In GF's newsletter today:
In the months since the beginning of 2017, General Fusion has made impressive progress. We are now well positioned to move forward with the design, construction, and operation of an integrated “proof of concept” prototype fusion machine. This machine is intended to take our technology readiness to the maturity level necessary to prepare for full commercialization and a demonstration fusion power plant. Initial design of this prototype machine is now underway and we are planning a development program which will lead to construction and operation in the next several years.
In other words, they are starting the design for their proof of concept prototype machine plus plan of experiments (I presume the experiment development plan is necessary for funding). Building the machine will take some time especially for forging the 3 meter chamber and fabrication of the likely 200 pistons.
The question is when will the order be placed for the big ticket long lead forging and what will the plasma goal be (what temperature in their chemical compression, C-4 detonation - or whatever used, experiments)?
Their conservative time of several years is consistent with what I said, and reflects some tough technical problems with plasma contamination during compression during shock compression in the lead sphere. Their trick for solving this projected problem has been to squirt lithium into the pocket that the plasma is to be injected into, or at least that was one idea. They are innovative, so there are likely more ideas being bounced around.
I expect that funding will move ahead with the assumption that their current plasma development will prove successful. Perhaps they feel TriAlpha is breathing down their neck?
Near term, cheap, dark horse fusion hits the air waves, GF - TED, LM - Announcement. The race is on.