Graham looked up the list of IOS bias assignments. None was form the emittance rig. I quickly tested the list in ILT, but nothing jumped out. Keerthi provided a battery setup, which I have now installed. Here are example scans, untouched, of forward and reverse bias. I leave it to you, dear reader, to figure out which is which.

18O4+ beam restored for the night. Take a scan and verify it's restored well. Nice.