May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 1/25

Status of VirgoPiero Rapagnani

Department of Physics, La Sapienza & INFN, Sez. Roma

On behalf of the Virgo CollaborationLIGO-G060281-00-Z

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 2/25

• LAPP - Annecy• INFN - Firenze/Urbino • INFN - Frascati• IPN - Lyon• INFN - Napoli• OCA - Nice

• ESPCI - Paris• LAL - Orsay• INFN - Perugia• INFN - Pisa• INFN – Roma

Inaugurated July 2003

NIKHEF – Amsterdam (joining)

EGO

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 3/25

Plan of the talk

•Virgo layout

•Activity after C6/C7 and present status

•Next VIRGO runs

•VIRGO+

•Advanced VIRGO

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 4/25

Virgo Optical Scheme

Laser 20 W

Output Mode Cleaner

3 km long Fabry-Perot cavities:to lengthen the optical path to 100 km

Input Mode Cleaner

Power recycling mirror: to increase the light power to ~1 kW

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 5/25

Free falling test masses

Thermal noise

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 6/25

ITF Operation Conditions…see also Losurdo talk on Wednesday

• Keep the FP cavities in resonance– Maximize the phase response

• Keep the PR cavity in resonance– Minimize the shot noise

• Keep the output on the “dark fringe”– Reduce the dependence on power

fluctuations

Keep the armlength constant within 10-12 m

ACTIVE CONTROLS NEEDED

LOCKING

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 7/25

Hierarchical Control

DC-0.01 HzTide control

0.01-5 Hz

5-50 Hz

1. Force reallocation over three actuation stages. Allows strong reduction of the force exerted on the mirror

2. After reallocation, reduce the actuators gain

IP displacement

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 8/25

Activity after C6/C7

Old

New

• Shut down: end of September 05• New injection bench:

• Toward the nominal power

– Full redesign– Faraday isolator– New Input Mode cleaner alignment scheme

• New Recycling mirror• Go to a monolithic mirror (flat geometry)• Change the input telescope• Use parabolic mirror on the “injection bench”• Adjusting the reflectivity (92%-95%) • increase of the recycling factor

• 750W expected on the beam splitter – x30 compared to C7

• Back to vacuum: end of November 05

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 9/25

Virgo re-commissioning (see also H.Heitmann talk…)

• December:– Realign the injection system– Restart the local controls

• January– Relock the input mode cleaner (5 Jan 06)– Realign the input telescope– Measure TF for the new recycling mirror.

• February– Relock the long cavity

• 95% beam matching up to now– Relock the reference cavity

• March– Relock the full Virgo

• Slow down by the usual problems:– Alignment, broke a translation stage, pico-motors, faulty electronics,…

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 10/25

Virgo status now

• Virgo locking scheme:– Variable finesse technique (described in detail in Heitmann talk):

• Lock on the half fringe• Used transmitted beam to lock the cavities• Start the frequency stabilization servo• Align PR mirror• Fringe offset adiabatically reduced• Use different error signals

• At present– ITF relock:

• PR aligned• Dark fringe achieved

– Power in the arms greater by a factor 10 than before shutdown

• still a factor ~3 to go

B8p

B1p_DC

L1

L2

l2

l1

l0

B2_3f_ACp

B7p

Starting StepRecycling MisalignedITF on Grey Fringe

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 11/25

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

Interferometer control

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

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NS/NS maximum range 1.5 Mpc

Virgo commissioning started in 2003:fast progress, approaching design sensitivity

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 13/25

• 2006– Interferometer restart: next month

– Noise hunting (see the talks by E.Cuoco and F.Paoletti)

– First Science Run in autumn (NS-NS horizon around 15/2.5 Mpc?)

• 2007 – A possible shutdown to fix problems

– Commissioning and noise hunting

– Nominal sensitivity

– Data taking > 50% of the time

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 14/25

10-24

10-23

10-22

10-21

10-20

10-19

10-18

1 10 100 1000 104

h (

Hz-1

/2)

Virgo

LIGO

Resonantantennas

Hz

GEO

Core Collapse@ 10 Mpc

BH-BH MergerOscillations@ 100 Mpc

Pulsars hmax – 1 yr integration

BH-BH Inspiral,z = 0.4

BH-BH Inspiral, 100 Mpc

QNM from BH Collisions, 1000 - 100 Msun, z=1

NS, =10-6 , 10 kpc

QNM from BH Collisions, 100 - 10 Msun, 150 Mpc

NS-NS Inspiral, 300 Mpc

NS-NS MergerOscillations@ 100 Mpc

First Generation Detectors

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 15/25

How Many Events?

