Making Our Fusion Reactor Better

Update, November 9, 2018: the video above highlights some of the upgrade projects. This video was shot at about the halfway point of the 11-month schedule for all engineering upgrades.


Our lab, the DIII-D National Fusion Facility, has ended its experimental campaign and entered into a nearly one year period of upgrade construction. This means there will not be any new data until some time in the middle of 2019. That 2019 data, however, is going to come from a variety of new experiments that were not even possible before the upgrades. Here are some of the projects that will scheduled for completion in the next eleven months (and wish us luck because we are the only major facility remaining in the United States):

  • A neutral particle beam, used to heat the plasma with 5 MW of power, is being retrofitted with a sliding rail that allows it to be aimed in different directions. The value of this aiming is that DIII-D will be able to produce plasma scenarios more similar to those expected for future reactors like ITER and DEMO.
  • The Electron Cyclotron Heating (ECH) system, which injects (so far) up to 4 MW of microwave power into the plasma, will be upgraded with a new injection path entering through the top of the reactor. All previous ECH injection, from all experimental facilities, has been done from the outer region of the machine. The benefit of this top-launch setup is that the power absorption is significantly improved. Basically, imagine taking about 1,000 kitchen microwaves and injecting them into the top of a fusion reactor with high efficiency.
  • A new type of wave injection, Helicon Waves, will be enabled by installing a helicon antenna on the outer wall. This wave injection is theoretically better at driving electrical current in the reactor compared to both ECH and neutral beams. This initial antenna is designed to provide 1 MW of input power.
  • Diagnostics: With something near 100 separate tasks to complete, I’m not going to list them all here. Researchers from around the world, but especially the United States (noting that earlier statement about DIII-D being the only domestic facility available), are bringing in some excellent ideas for new and improved plasma measurements that will take advantage of all the new plasma performance scenarios available next year.

Week one just ended, and this was the first time I’ve ever seen someone using a power saw to cut plumbing lines out of the machine hall.

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