CLIO Current Status of Japanese Detectors Daisuke Tatsumi National Astronomical Observatory of Japan

2 Contents 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.

3 The Japanese Detectors Two prototype detectors for LCGT are being developed in Japan. TAMA Location: Suburb of Tokyo, Japan Baseline length: 300m CLIO Location: Kamioka underground site, Japan Baseline length: 100m Feature: 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.

4 TAMA Brief History 1995Construction start 1999First observation experiment 2000World best sensitivity at the time hours Observation 2002Power recycling (PR) 2003Second 1000 hours observation with PR 2004The ninth observation experiment TAMA has started observation experiments since By the beginning of 2004, 3000 hours of data in total was accumulated through the nine observation experiments.

5 TAMA upgrade After the last observation experiment in 2004, TAMA detector is being upgraded to reduce the low frequency noises.

6 TAMA SAS (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. Vertical Double MGAS Filters Each of 0.5Hz resonance 3. Payload Top mass (Platform) Intermediate mass Mirror - Recoil mass

7 SAS Installation Schedule The SAS installation was started in September, In this summer, a Fabry-Perot cavity was locked with SAS. Now all of four test mass mirrors are suspended by SAS 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 locked with SAS, Oct:Third and forth SAS were installed to the perpendicular arm cavity (3), (4).

8 Stable lock of SAS Fabry-Perot cavity TIME Transmitted Power of SAS FP cavity Transmitted Power of old suspension cavity Locked FP configuration Feedback signal 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.

9 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 cavity length fluctuation

10 Improvement of angular 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 configuration by the end of next July.

11 TAMA 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.

CLIO 12 CLIO Cryogenic Laser Interferometer Observatory in Kamioka mine

CLIO 13 CLIO & LCGT Purpose 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.

CLIO 14 Construction All of vacuum pipes, cryostats and cryocoolers were installed by the June, 2005.

CLIO 15 First operation of the cryogenic interferometer has been demonstrated on 18 February, 2006 ! 20K 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 Temperature (K)

CLIO 16 CLIO sensitivity at 300K k 10k Frequency (Hz) Displacement (m/rtHz) 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 best noise 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

CLIO 17 Observable ranges for Inspiral 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

CLIO 18 CLIO 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.

19 DECIGO DECi-hertz Interferometer Gravitational Wave Observatory Pre-conceptual Design FP Michelson interferometer Arm length: 1000 km Orbit and constellation: TBD Laser: 532 nm, 10 W Mirror:  1 m, 100 kg Finesse: 10 BH+BH(1000M sun 3 year-correlation merger  GW = 2.2  Laser Drag-free satellite Arm cavity Drag-free satellite PD Foreground NS+NS ( M sun ) z 26: 7200/yr) z 12: 32000/yr) z 9: 47000/yr) IMBH ( M sun ) z 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.

20 Activities 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.

21 TAMA inspiral analysis by H. Tagoshi, et al.

22 TAMA inspiral analysis (1) Search for inspiraling compact binaries were performed by using TAMA data in PeriodData length [hours]Analyzed data [hours] DT4 Sept. ‘ DT5 Mar. ‘ DT6 Aug.-Sept. ‘ DT8 Feb.-Apr. ‘ DT9 Nov.’03-Jan.’ 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).

23 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%) DT DT DT Upper limit on the Galactic event rate Single upper limit is given by Conservative upper limit (gr-qc/ , PRD in press) by using data of 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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