1. MHD Induced Fast Ion Loss Diagnostic for Alcator C-Mod
M. García-Muñoz, J. A. Snipes*
MPI für Plasmaphysik, EURATOM Association, Garching bei München, Germany
*MIT Plasma Science and Fusion Center, Cambridge, MA USA
Fast ion
3D-Collimator
Scintillator housing
plasma
fast ions
The strike points of the ions on the scintillator plate depend on their gyroradius and pitch angle (magnetic spectrometer)
The ion loss pattern is imaged by a double system:
- A CCD-camera (slow 25 Hz, but high spatial resolution 756x290 pixels)
- A set of PMTs with 1 MHz overall bandwidth
Manuel García-Muñoz, Alcator C-Mod Ideas Forum, MIT PSFC, Cambridge, MA – 15 December 2006
Manuel García-Muñoz

2. Time resolved energy and pitch angle in ASDEX-Upgrade
CCD image
Energy range
Deuterium ions from
E=60 keV ( ~ 25 mm)
up to E=800 keV
( ~ 110 mm)
Hydrogen ions from
E=100 keV ( ~ 25 mm)
up to E > 1 MeV
PMT signal
(2 MHz sampling rate)
Manuel García-Muñoz, Alcator C-Mod Ideas Forum, MIT PSFC, Cambridge, MA – 15 December 2006
Manuel García-Muñoz

3. Time Resolved TAE Induced Fast Ion Losses
Magnetics Spectrogram
Fast Ion Loss Spectrogram
Attempt to quantify the fast ion loss due to TAEs with high time resolution
Modeling is required to extrapolate detected signal to a total fast ion loss
Manuel García-Muñoz, Alcator C-Mod Ideas Forum, MIT PSFC, Cambridge, MA – 15 December 2006
Manuel García-Muñoz

4. MHD Induced Fast Ion Loss Diagnostic for Alcator C-Mod
Motivation: To gain physics understanding of MHD induced fast ion losses. Exploit capabilities of TAE antennas. Can we get a direct relationship between TAE magnetic amplitude and the subsequent fast ion loss? Fast ion losses due to NTMs? ELMs? Multi-machine experiments between AUG, JET, and C-Mod. Scaling towards a quantitative prediction of the expected fast ion losses due to these modes in ITER through a comparison of experiment and modeling.
Goals: Develop and install of a new fast ion loss diagnostic for C-Mod with a bandwidth of 2 MHz.
Direct correlation between magnetic perturbation amplitudes and the subsequent fast ion loss
Plan of execution:
Design of the Fast Ion Loss Diagnostic for C-Mod with 1 MHz response
Installation of detector during next shut down
Apply the existing codes (HAGIS, GOURDON, ORBIT) to compute fast ion trajectories in C-Mode plasmas with MHD activities
Model the results with NOVA-K and compare to ITER modeling
Manuel García-Muñoz, Alcator C-Mod Ideas Forum, MIT PSFC, Cambridge, MA – 15 December 2006
Manuel García-Muñoz