Studies of basic limitations on production, transport and acceleration of the high intensity polarized H⁻ beam in the RHIC polarized ion source

Basic limitations on the high-intensity polarized H⁻ ion beam production and transport were experimentally studied in charge-exchange collisions of the neutral atomic hydrogen beam in the Na-vaporjet ionizer cell. The energy dependence of space-charge effects on the beam instabilities and losses were studied and described in the model of synthetic H⁺ — H⁻ beam transport. A xenon gas admixture to the H⁻ ion production cell and beam transport line greatly improves the space-charge compensation, which is also successfully described in the simulations. These studies are the part of the polarized source upgrade project for RHIC.