Impurity-Seeded Power Exhaust

The power flux of energetic particles that is exhausted from diverted plasma and concentrated on a divertor target plate is substantial in present experiments and will be much more challenging even in future tokamaks such as ITER. Georgia Tech researcher’s suggested the injection of impurities such as Ne and Ar, which radiate copiously at plasma edge temperatures but are fully ionized at plasma core temperatures, for the purpose of converting some of the exhausting energy flux into radiative energy that would be distributed more uniformly over the chamber wall, thus reducing the concentrated flux to the divertor target plate. Calculations for ITER were encouraging, and experiments were performed on DIII-D, ASDEX-U and elsewhere confirming this concept, leading to the “radiative edge” and “radiative divertor” concepts that have been adopted for ITER.


Murakami, M., et al. “Physics of confinement improvement of plasmas with impurity injection in DIII-D.” Nuclear fusion 41.3 (2001): 317.


Mandrekas, J., et al. “Analysis of DIII‐D Radiative Edge Discharges.” Contributions to Plasma Physics 40.3‐4 (2000): 498-502.

“Physics of Confinement Improvement of Plasmas with Impurity Injection in DIII-D,” IAEA- CN77/EX5/1, 18th Murakami, G.L. Jackson, J. Mandrekas


“Transport Performance Simulations of Radiative Power Exhaust Solutions and a Reduced-Cost Option for ITER”, Fusion Technology, 34, 377 (1998); J. Mandrekas, W. M. Stacey and F. Kelly.


“Robustness of Radiative Mantle Plasma Power Exhaust Solutions for ITER”, Nucl. Fusion, 37, 1015 (1997); J. Mandrekas, W. M. Stacey and F. Kelly.


“Impurity-Seeded Radiative Power Exhaust Solutions for ITER”, Nucl. Fusion, 36, 917 (1996); J. Mandrekas, W. M. Stacey and F. Kelly.

“Power Balance in ITER Plasma and Divertor”, Contr. Plasma Phys., 36, 240 (1996); D. Post, B. Braams , J. Mandrekas, W. M. Stacey, N. Putvinskaya.

“Radiative Power Exhaust for ITER”, Contr. Plasma Phys., 36, 245 (1996); J. Mandrekas, W. M. Stacey and F. Kelly.

“Analysis of the Performance of the ITER Divertor and Analysis of the ITER Tokamak Edge Parameter Database”, 16th IAEA Fusion Energy Conf. (Montreal, 1996); many authors.


“An Impurity-Seeded Radiative Mantle for ITER”, Nucl. Fusion, 35, 843-852 (1995); W. M. Stacey and J.. Mandrekas.