CLIOCLIO

Current Status ofCurrent Status ofJapanese DetectorsJapanese Detectors

Daisuke TatsumiNational Astronomical Observatory of Japan

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ContentsContents• The Japanese Detectors

– TAMA– CLIO– DECIGO

• Analysis (Brief introduction)

– Inspiral (Tagoshi)– Veto analysis (Ishidoshiro)– Noise characterization (Akutsu)

This is a content of my talk.First, I would like to talk about the current status of TAMA, CLIO and DECIGO detectors.And then I will give a brief introduction to the current activities of data analysis.

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The Japanese DetectorsThe Japanese DetectorsTwo prototype detectors for LCGT are being developed in Japan.

•TAMALocation: Suburb of Tokyo, Japan

Baseline length: 300m

•CLIOLocation: Kamioka underground site, Japan

Baseline length: 100mFeature: Cryogenic Sapphire Mirrors

One is TAMA detector which is located in west suburb of Tokyo.It has a baseline length of three hundred meters.The another is CLIO detector which is located in Kamioka mine.This mine is about three hundred kilo-meters away from Tokyo.The most important feature of this detector is that it adopts cryogenic sapphire mirrors.

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TAMATAMA

Brief History1995 Construction start

1999 First observation experiment

2000 World best sensitivityat the time

2001 1000 hours Observation2002 Power recycling (PR)2003 Second 1000 hours

observation with PR2004 The ninth observation

experiment

TAMA has started observation experiments since 1999.

By the beginning of 2004, 3000 hours of data in total was accumulated through the nine observation experiments.

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TAMA upgradeTAMA upgradeAfter the last observation experiment in 2004, TAMA detector is being upgraded to reduce the low frequency noises.

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TAMA SAS TAMA SAS (Seismic Attenuation System)(Seismic Attenuation System)

TAMA-SAS(IP + GASF + Payload)

1. Horizontal Inverted Pendulum resonant freq. : 30mHz

To reduce the seismic noise, new isolation system is being installed. This figure shows a schematic view of TAMA SAS.To isolate horizontal motion, an inverted pendulum is implemented.For vertical motion, double stage MGAS filters are used.Finally mirror was suspended by a double pendulum.

2. VerticalDouble MGAS FiltersEach of 0.5Hz resonance

3. PayloadTop mass (Platform) Intermediate massMirror - Recoil mass

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SAS Installation ScheduleSAS Installation Schedule

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3

4

The SAS installation was started in September, 2005.In this summer, a Fabry-Perot cavity was locked with SAS.Now all of four test mass mirrors are suspended by SAS.

2005 Sep: First SAS was installed for inline end mirror (1)

2006 Jun: Second SAS was installed

for inline near mirror (2)

Aug:A Fabry-Perot cavity was lockedwith SAS,

Oct: Third and forth SAS were installed to the perpendicular arm cavity (3), (4).

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Stable lock ofStable lock of SAS Fabry-Perot cavity SAS Fabry-Perot cavity

TIME

Transmitted Power of

SAS FP cavity

Transmitted Power of

old suspension cavity

Locked FP configuration

Feedbacksignal

to Mirror

With the locked Fabry-Perot configuration, we operated the interferometer.In this configuration, one arm was installed SASs but another one was still old suspensions.The cavities were locked for six and a half hours.Even if in the daytime of the working days, stable locks were realized by SAS.

This is a important progress for TAMA, because many human activities disturbed our observations.

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This figure shows the improvement of a cavity length fluctuation by using SAS.Above 2 Hz region, the SAS improved the seismic noise more than 24 dB.

Improvement of Improvement of cavity length fluctuation cavity length fluctuation

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Improvement of Improvement of angular fluctuationsangular fluctuations

The angular fluctuation of the mirror is also reduced by SAS.Above 3 Hz region, the SAS improved the angular fluctuations more than 25 dB.

Actual improvements at 100 Hz region will be confirmed by locked Fabry-Perot configuration.And then, our detector will be tuned for power-recycled Fabry-Perot Michelson configurationby the end of next July.

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TAMA SummaryTAMA Summary

- To improve low frequency sensitivity, we are installing SAS for the test masses.

- We confirmed * Stable mass lock of a cavity with SAS,* Improvement of length fluctuation and* Improvement of angular fluctuations.

We are currently tuning SASs for another cavity.

- We plan to take data in the next summer and plan to continue TAMA operations with R&D for LCGT.

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CLIOCLIO CLIOCLIOCCryogenic ryogenic LLaser aser IInterferometer nterferometer OObservatorybservatory

in Kamioka minein Kamioka mine

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CLIOCLIO

CLIO & LCGTCLIO & LCGTPurpose of CLIO (100m arm length)

Technical demonstration of key features of LCGT.

LCGT is a future plan of Japanese GW group.LCGT

is located at Kamioka underground site for low seismic noise level,

adopts Cryogenic Sapphire mirrors for low thermal noise level and

has arms of 3km long.

Except for the arm length, CLIO has same features of LCGT.Therefore, the detector can demonstrate them as a prototype of LCGT.

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CLIOCLIO

ConstructionConstruction

All of vacuum pipes, cryostats and cryocoolers were installed by the June, 2005.

