• Suspensions
• Mechanical_Resonances

Summary of Mechanical Resonances at the 40m Lab

Resonances of the Seismic Stacks at the 40m.

• Horizontal
  f0 [Hz]	2.5	7.5	13.0	33.0
  Q	1.67	2.0	2.0	2.0

  	Vertical
  f0 [Hz]	8.7	21.0	32.0	55.0
  Q	2.67	2.33	2.0	3.33

Suspension Resonances at the 40m

• Seismic_Isolation_TM_Chambers.pdf (New definition of X/Y)

• 40m Elog, July 2011 with new measurements

• After the 2021 vent, diagonalization was performed on all optics here and here. This test to this date was never been done successfully on LO2. Its frequencies are therefore extracted from the free-swing test only.

  Freqs	Pitch
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Dec/2010 (Air)							0.474		1.04
  Apr/2011 (Vacuum)	0.672	0.748	0.763	0.612	0.567	0.747	0.514	0.601	0.829	0.860
  Jul/2022 (Vacuum)	0.678	0.748	0.77	0.541	0.533	0.748	0.586	0.739	0.725	0.816	0.832	0.800	1.008	0.677	0.816	0.885	0.72
  Freqs	Yaw
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Dec/2010 (Air)							0.804		0.828
  Apr/2011 (Vacuum)	0.807	0.820	0.845	0.833	0.808	0.792	0.831	0.855	0.909	0.894
  Jul/2022 (Vacuum)	0.797	0.815	0.841	0.742	0.815	0.794	0.758	0.634	0.847	0.649	0.668	0.659	0.66	0.775	0.724	0.751	0.776
  Freqs	Pos Pendulum
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Dec/2010 (Air)							0.979		0.908
  Apr/2011 (Vacuum)	0.968	0.970	0.980	0.993	0.962	0.957	0.966	0.988	0.951	0.982
  Jul/2022 (Vacuum)	0.967	0.968	0.978	0.939	0.969	0.990	0.978	0.987	0.962	0.979	1.028	1.015	0.92	0.981	0.996	1.019	0.978
  Freqs	Side Pendulum
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Dec/2010 (Air)							0.993		0.949
  Apr/2011 (Vacuum)	0.995	0.993	0.971	0.999	0.972	0.995	0.986	1.003	1.038	1.016
  Jul/2022 (Vacuum)	0.995	0.990	0.969	0.990	0.985	0.959	0.959	0.948	1.000	0.954	0.988	0.991	0.991	1.001	0.999	0.989	0.997
  @	Bounce
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Dec/2010 (Air)							16.1		16.4
  Apr/2011 (Vacuum)	16.4	16.5	16.4	16.4	16.4	16.0	16.1	16.1	16.5	16.4
  Jan/2015 (Vacuum)	16.31	16.56	16.35	16.38	16.44	16.05	16.09	16.09	16.42	16.39
  Freqs	Roll
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY	AS1	AS4	LO1	LO2	PR2	PR3	SR2
  Mar/2012 (Vacuum)						23.5
  Jan/2015 (Vacuum)	23.91	24.06	23.95	23.92	23.99	23.51	23.49	23.49	24.03	23.99

  @	Violin Modes
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  (Hz)	~645	644.69	~645	~627.75	~645	~645	~645	~645	~631 (638?))	624.10
  elog ref		9884		8533					9290 (10746)	10394
  (Hz)									2285?
  elog ref									10757
  (Hz)				1883.48					1892.88
  elog ref				10753					9299

Old data

• (Old definition of X/Y)

  Freqs	Pos Pendulum
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  Design	1.000	1.000	1.000	1.000	1.000	1.000	.800	.800	.800	.800
  Shihori	.977	.977	.980			.969	.797	.789	.797	.793
  6/09/05	.975	.972	.980	.969	.984	.965	.796	.791	.784	.792
  6/20/05	.974	.972	.976	.958		.964	.795	.789	.741	.791
  6/28/05	.974	.972	.976	.963	.942	.964	.795	.789	.748	.791
  Freqs	Side Pendulum
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  6/09/05	1.000	.992	.997	.996	.968	.995	.801	.7965	.802	.796
  6/20/05	1.000	.993	.997	.996		.994	.799	.797	.804	???
  6/28/05	1.000	.993	.997	.996	.978	.994	.800	.797	.802	???
  Freqs	Pitch
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  Design	.744	.744	.744	.744	.744	.744	.500	.500	.500	.500
  Shihori	.660	.703	.660			.750	.531	.531	.586	.531
  6/09/05	.672	.716	.617	.707	.735	.742	.528	.531	.591	.545
  6/20/05	.669	.712	.659	.666		.738	.528	.530	.589	.541
  6/28/05	.669	.712	.660	.689	.729	.737	.528	.529	.590	.541
  Freqs	Yaw
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  Design	.856	.856	.856	.856	.856	.856	.600	.600	.600	.600
  Shihori	.836	.816	.816			.813	.594	.594	.605	.602
  6/09/05	.837	.815	.813	.810	.811	.810	.604	.595	.619	.599
  6/20/05	.836	.814	.814	.808		.809	.601	.589	.606	.595
  6/28/05	.836	.814	.814	.810	.798	.808	.601	.589	.609	.596
  Freqs	Bounce
  Optics	MC1	MC2	MC3	PRM	SRM	BS	ITMX	ITMY	ETMX	ETMY
  Design	16.72	16.72	16.72	16.57	16.57	16.23	11.59	11.59	11.59	11.59
  6/20/05	16.3	16.5	16.4	16.2	16.4	16.1	11.8	11.9	12.1	12.0
  6/28/05	16.5	16.5	16.3	16.2	16.4	16.1	11.8	11.9	12.1	12.0

PZT

• Piezo-Jena Tip-Tilt PZT actuators, on DLC mounts
• These resonances are in Hz

INPUT STEERING

• 	YAW	PIT
  PZT1
  PZT2

OUTPUT STEERING

• 	YAW	PIT
  PZT1
  PZT2	615	586

•