1. Spatially and temporally resolved measurements of runaway electrons in the
TEXTOR tokamak
Bad Breisig

2. Thanks to ILPP Universität Düsseldorf T. Toncian and O. Willi
Technical staff ILPP Düsseldorf
FZ- Jülich
K.H. Finken, M. Jakubowski, B. Schweer, Y. Xu
A. Hiller

3. Overview Introduction, experimental set-up Experimental results
Outlook

4. Runaway elektron
Accelerating force:
Drag force:
Runaway electron:

5. Runaway diagnostics The synchrotron radiation measurements
K.H. Finken et. al., Nucl. Fus. 31, 859 (1990).
Neutrons detector
O.N. Jarvis et.al., Controlled Fusion and Plasma Heating
(Proc. 15th Eur.Conf. Dubrovnik, 1988), Vol. 12B, Part I,
European Physical Society 334 (1988).
B. Esposito et. al., Phys. Plas. 10, 2350 (2003).
A new probe measurements

6. Synchrotron radiation
K.H. Finken et. al., Nucl. Fus. 31, 859 (1990).

7. New probe γ e- e- a = 46 cm e- e- γ e- a = 44 cm
Plasma boundary γ
53 cm e- e-
a = 46 cm e- e- γ e-
44 cm
a = 44 cm
Time resolution : 100ns
Spatial resolution: 20 mm

8. Experimental scheme

9. Probe scan data Measurements of runaway electrons at minor radial
positions between 53 cm and 44 cm of the probe.

10. Runaway electrons measurements in the TEXTOR vessel
Discharge ;
1-probe position,
2-probe signal, probe position at 44 cm;
Discharge ; probe signal,
probe position at 45 cm;
Discharge ,
neutron measurements;
the synchrotron signal measurements inside the plasma
between 1.4 m and 1.9 m major radius;

11. Spectrometer Spectrometer Time resolution : 100ns
Spatial resolution: 2 mm

12. Energy spectrum
Minimum electron energy registered by every crystal
Electron beam with Gauss distribution,
electron temperature 3MeV
Geant 4

13. Conclusion:
Runaway electrons were studied in the interior and exterior region
of the plasma.
Direct measurements of runaway electrons at the plasma
boundary was carried out.
Population of the runaway electrons exponentially increased up to the
plasma edge.
Good possibility to study plasma interaction with high Z materials and carbon
Outlook:
Construction of the new spectrometer to measure runaway electrons spectrum
between 3 and 30 MeV.
3D-simulations of the runaway electrons transport through the probe (Geant 4).
Cross calibration of the probe by means of the new Amplitude laser system.

14. Thank you!