Honestly, that's above my physics pay grade. I wish it was not, but the brain fog and constantly being on pain meds makes doing the math nearly impossible.
Okay, looked it up...probably should have done that first actually. Whole lot of this physics stuff goes over my head, but according to Wikipedia the most promising approaches for aneutronic fusion are helium-3 and proton-boron (which is actually just whacking an extra proton into a boron atom). Pure helium-3 is apparently totally outside the confinement and plasma temperatures relevant to building a reactor. Deuterium-helium-3 is maybe possible but also requires higher confinement and temperature, and can't be really made fully aneutronic. Boron...oof, totally out of my depth here, but by the sound of it a tokamak (or any other kind of magnetic confinement reactor) isn't even in consideration, it's all inertial and involves huge lasers and proton beams.
But! I was wrong about magnetohydrodynamic capture. It does work with magnetic confinement reactors, and a slightly different kind called inductive conversion is suitable for pulsed reactors too.
I also remember reading some properly crazy stuff about non-fusion magnetohydrodynamic generators built by the Russians during that brief '90s phase of cooperation with the US, but that's a different subject entirely.
What I've read on Atomic Rockets says that D+3He fusion needs to run with a lot of extra 3He in the mix instead of what the "stoichiometric" reaction math says, since the live mix ends up fusing some deuterium together and it's this side reaction that spits out neutrons.
MHD generators need high temperatures to produce ionized gazes. I think, one problem with them is their limited live, which would probably still outlast every fusion reactor by more than a factor of 100 (three days or so...).
I believe, temperature management is one key problem of continuously operating fusion reactors. Within a few centimetre the temperature drops from 6 Million degree Celsius to minus 250 degree. Water as an intermediate cooling fluid (supercritical or pressurized above boiling pressure) is surly not a bad idea to keep control. Replacing the water with high temperature gases for MHD generators, will keep the next 100 generations of fusion researches busy.
The amount of work to do for cheap fusion electricity will never decline...
There are many fusion methods based on fuel or method of introduction. But sake theres 5 major fusion methods commercially exploited.
First and most Ubiquitous is "Magentic Confinement fusion" or MCF. It uses highly cooled ring or donut shaped magents to heat, collide and contain plasma. Dubbed Tokamak, a Russian Term for toroid, magnetic coil. This most widespread fusion variant namely including ITER, globally 200 have been built since 1950s of which US built more than 40.
2nd is the American Way "Inertial Confinement Fusion" or in Science fiction dubbed as Laser fusion. The system resembles a disco ball where hundreds laser or ion beams fired at single target no bigger than airsoft pellet. A fuel pellet undergoes rapid thermal heating as container obliterates and collapses, the process is so rapid it collapses to over 100,000 times its original density. The conditions produce high temperature and pressure briefly but not ideal repetitive environment thus used science experiments as wel testing validity nuclear arsenal.
Then there's the Canada way "Magnetized Target fusion" dubbed Steampunk or Steam Piston fusion. The system uses a network of pneumatic pistons to collapse a pre heated focused plasma, a magnetic toroid spins inside to run its magnetic flux for generation. Alternative proposed power generation is permit focus channel plasma thru series coiled tubes which would act motionless dynamo allowing production of steam or fluids.
US versions wish exploit X-ray/higher energy photovoltaic layers.
4th technique plus Field reverse configuration or FRC.
Series preheated plasma generators convert fuel to plasma beforehand, concentric rings magnets flux and spin the plasma and accelerate it towards center target, after achieving velocity of 300 km/s or 0.1% lightspeed collision generates fusion and responding magentic flux triggers conductor coils to make power, sub variant a neutral ion beam Slams preheated plasma and magnetic flux generated by fusion acts to hold its own plasma, the fusion "exhaust" is only permitted escape Single outlet, which heats a matrix liquid metals or/which can generate steam power.
5th design Stellerator German method thou invented in US.
The weirdest one often referred to Spaghetti or CrazyStraw. A preheated plasma is introduced in an irregular shaped vacuum chamber, as the plasma ribbon accelerates it achieves fusion when torque forces plasma ribbon to collapse on its own but fusion will cause an expansion. Which is countered by shape transition causing it to be compressed again.
