[Koji, Rana, Jenne]
One coil of the TT produce 36nrad/rtHz at DC.
- C1:IOO-TT2_UL_EXC was excited with 5 count_pk at 0.04Hz.
- LSC_TRY exhibited the symmetric reduction of the transmission from 0.95 to 0.90.
1 - (theta/theta0)^2 /2 = 0.90 / 0.95
=> theta / theta0 = 0.32
- 40m beam waist radius is 3.1mm. This means the divergence angle is 1.1e-4 rad.
=> 1.1e-4*0.32 = 3.6e-5 rad
=> 3.6e-5/5 = 7.2 urad/count (per coil)
- DAC noise 1/sqrt(12 fs), where fs is the sampling rate (fs = 16384)
=> 0.002 cnt/rtHz
- One coil causes 7.2u*0.002 = 14 nrad/rtHz (at DC)
- One suspension cause 29 nrad/rtHz (at DC) |