Fusion research benefits from its wide variety of researchers and approaches. Not all of the ideas and concepts belong to EUROfusion. For several years it was mostly  private companies, even far beyond European borders that were trying to bring fusion energy to life. Fusion in Europe introduces different approaches in series and explains precisely what is concealed behind the catchy claim designed to attract the attention of investors.

1. Facts

Management Dr Dale A. Prouty (CEO)
Dr Michl W. Binderbauer (Chief Technology Officer)
Dr Toshiki Tajima (Chief Science Officer)
Funding Tri Alpha Energy (TAE) is the world‘s largest private fusion company backed by technology investors including New Enterprise Associates, Venrock (venture arm of the Rockefeller family), Wellcome Trust, Art Samberg, Buchanan Investments and others. It has raised nearly $500 million in capital to date.
Headquarters Foothill Ranch, California, United States of America
Established 1998

2. Idea

C-2U, the test device from Tri Alpha. Picture: Tri Alpha Energy

Tri Alpha Energy (TAE) wants to revolutionise the fuel of fusion reactions. The  company intends to burn a mixture of hydrogen and boron. This reaction is  aneutronic, producing three alpha particles, which is where Tri Alpha Energy gets its name. According to TAE, there is a virtually unlimited supply of boron, estimated at over 100,000 years supply obtained from terrestrial sources alone.

Burning the hydrogen-boron fuel requires temperatures of about 3 billion degrees Celsius. TAE uses a linear field-reversed configuration (FRC) in combination with an intense neutral beam injection to create a well-confined plasma. It relies on the build-up of a fast ion population within the FRC to sustain the very energetic plasma. The fusion energy comes in the form of energetic photons which can be converted to generate power. FRCs have been investigated since the 1960s but were unable to achieve long-lasting and stable plasmas. In August 2015, the company demonstrated sustained plasma performance for up to 11 milliseconds in its C-2U national lab-scale machine. Their next step is to scale up their experiments and install stronger beams to heat the plasma and demonstrate the performance at higher temperatures. TAE is currently constructing a new machine, called C-2W, and expects to demonstrate this next milestone within the next three years.

Roger Jaspers is Chairman of FuseNet, coordinator of the Fusion Master Programme at the Eindhoven University of Technology in The Netherlands and founder of the Fusion Academy. Picture: private

3. Opinion

The Tri Alpha concept looks attractive: the use of proton boron (p-B) as fuel produces no neutrons and it is a linear machine, so scaling up to reactor-size is relatively straightforward.  Also the recently reported breakthrough which confines plasma for about 10 ms, is very encouraging. But we must temper our expectations somewhat since the achieved temperature (~1 keV) and confinement time are still several orders away from the required values for net energy production. Moreover, one should realise that changing from deuterium-tritium (DT) fuel to p-B fuel will result in a reduction of fusion power by more than a factor 100 (due to the lower density for the same pressure, and the reduced fusion probability). So why not first demonstrate the concept for the D-T reaction? The final challenge is the need to maintain a high energy non-thermal ion  population in an energetically favourable way. With the large investment obtained recently, Tri Alpha now has the means to try to tackle these issues. I look forward to the results!