measurements that are grossly inconsistent with EU's claim of these electrons powering their “Electric Sun“.
- The measured electron flux was omni-directional. This is because these electrons diffuse into the heliopause region, scattering to sufficiently to lose information of their original direction. If there were an electric field driving these electrons sunward, it should show up as a strong directional character in the electron measurements.
- The measured electron flux is a power law, E^-1.5. We can use this to estimate the total electron flux and compare it to the number used in Dr. Scott's 'update'. Examining the Figure 1 from the original paper, we find that the omnidirectional flux measured by Voyager 1 (the larger of the two measurements) is about 100 particles/m^2/s/sr/MeV @ 4MeV. We can use this number to calibrate the calculation.
If we use E=4MeV in the above formula, we obtain a flux of about 100 electrons/m^2/s/sr/MeV. With this spectral power law, this gives a total particle flux of about
if we integrate (sum) all the particles in the energy range from 1MeV to infinity. Now the measured flux is omnidirectional because the Voyager detector has a fairly large field-of-view.
However, Dr. Scott claims the electron flux is all inbound, directed towards the Sun.
For the sake of argument, we'll compute the omnidirectional flux, but interpret it as a measured inbound flux. Since there are 4*pi steradians (sr) in a full sphere, we can multiply the directional flux by 4*pi to get the total flux:
(particle density) * (particle velocity) = 4*pi*df/dOmega = 4*pi*1600 particles/m^2/s
or about 20,000 electrons per square meter per second.
Since 1MeV electrons are relativistic, we can take the velocity as approximately 'c' and use this number to estimate the electron density.
n*v = 2e4 electrons/m^2/s
n= (2e4 electrons/m^2/s)/(3e8 m/s) = 7e-5 electrons/m^3 =7e-11 electrons/cm^3
Yet the electron density used by Dr. Scott is 1e4 electrons/m^3 (Thunderbolts), over 100 MILLION times larger than the most optimistic interpretation of the measured value!
Why is that? Will EU supporters again invoke mystically undetectable 'drift electrons' (see Electric Cosmos: The Solar Capacitor Model. III)?
Such 'drift electrons', if they existed, would pose a real threat to multi-million dollar space assets. Satellite engineers know that space plasmas are *very* detectable as no satellite is a uniform perfect conductor. This is probably why I have yet to find an EU 'engineer' actually involved in designing and building satellites!
So where did Dr. Scott get his electron flux measurement? It looks like he just took his old estimate and scaled it.
Why didn't Dr. Scott find out what the real value was? Did he just make up the value because it was convenient?
References
- Voyager CRS Instruments
- The Voyager Cosmic Ray Instrument. D.E.Stillwell, W.D.Davis, R.M.Joyce, F.B.McDonald, J.H.Trainor, W.E.Althouse, A.C.Cummings, T.L.Garrard, E.C.Stone, and R.E.Vogt. IEEE Transactions on Nuclear Science 26, 513-520 (1979)
6 comments:
Voyager measurements
... about 20,000 electrons per square meter per second.
Since 1MeV electrons are relativistic, we can take the velocity as approximately 'c' and use this number to estimate the electron density.
n*v = 2e4 electrons/m^2/s
n= (2e4 electrons/m^2/s)/(3e8 m/s) = 7e-5 electrons/m^3 =7e-11 electrons/cm^3
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-The detectability issue-
Why is that? Will EU supporters again invoke mystically undetectable 'drift electrons'
....
Lets start from here and find an explanation...
1-The scattering issue that you brought up in another page
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You do know that
[b]Relativistic electrons are[/b] rather [b]collisionless in a plasma,[/b] collisions frequency goes down with the square of the velocity (roughly), so basically what you, in simple approximation, [b]these electrons will get to the sun, specially if we assume they will flow along the parker spiral.[/b]
2-Why they are undetectable...
The explanation is that these incoming Galactic high energetic electrons flow along the parker spiral for entering the Sun.
