A concept of volumetric neutron source (VNS) based on tokamak foresees its high availability, therefore the most simple and reliable technical solutions are required for design of the facility, its systems and units. Electromagnet system with "warm" multiturn coils satisfies these requirements. In this case the power consumption decrease for such system is one of the main purposes of design development.

The VNS magnet system design is associated in many respects with the maximum level of coil material irradiation, which depends on inner radiation shield thickness. The ceramic electric insulation is required for the coils if the shield thickness is less than 0.2 m.

The VNS toroidal field (TF) system is operated in steady-state mode under high thermal and electromagnetic loads. The coil mechanical stresses obtain 200-300 MPa, and maximum coil turn temperature is 90-120 C. The copper alloy of Cu-Cr-Zr type is used as a coil conductor material.

The TF system design is presented, the ways of its optimization are considered, the electromagnetic-, heat- and stress-analysis results are given in the report. The TF system circuit-diagram is optimized to decrease a voltage between the adjacent turns.

The general tokamak arrangement and the requirements of simple VNS de-moutability need electric joints in the TF coil design. The problems and design of turn electric joints are considered.

The coil water cooling system is described, the water irradiation problem are discussed.