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
SuspensionSuspensionPerformancePerformance
10
Type-Bp(Original iETM)
Fixed Type-Bp(New iETM)
Type-C(IMC)