An operational regime for achieving high ion temperatures in the GAMMA10 central cell

An operational regime for achieving high ion temperatures in the GAMMA10 ce ntral cell has been experimentally investigated by analysing the correlatio n between ion temperatures and electron density profiles measured under var ious experimental conditions performed over the last 10 years. The analysis shows that broadened density profiles or excessive high ion temperatures ( or both) induce significant degradation of the stored energy. It has been f ound that the peaked density profile is a necessary condition to achieve hi gh ion temperatures and high stored energy. The analysis reveals the presen ce of the operational regime to achieve high ion temperature plasmas. The c hange of the magnetic field line shape in the central cell has successfully contributed to achieve a high ion temperature of about 10 keV at the plasm a centre due to the formation of the peaked density profile in the GAMMA10 central cell.