skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Experimental observation of increased threshold electric field for runaway generation due to synchrotron radiation losses in the FTU tokamak

Journal Article · · Physical Review Letters
 [1];  [2];  [3]
  1. Universidad Carlos III, Madrid, Spain
  2. ORNL
  3. ENEA, Frascati

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, E{sub R} = n{sub e}e{sup 3}ln{Lambda}/4{pi}{var_epsilon}{sub 0}{sup 2}m{sub e}c{sup 2}. 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.

Research Organization:
Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
Sponsoring Organization:
USDOE Laboratory Directed Research and Development (LDRD) Program
DOE Contract Number:
DE-AC05-00OR22725
OSTI ID:
991692
Journal Information:
Physical Review Letters, Vol. 105, Issue 18; ISSN 0031-9007
Country of Publication:
United States
Language:
English