Overview of GOL-NB experiments in 2025
Vladimir V. Postupaev, Vldimir V. Batkin, Aleksandr V. Burdakov, Rinat G. Gorokhovsky, Ivan A. Ivanov, Peter V. Kalinin, Konstantin N. Kuklin, Konstantin I. Mekler, Nikita A. Melnikov, Aleksey V. Nikishin, Sergey V. Polosatkin, Andrey F. Rovenskikh, Evgeni Sidorov, Dmitry Ivanovich Skovorodin, Evgeny N. SkuratovAn overview of new experimental results obtained at the GOL-NB multiple-mirror trap over the past two years is presented. The main scientific objectives of GOL-NB are the direct demonstration of the multiple-mirror confinement efficiency with hydrogen plasma. The device has a configuration that simulates, at reduced plasma parameters, the configuration of a reactor-class facility with a central gas dynamic trap and sections with a strong magnetic field attached to it, which can be turned on both as long solenoids or as multiple mirrors. Plasma is heated by 1 MW neutral beam injection. The following elements are discussed in the paper: magnetohydrodynamic (MHD) stability, plasma parameters in the central trap, neutral beam trapping and fast ion spectrum, comparison of the multiple-mirror and solenoidal configurations at high collisionality, and measures for the reduction in neutral density. The main goals of the experiments were plasma properties characterisation in the central trap and studies of plasma flow in the strong-field sections. We also introduce two new systems for additional plasma heating, a low-energy electron beam mounted at the exit plasma receiver and a 13.56 MHz ICRH system, which is under tests at several kilowatts of input power.