ligo-g020090-00-z 2) accomplishment of japan rse '98-'01 -- result of osamu’s rse...

LIGO-G020090-00-Z

2) Accomplishment of Japan RSE '98-'01 -- Result of Osamu’s RSE Experiments --

LSC Meeting @ Livingston 2002

Kentaro SomiyaUniversity of Tokyo

I

17.25MH

EOM I solator

Asymmetry

(～ 3m)

51.75MHz

x3

17． 25MHz

Review of Japan RSE 1998-2001

3rd SB

0th , 1st , 2nd (No 3rd SB)

•Suspended by single pendulum.•Staying in vacuum chamber.•Aligned in parallel (not L).•No Power Recycling.•No detuning.•Only single modulation.•Third harmonics demodulation with 60 degree asymmetry.

Arm cavity 4m

Prototype RSE interferometer

RSE cavity 8.75m

Large vacuum chamber

Small vacuum chamber 3m Pipe

Opticalbench

Detectorbench

←To smallchamber

FM BSlense

FM lense

Experimental Setup

Compact single pendulum with eddy current damping.

Result : RSE lock!

•Suspended RSE lock.

•Typically 10min. lock.

•Relative TF (Signal Gain) is measured with end mass swept mechanically.

•Details are written on Osamu's doctor thesis.

6

80.1

2

4

6

81

2

T.F

.

103

2 3 4 5 6 7 8

104

2 3 4

Frequency[Hz]

SR/FPMISR/FPMI(cal.)

Interesting! : SR lock with natural detuning

•SR is locked on a side robe of error signal (Polarity is changed).

•Unstable lock produces natural detuning effect.

•It seems to be averaged for higher frequencies.

Next Step

•Stabilization

•Power Recycling

•Detuning

•Sweeping??

We built a new RSE experiment in Feb. 2002!!