aLIGO LHO Logbook

H1 ISC

francisco.llamas@LIGO.ORG - posted 17:04, Thursday 12 September 2024 - last comment - 11:58, Friday 20 September 2024(80063)

A2L DHARD from AS_A Offsets - Testing different values and sensing function

Sheila, Louis, Francisco

Following LHO:80044, we measured ASC-DHARD_P(Y) for different ASC-AS_A_DC_YAW_OFFSET and found the loswet values of DHARD_Y at an offset of -0.05.

The "DTT_AS_A_*.png"s show the outputs of DHARD_DARM_240912 when changing AS_A_DC_OFFSET with a reference trace for when the offset was nominal (ASC-AS_A_DC_YAW_OFFSET = -0.15). Each trace has a marker at the two highest peaks in the ASC-DHARD power spectrum (the middle plot on the left). DTT_AS_A_neg0_05 shows the lowest value in the power spectrum compared to DTT_AS_A_neg0_10, while preserving coherence (lowest-left) and phase values (middle-rigt), compared to DTT_AS_A_0. AS_A_NDSCOPE corroborate on the times at which these measurements were done and the values for AS_A offset.

Having an optimal value for the YAW offset, we ran a second set of simulines injections (LHO:80061) to see if there would be any differences on the sensing function. compare_measurements is a (basic) script to retreive the sensing function from calibration measurement reports and saves plots of the transfer function and the uncertainty from the measurements. From out_10-30Hz, we see a ~8% change in the sensing function with no significant change in the measurement uncertainty (from unc_10-30Hz). However, the sensing funciton from 20240907T183913Z is on top of the 20240912T165244Z (aka offset -0.05).

An alog with more detail for the changes in the sensing function is being prepared.

Images attached to this report