Development of photon calibrator system in KAGRA Outline 2 - - PowerPoint PPT Presentation

Development of photon calibrator system in KAGRA

Academia Sinica Yuki Inoue On behalf of KAGRA collaboration

Supported by Wang-Yau Cheng, Rick Savage, Tomotada Akutsu…

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Outline

• Introduction
• KAGRA photon calibrator
• Systematic error
• Summary

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Introduction

• Direction
• Mass
• Distance

The reconstruction of h(t) is one of the most important for the gravitational wave experiment

h(t)

Gravitational waveforms

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Reconstruction of h(t)

• The uncertainties of A and C determine the

measurement accuracy of gravitational waveforms.

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Photon calibrator

• R. Savage team in LIGO achieve to

establish the low uncertainty calibration method.

• The photon calibrator (Pcal) is one of

the powerful tools to calibrate the parameters directly.

Photon pressure S.Karki et al.(2016)

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δx = ΔP c cosθ s( f ) 1+ M I ! a ⋅ ! b ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

Absolute force Transfer function Rotation

Uncertainty of photon calibrator in LIGO

• They try the crosscheck between Pcal and

another methods.

• The photon calibrator looks small uncertainty.

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LHO LLO

LIGO-P1500248

KAGRA photon calibrator

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5 phases of study

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Design phase Development phase Characterization phase Install phase Observation phase

KAGRA Pcal

36m EYA

Beam waist

Transmitter module Receiver module Periscope Camera system Baffle Oplev

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Instruments summary

advanced LIGO KAGRA Mirror material Silica Sapphire Mirror mass 40 kg 22.8 kg Mirror diameter 340 mm 220 mm

laser Power of calibrator 2W->10W

10W Laser frequency 1047 nm 1047 nm Incident angle 8.75 deg 0.72 deg

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Current status of Lab. in KEK

Class 4 laser room

Digital system

Telecamera Control PC Receiver module Transmitter module Readout tower

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Transmitter module

• placed the mirror and lenses on the optical table
• mount the aluminum cover for safety

Transmitter module

SolidWorks 教育版(実習にのみ使用可)

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AOM IS Detector Laser

Goals of KAGRA Pcal

• Calibration of interferometer output
• Hardware signal injection
• Beam position control (Pico-motor)
• High power (~10W)
• WAOM (Independently control)

Development items

(1st phase bKAGRA)

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(2nd phase bKAGRA) (3rd phase bKAGRA)

Systematic errors

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Uncertainty of laser power

• Monitor the power

with integrating sphere

Parameter uncertainty Laser power 0.57% Angle 0.007% Mass of test 0.005% RotaLon 0.40% Total 0.75%

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δx = ΔP c cosθ s( f ) 1+ M I ! a ⋅ ! b ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

Absolute force Transfer function Rotation

Calibration standard

• The uncertainty of the PCAL is limited by the power standard in NIST.
• Calibrate the GS in NIST.
• Each observatory makes the WSs which are calibrated by GS.

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Uncertainty of Rotation

• Rotation effect corresponds to

geometrical factor.

• Uncertainty of beam position

generate the systematic error

Parameter uncertainty Laser power 0.57% Angle 0.007% Mass of test 0.005% RotaLon 0.40% Total 0.75%

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δx = ΔP c cosθ s( f ) 1+ M I ! a ⋅ ! b ⎛ ⎝ ⎜ ⎞ ⎠ ⎟

Absolute force Transfer function Rotation

Telecamera

• In order to monitor the beam position, we employ the telecamera.
• Requirement: less than 1mm.

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KAGRA Telecamera

D810(36million pixel )

SolidWorks 教育版(実習にのみ使用可)

Telecamera test

36m We place the target maker 36m away from telecamera. Result Zoom in The resolution of telecamera meets our requirement.

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24mm 24mm D810(36million pixel )

Estimation of beam position

LIGO

LIGO estimate the origin of mirror surface by fitting mirror edge We try and demonstrate the estimation of the mirror origin with

• uter circle.

We use the openCV for analysis.

Trimming data Estimate this point Outer circle

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Analysis and result

X[mm] 2 4 6 8 10 12 14 16 18 20 22 24 Y[mm] 2 4 6 8 10 12 14 16 18 20 22 24

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1

Trimming Gray scale Threshold Masking ーfitting

Resolution: 0.1 mm

Fitting[mm] Design[mm] Radius 6.9±0.1 7.0 X center 11.9±0.1 12.0 Y center 11.9±0.1 12.0

Established image analysis method for estimation of beam position

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5 phases of study

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Design phase Development phase Characterization phase Install phase Observation phase

Summary

• The calibration is one of the most essential and

important technologies for the accurate measurement of gravitational waves.

• LIGO achieve to make the low uncertainty

calibration technology, photon calibrator.

• KAGRA is making the Pcal calibrator.
• Design of KAGRA Pcal have already done. We will

install the Pcal at 2018 April.

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Schedule

• 2016 Nov.-2017 Mar.: Development and

characterize of the camera system

• 2017 Apr. - May.: Installation of the Camera system
• 2017 June - 2018 Mar.: Development and

characterization of the Transmitter module and Receiver module

• 2018 June: Development of new technologies

(WAOM…)

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Modal simulation with COMSOL and ANSYS

• Density:
• 4.00g/cm3
• Young’s module
• 400Gpa
• Poison ratio
• 0.3

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Drum head mode Butterfly mode 15,914Hz 23,659Hz

Ansys Ansys

23,661Hz 15915Hz

COMSOL COMSOL

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Elastic deformation

• Total motion can decompose the elastic deformation and free mass motion.
• The amplitude of the elastic deformation strongly depend on the beam

positions.

• require to reduce the elastic deformation with choosing optimal beam positions

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Elastic deformation Free mass motion

Total motion Elastic deformation Free mass Motion

Drumhead and butterfly mode

KAGRA advLIGO Material Sapphire Silica Density 4.00g/cm3 2.20g/cm3 Young’s modulus 400Gpa 72.6GPa Poisson ratio 0.3 0.1631 Butterfly 15,914Hz 5,946Hz Drumhead 23,659Hz 8,153Hz

LIGO KAGRA

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Drumhead mode Butterfly mode

15,914Hz 23,659Hz 5,946Hz 8,153Hz Optimal beam position are corresponding to drumhead node point.

Elastic deformation of LIGO

• Optimal points is 111.6mm
• The free mass motion corresponds to unity.

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Elastic deformation of KAGRA

• Optimal position is 82.8 mm
• Sapphire have an advantage of the elastic deformation.

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Frequency [Hz] 2000 4000 6000 8000 10000 12000 Displacement ratio 0.96 0.97 0.98 0.99 1 1.01 1.02 1.03 1.04

79.8mm) ±

• 3.0mm(

81.8mm) ±

• 1.0mm(

82.8mm) ±

• ptimal positions(

83.8mm) ± + 1.0mm( 85.8mm) ± + 3.0mm(

LIGO 3mm point