Next Big Future by brian wang | April 3, 2017
General Fusion has revealed that one of the most critical and complex areas of its research and development – plasma injector technology – has now reached the minimum performance levels required for a larger scale, integrated prototype.
First plasmas had been expected for the PI3 (Plasma Injector 3) in late 2016. There seems to have been some unsurprising slippage in the PI3 start of testing.
General Fusion presented its most recent plasma injector results at the American Physical Society’s Division of Plasma Physics annual meeting in November, 2016, demonstrating plasma that now lasts long enough to be compressed using the company’s system. The results were produced on the company’s 40cm diameter experimental scale SPECTOR plasma injectors, and the technology is now being developed into a new large-scale injector, matching the size required for integration with General Fusion’s compression technology.
General Fusion’s proprietary fusion system is designed to use compression to heat a magnetized plasma of superheated hydrogen gas to temperatures above 150 million degrees Celsius. The company’s program is now advancing to the next stage – developing and integrating plasma injector, compression chamber and pistons in the design of a larger scale prototype.
Previously General Fusion had the timeline of
• Plan to demonstrate proof of physics DD equivalent “net gain” in 2013
• Plan to demonstrate the first fusion system capable of “net gain” 3 years after proof
• Validated by leading experts in fusion and industrial engineering
• Industrial and institutional partners
Getting the PI3 and other scaled up components into a net gain prototype looks like something that General Fusion would be reasonably expected to achieve by 2025.
There was a first commercial fusion proposal for increased investment in Canada It is the Fusion for 2030 roadmap for Canada.
The General Fusion magnetized target fusion approach is the bottom of the following chart.
It should be noted that engineering the demo (like the multi-billion dollar international tokamak project is not making a first commercial scale first of a kind reactor. Demo would be at commercial scale but would not have the economics or capability to operate commercially. The ITER plan would have decades of further work to get to commercial fusion reactors.
About once every 6 months, Nextbigfuture looks at the prospects for commercial nuclear fusion.
General Fusion has decent funding of about $100 million (major backing from the governments of Canada and Malaysia and Jeff Bezos).
The small projects with a technical chance of success are
LPP Fusion (dense plasma focus) is critically underfunded but is making shoe string efforts to move their demonstration forward. This year they are advancing their Tungsten anode tests and even their Berrylium tests.
Helion Energy has working prototypes and are trying to build a breakeven machine.
Tri-alpha energy is the best funded of the nuclear fusion startups with about $500 million.
There have not been reports of major progress from Helion Energy and Tri-alpha Energy.
Combined there currently seems to be a somewhat less than 10% chance of truly engineering commercial nuclear reactors before 2030.
Some are more technically promising in that they would seem to be able to rapidly scale to higher energy returns (more energy out than in) but most are very poorly funded. Funding problems cause delays and do not leave the resources to quickly overcome development adversity.
The physics and technical challenges have continued to prove to be very difficult. It is good that there are many different approaches.
Ongoing advances in critical technologies will make the problem of commercial nuclear fusion more solvable over time.
Better superconductors help. We are now getting to relatively common superconductors in the 10 to 30 tesla ranges. Getting to 100+ tesla would be extremely useful for various nuclear fusion designs.
Rapid fire (once a minute or better) exawatt lasers would be another path to commercial nuclear fusion.
Ultra advanced rapid fire exawatt lasers and super powerful superconductors could be the capabilities that overpower the technical and other challenges to nuclear fusion. This could make commercial nuclear fusion highly solvable by 2040.
Before 2030, Nextbigfuture would give the first breakthrough commercial molten salt nuclear reactors as a 80%+ probability. China and other companies will also probably have next generation breeder reactors, pebble bed reactors and supercritical water reactors by 2030 or 2035.
Japan recently fired a 2 petawatt laser and believe this could be a pathway to commercial nuclear fusion.
Ultrapowerful lasers have been increasing in power by 1000 times every ten years for the past forty years.
Current technology is sufficient for the ten petawatt lasers.
The formulation for the glasses needed for exawatt lasers is known but there is currently no vendor.
Liquid cooling can enable one shot per minute or better. There are other laser types that have lower power but very high repetition rates. One of many goals is to increase the power and increase the repetition rate.
30 Petawatts once per second with 30kJ of energy should be enough for proton boron fuel commercial fusion
The researchers at the Japan LFEX 2 petawatt laser calculated that 30PW picosecond laser pulses with 30kJ energy irradiating a solid cylinder of HB11 fuel of centimeter length and millimeter radius in a 10 kilotesla magnetic field may produce more than 280kWh electric energy (worth about $28). The calculation assumed a spherical reactor of more than 1 meter radius around a central reaction unit that is charged to −1.4 million volts. This voltage stops the generated alpha particles and converts their kinetic energy into electric energy. A very small fraction of this energy is needed to drive the lasers, and we further estimated costs of about $18 per shot associated with replacing the HB11 fuel and the reaction unit (which is destroyed each time) and recharging it. At a rate of one reaction per second, the generated electricity would produce a net income of over $300 million/year.
