T Akutsu 1, S Telada 2, T Uchiyama 1, S Miyoki 1, K Yamamoto 1, M Ohashi 1, K Kuroda 1, N Kanda 3 and CLIO Collaboration. 1 ICRR, Univ. of Tokyo, 2 AIST, 3 OCU and CLIO Collaboration Dec th GWDAW, Potsdam, Germany

Dec GWDAW11 Potsdam Germany Contents I.Cryogenic Laser Interferometer Observatory II.First test run III.Influence of cryocooler IV.Summary

Dec GWDAW11 Potsdam Germany 1. Cryogenic Laser Interferometer Observatory (CLIO) Where is CLIO? Tokyo (NAOJ) Kamioka 220km Construction started from 2003 spring.

Dec GWDAW11 Potsdam Germany 1. Cryogenic Laser Interferometer Observatory (CLIO) 1. Reduction of thermal noise limiting sensitivity is targeted using sapphire mirrors and sapphire suspension fibers. 2. Stable operation is expected owing to the low seismic noise of KAMOIKA mine. - Seismic noise at the Kamioka mine is 1/100 lower than that at a city area. - Cooled sapphire mirrors around 20K CLIO operation using cryogenic mirrors was done Apr.2006 ! CLIO is operated at room temperature for noise hunting. Now Motivation of CLIO : Proto-Type for LCGT

Dec GWDAW11 Potsdam Germany 1. Cryogenic Laser Interferometer Observatory (CLIO) Current best sensitivity Observable range (S/N=10) Dec Operation at room temperature Sensitivity Frequency Observable range Calculation by T.Uchiyama and K.Yamamoto

Dec GWDAW11 Potsdam Germany 1. Cryogenic Laser Interferometer Observatory (CLIO) Apparatus of CLIO Compressors Cryostat tank Graphic by S.Miyoki and revised by T.Akutsu cryocooler Inline Perpendicular

Dec GWDAW11 Potsdam Germany Cryocooler 4K cold head Heat link Radiation shield Optical bench for PD Cryostat tank 2. First test run for Data Taking Cryocoolers Vibrations, Acoustic noise - Stable operation is expected owing to the low seismic noise of KAMOIKA mine. Motivation of CLIO In the future, we would like to evaluate the data both, at 20K and at room temperature.

Dec GWDAW11 Potsdam Germany Cryocooler 4K cold head Heat link Radiation shield Optical bench for PD Cryostat tank 2. First test run for Data Taking Cryocoolers (ultra low vibration type) Vibrations, Acoustic noise Sound level meter in the PD room Cryocooler switch on! How does a cryocooler have influence on the feed back signal ? A PD is near a cryostat tank

Dec GWDAW11 Potsdam Germany 2. First test run for Data Taking Calculation by T.Uchiyama and K.Yamamoto Observable range (S/N=10) Data taken on Nov was used in this work First Data Taking Sensitivity at data taking 49kpc at best sensitivity Nov hours Nov hours  Without alignment control  Consecutive lock BOLFUR suspension wires No heat link Room temperature Configuration at the present

Dec GWDAW11 Potsdam Germany Fluctuation of sensitivity Apparently, it seems that acoustic noise does not influence the data so much. Influence on noise level 3. Contamination of cryocooler Histogram of fluctuation

Dec GWDAW11 Potsdam Germany 3. Contamination of cryocooler In order to search the effect of burst-like noise, we used a slope filter (P.R.D ). Time of analyzed data No remarkable difference between on and off of the refrigerator. Influence on burst-like noise Switch off 39 min. Switch on 15 min. Evaluation of hrss : A&A (2002)

Dec GWDAW11 Potsdam Germany 3. Contamination of cryocooler Nov Observable Range1.4Msol-1.4Msol (S/N=10) Do cryocoolers really have any influences for the data? Cryocooler on car unlock

Dec GWDAW11 Potsdam Germany 3. Contamination of cryocooler Histogram for observable distance PDs and its beam guiding optics will be installed in a vacuum tank in January 2007! Acoustic influence would be much reduced. mean std Switch off 34.22kpc 2.27 Switch on 32.38kpc 2.48 Do cryocooler really have any influence for the data? Cryocoolers have an affect on the data.

Dec GWDAW11 Potsdam Germany Summary  CLIO Demonstration of the cryogenic operation was done Apr Present operation is at room temperature for noise hunting.  Data Taking First test run was implemented on Nov  Contamination of cryocooler - No remarkable influence as for burst noise. - A little influence for floor level by observable range. - More complete countermeasures for acoustic noise will be prepared. Next schedule Next data taking is planned on Jan after some acoustic countermeasures.

Dec GWDAW11 Potsdam Germany Appendix Seismic noise level at Kamioka site and Mitaka site 1/100 -1/1000

Dec GWDAW11 Potsdam Germany Appendix -Difference between the seismic noise on the surface and in the ground of the isolated area is distinguishing above 1 Hz. - Stable operation without alignment control is demonstrated for ?? hours. (Normally, GWDs on the ground without alignment control is impossible.)

Dec GWDAW11 Potsdam Germany 1 st Targeted Displacement Noise Thermal Noises limit the sensitivity around 100Hz, and they will be reduced after cooling. Laser power : 200mW for one arm Mirror Mass : 1.8 kg

Dec GWDAW11 Potsdam Germany Low Vibration Refrigerator - outlook -

Dec GWDAW11 Potsdam Germany Ultra-Low Vibration Refrigerator - vibration reduction performance - Vibration of the 4K vibration reduction stage in time. Vibration on the 300K stage in the Cryostat in the KAMIOKA mine X-axisY-axisZ-axis The values show mainly the operation frequency vibration.

Dec GWDAW11 Potsdam Germany Cryostat - outlook -

Dec GWDAW11 Potsdam Germany Appendix mean std off 2.88e e-20 on 2.93e e off 7.58e e-20 on 8.19e e off 9.92e e-20 on 1.05e e off 1.54e e-20 on 1.53e e-20

Dec GWDAW11 Potsdam Germany 1. Cryogenic Laser Interferometer Observatory (CLIO) The sounds caused by cryocoolers is loud although its system has low vibration. Sound level meter in the PD room Acceleration meter under a cryostat tank Cryocooler switch on! Cryocooler switch on! How does it have influence for the data quality ? average root-mean-square (average root-mean-square )

Dec GWDAW11 Potsdam Germany Appendix Observable range