Curiosity › Science › Physics › Why we need higher temperature on earth for fusion reactors? › Reply To: Why we need higher temperature on earth for fusion reactors?
You’re right. Fundamentally for nuclear fusion to occur on Earth, you need very high temperatures and pressure so that the hydrogen isotopes (basically two protons) overcome their mutual repulsion to fuse together.
At the core of the Sun, the pressure is extreme (26.5 x 10^15 pascal) due to the gravitational force of the hydrogen and helium. And this pressure contributes more to creating a viable condition for the fusion.
On Earth, however, you cannot create such high pressure. The highest pressure we could possibly achieve in our fusion reactors is around 2.5 x 105.
The denser and hotter the plasma is the more chances of fusion to occur. Hence, on earth, we make the plasma hotter than the core of the sun and try to achieve high densities (which means we are trying to achieve higher pressures too).
I hope this helps, Shamil. Thanks for visiting Geekswipe. :)