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AdV-COM (AdV commissioning (1st part) )

masserot - 8:58 Wednesday 20 September 2023 (61723)

PRCL_INPUT: B4_56MHz_{I,Q} weight trials

As trial, with the ITF in LOW_NOISE_3, the weights of B4_56MHz_{I,Q} have been changed with a ramp of 30s (plot);

at 2023-09-20-05h39m39, the weights used in LOW_NOISE_1 were restored (blue rectangle)
at 2023-09-20-06h16m30, a trial to restore the LOW_NOISE_3 weights was done, but the weights were swapped between B4_56MHz_{I,Q} (red rectangle)
at 2023-09-20-06h30m56, the LOW_NOISE_3 weights were correctly restored (green rectangle}

Images attached to this report

61723_1695193078_ITF_LOW_NOISE_3-PRCL_INPUT_B4_56MHz_weights-20230920-05h35_06h30-UTC.png

Comments to this report:

masserot - 9:55 Thursday 21 September 2023 (61736)

This morning the ITF was locked at LOW_NOISE_3 with

PRCL_INPUT = 72 *"B2_6MHz_I" -120.062 * "B4_56MHz_I" + 38.373* "B4_56MHz_Q" .
The basic error signal for PRCL is B2_6MHz_I

With the ITF in LOW_NOISE_1 , for this lock period, PRCL_INPUT was equal to

PRCL_INPUT = 72 *"B2_6MHz_I" -2.541 * "B4_56MHz_I" + 3.911* "B4_56MHz_Q"

At 2023-09-21-04h29m40-UTC PRCL_INPUT was set be equal to only 72 *"B2_6MHz_I" with a ramp of 120s:

the first plot show the trend of the full LOCK
the second plot is a zoom of the trend when the PRCL_INPUT weigths were updated
The third plot and its zoom compare the ITF length error signals before(purple) and after (blue) the PRCL_INPUT channel weights update

The last plots show PRCL, MICH and SRCL FFT Time plots where the time period with PRCL_INPUT equal to 62*B2_6MHz_I only is highlighted (red rectangle)

Images attached to this comment