= Type-C (TAMA) suspension =

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

 *[[http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/IMC%20Suspension|Note by K. Arai(2014)]]

Type-C can be roughly divided into '''2''' types.<<BR>>
'''PO''' (Pick-off) type suspends the mirror with the thickness of about '''3cm'''.<<BR>>
'''TM''' (test mass) type suspends the mirror with the thickness of about '''6cm'''.<<BR>>
Main differences are in the intermediate mass and frame design.

== iKAGRA ==

In 2017, '''5''' type-C suspensions were installed in iKAGRA.<<BR>>
In the final iKAGRA configuration, 7 mirrors were suspended and 6 of them were Type-C.

=== Mode Cleaner suspensions ===

The thickness of the mode cleaner mirrors are about 3cm.<<BR>>
(In TAMA, thickness of the MCe mirror was about 6cm; it means that its suspension was TM type. )<<BR>>
So the suspensions for the MC mirrors are PO-type.<<BR>>
Following the suggestion by K. Arai,<<BR>>
*[[KAGRA/Subgroups/VIS/Type-C/Design2016|Design change for new suspensions(by K. Arai)]]<<BR>>
main frames have been redesigned by H. Ishizaki.  

Mode cleaner suspensions will be used for long term even after the iKAGRA.<<BR>>
Nakano-san installed MC_i, MC_e, and MC_o.
The thickness of the MC mirrors are about 3cm.
This type of the is called as PO(pick-off).

=== Temporarily used suspensions ===
As ETMX and ETMY, TM type mirrors were used.
Work log about 2 iKAGRA ETMs is [[KAGRA/Subgroups/VIS/Type-C/iKAGRA_ETM|here]].
The last one is coming from CLIO, the size of the BS mirror was 4cm in thickness and 15cm in diameter. 

<<Navigation(children)>>
== bKAGRA ==

 *Two suspensions used at the X/Y ends, are used as IMMT1 and IMMT2 for bKAGRA.
 [[KAGRA/Subgroups/VIS/iKAGRAbKAGRA|Memo by Yamamoto-san]]
 *[[KAGRA/Subgroups/VIS/Type-C/IMMT|IMMT Preparation]]
 
 
=== Drawings ===
 *[[KAGRA/Subgroups/VIS/Type-C/OSEM|OSEM]]
 *[[KAGRA/Subgroups/VIS/Type-C/Drawings|Drawings]]
 *Magnet and standoff fixture jig
 *[[http://gwwiki.icrr.u-tokyo.ac.jp/JGWwiki/IMC%20Suspension|IMC_suspension]]