• Waveform accurately predicted: VIRGO/LIGO can detect a NS/NS

event as far as 30 Mpc• Uncertain event rates. Calculated by:

– statistical analysis (observed binary systems)– theoretical investigations (population synthesis, evolution models)

COALESCING COMPACT BINARIES

NS/NS NS/BH BH/BH

Milky Way event rate 10-5 - 10-3 yr-1 10-6 - 10-4 yr-1 0 - 10-4 yr-1

Detector range 20 Mpc 40 Mpc 100 Mpc

Detection rate 10-3 - few yr -1

[Burgay et al., 2003 - Nutzman et al., 2004]

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 16/25

After 2007: Expanding the Accessible Universe:

Seismic

Thermal

Shot

Where and how can we reduce the detector noise?

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 17/25

Virgo+ (see also M.Punturo Talk on Wednesday)

• Virgo will be upgraded with a set of medium scale, low cost (~1-2 MEuro), incremental improvements with:

– Compatibility with the main Virgo subsystems (“plug and play”),

same optical layout – Limited shutdown– Limited commissioning time

• Four independent items have been identified:

1. Monolithic payloads with fused silica suspensions

2. New laser, 50 W

3. Mirror thermal compensation

4. Electronics and control system upgrades

• To be installed after design sensitivity has been reached and a long data taking has been performed

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 18/25

Virgo+ Sensitivity(b)bulk= 10-9 [Penn et al. 2005](a)bulk= 10-7 [Virgo design model]

Depending onthermal noise model

Newtonian noise

Events Virgo Virgo+ (a) Virgo+ (b)

NSNS 12 (31) 46 (114) 22 (56)

BHBH 58 (145) 234 (584) 116 (291)

Inspiral Range: averaged orientation (optimal orientation) [Mpc]

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 19/25

QuickTime™ and aTIFF (Uncompressed) decompressor

are needed to see this picture.

1. Monolithic payload• GOAL: pendulum thermal noise reduction

• Fused silica fibers technology well established and adopted at GEO

• Change of reference mass material from metal to dielectric

• Engineering started: – Fibers production facilities being installed @EGO (H2O2 Perugia, CO2

laser Glasgow)– Installation of the payload infrastructure for assembly (Roma)– Production of a dummy payload (Perugia,Roma) – Definition of a safe hanging procedure to be defined– Safe control strategy to avoid fatal shocks to be defined– Payload handling: cleaness and transport

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

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2. Laser

• GOAL: reduce shot noise / reduce laser unlocks rate

• Limited power increase (50 W) allowed if input optics unchanged (in any case we need to analyse carefully the input optics response in view of the increase)

• Technology for high power laser suitable for advanced detectors almost ready ( collaboration with GEO is crucial for VIRGO)

3. Thermal compensation• GOAL: improve the spatial overlap between the carrier and

sidebands spots spoiled by mirror thermal deformation• Technology is mature: heating rings used at GEO, CO2 laser at

LIGO• VIRGO-Napoli et al. coordinate the construction effort

4. Electronics• GOALS:– Reduce control noise– Cope with the increasing complexity of the needed control strategies

• Pisa/Annecy/EGO R&D project in progress:– New DSP board– New ADC with higher sampling frequency (60 kHz) and more bits– New actuation electronics (DAC with more bits, low noise coil

drivers)– New communication board (10x faster), New timing board

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 21/25

Provisional schedule2005-2007• Possible implementation of some short term

upgrades (electronics, thermal compensation)• Working groups activity• Technical design (end 2007)

2008• Implementation of Virgo+

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 22/25

2006-2007• Working groups activity

– Signal Recycling– High Power – New optics and optical configuration

• Technical design

2008-2009• Engineering activities for Advanced Virgo

> 2010• Advanced Virgo upgrades

Advanced VIRGO

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 23/25

Advanced VIRGO vs VIRGO+Plaser after IMC = 100 W, mirror weight = 40 kg, PR gain = 50, finesse = 600

Credit: M.Punturo

NS-NS NS-BH BH-BH SNeEvent Rate (per year) 0.025-10 10-3-15 3 10-2-90 1Range (Mpc) 114 230 584 10

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 24/25

Next Decade Network

10-25

10-24

10-23

10-22

10-21

10-20

10 100 1000 104

Advanced Virgo

Hz

Core Collapse@ 10 Mpc

BH-BH MergerOscillations@ 100 Mpc

Pulsarsh

max, 1 year integrationLCGT-I

h/ĆHz

3rd Generation ITF

BH-BH Inspiral,z = 0.4

BH-BH Inspiral, 100 Mpc

QNM from BH Collisions, 1000 - 100 Msun, z=1

NS, =10-6, 10 kpc

QNM from BH Collisions, 100 - 10 Msun, 150 Mpc

AdvancedLIGO

NS-NS Inspiral, 300 Mpc

2012-2018 Networkh (Hz-1/2)

May 29th 2006

ELBA GWDAW-VESF MeetingGravitational Wave Advanced Detector Workshop

P. Rapagnani 25/25

LIGO - Virgo

LIGO+ - Virgo+

AdvLIGO - AdvVirgo

A hope for the near future:The Beginning of a New Astronomy…