Speaker
Jaroslav Cerovsky
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P2.1006.pdf
Simulation of trajectories of runaway electrons for support diagnostics
at the COMPASS tokamak
J. Cerovsky1,2 , O. Ficker1,2 , J. Mlynar1 , J. Urban1 , E. Macusova1 , V. Weinzettl1 , M. Farnik1,2 ,
J. Zebrowski3 , M. Jakubowski3 , M. Rabinski3 , M. J. Sadowski3 , R. Panek1 , M. Hron1
and the COMPASS team1
1 Institute of Plasma Physics of the CAS, Prague, Czech Republic
2 FNSPE, Czech Technical University in Prague, Prague, Czech Republic
3 National Centre for Nuclear Research (NCBJ), Otwock, Poland
The Cherenkov detector is one of the few runaway electron diagnostics, which do not rely on a
detection of secondary radiation caused by an impact of high energetic particles on the limiter or
the first wall of the tokamak. The capability of a direct observation of runaway electrons together
with a possibility of setting energy thresholds for incoming particles makes the Cherenkov
detector a useful diagnostics tool for an investigation of runaway electrons dynamics. In the
past years experiments focused on observation of runaway electrons by the Cherenkov-type
detector were performed at the COMPASS tokamak. One of features of the Cherenkov detector
is a measurement in the well defined location of the tokamak with high temporal resolution.
Due to safety reasons, the Cherenkov detector is placed in the shadow of the low field side
protection limiter in most discharges performed on the COMPASS tokamak. The open question
is whether runaway electrons can reach the detection head of the Cherenkov detector or are
preferably lost at the protection limiter. The aim of this work is a simulation of trajectories
of escaping runaway electrons and finding the location of their impact in order to determine
possible parameters of runaway electrons, which can be detected by the Cherenkov detector.
For these purposes, the pushers for tracking of relativistic particles were implemented in the
Python environment and particles are tracked in the reconstructed axisymmetric magnetic field
of the COMPASS tokamak (calculated by the EFIT code).
References
[1] Panek R. et al. 2016 Plas. Phys. Contr. Fusion 58 014015
[2] Mlynar J. et al. invited, this conference
