Type-C (TAMA) suspension

• Type-C suspension is a relatively small double pendulum with intermediate mass passively damped with eddy current damping. Among the large suspensions used in KAGRA, type-C is the smallest one. Some of the type-C were once used for TAMA300, originally designed by K. Arai in 1990s. So type-C suspension is sometimes called as TAMA-type suspension.

iKAGRA

• Five TAMA-type suspensions were used in iKAGRA.
  In the final iKAGRA configuration, 7 mirrors are suspended and 6 of them are Type-C. Three are PO(pick-off) type; MC_i, MC_e, MC_o with the mirror thickness with about 3cm, and 2 are TM(test mass) or RM type; ETMX, ETMY with the mirror thickness of 6cm. Other one is coming from CLIO, the size of the BS mirror was 4cm in thickness and 15cm in diameter.

  Work log about 2 iKAGRA ETMs is here.

• ETM Transfer function
• long term drift

Toward bKAGRA

• Two suspensions that were used as at the X/Y end, will be used at IMMT for bKAGRA.

  Memo by Yamamoto-san

• IMMT Preparation

• IMC Modification

bKAGRA

• Design change for new suspensions

References

• OSEM
• Drawings
• Jig