Taking advantage of this 3rd cavity, a first attempt to raise the current was performed on Sunday October 19. After a plateau at 300 mA, the current was first raised up to 350 mA and maintained at this level for one hour and a half, then raised up to 400 mA and kept at that value for a little over an hour.
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All parameters (pressures, temperatures, ..) were recorded and revealed nothing abnormal. The bunch by bunch feedback that removes the transverse beam instabilities has been working nicely and kept the coupling at the 1% level (ratio of the vertical emittance to the horizontal emittance). The RF provided without difficulty a power of 400 kW to the beam.
The table below shows the average pressure, coupling and lifetime for the 3 current values, in the filling mode used (312 filled bunches over 416), with an RF voltage of 3 MV.
| Current | Average pressure | Coupling | Lifetime |
| 300 mA | 1.1 10-9 mbar | 0.7 % | 13.4 h |
| 350 mA | 1.6 10-9 mbar | 0.8 % | 10.8 h |
| 400 mA | 2.3 10-9 mbar | 1.0 % | 8.7 h |
When raising the current up to 450 mA, a pressure increase developed at a flange in the medium straight section of cell 4 and prevented from going further.
New tests are now scheduled during the run of November to try and reach 500 mA. Once a stable operation will have been demonstrated at the equipment level of the machine, a radiation survey will be carried out around the storage ring tunnel to validate the shieldings for this new operating current.