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CLIOCLIO First operation of First operation of the cryogenic interferometerthe cryogenic interferometer

First operation of the cryogenic interferometerhas been demonstrated on 18 February, 2006 !

This figure shows mirror temperatures as a function of time. During the lock, the mirrors keep its temperature around 20K.

20K

23K

Near Mirror

End Mirror

about 50 min. Lock

Tem

pera

ture

(K

)

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CLIOCLIO

CLIO sensitivity at 300KCLIO sensitivity at 300K

10010 1k 10k

Frequency (Hz)

Dis

pla

cem

en

t (m

/rtH

z)

After the several cryogenic operations,CLIO detector has been operated at 300K.To improve the sensitivity, noise hunting is in progress. This figure shows the current bestnoise spectrum of CLIO.At all of frequency regions, the differences from the target sensitivity at 300K are about a factor of 4.

Current Best

Target sensitivity at 300K

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CLIOCLIO Observable ranges forObservable ranges forInspiral GW signalsInspiral GW signals

For neutron star binaries, CLIO and TAMA can observe the event within 49kpc and 73kpc, respectively.

We can say that the two detectors have almost same sensitivity.

At over 10 solar mass region, CLIO keeps good sensitivities due to its low seismic noises. It is the greatest benefit of underground site.

CLIO

TAMA

LISM

1.4Msolar

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CLIOCLIO

CLIO SummaryCLIO Summary

- The first operation of the cryogenic interferometer was successfully demonstrated. - Current sensitivity at 300K is close to the target sensitivity within a factor of 4.

- Several observation experiments at 300K are in progress. (Details of detector characterization will be given by Akutsu)

- Once the displacement noise reaches at thermal noise level, its improvement by cooling will be demonstrated.

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DECIGODECIGO DECDECi-hertz i-hertz IInterferometer nterferometer GGravitational Wave ravitational Wave OObservatorybservatory

Pre-conceptual DesignFP Michelson interferometerArm length: 1000 kmOrbit and constellation: TBD Laser: 532 nm, 10 WMirror: 1 m, 100 kgFinesse: 10

NS+NS@z=1

BH+BH(1000Msun )

@z=1

3 year-correlation

merger

merger10210-2 100

10-24

10-22

10-20

10-18

G

W = 2.210 -16

Laser

Drag-freesatellite

Arm cavity

Arm cavity

Drag-free satellite Drag-free satellite

PD

PD

Foreground

NS+NS (1.4+1.4Msun)•z<1 (SN>26: 7200/yr)•z<3 (SN>12: 32000/yr)•z<5 (SN>9: 47000/yr)

IMBH (100+100Msun)•z<1 (SN>1000: ?/yr)

The DECIGO project is also in progress.The pre-conceptual design has been finished.Most important feature of this detector is adopting the Fabry-Perot Michelson scheme.Its baseline length is 1000 km.Each of cavities has a finesse of 10.By using this detector, GW signals of deci-hertz region will be detected.

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Activities of Data AnalysisActivities of Data Analysis

• Detector Characterization– Veto analysis by Ishidoshiro– CLIO data by Akutsu

• Inspiral– A combined result of DT6, 8 and 9

for galactic events was obtained by Tagoshi

Finally I would like to give a brief introduction to the activities of data analysis.In this afternoon session of detector characterization, two talks will be given.One is veto analysis of TAMA data by Ishidoshiro.The other is the evaluation of the first CLIO data by Akutsu. The last topic is the inspiral search of TAMA data by Tagoshi.

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TAMA inspiral analysis

by H. Tagoshi, et al.

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TAMA inspiral analysis (1)Search for inspiraling compact binaries were performed by using TAMA data in 2000-2004.

Period Data length [hours] Analyzed data [hours]

DT4 Sept. ‘00 154.9 147.1

DT5 Mar. ‘01 107.8 95.26

DT6 Aug.-Sept. ‘01 1049 876.6

DT8 Feb.-Apr. ‘03 1163 1100

DT9 Nov.’03-Jan.’04 556.9 486.1

2705

2462.8

Total length of data analyzed (DT 4,5,6,8,9)

Length of data for upper limit (DT 6,8,9)

We derived a single (combined) upper limit from DT6, 8, and 9 data. This enable us to derive a more stringent upper limit than previous works. (DT4 and 5 data were not used for upper limit, since they were shorter and sensitivity was much inferior than later DT6-9 data).

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TAMA inspiral analysis (2)

Data length

[hours]

Detection probability of Galactic signals

Threshold of ζ

(false alarm rate = 1 /yr)

Upper limit to the Milky Way Galaxy events [events /yr] (C.L.=90%)

DT6 876.6 0.18 21.8 130

DT8 1100 0.60 13.7 30

DT9 486.1 0.69 17.7 60

0.042 0.031

0.045 0.070

0.056 0.032

0.049 0.073

0.035 0.028

0.029 0.056

8.0

4.6

4.9

4.6

59

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Upper limit on the Galactic event rate

1 3Msolar

Single upper limit is given by

RNULiTi

i

Ti

R17 1.513.02 [yr -1]

Conservative upper limit

R20 [yr -1]

(gr-qc/0610064, PRD in press)

by using dataof 102.6 days

By using data of a hundred days, we set a combined upper limit to be 20 events per year on galactic events.

This result was accepted by PRD.

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End