1. ILIAS WG1 - April 7 th, 2005 G.W. ANTENNA NAUTILUS LNF - FRASCATI G.W. ANTENNA EXPLORER CERN - GENEVA Bar Al 5056 M = 2270 kg L = 2.97 m Ø = 0.6 m A = 915 Hz @ T = 2.5 K Cosmic ray detector Bar Al 5056 M = 2270 kg L = 2.91 m Ø = 0.6 m A = 935 Hz T=130 mK - dilution refrigerator Cosmic ray detector

2. ILIAS WG1 - April 7 th, 2005 DATA TAKING DURING THE LAST 15 YEARS 1990919293949596979899 00 01 02 EXPLORER NAUTILUS 03 96979899 00 01 02 03 h from 10 -18 to 4·10 -19 h from 10 -18 to 3·10 -19 0404 0404 0505 0505

3. ILIAS WG1 - April 7 th, 2005 From March 2004 it has been working with an effective temperature around 4 mK corresponding to h = 5 · 10 -19. The sensitivity could be increased modifying the electrical field in the transducer. This year the data taking was not interrupted during the winter closure of the CERN. EXPLORER STATUS

4. ILIAS WG1 - April 7 th, 2005 After a hardware upgrade, NAUTILUS has resumed operations in March 2003. In this phase it is working at 3.5 K with a duty cycle larger then 85 %. The effective temperature is around 1 mK corresponding to h ~ 3 · 10 -19 Further improvement is possible changing the experimental parameters. NAUTILUS STATUS

5. ILIAS WG1 - April 7 th, 2005 DATA TAKING DURING 2004-2005 EXPLORER NAUTILUS 5 ·10 -19 3·10 -19

6. ILIAS WG1 - April 7 th, 2005 Since May 2004 operations in coincidence between ALLEGRO EXPLORER NAUTILUS Starting from December 2004 to February 2005 ALLEGRO AURIGA NAUTILUS EXPLORER operated together Now AURIGA NAUTILUS and EXPLORER are operating together NEW IGEC OPERATION We hope to have soon VIRGO AURIGA EXPLORER and NAUTILUS operating together to exchange data

7. ILIAS WG1 - April 7 th, 2005 NAUTILUS OPERATIONS DURING October 2004 Liquid Helium Refillings Duty Cycle  85 %

8. ILIAS WG1 - April 7 th, 2005 NAUTILUS OPERATIONS DURING march 2004 Liquid Helium Refillings

9. ILIAS WG1 - April 7 th, 2005 EXPLORER OPERATIONS DURING October 2004 Liquid Helium Refillings Duty Cycle  85 % Liquid Nitrogen Refilling

10. ILIAS WG1 - April 7 th, 2005 EXPLORER OPERATIONS DURING march 2004 Liquid Helium Refillings Liquid Nitrogen Refilling Field increased

11. ILIAS WG1 - April 7 th, 2005 EXPLORER - 5 April 2005 1h starting 1am 1h starting 11am night day

12. ILIAS WG1 - April 7 th, 2005 NAUTILUS - 5 April 2005 1h starting 1am 1h starting 11am night day

13. ILIAS WG1 - April 7 th, 2005 EXPLORER and NAUTILUS December 11th, 2004 (-1/2)

14. ILIAS WG1 - April 7 th, 2005 EXPLORER and NAUTILUS April 5th, 2005

15. ILIAS WG1 - April 7 th, 2005 EXPLORER- increasing the field – march 2005

16. ILIAS WG1 - April 7 th, 2005 EXPLORER march 2005 Fit with a model

17. ILIAS WG1 - April 7 th, 2005 EXPERIMENTAL CONFIGURATION Small gap capacitive transducer Al 5056 m t = 0.75 kg t = 916 Hz C t = 11 nF E = 2.6 MV/m Superconducting matching transformer Lo=2.86 H Li=0.8  H K=0.8 High coupling dc-SQUID M s = 10 nH  n = 3 ·10 -6  o/  Hz L0L0 LiLi

18. ILIAS WG1 - April 7 th, 2005 CtCt CdCd R L1L1 L2L2 L in Brownian force acting on the Antenna 4K b T  a  M a /Qa GW Brownian force acting on the Transducer 4K b T  t  M t /Q t Brownian noise electrical circuit 4K b T  el  L/Q el Noise SQUID  n Coupled by electrical field

19. ILIAS WG1 - April 7 th, 2005 2 x10 6 V/m 6 x10 6 V/m 1 x10 7 V/m EXPLORER Increasing the field

20. ILIAS WG1 - April 7 th, 2005 EXPLORER – different components of noise - 2 x 10 6 V/m

21. ILIAS WG1 - April 7 th, 2005 EXPLORER – different components of noise - 6 x 10 6 V/m

22. ILIAS WG1 - April 7 th, 2005 EXPLORER – different components of noise - 10 7 V/m

23. ILIAS WG1 - April 7 th, 2005 MINIGRAIL Strain sensitivity (Hz) -1/2

24. ILIAS WG1 - April 7 th, 2005