Download 1 - Ego Virgo

1.3.4 N5: Gravitational Wave Antenna (GWA)
Coordinator: R. Flaminio (CNRS/IN2P3/LMA and EGO)
Deputy Coordinator: K. Danzmann (MPI/Hannover)
The objective of this network is to increase the level of European coordination in the field of
gravitational wave research in order to maximize the return on the large investment already
made, to enhance the performance of the existing detectors, and to prepare the future of this
discipline in Europe. The network is used to exchange information on subjects of common
interest such as commissioning and operation of existing detectors, to foster the development
of common methodologies for joint observations, and to support the elaboration of a common
strategy for future gravitational wave detectors in Europe.
Several institutions, participating in ILIAS, are active in this network. The participation of
contractors in terms of persons-months is given in Table 1. A single contractor, namely the
European Gravitational Observatory (EGO), ensure the financial management of this
network.
The GWA network activity is progressing as foreseen. The network includes three Working
Groups: WG1 on antenna commissioning and characterization, WG2 on joint operation of
antennas, and WG3 defining a European strategy for future detectors. All the working groups
are holding meeting on a regular bases. The list of meetings organized since April 1 st 2007 is
given in Table 3. All the documentation concerning this network is available on the WEB at
http://www.ego-it/ILIAS-GW/
N5 – Table 1a: Participants institutes.
Participant number
Participant short name
Person-months
2
3
9
13
14
15
19
CNRS
INFN
MPIK
IFN
EGO
Leiden
U.Glasgow
6
16.5
9.5
0
9
0
3.5
N5 – Table 1b: Other entities.
Institution
Country
Participation in
Friedrich Schiller University Jena
Germany
Annual general
meeting, WG3
Laser Zentrum Hannover
Germany
WG3
CNR IFSI-Frascati
Italy
WG1, WG2
Polish Academy of Sciences Warsaw
Poland
WG2
Universidad de les Illes Balears
Spain
WG2
Cardiff University
U.K
WG2, WG3
University of Birmingham
U.K.
WG2, WG3
Imperial College London
U.K.
Annual general
meeting
N5 – Table 2: Deliverables.
Deliverable/
Milestone No
1
Deliverable/Milestone Name
WG1 annual report
Workpackage
/Task No
WP1
Lead
Contractor(s)
EGO (14)
INFN (3)
Planned
(in months)
Achieved
(in months)
48
48
3
WG2 annual report
WP2
5
WG3 annual report
WP3
MPI (9)
CNRS (2)
EGO (14)
INFN (3)
CNRS (2)
Glasgow (19)
EGO (14)
INFN (3)
MPI (9)
Glasgow (19)
48
48
48
48
N5 – Table 3: Workshops/Meetings.
Date
19/06/07
20/06/07
22/10/07
25/10/07
05/03/08
06/03/08
Title/subject of meeting
/workshop
Location
Number of
attendees
Working group 1 meeting
Cascina, Italy
11
Working group 1 meeting
Hannover,
Germany
21
Working group 1 meeting
Cascina, Italy
15
26/02/08
WG2: GRB-GW workshop
Rome, Italy
16
02/04/07
03/04/07
WG3: Design study and
Virgo+ review
Cascina, Italy
8
13-18-1920-2326/04/08
WG3: Strategy definition
for 3rd generation GW
detector
WG3: Strategy definition
for 3rd generation GW
detector
WG3: Strategy definition
for 3rd generation GW
detector
WG3: Strategy definition
for 3rd generation GW
detector
Phonoconference
11
Phono conference
9
Phonoconference
9
Phonoconference
6
2/05/08
9/05/08
7/06/08
24/08/08
31/08/08
16/10/07
17/10/07
WG3: Virgo+ review
Cascina, Italy
14
09/01/08
10/01/08
WG3: Virgo+ review
Cascina, Italy
9
28/01/08
30/01/08
WG3: Advanced Virgo
design
Cascina, Italy
5
2nd joint ENTApP – GWA
meeting
4th ILIAS-GWA Annual
general meeting
Tubingen,
Germany
Tubingen,
Germany
10/10/07
08/10/06
09/10/06
44
65
Website address
http://www.ego-gw.it/ILIASGW/N5-WP1_19Jun2007.html
http://www.ego-gw.it/ILIASGW/N5-WP1_23Oct2007.html
http://www.ego-gw.it/ILIASGW/N5-WP1_5Mar2008.html
http://www.ego-gw.it/ILIASGW/N5WP2Rome26Feb08.html
http://www.ego-gw.it/ILIASGW/FP7-CascinaApr02/index.html
http://wwwcascina.virgo.infn.it/
collmeetings/DMwebpages/seco
ndVirgoplusReview.html
http://wwwcascina.virgo.infn.it/
collmeetings/DMwebpages/EG
OVirgoplusReview-Jan08.html
https://workarea.egogw.it/ego2/virgo/collaborationmeetings/2008-agendas/2008January_28th-30th
http://www.tat.physik.unituebingen.de/ENTApP/
http://www.ego-gw.it/ILIASGW/ILIASGW4/
N5 – Table 4 : Role of participant contractors
Deliverable/
Milestone No
Deliverable/Milestone Name
Workpackage
/Task No
Contractor(s)
EGO (14)
INFN (3)
1
WG1 annual report
WP1
MPI (9)
CNRS (2)
EGO (14)
CNRS (2)
INFN (3)
2
WG2 annual report
WP2
MPI (9)
Glasgow (19)
3
WG3 annual report
WP3
EGO (14)
Role
Management and reimbursement of all travel expenses
Participation to all WG1 meetings
Hosting of meetings
Writing of annual report
Coordination of WG1 activity
Organization of meetings
Participation to all WG1 meetings
Writing of annual report
Preparation of next 12 months plan
Coordination of WG1 activity
Organization of meetings
Participation to all WG1 meetings
Writing of annual report
Hosting of meetings
Preparation of next 12 months plan
Participation to all WG1 meeting
Management and reimbursement of all travel expenses
Writing of annual report.
