Ibrahim, Oli, Betsy

Context:

The first article BBSS was built late 2023 and TFs taken for the first time 01/05/2024. These can be found in alog 75787 among other places in the X1 logbook. Transfer functions largely agreed with the dynamical model with a few changes outlined in alog 76381.

Last few months:

Following RAL's most recent trip, we have rebuilt the BBSS with the following major changes:

• wire loop frequency and length changed from 1.717m, 87.20hz to 1.709m, 88.0hz. There was also some kinking in the wires around the prism following the secondary prism height determination experiment.
• Blade height changed to 24mm to fix pitch hysteresis
• Glued on primary prism vs. metal one
• Minor planned modifications to tablecloth and OSEM brackets/cams
• Percieveable roll on M3 that we have not fixed.

The Present:

As of 07/03, M1 OSEMs have been reconnected, centered and the second round of TFs taken on 07/03 (attachment 1). In comparison with 01/05 results (attachment 2), they seem extremeley noisy. Diagnostics in the following alog.