3 ms·
The way I understand it, is that with Q>1 in a confined plasma you no longer need external heating and can just let the fusion heat power the plasma. I.e. you "
by rndphs 5y ago
The way I understand it, is that with Q>1 in a confined plasma you no longer need external heating and can just let the fusion heat power the plasma. I.e. you "ignite" it and it burns within confinement (self-sustaining). Whereas if Q<1 you need to continuously provide heating, and the efficiency of that heating is probably quite low so the "total" Q appears lower.
Basically, once you have ignition + confinement, Q no longer matters as you no longer have to heat the plasma to sustain it. Correct me if I'm wrong.
- JumpCrisscross 5y ago> once you have ignition + confinement, Q no longer matters as you no longer have to heat the plasma to sustain it Assuming immutable containment and continuous fusion. In reality, combinations of heat dissipation, cycling (to permit material replacement and/or cooling) and even powering the computers and magnets subtracts from the theoretical power output. In indirect-drive inertial confinement, the NIF drops a Hohlraum containing a fuel pellet and then does things to cause it to fuse. That's the burn. The pellet then falls, a new one is released, and the lasers pulse anew. The energy from the first burn may provide power for the second pulse, but in between is a lot of ground to be lost and thus purchase for Q.