Differences between revisions 2 and 12 (spanning 10 versions)
⇤ ← Revision 2 as of 2012-03-08 09:26:57 →
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Editor: KiwamuizumiATligoDOTorg
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← Revision 12 as of 2012-03-08 20:55:02 → ⇥
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Editor: KiwamuizumiATligoDOTorg
Comment:
Deletions are marked like this. Additions are marked like this.
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   * ''' Gain of whitening filter = 30 dB ''' for both the I and Q.
   * ''' Demodulation phase = 5.4 deg ''' (at which the I signal doesn't respond to the Michelson displacement).
   * ~ very tiny DC light is on the RFPD		    * ''' Gain of whitening filter = 30 dB '''
   * ''' Demodulation phase = 17.6 deg '''
 <<BR>>
Line 15: Line 15:
   * ''' Gain of whitening filter = 42 dB ''' for both the I and Q.
   * clear		    * ''' Gain of whitening filter = 42 dB '''
   * ''' Demodulation phase = -38.050 deg '''

<<BR>>
  * ''' LO = 11065910 Hz ''' by a Marconi
Line 20: Line 23:
 || AS55 || ~0 ||
 || REFL || 1.9 mW ||		  || AS (before the attenuation)|| 0.02 mW ||
 || AS55 || ? mW ||
 || REFL (before the attenuation)|| 644 mW ||
 || REFL11 || ? mW ||
 || REFL33 || ? mW ||
 || REFL55 || ? mW ||
 || REFL165 || ? mW ||
Line 42: Line 50:
 {{attachment:oltf_prmi.png }}
Line 51: Line 60:
<<BR>>
Line 52: Line 62:
[[Interferometer_Characterization#Calibration_of_Actuator_responses| summary of the actuators]]
 . {{{
     ITMX = 4.913e-09 / f2 [m/counts]
     ITMY = 4.832e-09 / f2 [m/counts]
     PRM = 2.022e-08 / f2 [m/counts]
}}}
Line 53: Line 69:
 * There is a big RAM signal in the I signal. The signals float from -100 counts to 0 counts as the Michelson freely swings.
   * The amount of the RAM looks changing as a function of time.
 * The Q signal looks having not so much RAM effect.
  		  * Is something going on ?

PRMI Noise budget

Measurements

  • 7/Mar/2012 by KI

Sensor in use

  • AS55_Q for MIHC

    • Gain of whitening filter = 30 dB

    • Demodulation phase = 17.6 deg


  • REFL33_I for PRCL

    • Gain of whitening filter = 42 dB

    • Demodulation phase = -38.050 deg


  • LO = 11065910 Hz by a Marconi

DC light

  • port name

    DC power [mW]

    AS (before the attenuation)

    0.02 mW

    AS55

    ? mW

    REFL (before the attenuation)

    644 mW

    REFL11

    ? mW

    REFL33

    ? mW

    REFL55

    ? mW

    REFL165

    ? mW

Sidebands

  • The values noted here were estimated from the OSAs at the AS and REFL ports.

Optical gains

  • Parameters

    description

    values

    notes

    Estimated Optical gain

    80 uW/m

    Measured pk-pk Michelson error signal

    1000 counts

    Michelson was freely swinging

    Raw optical gain

    5.9052 x10^9 [counts/meter]

    = 4 * pi / lambda * (pk value of the error signal)

    Conversion loss of mixer

    6.5 dB

    from the spec sheet of JMS-1H

    ADC conversion

    1638.4 counts / V

    16 bit, +/-20 V

    Trans impedance at 55 MHz

    556.3 Ohm

    AS55 characterization

    Responsibity of diodes

    0.8 [A/W]

    from the spec sheet of CS3102

    Attenuation in the AS path

Servo filters

  • oltf_prmi.png

  • UGF = 55 Hz
  • Only FM5 (10:1000) was activated.
  • G = -2
  • No limiter in the digital path.
  • Feeding the signal back to BS.
  • Dewhitening filters in BS are ON.
  • Assumption : BS actuator has a pole at 1 Hz with Q = 5
  • Time delay = (without considering the effects from the analog circuits and the down sampleing filters.)


summary of the actuators 

  •      ITMX  = 4.913e-09 / f2   [m/counts]
     ITMY  = 4.832e-09 / f2   [m/counts]
     PRM   = 2.022e-08 / f2  [m/counts]

RAM effects

  • Is something going on ?

Interferometer_Characterization/PRMI_Noise_Budget (last edited 2012-03-08 23:13:09 by KiwamuizumiATligoDOTorg)