We first measured the distance of the ESD from the disk in the test chamber (CR0). We had to remove the retaining ring to have reliable measurements

• distance between top of the ESD and mounting plate: 12.30 mm
• distance between top of the disk and mounting plate: 10.53 mm
• ESD thickness: 0.55 mm

So initially the distance between disk and ESD is 1.22 mm

We re-aligned the optical setup to a horizontal reference, and moved down the ESD as much as we could. It's not completely clear if the ESD is touching the disk. We'll see after pump down. The new distance from the top of the ESD to the mounting plate is about 11.80 mm, so we should have moved the ESD 0.5mm closer to the disk.

Pump down started at ~1:30pm

Excitations

• Old configuration, 1.2mm distance ESD-disk:
  • GPS before exc. 1186417492 
  • GPS after exc. 1186417546
• New configuration, 0.7mm distance ESD-disk
  • GPS before exc. 
  • GPS after exc.