Participation to WG2 meetings
Coordination of WG2 activity
Organization and participation to WG2 meetings
Writing of annual report
Preparation of next 12 months plan
Participation to WG2 meetings
Coordination of WG2 activity
Organization and participation to WG2 meetings
Writing of annual report
Preparation of next 12 months plan
Management and reimbursement of all travel expenses
Writing of annual report
Participation to all WG3 meetings
Hosting of meetings
CNRS (2)
Coordination of WG3 activity
Organization of meetings
Participation to all WG3 meetings
Writing of annual report
Coordination of WG3 activity
Organization of meetings
Participation to all WG3 meetings
Writing of annual report
Participation to all WG3 meetings
Glasgow (19)
Participation to all WG3 meetings
INFN (3)
MPI (9)
Activity of working group #1: Antenna commissioning and characterisation
Working group #1 is devoted to the commissioning and characterization of existing antennas.
The focus of the working group activity is the commissioning of the two large interferometers
operating in Europe, Virgo in Italy and GEO in Germany. The working group composition is
given in the corresponding report. All the participants are deeply involved in the
commissioning of existing antennas.
Since April 2007 the group has held three face-to-face meetings. The minutes of the meetings
and all the slides presented are available on the web at http://www.ego-gw.it/ILIAS-GW/N5WP1_meetings.html.
As in the years before, the comparison of noise sources of the GEO and Virgo detectors has
been very fruitful for both sides. Both detectors are still in a phase, where the sensitivites are
limited by non-fundamental noise sources for some fractions of the detection band, and
therefore exchange on the methods to mitigate these noise sources is important for a rapid
progress. Over the last year, GEO has been taking science data in the LSC- S5 frame up to
October 2007. During this time the detector was operated in the so called night and weekend
mode, acquiring science data at nights and weekends, and providing commissioning time
during day-time working hours. Virgo has held its first long science run (VSR1), overlapped
with S5 from May 18th to Oct 1st 2007. After the run a new phase of commissioning has
started, leading to important sensitivity improvements.
Also this year the focus of the discussion within this working group has been the analysis and
comparison of the main noise sources limiting the sensitivity of Virgo and GEO. One of the
main subject has been the identification and the reduction of control noises. Important
progresses were made both at GEO and Virgo and shared within the working group. Another
important point was the identification and the reduction of noises due to unwanted diffused
light. Methodologies to conduct these investigations were developed at Virgo and at GEO and
shared within the working group. In addition important progresses were made in the study of
the effect of magnetic noise at Virgo.
The second parameter which describes the performance of these detectors is their duty cycle.
Since this year both Virgo and GEO underwent long data taking periods it was possible to
study accurately their long term behaviour. The main result regarding the noise sources from
running GEO and Virgo over extended periods of time is the fact that in general the noise
sources are very stationary, if there are no uncontrolled parameters of the system left.
Regarding the stability of the locked state, both detectors can be described as very stable by
now. It turned out that both detectors were able to reach duty cycle larger than 80% with
locking periods as long as a day or more.
Characterization methodologies were also compared and shared. Thanks to a rich exchange of
good practices, to date, both projects run automated scripts computing the band-limited-rms
sensitivities in different frequency bands. Results are documented per unit time and made
accessible to the commissioners for further analysis. The procedure to automatically calculate
the detector noise budget was also re-discussed.
This working group also discussed and shared the automation and operation procedures. Due
to its maturity, the GEO automation and operation procedures have been essentially the same
for the last year. The detector is left unattended over nights, and can recover full lock
automatically in most cases, where the lock was lost. Important progresses were made at
Virgo which now also have an automatic relocking procedure used routinely during nights
and weekends when the interferometer is left unattended.
Finally the working group has issued recommendations for one of the future upgrades
foreseen at GEO (that had already been implemented at Virgo) and one of the future upgrades
foreseen at Virgo (that had already been implemented at GEO). This kind of exchanges are of
course very useful to anticipate any problem one may encounter when these upgrades are
implemented.
