Speaker
Valeriia Istokskaia
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.1034.pdf
Tokamak GOLEM for fusion education - chapter 9
V. Istokskaia1 , M. Shkut1 , J. Cerovsky1 , M. Farnik1 , B. Leitl1 , L. Hudec1 , P. Macha1 ,
V. Svoboda1 , J. Stockel1,2 , J. Adamek2
1 Faculty of Nuclear Sciences and Physical Engineering CTU in Prague, Prague, Czech Rep.
2 Institute of Plasma Physics AS CR, Prague, Czech rep.
The GOLEM tokamak (R = 0.4 m, a = 0.085 m, Btor < 0.5 T, Ipl < 8 kA) is the oldest tokamak
in the world still operational. Its main mission is education of future fusion specialists in the
Czech Republic. Furthermore, the GOLEM tokamak serves also as a training facility of students
throughout the world, because of its unique fully remote control system [1]. This contribution is
devoted to description of several students0 projects, related mainly to diagnostics development,
investigation of selected issues of tokamak physics and plasma performance on GOLEM:
• Design of new amplifiers for two linear AXUV arrays of 20 photodiodes. This detection sys-
tem will be implemented to a pinhole camera and integrated to the GOLEM diagnostics sys-
tem. By using tomography methods, the temporal evolution of the plasma radiation and the
plasma position in the poloidal cross section will be determined.
• A research on runaway electrons (RE) physics is focused on generation mechanisms of RE,
detection of HXR radiation and investigation of RE losses. Furthermore, some selected fea-
tures of runaway discharges are investigated. In particular, the combined probe head composed
of the Ball Pen and Langmuir probe [2] is exploited to measure the radial profiles of plasma
potential and the electron temperature during the Anomalous Doppler Instability.
• Investigation of plasma radiation by using spectroscopy methods and applying the coronal-
radiative model. Ratio of helium and hydrogen spectral lines are used to determine the electron
temperature. Results are compared with other methods of Te measurements on GOLEM.
• Improvement of plasma performance. A table-top experiment modelling power supplies cir-
cuits of the GOLEM tokamak is designed to test the plasma current control without interfering
tokamak operation. It is shown that by adding precisely selected resistors to the primary cir-
cuit, a flat-top phase of plasma current can be achieved. Furthermore, a guideline for discharge
scenarios for different values of electron density is now being created.
References
[1] V. Svoboda, et al., Fus. Eng. and Des. 68, 1310-1314 (2011)
[2] J. Adamek, et al., Rev. Sci. Instr. 87, 043510 (2016)
