Discussion on PR suspension modification

Participants: Takahashi, Barton, Sekiguchi, Okutomi, Fujii, Shoda

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== Plan IP ==
 * IP packaging
  * The base plate should be smaller. -> Ask Uraguchi-san
  * We do not want the cylinder between the base plate and the plate for the LVDTs.
   * In NIKEF IP, they support the LVDT plates with 3 poles. -> '''Can we get that CAD drawing? (Takahashi)'''

 * Position of the IP leg
  * The resonant freq. in YAW is higher than 0.1 Hz with the current design. If we want resonant freq. lower than 0.1 Hz, legs should be closer to the center.
    -> '''What is the requirement for the IP resonant freq? (Fujii)'''

 * EQ stop for BF
  * EQ stop for the BF should be connected to the IP base or the LVDT plate. Not on the SF plate because of the back action of the EQ stop resonance. -> Ask Uraguchi-san

 * Jacks beneath the legs
  * The top plate can be modified so that we can put the jacks on the top plate, and put the top plate directly on the inner frame. -> Ask Uraguchi-san

 * Damper for BF
  * Do we need the passive damper on the BF like the SF in the Type-B? -> '''Check (Fujii)'''

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== Plan BF ==
 * Sensors and actuators on the BF
  * We can have 3 sensors and actuators to actuate T, L, and Y, which is like IP sensors and actuators. Then, alignment structure in YAW on SF may not be necessary.
 * We have to suspend additional structure from the Traverser -> '''Check the capability of the load on the Traverser (Shoda)'''
 * The way to modify the BF cap should be investigated further (comment by Akutsu)

==== In case we have actuators on the EQ stop ====
 * The resonance of the EQ stop is the biggest problem.
  * We may need the damper for the EQ stop. -> '''Structure analysis (Shoda)''' 

==== In case we have the BFRM ====
 * How much weight do we need for BFRM? -> '''Simulation (Shoda)'''
 * If we have fancy shape of the BFRM, we may not need to modify the EQ stop around the BF. -> '''Check (Shoda)'''