Activity of working group #2: Joint operation of antennas and network data analysis
Working group #2 is devoted to the joint operation and data analysis of the existing European
gravitational wave antenna. The aim is to promote discussions among European gravitational
wave data analysts and to study network data analysis methodologies for gravitational wave
searches; in particular for those involving European detectors. All the members of the
working group are deeply involved in the analysis of the data produced by the experiment
they are involved in (AURIGA, GEO, MiniGRAIL, Nautilus and Virgo).
Since April 2007 the group organized two face-to-face meetings and one workshop. Slides
and agenda of the meetings are available on the ILIAS-GWA web site (http://www.egogw.it/ILIAS-GW/N5-WP2_meetings.html ). During the last year the activity of the working
group proceeded according to the plan.
Over the past year, GWA-WG2 has continued its efforts to promote discussion between the
European gravitational wave (GW) data analysis community. The implementation plan has
laid out efforts focusing on exchanging knowledge between members of the gravitational
wave community and other communities (namely observational astronomers and theoretical
astrophysicists). This focus allowed members of GWA-WG2 to develop new searches or
extend pre-existing ones for GW in conjunction with observations in the electromagnetic
spectrum. We have continued to support ongoing collaborative analyses between the LIGO
Scientific Collaboration (LSC) and the Virgo collaboration which involve many members of
GWA-WG2. This joint analysis has produced two publications reporting on the results of
initial investigations into a joint LSC-Virgo analysis for burst and inspiral GW sources (see
WP2 technical report for the references), in addition to several other papers related to GW
searches performed within the LSC and Virgo collaborations. Moreover, the LSC-Virgo
stochastic code developed with support from GWA-WG2 is now being applied to data jointly
acquired during the LSC S5 run and the Virgo VSR1 run. There has also been joint analysis
work between the AURIGA and Virgo collaborations, performing a search for GW bursts.
This analysis has now produced a paper which has been submitted and is pending publication.
Our efforts to increase the interaction between GW data analysts and theoretical astronomers
have led us to organize a second ENTApP-GWA joint meeting in Tubingen on the 10th of
October, 2007. This meeting brought together theoretical astrophysicists from ENTApP with
data analysts from GWA to exchange knowledge and discuss details of research performed on
different sources of GW. For the GW data analysts, obtaining more information about their
signal parameter space is a crucial step in making efficient, effective searches. For the
ENTApP members, it was important to get details of GW searches to so as to tailor their
models and simulations to prove data analysts with a better scientific picture of their targeted
GW source. There has also been a workshop organised to discuss the implications of gammaray burst observations on GW searches. This workshop was held in Rome on the 26th of
February, 2008.
Finally the scientific case for a future gravitational interferometer was further developed. The
focus during the last year was put on the capabilities of a detector that, like the envisaged
Einstein Telescope, would reach a spectral sensitivity in the range of 10-25. In particular a
study was started on the physics program one could perform thanks to the detection of low
frequency gravitational waves emitted by the coalescence of binary black holes.
Activity of working group #3: A European strategy for future detectors
Working group #3 is devoted to the elaboration of a strategy for the future development of
gravitational wave detectors in Europe.
The activity during the last year progressed as foreseen. Since April 2007 the group organized
four face-to-face meeting and several teleconferences. All the presentations are available on
the web at http://www.ego-gw.it/ILIAS-GW/N5-WP3_meetings.html. At each meeting
appropriate experts external to the working group were invited according to the agenda of the
meeting.
The main activities supported since April 2007 were 1) the review of the Virgo+ project, 2)
the preparation of a conceptual design for Advanced Virgo and 3) the preparation of a work
plan for the design of a new European infrastructure devoted to gravitational wave detection.
Three reviews of the Virgo+ project took place during the last year. Members of WG3
external to the Virgo collaboration were involved in the technical review of the first upgrade
of the Virgo detector called Virgo+. The funds made available by ILIAS were also used to
support the participation of physicists not directly involved in GW detection to the review of
the Virgo+ project. The implementation of the Virgo+ upgrade is starting in this period and
should last until the end of the summer 2008.
The main outcome of the second activity was the Advanced Virgo conceptual design which
was delivered to the Virgo funding institutions (INFN and CNRS) last November. The
conceptual design includes a proposal for the project organization, a first planning and a first
evaluation of the cost. The funds available within ILIAS were used to support the
participation of members of the GEO collaboration (Germany and UK) to the conceptual
design of Advanced Virgo.
The discussion held within this working group since the beginning of the ILIAS project lead
to the preparation of a design study proposal which was submitted to the EU in May 2007.
The goal of this study is to produce a conceptual design of a new infrastructure devoted to
gravitational wave detection. The antenna hosted in such an infrastructure, called the Einstein
Telescope, should include several new technologies that have been widely discussed within
WG3 since the beginning of the ILIAS project. This study will be the first joint project
involving all the European countries working on gravitational wave detection.
Other meetings
In addition to the activities of the working groups the ILIAS-GWA network supported other
networking activities.
The network annual general meeting was organized together with the STREGA project last
October at the University of Tubingen in Germany. This general meeting was the occasion to
present and discuss the activities going on in each working group.
More recently the participation of the GW community to the ILIAS annual general meeting
was organized. Each of the GWA working groups reported about its activity including a
report about the status of the ET project.