Speaker
Daniele Carnevale
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/I3.113.pdf
Runaway Electron Beam Control
D. Carnevale1 for the FTU team2 , the EUROfusion MST1 team3 and JET Contributors4
1 Dip. di Ing. Civile ed Informatica, Università di Roma Tor Vergata, Italy
2
See the author list of “ G. Pucella et al., Proc. 25th IAEA FEC 2014”
3 See the author list of “Meyer et al. 2017, Nucl. Fusion 57 102014”
4 See the author list of “ X. Litaudon et al 2017 Nucl. Fusion 57 102001”
Post-disruption runaway electrons (RE) beam mitigation is one of the main concerns for ITER
operations. RE beam control algorithms (Tore-Supra [1], DIII-D [2], FTU [3] and TCV [4])
for stabilization and current reduction can be combined with SPI/MGI and provide redundancy
and backup in case of SPI/MGI failure. DINA simulations have shown that RE beam control
could be effective for Current Quenches (CQ) below 4 MA in ITER. In the first part of the
work the RE Control (REC) architecture to stabilize the RE beam position and ramp down its
current is presented and experimental results on FTU and TCV are discussed. REC effective-
ness is demonstrated by analyzing Hard X-ray (HXR) monitors and the Runaway Electrons
Imaging and Spectroscopy (REIS) system. An estimation technique to retrieve the RE energy
distribution function from REIS is proposed. RE beam instabilities and their correlation with
toroidal electric field and density are discussed. Further, experimental results will be presented
from FTU on deuterium pellet and heavy particle injection into steady-state flat-top discharges
with runaway electrons and on RE beams. Analyzed data from the fast scanning CO2 -CO in-
terferometer and spectroscopy diagnostics are also reported to help understanding the particle
interaction with the RE beam to possibly extrapolate information for ITER predictions. Finally,
the REC installation at JET to improve the RE beam stabilization will be introduced.
Acknowledgement: This work has been carried out within the framework of the EUROfusion Con-
sortium and has received funding from the Euratom research and training programme 2014-2018 under
grant agreement No 633053. The views and opinions expressed herein do not necessarily reflect those of
the European Commission.
References
[1] Saint-Laurent F. et al., Proc. 38th EPS Conf. Plasma Physics O3 118, 2011
[2] Hollmann E. M. et al., NF 53 083004, 2013
[3] Esposito B. et al, PPCF, ISSN: 0741-3335, Vol 59, 2016
[4] Carnevale D. et al., 44th EPS, P 1.152, 2017
