The threshold electric field for runaway generation has been investigated during runaway suppression experiments by means of electron-cyclotron-resonance heating in the flattop phase of FTU discharges. Runaway suppression has been experimentally found to occur at electric fields substantially larger than those predicted by the relativistic collisional theory of runaway generation, ER=nee3lnΛ/4πε02mec2. These experimental results are consistent with an increase of the critical electric field due to the electron synchrotron radiation losses. No runaway electrons are found in FTU experiments below the radiation threshold. These results support evidence for a new threshold electric field for runaway generation that accounts for the effect of the synchrotron losses, and which should be considered when making predictions on runaway generation and mitigation in devices such as ITER. © 2010 The American Physical Society.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
Martín-Solís, J. R., Sánchez, R., & Esposito, B. (2010). Experimental observation of increased threshold electric field for runaway generation due to synchrotron radiation losses in the FTU tokamak. Physical Review Letters, 105(18), -. . https://doi.org/10.1103/PhysRevLett.105.185002