LogFAQs > #945265310

The analysis done so far shows that the planned fusion energy output of the SPARC reactor should be able to meet the design specifications with a comfortable margin to spare. It is designed to achieve a Q factora key parameter denoting the efficiency of a fusion plasmaof at least 2, essentially meaning that twice as much fusion energy is produced as the amount of energy pumped in to generate the reaction. That would be the first time a fusion plasma of any kind has produced more energy than it consumed.

The calculations at this point show that SPARC could actually achieve a Q ratio of 10 or more, according to the new papers. While Greenwald cautions that the team wants to be careful not to overpromise, and much work remains, the results so far indicate that the project will at least achieve its goals, and specifically will meet its key objective of producing a burning plasma, wherein the self-heating dominates the energy balance.

Greenwald says there is still much to be learned about the physics of burning plasmas, and once this machine is up and running, key information can be gained that will help pave the way to commercial, power-producing fusion devices, whose fuelthe hydrogen isotopes deuterium and tritiumcan be made available in virtually limitless supplies.
The details of the burning plasma "are really novel and important," he says. "The big mountain we have to get over is to understand this self-heated state of a plasma."

Overall, Greenwald says, the work that has gone into the analysis presented in this package of papers "helps to validate our confidence that we will achieve the mission. We haven't run into anything where we say, 'oh, this is predicting that we won't get to where we want." In short, he says, "one of the conclusions is that things are still looking on-track. We believe it's going to work."