Answer to Question #103827 in Atomic and Nuclear Physics for John O'Renick

Question

D-De fusion only needs one million degrees to ignite. and so is used to explore fusion in experimental reactors. I read that in a protostar, it doesn’t get much hotter, but http://hyperphysics.phy-astr.gsu.edu/hbase/NucEne/fusion.html says it produces 3.27 MeV or 4.03 MeV, producing an He-3 or a tritium.

If D-D is easy, why isn’t it explored for fusion power? Not enough energy, or is the cross section (likelihood of a reaction?) too low, or?

3.27 MeV = ~38 billion degrees kelvin: 4.02 = 47 billion. Assume you could fuse a D-D plasmoid (by inducing a current and so a field-reverse configuration “pinch” in it? Could that be enough?)—and you then slammed two or more D- He-3 plasmoids on top of that at thousands of km/sec; could the D-D fusion act as the “spark” to ignite the D + He-3 and He-3 + He-3?

If you then slammed protons on top of that, and crushed it all down with an external magnetic field, do you think you might ignite proton-proton fusion?

Answer 1

"If D-D is easy, why isn’t it explored for fusion power? Not enough energy, or is the cross section (likelihood of a reaction?) too low, or?"

You already answered your question in the following parts where you described the way the reaction will be carried:

"By inducing a current and so a field-reverse configuration “pinch” in it? Could that be enough? And you then slammed two or more D- He³ plasmoids on top of that at thousands of km/sec. If you then slammed protons on top of that, and crushed it all down with an external magnetic field..."

Surprisingly, such methods and technologies require much more energy that the reaction will produce. The cost of service and maintenance will be very high as well. Therefore it isn’t explored for fusion power. It may be possible theoretically, but not practically. Maybe later.