Reports until 17:51, Thursday 24 October 2024
H1 ISC (DetChar)
christopher.wipf@LIGO.ORG - posted 17:51, Thursday 24 October 2024 (80867)
DAC noise of 28-bit DACs

A new LIGO-designed DAC was installed recently on ETMX L2 (PUM) channels. To assess the noise of the new DAC, I re-ran the PUM DAC noise budget using data from 2024-10-21 23:00 PDT. This DAC noise projection is made by subtracting drive signals from the PUM noisemons.

From the first attached plot, we can see that above 20 Hz, ETMX's new DACs are about 5x quieter than the others, which are General Standards 20-bit DACs without dither. The new DAC noise is similar above 20 Hz to what is seen in L1, using GS 20-bit DACs with dither applied.

Sub-budget plots showing the performance of the individual channels are also attached.

Images attached to this report