Electron Screening Plasma

Just imagine! While the Sun is considered as very hot having about 15 000 000 degrees in C in its core this temperature is not really hot in terms of kinetic energy of particles. Their kinetic energy is just about 1.4 keV. This is a very modest energy and many atoms in the solar interior are not fully ionized. Instead their nuclei are dressed by an electron suite around. Is this important? Yes! This means that the following reactions:

• $Be^7+e^-\to Li^7+\nu_e$
• $Be^7+p\to B^8+\gamma$

having ratio 1000:1 when $Be^7$ is naked will have another proportion in the presence of screening electrons around the $Be^7$ nucleus. Naively one could expect that the rate of $Be^7+e^-\to Li^7+\nu_e$ reaction will be suppressed while the rate of $Be^7+p\to B^8+\gamma$ will be enhanced just because of some electrons repulsing plasma electron for $Be^7+e^-\to Li^7+\nu_e$ reaction and attracting plasma proton for $Be^7+p\to B^8+\gamma$. This could change their rates to a more balanced proportion and (as I hoped when this idea came to my mind) could explain the Solar Neutrino Puzzle (the main problem before SNO was no room for beryllium neutrinos happened from $Be^7+e^-\to Li^7+\nu_e$ reaction). This was one of my first articles...

• Electron screening in Be-7 + p ---> B-8 + gamma reaction.

V.B. Belyaev (Dubna, JINR & Osaka U., Res. Ctr. Nucl. Phys.) , D.E. Monakhov (Dubna, JINR) , D.V. Naumov (Dubna, JINR & :Irkutsk State U.) , F.M. Penkov (Dubna, JINR) . Mar 1998. 7pp.

Published in Phys.Lett.A247:241-245,1998.

e-Print: astro-ph/9803003

SPIRES link

Working on this paper I rediscovered that the nuclear reactions happen at much higher energies in the plasma - so called - Gamov window. Thus the effect of electron screening being very important at energies of few keV (factor 10-20) becomes 10-20% at 10-15 keV (energies at which the reactions happen). It was very exciting for me to realize all that in 1998.