Electron-assisted fusion

What is important here is, with increasing pressure the shielding effect of electrons should get statistically more significant, as there is higher probability of occurrence of electrons BETWEEN atom nuclei, not OUTSIDE them. The number of free electrons per atom would affect the value of derivative of the trend, but not it's sign.

How significant this effect would actually be is the another question. If you favor the shielding effects of electrons for explanation of cold fusion, you could try to calculate it.

Quote from Jarek

Again, the only option for non-negligible electron assistance is that there is a single electron remaining between the two colliding nuclei.

I like Longview's point about pressure (ion density) and confinement time. A textbook of mine says that the pressure in the core of the sun is ~ 4e11 atm. I wonder whether screening is relevant here. It would be nice to see a textbook discussion of the 1e-28 probability before reaching for an explanation that adduces screening from electrons that are confined between protons.

Quote from Wyttenbach

I recently read that the measured solar neutron rate is not adequate for hot fusion and we must draw a new picture. May be somebody has the paper.

That would be an interesting read.

The vacuum lifetime of free neutrons would, at a mean of about 15 minutes, even if "clock adjusted" for relativistic gravitational effects, together with effective neutron flux or density of whatever order likely says neutrons never get far out of the solar core. Even if the core environment somehow greatly increased their T_1/2 (seems possible), they would have a strong gravitational incentive to move inward not out. The neutron has density of about 10²⁶ grams per cubic meter, that is about 10²⁴ times higher than the claimed mean of the central core itself at 150 g/M³.

Those vanishing neutrons generally only undergo beta decay... so that paper may be looking at the accompanying solar neutrino flux as an "observable".

For the pp chain, free neutrons are not a consideration. These are the reactions:

• p + p → pp + γ
• pp → d + e⁺ + ν

It's the decay with positron emission that causes the proton to flip to a neutron, but I believe this would take place in the context of the pp resonance (similar to a bound state), and not a spontaneous decay of a proton to a neutron.

So, Eric, are you saying there are no solar neutrons anyway?

Quote from Longview

So, Eric, are you saying there are no solar neutrons anyway?

I assume there is spallation, which would free up some neutrons. But consider that if the conditions are such that tunneling is needed in the core, it seems unlikely that there will be much in the way of spallation.

Quote from Eric Walker

a spontaneous decay of a proton to a neutron

You probably meant "decay of a neutron to a proton". Otherwise it's not likely to happen anytime soon (10^34 years h-l).

Quote from magicsound

You probably meant "decay of a neutron to a proton". Otherwise it's not likely to happen anytime soon (10^34 years h-l).

No, I meant spontaneous decay of a proton to a neutron (an endothermic process), omitting to mention that this isn't something that really happens on the assumption that it's common knowledge. I was suggesting that free neutron capture is not how deuterium is formed in the sun. (I may have misunderstood the earlier points being made about free neutrons.)

Quote from Jarek

Zephir, Eric - please just do the math.
Solar core is believed to have density 150g/cm^3 ( en.wikipedia.org/wiki/Solar_core ).

Jarek, I get that you want to show that the commonly accepted account of the pp chain is inadequate to explain the reaction rate in the solar core, and that to explain it you need to somehow position electrons between the protons in order to bring about screening. In order to make this argument, you must start with the mainstream derivation for the reaction rate, which will show some math that leads to the accepted reaction rate, and then show which steps are inadequate.

What you're doing is to attempt to derive your own calculation from geometric considerations and distances between reactants, which you then believe you're showing to be inadequate. This approach is ineffective because (1) the mainstream derivation will no doubt get to the desired rate, and, if you're correct, is simply flawed in some subtle way; and (2) you're producing a calculation which astrophysicists are likely to recognize as being only partly related to the one they're using, which unintentionally sets up a kind of straw man argument.

Quote from Jarek

Eric, so please explain where proton gets 1000x larger energy than thermal - to get to ~fm distance required for fusion?

Jarek, your question is for the authors of astrophysics textbooks. Consult a few until you find the derivation, look it over, find out what's wrong with it, and then report back to us what you discover.

Quote from Jarek

Thermal energy in solar core is 1.4keV, p + e -> n needs 782keVs.
So Boltzmann says their concentration should be ~exp(-782/1.4) ~ 10^-243.

Any Bolzmann statistics has a head and a tail. So there are certainly particles with the right speed. Not taking into count that there are massive fields inside and outside the sun which can speedup particles far beyond the needed energies.

But Neutrino research is just catching up. I guess we should wait for the newest results and stop speculations!

How is the 11 year solar cycle explained if energy derived from nuclear reactions in the core of the sun takes a million years to reach the surface?

definitely not with cold fusion in it

Quote from Zephir_AWT

definitely not with cold fusion in it

15'000'000 C seems to be very cold .. at least for the JET people...

Where did the 15,000,000 temperature of the Sn's core come from? The temperature at the Sun's surface is the same as a Rossi reactor's meltdown.