Ondřej Ficker
6/7/17, 9:15 AM
Oral
The contribution will summarise the three main topics recetly investigated within the COMPASS RE campaigns: MHD related losses of RE, MGI injection with RE beam generation in the ramp-up phase and slow gas puff injection into low density plasma. Details on the recent progress in diagnostics will be also presented.
Eva Macúšová
6/7/17, 9:50 AM
Oral
This contribution will focus on the description of runaway electrons during the flattop phase in COMPASS discharges.
Mr
Mathias Hoppe
(Chalmers University of Technology)
6/7/17, 10:40 AM
Oral
Runaway electrons in tokamaks will emit synchrotron radiation due to their gyration around magnetic field lines. Because of the strong forward beaming of the radiation, the observed synchrotron images and spectra depends on both the energy, pitch angle and radial distribution of electrons, making synchrotron radiation a strong candidate for indirectly measuring the runaway electron...
Mr
Alex Tinguely
(MIT)
6/7/17, 11:20 AM
Oral
Alcator C-Mod's high magnetic field allows runaway electron synchrotron emission to be observed in the visible wavelength range. Visible spectrometers were used to measure synchrotron spectra at three magnetic fields: 2.7, 5.4, and 7.8 T. Assuming fixed energy and pitch, the spectral shape is expected to shift toward shorter wavelengths with increasing magnetic field. However, the similarities...
Dr
Emmanuel Joffrin
(CEA Cadarache)
6/7/17, 2:00 PM
Oral
Generation of run-aways electron (RE) beams is one of the major risks for the successful exploitation of ITER. In the past 15 years JET has been exploring the physics of run-away creation and the dynamics of the beam with different wall materials, namely carbon and Berylium/Tungsten mix (ITER-like wall). Recently, it has been observed experimentally that a full-blown run-away beam cannot be...
Mr
Cristian Sommariva
(CEA-Cadaracher/IRFM)
6/8/17, 9:15 AM
Oral
During a tokamak disruption, a large electric field is formed which can lead to the generation of a runaway electron (RE) beam. In large machines, runaway beams are sufficiently intense and energetic to represent a serious threat for operations. Therefore, the comprehension of the physics of RE and of their mitigation is of fundamental importance for future operations. Up to now, most RE...
Mr
Konsta Sarkimaki
(Aalto University)
6/8/17, 9:55 AM
Oral
Mr
Ola Embréus
(Chalmers University of Technology)
6/8/17, 10:50 AM
Oral
Full kinetic modeling of runaway dynamics is remarkably expensive computationally due to the range in scales involved, requiring simultaneous resolution of both the near-isotropic thermal electron population in the eV energy scale, as well as the strongly anisotropic runaways in the tens-of-MeV range. Because of this, a fluid description of runaway dynamics is highly desirable, where runaway...
Mr
Santosh Pandya
(Institute for Plasma Research)
6/8/17, 1:30 PM
Oral
There are very few methods that have the capability to provide energy-resolved measurements of Runaway Electrons. Hard X-Ray Monitor (HXRM) allows an estimation of the maximum runaway electron energy and the energy distribution function inferred from energy-resolved measurements. Implementation of HXRM system has been relatively easy on other worldwide Tokamaks. However, at ITER this will be...
