Date: 07/04/2018

We changed to cathod 23 - 7Be

For beam tuning we:

• Closed downstream iris (actuator = 82.5mm)
• Closed central iris (actuator = 85.5mm)
• Set target ladder to position I (95.010mm) - 3mm collimator

We found the cathode wheel could no longer be turned remotely, instead Lucio rotated the wheel by hand to cathode 23. We had low beam current at the cathode.

Lucio called Raffaele to confirm the cathode number used yesterday (eLog entry #33)

• Cathode 23 is new -> still has copper on front of cathode which is removed during cesium sputtering -> process takes 2-3 hours
• Instead we moved to cathode 19 - 7Be. Thiis is the cathode used for 7Be yesterday

We decided that when noting faraday cup currents we should also record the offset as well. Previously I was recording the measured minus offset value.

After tuning, and setting the CSSM magnet to 918.3 mT:

• FC - 4 = 410 - 260 = 150 pA (drifted from 450 - 260 = 190 pA)
• FC - 0 = 92 - 0 = 92 pA (drifted from 107 - 0 = 107 pA)
• FC - E1 = 50 - 5 = 45 pA

We felt ready to start a measurement with 7Be