With other methods in discussion
One called Z-pinch shear fluid. Dubbed crock pot fusion the system works by incorporating an extremely high electric current thru Deuterium/tritium to make a plasma beam, the beam travels thru a flowing matrix lithium-lead alloy.
The flowing matrix serves several things, 1: breed tritium for fuel requirements
2: acts as neutron/radiation shield
3: heated fluid acts as an exchange matrix to produce suitable heat exchange with another fluid as steam. A pump in liquid metal matrix allow flow to and back to feed steam turbine.
Zap Energy in Washington state, development of Z-Pinch shear fluid reactor. Unlike other reactors in fusion segment, Zap hopes to eliminate the most expensive parts associated with fusion.
- Superconducting magnets
- Cryogenic cooling
The reactor uses a Scintillator, similar to the old CRT television tube.
A massive electric pulse combined with a allotment of Deuterium/Tritium mix produces a heavy plasma beam 50 cm long and 1mm wide. To prevent immediate disruptions, different layers of plasma flow at variable speeds. This sheared axial flow naturally smooths out fast-rising instabilities, keeping the hot, dense plasma stable; as it's not required to fluctuate around a magnetic medium the plasma has one direction, DOWN and only down.
as Experiments with Beam diamater managment
A circulating blanket of liquid metal surrounds the reaction. This flowing wall of liquid metal (Lead-Lithium eutectic) surrounds cavity and contains the beam, also excites lithium to breed tritium fuel reaction and lead acts as a shield against neutron radiation.
Rather than maintaining a permanent reaction like other designs
the system runs on series of pulses, running at frequency of ten hertz. Thermal blanket of liquid metal meets a heat exchanger to produce conventional steam power.
Unlike conventional fusion, multi-million degree temperatures do not occur, There is no heavy duty magnetic confinement eliminating huge costs associated conventional plasma fusion. However one critique is that the volume of plasma inside the narrow pinch beam is relatively small relative to fusion machines such as magnetic mirrors, tokamaks, or other fusion devices. This caps the amount of fusion fuel, and subsequently, the amount of energy that can be made in a flowing pinch. Possible solutions include higher shot rates, multiple machines, and longer and wider pinch beams. So the reactor power is relatively light, potentiall solveable with larger more robust shot frequency. Other is the spot, or inducer producing the shot is vulnerable to melting/erosion so devices must be reinforced with stronger materials to survive.
Sounds promising to me, of course, as a combustion engine designer I like solutions which avoid overheating problems related to continuous combustion and prefer pulses .
A ''liquid wall'' which adsorbs the heat shock and radiation avoids all the troubles which surfaces have which are directly affected by all the radiation from the fusion.
Now I need to understand how the Scintillator produces a plasma. I guess, somehow it is being hit by a beam of electrons and starts to emit photons which produce the plasma?
Sounds promising to me, of course, as a combustion engine designer I like solutions which avoid overheating problems related to continuous combustion and prefer pulses .
A ''liquid wall'' which adsorbs the heat shock and radiation avoids all the troubles which surfaces have which are directly affected by all the radiation from the fusion.
Now I need to understand how the Scintillator produces a plasma. I guess, somehow it is being hit by a beam of electrons and starts to emit photons which produce the plasma?
Sounds promising to me, of course, as a combustion engine designer I like solutions which avoid overheating problems related to continuous combustion and prefer pulses .
A ''liquid wall'' which adsorbs the heat shock and radiation avoids all the troubles which surfaces have which are directly affected by all the radiation from the fusion.
Now I need to understand how the Scintillator produces a plasma. I guess, somehow it is being hit by a beam of electrons and starts to emit photons which produce the plasma?
Scintillator produces photons when struck radiation in reverse high energy photons can produce and energy. In this design the scintillator rapidly excites a discharge of tritium and deuterium gas.
It's the same technology in a plasma ball just over 50,000x more powerful and 10,000x briefer.
Pranos Fusion has unveiled Pragya, which is describes as India's first privately developed compact tokamak. The machine will test fusion technologies while helping build domestic capability in plasma science.
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