ASTRO-110 Lecture Notes - Lecture 24: Coronal Mass Ejection, Radiation Zone, Coronal Hole
Document Summary
Radiation zone: like the core, plasma in the radiation zone is so dense that photons can travel only a fraction of a millimeter before colliding with an electron. With each collision, the photons leave a little energy behind. The plasma is no longer fully ionized (produces gas) the partially ionized plasma can absorb photons, so the photons that started in the care are mostly absorbed by the time they reach the edge of the radiation zone. This marks the beginning of the convection zone. Photons cannot easily travel through the partially ionized plasma. Here, convection is the primary way that energy is carried from the hot lower levels up to the surface of the sun (energy moves quickly in the convection zone, taking only about a month to get to the surface) Deep within the convection zone, convection cells are quite large. The size of these cells gets smaller and smaller as we approach the sun"s surface.
