Alexa, Evan

We want to perform some ringdown measurements of the arms (particularly the Y arm) in order to corroborate our other loss measurements. We intend to use the technique described by Isogai et al., which has already been carried out at LLO (see, e.g., LLO#13748, LLO#11727).

In preparation, we've done the following work:

• We have placed a PDA255 on ISCT6, in front of ASAIR_B (since it is currently unused). The dc bandwidth of ASAIR_B is supposed to be 100 kHz, which is fine for observing the power decay (which probably has a ~2 ms time constant), but may not be fine for observing the initial power spike.
• In front of the PDA255 there is a 28 mm lens in order to provide a smaller spot size for the PD.
• Cyrus has paired the LVEA scope (TDS3038, I think) with a wireless router. With Chris's script for grabbing data from the scope, we should be able to take ringdown measurements comfortably from the control room.

Tomorrow we'll try to take some data and analyze it.