TAMA300 Recombine2 Information

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1999/9

1999/9/1 Plan of improvement

• Adjustment of the alignment filtersdone!
• Install high power detectordone!
• Adjustment of BS drift controldone!
• Intensity stabilisationdone!

1999/9/3 Experiment with the IFO

• Today's longest stretch of lock ~ 3h 52m 41s
• The IFO has been operated with High Power Photo Detector owing to bypassing the preamplifying stage of HPPD. Saturation of the photodetector output during lock has been avoided.
  Noise spectrum -> Now analyzing
• The improvement by the BS drift control was confirmed
  Both Pitch and Yaw of BS have been controlled so as that the spot is located at the center of NS end QPD. -> It was confirmed that the contrast decreased when turning off the drift controll.

1999/9/7 Experiment with the IFO

• The best record of the sensitivity has been updated. This is the result of using the high power photo detector and intensiti stabilization.
• The best sensitivity was 2x10^-17 m/Hz^1/2
  

1999/9/10 Detector meeting (10:00~12:00)

• The best record of the IFO sensitivity has been updated. This improvement is the result of using the high power photo detector and intensiti stabilization. (Ando)
  
• Control loops for BS Orientation Drift have been worked well. Gain-up at the lower frequency region will be implemented. (Arai)
  
• Intensity stabilization loop has been recovered from the crash of the crystal. Beam intensity has been controled by monitoring one of the picked-off light between the beamsplitter and the front mirror. Another picked-off light has been used as a monitor. The photodetectors are located in the BS tank. Stabilization at high frequency region has been observed although the intensity was not stabilized well in low frequency region. Now investigation is being carried on. (Nagano)
  
• An experiment on stack temperature control will be performed tonight. dL- feedback signal is going to be passed to the West End stack temperature control. This system will reduce the dragging of the BS by the inout mirror displacement caused by dL- feedback drifting. (Takahashi)
  
• We are in the midst of a table top experiment of the beam centering. The signal obtained by dithering the angle of a mirror of the Michelson interferometer is reduced by adjusting the spot centering. (Soumiya)
  
• Data Taking2 will be performed for three days from 17th to 19th. The signals to be obtained will be same as those of Data Taking 1. The systems of intensity stabilization, BS orientation control, and stack temperature control are going to be implemented to the IFO.
  
• Next Detector Meeting will be held on 8th, Oct from 10:00AM. The location will be informed later,.
  

1999/9/10 Experiment with the IFO

• Subject: Measuring the sensitivity, Temperature control of the stacks, improvement of BS Drift Control
• The best record of the sensitivity has been updated. 8x10^-18 m/Hz^1/2
  
• It was confirmed that the stack temperature control system surpress the drift of the dL- feedback signal.
• The improved version of the BS Drift Control worked although it was necessary to increase the control gains gradually.
• The operation of the IFO was not so stable. An unlock per an hour has been observed.

1999/9/16 Project meeting (13:30~)

1999/9/16 Data Taking 2 Preparation (DT2prep)
1999/9/17~19 Data Taking 2nd Run (DT2)

• 9/16 (Thu) Evening
  Briefing for the shift members
  Prepration, adjustment
• 9/17 (Fri), 18 (Sat), 19 (Sun)
  Any kind of help is welcome! (with respect to man-power, foods, beverages, cheers, and so on)
  Closing time of each day could be postponed if the IFO does not lose lock.
  
  IFO Shift Table
  

  		17 (Fri)	18 (Sat)	19 (Sun)
  18:00 -	Laser startup	Nagano	Nagano	Nagano
  19:00 -	Initial alignment	Ando,Nagano, Kawamura	Ando, Arai, Gerhard	Ando,Nagano, Takahashi
  20:00 -	Shift1	Nagano, Kawamura	Arai, Gerhard	Nagano, Takahashi
  01:00 -	Shift2	Ando, Soumiya	Ando, Moriwaki	Arai, Numata
  06:00 -	Shutdown

  
  
  Data Taking Shift Table
  

  		17 (Fri)	18 (Sat)	19 (Sun)
  20:00 -	Briefing
  21:00 -	Initial check	Tatsumi, Miyoki	Tatsumi, Kanda, Yakura, Watanabe	Tatsumi, Telada
  22:00 -	Data taking	Miyoki	Kanda, Yakura, Watanabe	Telada
  06:00 -	Shutdown	Tatsumi, Miyoki	Tatsumi, Kanda, Yakura, Watanabe	Tatsumi, Telada

1999/9/20 Data Taking 2 (DT2) Report

• DT2 Report: Interferometer Group
  • The IFO was operated for three days. Total operation time was 31 hours. Duty ratio was 94%.
  • The longest stretch of the lock was 7h 43m (from 0:47AM to 8:30AM of the 2nd day). It updated the record time.
  • Sensitivity: About1x10^-17 m/sqrt(Hz)
  • A bunch of non-stationary glitch es frequently degrades the sensitivity. When the glitches were observed, the sensitivity was worse more than 10 times of the best one. The one-third of the obtained data may be deteriorated.
  • In comparison with DT1, the stability of the arm cavity transmissivity and the contrast was greatly improved owing to the presence of BS drift control and stack temperature control system.

1999/9/22~24 Japan Physics Society meeting@Shimane University