Physical Startup of the TWAC Storage Ring

C6+ ions with energy 200 MeV/nucleon have been accumulated in the chamber of the ring magnet of the U-10 proton synchrotron used as a storage ring in the TWAC setup. A C4+ ion beam from the laser source was first accelerated in the I-3 injector up to 1.3 MeV/nucleon and in the UK booster synchrotron up to final energy with periodicity 3.5 sec. Ions have been accumulated in U-10 using the multiple charge-exchange injection scheme C4+ → C6+. An increase in the ion intensity in the accumulator has been observed during several injection cycles. Experimental data on the attained parameters of the accumulated beam are presented, and the status of the optimization of the accumulation regime is discussed.