G-Pisa. INFN-Group V. F. Bosi, A. Di Virgilio INFN-Pisa

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1 G-Pisa INFN-Group V F. Bosi, A. Di Virgilio INFN-Pisa M. Allegrini, J. Belfi, N. Beverini, G. Carelli, I. Ferrante, A. Fioretti, E. Maccioniand M. Pizzocaro Univ. of Pisa and CNISM F. Sorrentino Univ. of Florence A. Porzio and S. Solimeno Univ. of Naples and CNISM in collaboration with U. Schreiber, A. Velikoseltzev Technischen Univ. Muenchen, and Fundamentalstation Wettzell, Germany J.P. Wells and R. Graham Univ. of Canterboury, Chrischurch, NewZealand

2 Sagnaceffectin short Beat frequency of the two laser modes proportional to Ω, Angular Rotation ofthe Ring Angela Di Virgilio, 10 Febbraio

3 Shot Noise of a gyrolaser Ω c T = hνµ sn 2πKL 2P t 0 K ring laser scaling factor: depends on perimeter and wavelength, for a square ring K= L present large gyrolaserare a factor 3 above theoretical shot noise limit (middle curve absorptions and transmission ~1ppm, power 10nW)

4 GyroLaserProblem frequency locking and pulling Mode Locking: the two lasers are forced to lase at the same frequency. Frequency pulling: the response is not linear for very low rotation signals mode locking and frequency pulling are caused by diffused light

5 Bias from the Earth l ~ (csλ)/(πdp) λ/d diffraction angle Frequency of injection locking compared with the, SagnacFrequency at Pisa (Backscattering uniform with incident angle, we should gain a factor 10.

6 several devices have been developed, speedmeters, main advantage: no moving parts autopilot aircraft nav. submarine nav. daily polar motion rotation rate of galaxy o /h 2007 small ring laser gyros large ring laser gyros fiber optic gyros passive ring resonator R. Rodloff(1990)

7 C1 G0 UG2 Cashmere Caverns, Christchurch C2

8 G Ring Laser, Wettzell

9 G-Pisa has been financed by the INFNCom. V with the following purposes: learn the technique develop a small device (side about 1m) to improve the performances of next generation gravitational wave detection active stabilization of the gyro perimeter cavity Investigate the feasibility of a general relativity test Angela Di Virgilio, 10 Febbraio

10 Alignment control Feedback the more sensitive is the sensing device the closer to the test mass can be located Gyros Angela Di Virgilio, 10 Febbraio

11 Simple Mechanical Model feedback between third and fourth stages gyros Angela Di Virgilio, 10 Febbraio

12 Gyrolasers system integrated in the SA suspensiopns can be used to make future Gravitational Wave Detectors similar to table top interferometers Angela Di Virgilio, 10 Febbraio

13 Angela Di Virgilio, 10 Febbraio

14 G-Pisa (Pisa-Napoli) 3 Luglio 2008: Il prototipo e' stato completato 3-6 Luglio: ilprototipoe' statomessosotto vuoto la seconda settimana di luglio sono stati installati gli specchi, allineata la cavita', inserito il gas (Elio-Neon miscela standard) 8 Luglio2008 ilgyrolaserha cominciatoa laserare 9 Luglio read-out funzionante, misurato ringdown della cavita' compatibile con una finezza Angela Di Virgilio, 10 Febbraio

15 Gas cell experiments Angela Di Virgilio, 10 Febbraio

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22 G-Pisa raw data (typical) Angela Di Virgilio, 10 Febbraio

23 G-Pisa G (Wettzel) Sensitivity is more than 1000 times better than G- Pisa,butG-Pisaisgoodenoughfor AdVirgo Angela Di Virgilio, 10 Febbraio

24 G-Pisa will be installed very close tothe VirgoCentralArea in order tomake tilts measurements (spring 2010) Angela Di Virgilio, 10 Febbraio

25 Angela Di Virgilio, 10 Febbraio

26 Active Perimeter Control(1 PZT) The stability is at the level of 0.5 nm (100 s integration time) Effect on the Sagnac signal Deep PERIODIC PULLING of frequency vs TEMPERATURE Angela Di Virgilio, 10 Febbraio

27 Future PerimeterControl Improvement: 2 PZTControl Angela Di Virgilio, 10 Febbraio

28 TestsofRelativity G.E. Stedman, Phys. Report 2001 FRAME DRAGGING(LENSETHIRRING) TESTS OF LOCAL LORENTZ INVARIANCE A PREFERRED FRAME TEST THEORY FOR A ROTATING OBSERVER GRAVITATIONAL WAVES Angela Di Virgilio, 10 Febbraio

29 General Relativity predicts that rotating bodies drag space time around themselves in a phenomenon referred to as frame-dragging orgravitomagnetism. (1918 by the Austrian physicists Joseph Lenseand Hans Thirring). The rotation of an object would alter space and time, dragging a nearby object out of position compared to the predictions of Newtonian physics. Thiseffecthasbeenmeasuredwith LAGEOSat the levelof10% accuracy (Ciufoliniand Pavlis), LARESshould makeitat 1% Angela Di Virgilio, 10 Febbraio

30 AstronomicalEvidence Relativistic jets may provide evidence for the reality of frame-dragging. Gravitomagnetic. Forces produced by the Lense-Thirringeffect (frame dragging) within the ergosphereof rotating black holes combined with the energy extraction mechanism have been used to explain the observed properties of relativistic jets. The gravitomagneticmodel developed by RevaKay Williams predicts the observed high energy particles (~GeV) emitted by quasars and active galactic nuclei; the extraction of X-ray and γ-ray photons; the collimated jets about the polar axis; and the asymmetrical formation of jets (relative to the orbital plane). Angela Di Virgilio, 10 Febbraio

31 G-GranSasso Earth s local gravito-magnetic (LenseThirring) effect measured in ground/under-ground experiments Accuracy from 10% down to 1% or better F. Bosi, G. Cella, A. Di Virgilio INFN-Pisa M. Allegrini, J. Belfi, N. Beverini, G. Carelli, I. Ferrante, A. Fioretti, E. Maccioni, F. Stefani Univ. of Pisa and CNISM F. Sorrentino Univ. of Florence A. Porzioand S. SolimenoUniv. of Naples and CNISM M. Cerdonio, A. Ortolanand J.PZendri, University of Padovaand INFN-LNL M.L. Ruggiero and A.Tartaglia Politecnico di Torino Ulrich SchreiberForschungseinrichtungSatellitengeodaesieand Technische Universitaet Muenchen- Fundamentalstation Wettzell Germany Jon-Paul Wells, University of Chrischurch, NewZealand

32 Design ofthe set-up withthe twin gyros 9/02/2010 Angela Di Virgilio 32

33 Publicationetal. Several contribution to conferences Secondbest presentationat the 2009 Sif Conference invitatedpaperin specialissueofnuovo Cimento CQG, SpecialIssue(AmaldiConference) Angela Di Virgilio, 10 Febbraio

34 Conclusions Nowweare expert in thisfield G-Pisawillbeinstalledin the VirgoCentralArea in April 2010, to measure tilts 2 piezo active perimeter control should be tested in the near future (hopefully) Comm2 is discussing G.GranSasso, which will be presentedin Apriltothe LNGSComitato Scientifico Wedo haveproblemsat the moment due tolack ofmoneytohaveexchangeswithgermanyand NewZealand Angela Di Virgilio, 10 Febbraio