On 26/11/2018:

The accelerator and chamber setup were still operating after the overnight run.

Far S2 bias = -130V, leak I = 1.59uA. Diode bias = -70.1V, leak I = 0.00uA.

8:35 pressures (mBar):

• TPU1 = 8.6e-7
• TPU2 = 3.1e-7
• TPD1 = 6.1e-7
• TPD2 = 6.3e-7
• CHUP = Sensor Off
• CHDW = No Sensor

Checking for beam-induced background, moved target ladder to position # 2 - blank 10mm aperture

Run # 181126084821

• Run time: 1204s
• Pulser ON, as before
• Target: Blank 10mm
• Beam: 6.0MeV 7Be 2+

Using blank 10mm frame FCC = 6pA

Stopped run - CSSM magnet was switched on halfway through. This this the magnet located immediately downstream of the chamber and we were worried about it affecting the noise. Switched off CSSM magnet.

Run # 181126090936

• Run time: 1239s
• Pulser ON, as before
• Target: Blank 10mm
• Beam: 6.0MeV 7Be 2+
• DT ~ 8%

Moved ladder to position #5 - natC III

Run # 181126093314

• Run time: 1416s
• Pulser ON, as before
• Target: natC III
• Beam: 6.0MeV 7Be 2+
• DT ~ 8%

Moved ladder to position #2 - blank 10mm aperture. Closed far S2 iris and switched beam to 6.0MeV 7Li 2+.

Using 10mm aperture FCC = 360pA. Using 3mm aperture FCC = 300pA.

Moved ladder to position #4 - CH2 XVIII. Opened Far S2 iris.

Run # 181126105357

• Run time: 1383s
• Pulser ON, 25Hz
• Target: CH2 XVIII
• Beam: 6.0MeV 7Li 2+
• DT ~ 12%
• See attached picture 1 for sample Far S2 front strip. See attached picture 2 for diode spectrum.

Ready to replace Far S2 12um mylar with 0.9um mylar protective foil