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Free neutrons in the sun's core?

I made a very rough attempt to estimate the density of free neutrons in the solar core. There is some non-zero rate for production of free neutrons. For example, the weak process pp -> deuteron+positron+neutrino which starts the pp chain is normally thought to produce a bound deuteron, but presumably there is some non-zero probability that it produces a proton and free neutron. These free neutrons then decay and there is a secular equilibrium. I am now seeking a better estimate than the very rough one I gave. Perhaps there is another neutron-producing process which dominates; perhaps someone knows how to estimate the rate of the one I thought of.

  • $\begingroup$ If you want better approximations than the usual, you should be consulting astrophysics literature. This is an important thing to get correct because astronomy strongly requires all the complications to be handled, and so they have considered the problem to death and hammered down a lot of nails. $\endgroup$ Commented Jul 28, 2023 at 7:16
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    $\begingroup$ @naturallyInconsistent I have read a lot of astrophysics literature related to fusion in stars but not yet come upon an estimate of the density of free neutrons in a sun-like star. Can you point me in the right direction? $\endgroup$ Commented Jul 28, 2023 at 9:15


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