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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
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
• 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
GWDAW 9 - December 15th, 2004
• 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
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
ROROGG GROUP TRANSDUCER GROUP TRANSDUCER
Antenna
Resonating disk
Teflon insulators
Pb washers
Gap 10 m
• “ROSETTE” SHAPED
12 c
m
GWDAW 9 - December 15th, 2004
The transducer The transducer mountedmounted on the on the antennaantenna
GWDAW 9 - December 15th, 2004
Old readout
New readout
WIDENING THE BANDWIDENING THE BAND
Increasing the Bandwidth of Resonant Gravitational Antennas: The Case of Explorer PRL 91, 11 (2003)
GWDAW 9 - December 15th, 2004
EXPLORER and NAUTILUS December 11th, 2004
(-1/
2)
GWDAW 9 - December 15th, 2004
DATA TAKINGDATA TAKING DURING 200 DURING 20044
EXPLORER NAUTILUS
5 ·10-19 3·10-19
GWDAW 9 - December 15th, 2004
NAUTILUS NAUTILUS OPERATIONS DURING OPERATIONS DURING October October 20020044
Liquid Helium Refillings
Duty Cycle
85 %
GWDAW 9 - December 15th, 2004
EXPLORER EXPLORER OPERATIONS DURING OPERATIONS DURING October October 20020044
Liquid Helium
Refillings
Duty Cycle
85 %
Liquid Nitrogen Refilling
GWDAW 9 - December 15th, 2004
GAUSSIANITY GAUSSIANITY
EXPLORER NAUTILUS
12 hours of data on Sept 4th, 2004
GWDAW 9 - December 15th, 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
GWDAW 9 - December 15th, 2004
• 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)).
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
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
GWDAW 9 - December 15th, 2004
MINIGRAILMINIGRAIL
Stra
in s
ensi
tivi
ty (
Hz)
-1/2