• KAGRA
• EngineeringRun
• ER191217_24
• postERtrial

Plans for trial just after ER

Noise investigation about FFUs in the corner stations by an operator

1. Preparation

   • Make marks on FFU switches that are not turned off in MCE, IFI, PRM, PR3, PR2, BS, SR2, SR3, SRM, OMC with "Pink Tape".
     (Operated FFU / Total FFU) table list is below.
     130 FFUs will be turned off. This corresponds to 26kW heating power.
     26kW corresponds to about two water cooler cooling power (2 x 14kW). We expect balance.

• Area Name

  MCF

  MCE

  IFI

  PRM

  PR3

  PR2

  BS

  SR2

  SR3

  SRM

  OMC

  Present (151)/Total(180)

  1/16

  2/16

  12/12

  12/12

  16/16

  20/20

  20/20

  20/20

  16/16

  16/16

  16/16

  several FFUs are disorder

  Remained in Test(35)/Total(180)

  1/16

  2/16

  2/12

  2/12

  4/16

  4/20

  4/20

  4/20

  4/16

  4/16

  4/16

• IEXYV	IEXYA	IEXYC(1F)	IEXYC(2F)	EXYT
  Present(2)/Total(10)	Present(2)/Total(10)	Present(2)/Total(10+1)	Present(4)/Total(14)	Present(3)/Total(3)	<--- KOACH are not included

• Corner Station (1F)

  180+2x24+ 2x10 + 10(Pre-Rooms) = 258 (~ 51.6kW )

2. IEXYV

   • Take a sensitivity by an operator.
   • 4 people stand by IEXYV FFU switchs.
   • Turn off remamined two FFUs at the same time.
   • Take the sensitivity again before alignment will change.
   • Turn on two FFUs that used to be turned on.
   • If you see any change in sensitivity, we recheck one by one for IEXYV.

3. IEXYC(1/2F) and Transmission Area

   • Take a sensitivity by an operator.
   • 4 people stand by IEXYC FFU switchs. 10 are near the KOACH, 14 near the Transmission area.
   • Turn off remained FFUs at the same time.
   • Take the sensitivity again before alignment will change.
   • Turn on FFUs that used to be turned on.
   • If you see any change in sensitivity, we recheck one by one for IEXYC-1F/2F.

4. IEXYA

   • Take a sensitivity by an operator.
   • 4 people stand by IEXYA FFU switchs.
   • Turn off remained two FFUs at the same time.
   • Take the sensitivity again before alignment will change.
   • Turn on two FFUs that used to be turned on.
   • If you see any change in sensitivity, we recheck one by one for IEXYA.

5. For Corner station 1F

   2. Method(1)
      • Take a sensitivity by an operator.
      • 5 people stand by (MCE, IFI, PRM), (PR3, PR2, BS), (SR2, SR3), (SRM OMC), and Pre-Room FFU switchs.
      • Turn off almost FFUs at the same time by 4 people, except for pink one.
      • Take the sensitivity again before alignment will change.

      • Check the difference btw FFU operation and almost no FFU operation.
        

   3. Method(2): If the alignment change is too huge for us to take a sensitivity.
      • We turn off IYC-C and BS-C coolers at the same time when we turn off 130 FFUs.
      • Take sensitivity uegently if possible.
      • Check the temp changes in the corner station.
      • If the temp seems to go down rapidly, we enlarge heating power. If the temp gose up rapidly, we turned on IYC-C again and heat up by heaters.
      • we expect do some try and error for several hours if we encounter serious temp change.
      • If alignment comes back, take sensitivity.
      • If it will take too much time to recover FPMI, we give up this trial.

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