Upgrading the SMOLA Helical Open Trap for Experiments in the Low Coulomb Collisionality Regime

The SMOLA facility was built at the Institute of Nuclear Physics, Siberian Branch of the Russian Academy of Sciences (INP SB RAS) to experimentally test the concept of helical confinement. This method is a development of the multiple‑bounce confinement scheme. A stream of rotating plasma flows out of the open trap through a magnetic field with helical symmetry that is periodically modulated along the field line. Confinement efficiency depends strongly on the ratio of the ion mean free path to the period of the magnetic‑field modulation. Experiments on the SMOLA facility confirmed improved plasma confinement both in the regime dominated by Coulomb collisions and at reduced collision frequency. Simulation of plasma flow regimes for next‑generation facilities requires a further reduction of the dimensionless Coulomb collisionality. For this purpose a SMOLA* installation is being constructed at INP SB RAS. The paper discusses the new magnetic configuration with mirror‑symmetric helical end‑plugs, an auxiliary ion‑cyclotron resonance (ICR) heating system, methods for generating plasma rotation, and features of the diagnostic suite.