New iKAGRA ConfigurationNew iKAGRA Configuration

Yuta MichimuraDepartment of Physics, University of Tokyo

11th KAGRA F2F (University of Tokyo) Feb 6, 2015

Original iKAGRA ConfigurationOriginal iKAGRA Configuration

2

2938.35 m

FI

from IMC

REFL

AS

TRY

TRX

IMMT1

IMMT2

PR2

PR3 BS

iETMY

iITMY

iETMXiITMX

iBRT

iBRT

2938.35 m

iBRT

• 3 km FPMI at room temperature

• Type-Bp for ETMs and ITMs

• 3 km Michelson at room temperature

• Fixed Type-Bp for ETMs

• No iBRT for TRX/TRY(we still need cameras for alignment)

New iKAGRA ConfigurationNew iKAGRA Configuration

3

2991.73 m

FI

from IMC

REFL

AS

IMMT1

IMMT2

PR2

PR3 BS

iETMY

iETMX

2988.40 m

iBRT

3.33 masymmetry

• move PR3 and ETMs (since ITM wedge is gone)

• IMMT1 RoC = 19.5 ± 1 mflat IMMT2

Optical Layout TweaksOptical Layout Tweaks

4

FI

from IMC

REFL

AS

IMMT1

IMMT2

PR2

PR3 BS

iETMY

iETMX

iBRT

5.3 mm

8 mm

8 mm

• Type-Bp to fixed Type-Bp

Suspension ChangeSuspension Change

5

Type-BpFixed

Type-Bpstandard filter

bottom filter

intermediate mass

test mass

Original iKAGRA SensitivityOriginal iKAGRA Sensitivity

6

quantum

seismic

frequency

3 km armsilica290 K1W at BSFinesse 209Type-Bp

Perfect FSS with CARM(CMRR=1/100)

10-4 Pa

gassusp thermal

New iKAGRA SensitivityNew iKAGRA Sensitivity

7

quantum

no arm cavity

seismic

worse suspension

frequency

no CARM

susp thermal

3 km armsilica290 K1W at BSMichelsonFixed Type-Bp

Perfect FSS with IMC(3.33 m MICH asymmetry)

10-4 Pa

gas

Summary of DifferencesSummary of Differences

8

Original iKAGRA New iKAGRA

Configuration 3 km FPMI 3 km Michelson

Temperature room temperature room temperature

Test mass suspension

Type-Bp(triple pendulum)

Fixed Type-Bp(double pendulum)

Sensitivity at 100Hz 2e-22 /√Hz 2e-20 /√Hz

3 km layout test with arm cavities no arm cavities

Frequency stabilization

as far as CARM as far as IMC

iBRT for ETM trans necessary unnecessary

AppendixAppendix

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SuspensionSuspensionPerformancePerformance

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Type-Bp(Original iETM)

Fixed Type-Bp(New iETM)

Type-C(IMC)

Frequency NoiseFrequency Noise

11

Frequency Noise with IMC ServoFrequency Noise with IMC Servo

12

Frequency Noise with CARMFrequency Noise with CARM

13