Summary and Plans for the WG3 activity

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Summary and Plans for the WG3 activity

• H.Lück, M.Punturo

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In the ILIAS proposal

• WP3 An European Strategy for Future Antennas
• Plan the enhancement of the performances of the
  European gravitational wave detectors and to
  organise their collective operation.
• Objectives
• To determine scientific objectives that could be
  attained through short term improvements,
  optimisation and association of detectors now
  available in Europe.
• To establish the bases for integrating existing
  and future gravitational wave detectors in a
  coherent network.
• To draft a plan for a European network of
  gravitational wave detectors at the 2010 horizon

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From the Annex 1
First years activity
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Working group members

• The members of this group, appointed at the first
  GWA Executive Board, are

Co-Chairmen Co-Chairmen
H.Lück MPI für Gravitationsphysik, AEI, Hannover, Germany M.Punturo INFN Perugia, Italy
Appointed Participants Appointed Participants
K.Strain IGR, Glasgow, Great Bretain
R.Flaminio EGO, Italy-France
V.Fafone INFN Frascati, Italy
M.Bonaldi IFN-CNR and ITC, Trento, Italy
D.Enard EGO, Italy-France
L.Gottardi Leiden University, Leiden, The Netherlands
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The first task

• Definition of a list of possible short term
  improvements
• Few words for an ambitious target
• Need of wide competences
• Many RD activities in the World

• Necessity to enlarge the working group
• Open the meeting to many European and external
  experts
• Need to interlace this activity with WP1, WP2 and
  STREGA activities (joint meetings)
• Connect the activity of this working group with
  the development programs of each experiment

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WP3 the method

• To organize the discussion and to reach the
  objectives, a list of items that are affecting
  (or will affect) the current (future) GW
  detectors has been defined

• Low frequency noise
• Advanced suspensions

• Middle frequency noises
• Mirror substrate materials
• Coatings

• High frequency noises
• High power lasers
• Signal recycling

• Technologies
• Reduction of the technical noises
• Thermal compensation
• Advanced detector injection optics

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WP3 the method

• Resonant detectors

Geometries and materials
Read-out schemes
Geometrically based mode selection
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WP3 the meetings

• First meeting Cascina (It), 8-9 July 2004
• Devoted to the presentation of the activities of
  each research group
• Status of each detector
• Organization of short and middle term objectives
• Discussion on the integration of the WP3
  activities in the merging process between the
  European GW collaborations
• Second meeting Hannover (Germany), 21-22 October
  2004
• Visit of the GEO detector
• High power laser research in GEO
• Mirror Substrate research in LSC
• Highlights on GEO High Frequency
• Co-located interferometers
• Highlights on advanced Virgo design
• Dual Detector

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WP3 the meetings

• Third meeting Legnaro (It), 27-28 January 2005
• Visit to the Auriga detector
• High frequency GW sources (in collaboration with
  WG2)
• Signal recycling technologies
• Presentation of a common scenario of development
  of resonant detectors
• Starting up of the common work between GEO and
  Virgo on detectors evolution

"Large meeting"

• Fourth meeting Glasgow (UK), 11-12 April 2005
• Meeting largely devoted to the GEO-Virgo future
  joint progresses
• Discussion on a coordinated evolution between
  Virgo and GEO
• Contribution of GEO members to the design of the
  advanced Virgo detector
• Technical talks
• GEO HF scientific case (WP2)
• Flat beams
• Fiber mode cleaner
• Limited amplifiers for resonant detectors
• Thermal noise activities in Glasgow

"Large meeting"
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WP3 Glasgow meeting Souvenir
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WP3 the meetings

• Fifth meeting Cascina (It), 9 June 2005
• Actuation electronics for future detectors
• Optical configurations for advanced VIRGO, SR
  (via telecon)
• Large mass spherical detector sensitivity
• New results on photothermal effect size and
  coating effects
• Thermal corrections (via telecon)
• The Last meeting Perugia (It), 21-23 September
  2005
• ESF Exploratory Workshop

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ESF workshop in Perugia

• Gravitational Wave Week in Perugia
• WP1 meeting
• European Science Foundation Meeting WP3
• GWA Executive Board

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Summary of the last year

• Many meetings and common discussions pushed to
  have a shared view of the evolution of the GW
  detectors in Europe
• Technical presentations focused the attention on
  the technologies that can be shared between the
  different detectors and developed in
  collaboration
• Fused silica suspension
• High power lasers
• Political discussion reduced the distance
  between the European GW scientific communities
• We are realizing the miracle to start the
  writing of an Advanced Virgo document with an
  important contribution by GEO members

