Subscribe options

Select your newsletters:


Please enter your email address:

@

News & Media

Latest ITER Newsline

  • Cryoplant | Filled from floor to ceiling

    The ITER cryoplant used to be a vast echoey chamber with 5,400 m² of interior space divided into two areas; now, it is filled from floor to ceiling with industr [...]

    Read more

  • Cryostat | Adjusting, welding, testing ...

    The assembly of the ITER cryostat—the stainless steel "thermos" that insulates the ultra-cold superconducting magnets from the environment—is progress [...]

    Read more

  • Tokamak Building | Full steam ahead

    In this central arena of the construction site, construction teams are active three shifts a day—two full work shifts and a third, at night, dedicated to moving [...]

    Read more

  • Poloidal field coils | Turning tables and hot resin

    One of only two manufacturing facilities located on the ITER site, the Poloidal Field Coils Winding Facility was constructed by Europe to house the winding, imp [...]

    Read more

  • Assembly Hall | One giant standing

    Two identical handling tools in the Assembly Hall will play a critical role in preparing ITER's nine vacuum vessel sectors for their final journey: transport by [...]

    Read more

Of Interest

See archived entries

Controlling ITER with fuellers, ticklers, and terminators

Leo Williams, Oak Ridge National Laboratory

The inside of a pellet selector, which directs pellets to different outputs in a fusion reactor. Photo: ORNL (Click to view larger version...)
The inside of a pellet selector, which directs pellets to different outputs in a fusion reactor. Photo: ORNL
When it's up and running, the ITER fusion reactor will be very big and very hot, with more than 800 m³ of hydrogen plasma reaching 170 million °C. The systems that fuel and control it, on the other hand, will be small and very cold.
 
Pellets of frozen gas will be shot into the plasma—some to keep it fuelled, some to manage plasma activity, and some to extinguish the plasma as needed.
 
The idea of using frozen pellets to fuel a magnetic fusion reactor is not new. Researchers with the Fusion Materials and Nuclear Systems Division at Oak Ridge National Lab (ORNL) have been working on the technology for 35 years. Their handiwork helps run fusion experiments across the world, including America's largest fusion reactor, the DIII-D tokamak operated by General Atomics in San Diego, California.
 
Their expertise also made them the right choice to take on the much more challenging job of controlling ITER, which is more than eight times larger than the largest fusion reactor now in existence.
 
"The pellets are much more efficient at fuelling the fusion plasma because they can penetrate fairly deep into the hot plasma before being ablated and ionized into additional plasma," explained Larry Baylor of ORNL's Plasma Technology and Applications Group.
 
"The alternative method of injecting gas that is primarily used in today's smaller devices will not add fuel efficiently in ITER because of its large size and high magnetic field."
 
Baylor said his group is working on three types of pellet, which he refers to as fuellers, ticklers, and terminators.
 
Continue reading the article on the ORNL website.


return to the latest published articles