gwdaw 9 - december 15 th, 2004 status of explorer and nautilus infn – ln frascati, ln gran sasso,...

GWDAW 9 - December 15th, 2004

STATUS OFSTATUS OF EXPLORER AND NAUTILUS EXPLORER AND NAUTILUS

INFN – LN Frascati, LN Gran Sasso, Sez. Roma 1, Roma 2 and Genova

Universities “La Sapienza” and “Tor Vergata” Rome, L’Aquila, Geneve

CNR – IFSI and IFN Roma

CERN - Geneve

Massimo Visco for ROG Collaboration


G.W. ANTENNAG.W. ANTENNA NAUTILUS NAUTILUS LNF - FRASCATILNF - FRASCATI

G.W. ANTENNA G.W. ANTENNA EXPLORER EXPLORER CERN - GCERN - GEENEVANEVA

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


DATA TAKING DURING THE LAST 1DATA TAKING DURING THE LAST 144 YEARS YEARS

1990 91 92 93 94 95 96 97 98 99 00 01 02

EXPLOREREXPLORER

NAUTILUSNAUTILUS

03

96 97 98 99 00 01 02 03

h from 10-18 to 4·10-19

h from 10-18 to 3·10-19

04

04


• EXPLORER was upgraded in 1999. After a tune-up period, it has been on the air since 2000 with a duty cycle close to 85%, excluding 6 months in 2002 and 3 months at the beginning of 2004.

• From March 2004 it has been working with an effective temperature around 4 mK corresponding to h = 5 · 10-19. The sensitivity can be increased modifying the electrical field in the transducer.

• This year we will not to interrupt the data taking during the winter closure of the CERN.

EXPLOREREXPLORER STATUS STATUS


• It has worked in the past run from 1999 to March 2002. The duty-cycle in 2001 was about 80% and the effective temperature smaller then 5 mK corresponding to h = 6 · 10-19

• 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 STATUSNAUTILUS STATUS


EXPERIMENTAL CONFIGURATION EXPERIMENTAL CONFIGURATION

Small gap capacitive transducer

Al 5056 mt = 0.75 kgt= 916 Hz Ct = 11 nF

E = 2.6 MV/m

Superconductingmatching transformer

Lo=2.86 HLi=0.8H

K=0.8

High couplingdc-SQUID

Ms = 10 nH n= 3 ·10-6 o/Hz

L0 Li


ROROGG GROUP TRANSDUCER GROUP TRANSDUCER

Antenna

Resonating disk

Teflon insulators

Pb washers

Gap 10 m

• “ROSETTE” SHAPED

12 c

m


The transducer The transducer mountedmounted on the on the antennaantenna


Old readout

New readout

WIDENING THE BANDWIDENING THE BAND

Increasing the Bandwidth of Resonant Gravitational Antennas: The Case of Explorer PRL 91, 11 (2003)


EXPLORER and NAUTILUS December 11th, 2004

(-1/

2)


DATA TAKINGDATA TAKING DURING 200 DURING 20044

EXPLORER NAUTILUS

5 ·10-19 3·10-19


NAUTILUS NAUTILUS OPERATIONS DURING OPERATIONS DURING October October 20020044

Liquid Helium Refillings

Duty Cycle

85 %


EXPLORER EXPLORER OPERATIONS DURING OPERATIONS DURING October October 20020044

Liquid Helium

Refillings

Duty Cycle

85 %

Liquid Nitrogen Refilling


GAUSSIANITY GAUSSIANITY

EXPLORER NAUTILUS

12 hours of data on Sept 4th, 2004


SEARCH FOR VARIOUS SOURCESSEARCH FOR VARIOUS SOURCES

• CONTINUOUS: – From the GC, 95.7 days EXPLORER hc = 3 • 10–24 - frequency interval 921.32 921.38 Hz

(P.Astone et al. Phys. Rev. D 65, 022001,2002 )

– From all the Sky, 2 days EXPLORER hc = 2 • 10–23 - frequency interval 921.00 921.76 Hz

(P.Astone et al., proceedings GWDAW 2002 – ROG – A. Krolak and collab.)

– New analysis in progress

• STOCHASTIC SOURCES: – Crosscorrelation of EXPLORER and NAUTILUS data over 10 hours in a band of 0.1Hz in 1997 -

GW(920.2 Hz) < 60. (P.Astone, et al., Astron. and Astrophys, 351, 811-814, (1999).)

– The common bandwidth now can reach 10 Hz: a new upper limit 1 is possible


• BURST SIGNALS:

GW detectorsGW detectors• Together with the other detectors of IGEC collaboration: no GW bursts above h 2 10-18

corresponding to 0.01M⊙ in the GC (International Gravitationl Event Collaboration, Phys. Rev. D 68, 022001 (2003)).

• P.Astone et al.: “Study of coincidence between resonant gravitational wave detectors”, Classical and Quantum Gravity, 18, 243-251, (2001).

• P.Astone et al.: “Study of the coincidences between the gravitational wave detectors EXPLORER and NAUTILUS in 2001”, Classical and Quantum Gravity 19, 5449-5463 (2002).

• The analysis of the data taken by the two experiments during 2003 and 2004 is in progress. The data are available for coincidence analysis with the other experiments.

GW - GW - ray detectors ray detectors• Analysis over 47 GRB (BeppoSAX) (95% probability):no signals with h>6.5·10-19 for a time

delay within 5 s, and with h>1.2·10-18 for a time delay within 400 s.(P. Astone et al, Physical Review D, 66, 2002 102002).

• Analysis of 387 GRB (BeppoSAX and BATSE) upper bound of h=2.5·10-19 in a time window of 10s (astro-ph/0408544)

GW – cosmic ray detectorsGW – cosmic ray detectors

• Search for small signals (P.Astone et al.,Physical Review Letter, 84, (2000)14-17)• Detection of unexpected large signals (P.Astone et al, Phys. Letters B 499, Feb 2001 16-22)

(P.Astone et al, Physics Letters B 540 179-184 (2002)).


0.001

0.01

0.1

1

10

100

0.001 0.01 0.1 1 10

Explorer 2003

Expected

Explorer 2002 >600 P m2

Nautilus 2003

Nautilus 2000-2001

Nautilus 1998

Nautilus 2000 T<1 K

Ev/

da

y in

tegr

al d

istr

ibut

ion

Events amplitude - Sqrt(K)

Correlation between cosmic rays and Correlation between cosmic rays and signals in the antennassignals in the antennas


TIME RESOLUTION AND EVENTS FROM TIME RESOLUTION AND EVENTS FROM COSMIC RAYS - EXPLORER 2003COSMIC RAYS - EXPLORER 2003

Selection of small events 4 <SNR (amplitude) <6

=5.7 ms


MINIGRAIL – NEW RUN November 2004MINIGRAIL – NEW RUN November 2004

New cryogenic run with 3 capacitive transducers and SQUID read-out.

Ø 68 cm - 1.4 ton 3kHz

T=72mK


MINIGRAILMINIGRAIL

Stra

in s

ensi

tivi

ty (

Hz)

-1/2

gwdaw 9 - december 15 th, 2004 status of explorer and nautilus infn – ln frascati, ln gran sasso,...

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