During the leak detection session of last friday, we identified a relatively small leak, with a rate of the order of E-5 mbar.l/s, at the pumping port at the 200m level along the FC pipe.

During yesterday afternoon and today morning, we isolated the FC cavity and replaced the faulty joint. The vacuum was then restored, and finally the joint was re-tested with helium.

Test result: passed, LR < 1E-8 mbar.l/s

Note: The SQZ vacuum system is now operating normally. The gate valves along the line are still closed and can be opened as needed .

Yesterday during the maintenance break we turned OFF the vacuum rack and the related vacuum equipment serving both SQB1 and SQB2, as another test to investigate about the irregularities in the pressure of SQB2 : the irregularities are still present. The rack is still OFF, and can be turned back on when convenient for ITF operations, requiring about half an hour to reach the steady state and one person present in the central building .

yesterday morning during the maintenance break we have restarted the vacuum equipment of SQB1 and SQB2 and get back the squeezing vacuum system to normal conditions. For what concern the vacuum side, we have completed the series of investigations about the reported fluctuations in the residual pressure: they do not seem caused by leaks, pumps, or other vacuum equipment, but appear as residual gas coming from SQB2 inner equipment, which is normally not a problem for the vacuum system. We will keep monitoring, see attached .