After vacuum expert (Jonathan) has arrived, we did a vacuum leak check with helium. The system turns out to be leak tight. The RGA spectrum (Figure 1.) shows we have still some amount of water vapor inside the cavity. I connect back our turbo pump and continued pumping with it. Jonathan doesn't have the authority to change the gate valve VBV1P02 (Figure 2.)settings and replacing it would take longer time. Checked with MCC and 1P01 is ON. Vacuum is slowly improving. We may have to decide tomorrow if we can turn on the ion pumps (1P02A & 1P02B) or bake the system.