Updated: Sep 29
On March 1st 1954 the US achieved net positive fusion. So why are fusion labs 70 years later droning on about achieving "net positive".
Net positive means more energy came out than was put in. In September 1954, 6 months after the infamous Castle Bravo fission-boosted-fusion bomb test, the US Navy launched the USS Nautilus, the first Atom powered submarine. 1954 was a watershed year for Atomic Engineering.
Fission-based atomic engineering is and has always been a field monopolized by governments. Fusion-based engineering, well, you can do that in your garage and nobody really cares.
Because if the nuclear reaction doesn't involve fissionable material there can't be enough energy in the reaction to actually go anywhere. It's a silent signal by those in power and in the know that fusion without fission is is like a car without an engine.
Where does fusion occur naturally?
Oh that's right. In the center of stars.
Our Sun is a hydrogen fusion reactor where the pressure and temperature are thousands of times greater than standard terrestrial conditions. The density of gaseous hydrogen on Earth for instance is ~0.0009g/cm3; whereas the density of hydrogen plasma in the sun is 150g/cm3, 167,000 times greater.
At 15.7 million Kelvin the temperature of the fusion reaction in the center of the sun is 4010x greater than the highest temperature material we have available.
Enter Electromagnetic confinement fusion.
Confinement fusion is the approach to not holding the plasma with anything physical but instead holding it with a magnetic field; or holding pre-reaction ingredients in a container that is destroyed upon initiation of the reaction.
Confinement fusion examples are: ITER, W7-X Stellarator, Jet, Dense Plasma Focus, Z-Pinch, NIF (Laser Fusion), and fusion weapons.
In all the examples above the fundamental approach to the reaction is to hold the ingredients, squeeze the shit out of them, and get a reaction. In fusion weapons the "squeeze the shit out of them" is done with a fission detonation of uranium or plutonium. A.K.A turning matter into energy (E=MC^2)
In all other fusion concepts the squeeze is done with some machination of the electromagnetic force. A.K.A turning energy into 'other' energy. (E=E+) Wait, what?
Furthermore, the pressure to achieve fusion at 15.7 million Kelvin is not possible with confinement fusion. To compensate for the lack of available pressure the temperature must be dramatically increased.
Confinement fusion concepts must get the plasma temperature to over 150 million Kelvin!
Why is nobody trying scaled down weapons fusion reactors?
Well, not nobody. NASA is working on a propulsion system called PuFF(Pulsed Fission Fusion) that combines a Z-Pinch with a pellet of uranium filled with hydrogen gas.
But the department of energy has barred NASA from doing more legitimate research because it's too much in the 'nuclear weapons zone'.
Effectively the energy police say no.
Every single fusion attempt out there that is not using fission to bootstrap the reaction will likely not work. Methinks the DoE knows this.
But since curious Ph.D.'s boldly going is exciting to investors, both government and private alike, the fantasy fusion research continues.
Legitimate fusion attempts always will cross into the 'weapons zone' and therefore will always be shutdown. Nobody wants to risk the breaking of international treaties. Even underground atomic detonations are highly controversial.
Furthermore, the CAGR of solar energy is at a pace that if it keeps up, will completely take over terrestrial energy.
The final frontier is the home for actual fusion research. We want to be able to get to our outer planets and out of our solar system in a timely manner. The most reasonable way to do that is with a PuFF or or similar device.
Until then, enjoy your fantasy fusion!