Gateway for:

Member Countries

Start-up Problems of Spherical Tokomak


Start-up, Neutron Fueling and Material Problems of a Spherical Tokomak reactor

Tech Area / Field

  • FIR-REA/Reactor Concept/Fission Reactors

3 Approved without Funding

Registration date

Leading Institute
TRINITI, Russia, Moscow reg., Troitsk

Supporting institutes

  • NIIEFA Efremov, Russia, St Petersburg

Project summary

The low aspect ratio or spherical tokamak (ST) offers the prospect of burning plasmas in a compact simple system at a lower cost than in conventional tokamaks.

Spherical tokamak experiments and theoretical studies have shown a number of advantages over the conventional tokamaks. Plasma in ST is observed to be resilient to current terminating disruptions, have good vertical stability and the potential for natural pertor operation. Calculations show the potential for high beta even without a conducting wall for added stability, large fraction of the current can be driven by the plasma pressure which together with present current drives schemes may lead to steady state operation without cryogenic superconductors. For a given edge safety factor q, the vacuum toroidal field can be an order of magnitude smaller than in a conventional tokamak for the same plasma current due to the small aspect ratio and natural high elongation.

The very exciting experimental results and power plant preliminary consideration indicate that this approach may offer a low cost way to fusion power.

The goal of the given work is the creation of the conceptual project of a fusion reactor based on the ST approach. It is assumed to carry out complex theoretical investigations of all aspects of ST fusion reactor and also experimental investigations of breakdown scenarios, current ramp-up and maintenance in the spherical tokamak GLOBUS-M.

The following works will be carried out:

a) Analysis of physical parameters, formulation of the main requirements and selection of the variants for realization of the energy d-t ST reactor. Analysis of the energy balance of the reactor.
b) Conceptual project design of the main systems of ST. Analysis and preliminary selection of the materials.
c) Scenario analysis of breakdown, current ramp up and flattop sustain. Analysis of ignition scenarios attainment.
d) Physical processes analysis of transition into burning stage (confinement of energetic alpha particles, plasma ions and electrons; plasma equilibrium and stability at high beta).
e) ST reactor neutronics.
f) Reactor fuelling cycle.
g) Critical elements of the reactor (first wall, pertor, central core, elements inside vacuum vessel, blanket etc.)

This project is opened for participants. Any scientists from America, Europe and Japan are invited for collaboration.


The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.


ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.

Promotional Material

Значимы проект

See ISTC's new Promotional video view