Wednesday - November 16, 2022 THIS TALK WILL BE RECORDED BUT THE VIDEO WILL ONLY BE ACCESSIBLE TO PPPL STAFF

4:00pm-5:15pm EDT - PPPL AUDITORIUM AND VIA ZOOM

Hosted by Frank Hoffmann

Dr. Larry Baylor
Oak Ridge National Laboratory, Distinguished Staff Member & Group Leader, Blanket and Fuel Cycle

Pellet Injection Technology For Fusion Applications

The formation and acceleration of pellets of cryogenically solidified hydrogenisotopes and impurity gases has long been under development for fueling and more recently for transient event mitigation in fusion plasmas. In addition to hydrogenic pellets providing fueling, small pellets of deuterium can be injected from the outside wall for shallow penetration to purposely trigger rapid small edge localized modes (ELMs) to limit heat flux damage from otherwise naturally occurring large ELMs. A more recent application of pellet injection being developed for deployment on burning plasma devices is that of disruption mitigation where large pellets of neon, argon, and deuterium mixtures are produced and shattered upon injection into disrupting plasmas to radiate the plasma energy in order to mitigate possible damage to in-vessel components. Densification of the plasma by the shattered pellets has the added benefit of collisional damping of energetic runaway electron seeds.

The technology to form and accelerate these pellets has been developed to the point of being able to continuously fuel plasmas using steady-state extruders coupled to repeating gas guns. The first deployment of this technology for long pulse fueling is onW7-X in collaboration with PPPL, IPP, and NIFS. The further development with tritium compatibility is underway for ITER. Disruption mitigation technology is less well mature and is being further developed for use on ITER. We review the present state-of-the art in these technologies and point out the areas where further development and improvement is needed.

To join via Zoom: 
https://pppl.zoom.us/j/361549769?pwd=R0d5d0hFUjZJNnBhRGR0RkszOGM1UT09
Meeting ID: 361 549 769
Passcode: colloquium
(Note: Additional Zoom information can be found on the lab calendar. All participants microphones will be muted. During the talk, please send any questions/comments via private Zoom chat to the colloquium host)