Paper Details

Compact tokamak systems provide a cost-effective
platform for investigating magnetic confinement principles,
plasma initiation mechanisms, and educational research in fusion
technology. The performance of such systems is largely governed
by the design and implementation of magnetic field coils respon-
sible for plasma current induction and confinement. This paper
presents the analytical design, fabrication, electromagnetic anal-
ysis, and experimental validation of a magnetic field coil system
developed for a compact table-top tokamak. The proposed system
comprises a central solenoid coil for plasma current induction
and a toroidal field coil assembly for magnetic confinement.
The design methodology is based on tokamak physics require-
ments and electromagnetic design principles, including plasma
current, toroidal magnetic field strength, safety factor, and geo-
metric constraints. Coil parameters such as the number of turns,
conductor dimensions, inductance, resistance, stored magnetic
energy, and current-carrying capability were determined through
analytical calculations. A capacitor-discharge pulsed power sup-
ply incorporating a Cockcroft-Walton voltage multiplier and
SCR-based switching circuit was developed to generate the high-
current pulses required for coil excitation.
The fabricated coils were characterized experimentally and
compared with analytical and numerical predictions. The central
solenoid coil generated a peak magnetic field of approximately
1.4 T, while the toroidal field coil assembly produced the magnetic
field distribution required for compact tokamak operation. The
voltage multiplier successfully generated an output voltage of
approximately 1.3 kV, and the central solenoid coil achieved a
peak discharge current of 88 A during pulsed operation. Finite-
element electromagnetic analysis further validated the magnetic
field distribution and coil performance.
The close agreement among analytical calculations, electro-
magnetic simulations, and experimental measurements confirms
the effectiveness of the proposed design methodology. The devel-
oped magnetic field system provides a practical and economical
platform for laboratory-scale tokamak experiments and educa-
tional research in magnetic confinement fusion.

JAYRAJSINH B SOLANKI, “Design, Fabrication, and Experimental Validation of Magnetic Field Coils for a Compact Table-Top Tokamak System”, International Journal of Advance Engineering and Research Development (IJAERD), Vol. 8, Issue 10, pp. 28-37, October 2021.