That explain why the detection instruments measure only the normal magnetic field of the Sun but not these incoming Galactic high energetic electrons detected at the Heliosphere by Voyager.
To Anonymous
This appears to be a follow-up from the thread on CosmoQuest: Electric Sun verified Don E Scott claims
Several problems
* computing the energy flux of these electrons over th entire area of the heliopause, I get 9e18 watts = 23 billionths of solar luminosity, still nowhere near enough to power the Sun.
* The Parker spiral moves out from the Sun at anywhere from 700-2000 km/s while your electrons move inward at 2.8e5 km/s. There is now way the incoming electrons will stay in the Parker spiral.
* At Earth orbit, with a solar wind magnetic field of about 10 nT, I get a gyroradius for 1MeV electrons of about 470,000 km so in less than a million kilometers, the electrons are redirected by 180 degrees.
* At the heliopause at 100 AU, assuming the magnetic field declines as r^-3, the gyroradius increases to about 3.2 AU, so if these electrons manage to avoid being scattered, they will be turned around before they get to 90 AU.
* And the above results are just at 1MeV. Considering the inflow will have a distribution of electron speeds, there will be wide variation in these values. I doubt these electrons will reach reach the Sun before they are lost amongst the denser solar wind electron population. That's why all the models explored are diffusion models.
* A relativistic plasma can be collisionless at some densities, but you don't have a relativistic plamsa configuration here. You have a relativistic 'beam' flow striking a slower, 'colder', denser plasma.
* Even if this did work, it would not solve why the solar surface radiates so uniformly since your electrons would be guided along plasma sheet and strike the Sun along the neutral field line. Since it requires the inbound electrons to hide along the Parker spiral, already demonstrated unlikely, they would strike the photosphere non-uniformly.
* You still have not addressed the question of how 'undetectable' these electrons are when they strike spacecraft hull, a spacesuit, or human tissue.
You wrote:
* At the heliopause at 100 AU, assuming the magnetic field declines as r^-3, the gyroradius increases to about 3.2 AU, so if these electrons manage to avoid being scattered, they will be turned around before they get to 90 AU.
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The detectability issue is definitively an interesting subject.
1-If as you said these incoming electrons will be turned around before they get to 90 AU....how do you explain that Voyager have not detected them before crossing the heliosphere?
2-If these incoming high eneregetic electrons dectected by Voyager have been scattered to undetectability in only 10 AU from 100 AU to 90AU what is the mechanism explaining that?
(Dropping by from Cosmoquest ATM)
If there were a 1-solar-luminosity beam *entering* the solar system and aimed at the Sun, it'd hit the night sides of the planets. (Obviously so for the non-magnetic ones, likely for the Earth too.) For a uniform radial flux, approaching the Sun over 4*pi steradians, this would exactly double the Earth's energy budget; the daytime hemisphere gets 1000W/m^2 reradiated from the Sun, plus the nighttime hemisphere would get 1000W/m^2 of electron beam heating. If you imagine the sun powered by an incoming beam in the equatorial plane, then the planets are all *hotter* at night than during the day. Nonsense.
To Anonymous (November 22),
When examining systems in nature, one must always keep in mind that more than one process can be acting simultaneously. Nature rarely builds sharp boundaries between processes the way engineers like to build technologies.
As noted before, the interaction between the OUTBOUND slow solar wind and the inbound FAST cosmic rays will not be collisionless. The two populations will collide and the fast stuff will lose energy and diffuse and mix with the outbound wind electrons, eventually being indistinguishable from them.
This is why models used in this region use variants of the Vlasov Equation, and this approach goes back to at least 1965 with Eugene Parker.
Either way, we can't distinguish these incoming electrons once they mix with the outgoing solar wind.
To Anonymous (November 24),
Even worse is for electrons with energy greater than about 1 million electron volts, they will form electron-positron pairs on striking atoms in the atmosphere.
Those positrons will hit other electrons in the atmosphere forming gamma-rays!
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