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This 1,5 years Plan
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Evaluation of the proposed short term improvements

• For the Virgo detector the following have been
  identified as short term upgrades
• The increase of the power circulating in the
  Fabry-Perot cavities by inserting a laser
  amplifier in the injection system.
• () The impact on the specification of the
  injection system is under evaluation particularly
  taking the thermal lensing of the Faraday
  Isolator into account.
• The installation of a thermal compensation
  system.
• () thermal lensing due to the larger power
  circulating
• () fine tuning of the reflectivity of the
  recycling mirror.
• Improvement of the actuation system, through a
  lower noise driving electronics.
• With the installation of a split path electronic,
  ().
• Realization of a monolithic fused silica
  suspension for the Virgo main mirrors.
• This permits to reduce the thermal noise of the
  suspension. The compliance with the stringent
  cleanliness and safety requirements of Virgo must
  be still verified in a strongly suggested
  engineering activity that should determine if
  this is really a short term upgrade

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EGO RD programme

• In its effort of supporting the European GW
  activities development, EGO is financing two RD
  activities in FS suspension
• Realization of a FS fiber production machine
  based on standard H2-O2 flames (Perugia)
• Completely automated
• Long fibers (gt70 cm)
• Ready to be mounted in the new experimental area
  in EGO
• Realization of a FS fiber production machine
  based on a CO2 laser (Glasgow)
• New design
• Ready in April
• The performances of these two tools will be
  evaluated in a long engineering program started
  in Virgo/EGO to finalize the realization of a
  monolithic FS suspension for Virgo

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Evaluation of the proposed short term
improvements

• () the GEO600 detector will get several
  sequential upgrades in the timeframe of 2007 to
  2014 in order to provide scientifically useful
  data in the frequency range above 500 Hz to the
  GW detector network. The following upgrades are
  under discussion
• Step-by-step laser power increase by first
  inserting amplifier stages into the beam path and
  later on switch to a different high power laser
  system. ()
• Reduction of the finesse of the mode cleaners in
  order to avoid technical problems.
• Thermal compensation of the BS lensing by
  irradiating the beam splitter with an auxiliary
  beam of a CO2 laser.
• Further reduction of the shot noise can be
  achieved by injecting squeezed light into the
  interferometer via the output port. This
  technique is under development in the
  laboratories in Hannover and can be implemented
  towards the end of the timeframe mentioned above
• An exchange of the main optics of GEO600, i.e.
  the folding mirrors, the inboard (end) mirrors
  and the beam splitter is an option for decreasing
  the thermal noise in the frequency range around 1
  kHz.(to be investigated)

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Evaluation of the proposed short term
improvements

• The currently operating resonant bar detectors
  (Auriga and the ROG detectors Explorer and
  Nautilus) will be upgraded in the time frame
  2006-2007. The target is to maintain their
  sensitivity comparable (in their 100 Hz detector
  bandwidth) with the sensitivity of the best
  operating interferometers and to give useful
  information on occurring astrophysical events
  during the planned future joint observation with
  interferometric detectors. These upgrades will be
  scheduled in order to keep always at least two
  detectors in data taking.
• The planned upgrades are
• The cooling of Auriga and Nautilus to
  ultracryogenic temperatures (about 100 mK),
  because all the fundamental noises in resonant
  detectors decrease with temperature.
• The implementation of nearly quantum limited
  readouts and more efficient electromechanical
  transducers.
• MiniGRAIL is close to start the first scientific
  run. The spheroidal modes will be monitored by
  three capacitive transducers. In order to fully
  exploit the sphere capability to reconstruct all
  the GW paramenters and the arrival direction, the
  near term planned upgrade will be the
  installation of the complete readout set up made
  of six transducers in the proper geometrical
  configuration and, as for bar detectors, the use
  of quantum limited SQUID amplifiers.

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This 1,5 years Plan
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Definition of the technologies to be shared
between the different European detectors
FS suspension Digital controls High power
lasers Signal recycling Coatings
SQUID amplifiers Capacitive transducers
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This 1,5 years Plan
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In progress
Done!
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Next future plan

• The activity evolution of the WP3 is defined in
  the plan
• Continue to support the writing of the Virgo and
  Advanced Virgo document
• Enlargement of the WP3 group to the Advanced
  Virgo working groups members
• Organize meetings dedicated to this subject
• Insert this document in a more general scenario
  of evolution of the European GW detectors
• Support the know-how exchange between the
  different detectors
• Start to look beyond the short term upgrades
• Next meeting?
• December in