thomas.roocke@LIGO.ORG - posted 18:04, Sunday 03 May 2026 - last comment - 19:06, Monday 04 May 2026(90097)
QOSEM Calibration Rig Setup
On Friday I setup the QOSEM calibration rig in the triple lab, in the staging building. It consists of a motorored translation stage (open loop picomotor), which drives the QOSEM flag into and out of the QOSEM body, while the sum and difference voltages produced by the sat amp are monitored. The position of the stage, and hence flag is readout by a Mach-Zender interferometer (SmarAct PicoScale). This is all controlled by a laptop running a python script.
The purpose of setting up this rig again is to better calibrate each QOSEM going on to the BBSS M1, by taking calibration data with the exact sat amp and flag that each QOSEM will use.
Today I finished setting up the QOSEM calibration rig in the triples lab. I grabbed the LHO production QOSEM sat amp from SUS-R2 for use in this calibration, and will match the flag and QOSEM pair to what they will be on the BBSS, such that the calibration is as valid as possible. The rig is all ready to go for calibration runs tomorrow.