List to be improved from TAMA SAS experiments

o Inverted Pendulum

• Cabling problem: Mechanical loss of the inverted pendulum is dominated by that of the cabling.
• Due to the loss, the IPs are over-damped and are spoiled its performance less than 1 Hz region.

o Active damping for vertical motions

• Because vertical sensors are no good with signal-to-noise ratio, any vertical active damping controls are not available.

o Local sensors

• Both of LVDT and Accerelometer (ACC) have larger noise levels than these of designed.
• Cabling tests including vacuum one are necessary for LCGT.

o Initial alignemnts

• Most of pico-motor actuators are not operated properly.
• (Need an actuator list of TAMA SAS with operation check)
• Mechanical clearances and the related actuation ranges should be consistent.
• Coil actuator for vertical position adjustment is not available.

o Magnet damping

• Intermidiate mass of the double pendulum part is over damped.
• Mechanical Q values should be less than several hundred, even if active damping controls are applied.

o Design Policy

• As typical seismic spectrum the worst one should be adopted.