@article{7316,
  author = {M. Lennholm and T. Blackman and I.T. Chapman and L. G. Eriksson and J. P. Graves and D. F. Howell and M. de Baar and G. Calabro and R. Dumont and M. Graham and S. Jachmich and M. L. Mayoral and C. Sozzi and M. Stamp and M. Tsalas and P. de Vries},
  title = {Feedback control of the sawtooth period through real time control of the ion cyclotron resonance frequency},
  abstract = {Modification of the sawtooth period through ion cyclotron resonance frequency (ICRF) heating and current drive has been demonstrated in a number of experiments. The effect has been seen to depend critically on the location of the ICRF absorption region with respect to the q = 1 flux surface. Consequently, for ICRF to be a viable tool for sawtooth control, one must be able to control the ICRF absorption location in real time so as to follow variations in the location of the q = 1 surface. To achieve this, the JET ICRF system has been modified to allow the JET real time central controller to control the frequency of the ICRF generators. An algorithm for real time determination of the sawtooth period has been developed and a closed loop controller, which modifies the frequency of the ICRF generators to bring the measured sawtooth period to the desired reference value, has been implemented. This paper shows the first experimental demonstration of closed loop sawtooth period control by real time variation of the ICRF wave frequency.
},
  year = {2011},
  journal = {Nuclear Fusion},
  volume = {51},
  number = {7},
  pages = {073032},
  month = {Jul},
  isbn = {0029-5515},
  doi = {10.1088/0029-5515/51/7/073032},
  note = {ISI Document Delivery No.: 781LITimes Cited: 0Cited Reference Count: 33},
  language = {English},
}