PCS 181 Lecture Notes - Lecture 7: Strong Interaction, Neutrino, Alpha Particle
Document Summary
75% hydrogen, 24% helium, 1% everything else. Tcore = 10 x 106 k = Hydrogen fusion nuclear reactions in the core. A star spends its life in a delicate balance between outward radiation pressure and inward gravitational pull. ~90% ~95% of stars are main sequence . 1h + 1h = 2h + e+ + v (deuterium, position, neutrino). 2h =1h=3he + v (helium, istotope, radiation burst). 3he = 3he = 4he +1h +1h (helium, hydrogen). *note: fill in the missing blanks for the above equations on. Strong force nuclear force 2 particles with in 10-15 m together. Dominant nuclear reactions that take place in 90-95% stars. Note that four hydrogen nuclei fuse to form one helium nucleus and . A small amount of mass is released as energy. But a typical star has 1038 such reactions each second! Therefore, the energy produced each second is. (4. 3 x 10-12j) (1 x 1038) = ~ 4 x1026 w.