Transcript 2007, 3rd ILIAS annual meeting

The commissioning of Virgo and GEO
The link with N5-WG1
G.Losurdo – INFN Florence
H.Grote – AEI Hannover
on behalf of N5-WG1
GW detection in Europe
Resonant detectors
Auriga – I
Legnaro (PD)
Explorer – I
CERN
Nautilus – I
Frascati (RM)
Interferometers
GEO600 – D/UK
Hannover
Virgo – F/I/NL
Cascina (PI), EGO
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
2/19
Detector plans
S5
Commissioning
2006
Commissioning
2007
Run
LSC-Virgo MoU
for data exchange
and joint analysis
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
3/19
Inst. duty cycle [%]
GEO600 in LSC-S5
May 1 - Oct 15: 168 days
days
Histogram of sensitivities (BLRMS 555-565Hz)
May-September

Instrumental duty cycle: 94.3 %

Science time duty cycle: 91.0 %

Longest lock:

Good stationarity
102 hrs
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
4/19
After S5
GEO runs in overnight/weekend mode since Oct 15
Continue commissioning (at least until spring 2007) to:

improve sensitivity

allow long term operation

understand better the noise sources
What next?

Re-join S5 until its end or commissioning until end 2007?

Stay on run during 2008

Sequential upgrades starting 2009
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
5/19
Virgo last year

Work on several issues aimed to
– improve robustness
– improve sensitivity
– understand fully the noise

Weekly Science Runs (WSR): detector taking data during some
weekends. Nine WSRs held so far
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
6/19
Detector progress
GAUSSIANITY
WSR 1 – Sep 06
WSR 8 – Feb 07
WSR 5 – Nov 06
WSR 7 – Jan 07
SENSITIVITY
interferometer power
Main actions
55.5 hrs lock
STABILITY
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007

Reduction of longitudinal control
noise

Reduction of scattered light effects

Improvements of the
interferometer controls
G.Losurdo – INFN Firenze
7/19
WSRn: towards S5
WSR #
date
duty cycle (% locked)
1
Sep 8-11, 2006
90
2
Sep 22-25, 2006
65
3
Oct 6-9, 2006
cancelled
4
Oct 13-16, 2006
cancelled
5
Nov 10-13, 2006
65
6
Dec 1-4, 2006
80
7
Jan 12-15, 2007
76
8
Feb 9-12, 2007
94
9
Feb 17-19, 2007
100
Commissioning going on
Planned start of the long science run: May 18th
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
8/19
Noise hunting

Noise not completely understod.

Noise hunting going on on both detectors

Collaboration going on in WG1 to face common problems
mark the gap between the understood noise and the measured one
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
9/19
The role of N5-WG1
N5-WG1 - the mission

Objectives
– To speed up the commissioning and the characterization of Virgo and
GEO by means of a deeper collaboration between the two teams
– To develop common methods of characterization of interferometric
GW detectors to be applied to Virgo and GEO
– To suggest short term improvements of the existing interferometric
detectors on the base of the commissioning experience

Activity:
– face-to-face meetings: detectors status overview, commissioning
issues, “hot topic”
– parallel projects: joint work on specific commissioning topics
performed by smaller groups
– visits to labs and detector sites, control room sessions
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
11/19
N5-WG1 – the group
GEO600
Virgo
A.Freise
S.Hild
H.Grote (co-chair)
G.Degaillaix
H.Lueck
J.Smith
M.Barsuglia
H. Heitmann
P.La Penna
G.Losurdo (co-chair)
E.Tournefier
Bar detectors
L.Taffarello
M.Visco
Many others attending and giving talks…
P.Ajith, L.Barsotti, V.Dattilo, M.Evans, I.Fiori,
R.Gouaty, R.Flaminio, V.Iafolla, M.Mantovani,
J.Marque, G.Mayer, G.Vajente, B.Willke, J.P.Zendri,…
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
12/19
N5-WG1 - Meetings held so far
PARALLEL PROJECTS
WG1 meetings
1st meeting, Cascina, Jul 7-8 2004
2nd meeting, Hannover, Sep 23-24 2004
3rd meeting, Cascina, Jan 24-26 2005
4th meeting, Hannover, April 7-8 2005
5th meeting, Telecon, Jul 14 2005
6th meeting, Perugia, Sep19-20 2005
7th meeting, Hannover, Dec 12 2005
8th meeting, Frascati, Mar 20-21 2006
9th meeting, Potsdam, Jul 21-22 2006
10th meeting, Cascina, Nov 13-14 2006
11th meeting, Hannover, Jan 23-24, 2007
12th meeting, CERN, Mar 29-30, 2007
The windmills project
1st telecon, May 12, 2005
Team meeting, Cascina, 7-9 June 2005
Seismic survey, GEO600 site, July 25-29 2005
2nd telecon, August 25, 2005
The beam centering project
1st report, Napoli-Cascina, June 10-14, 2005
The alignment simulation project
1st meeting, Birmingham, August 2006
The joint noise hunting project
1st report, Cascina, September 11-22 2006
2nd report, Cascina, October 16-20 2006
3rd report, Cascina, November 13-17 2006
4th report, Cascina, January 14-19 2007
5th report, Cascina, March 2007
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
13/19
Common problems: stray light

Stray light (or scattered light) is an important noise source for all of
the interferometric detectors, and is hard to foresee and modelize

Extremely small amounts of light power can cause significant
problems

Diagnostics:
– Search of spurious beams
– Acoustic noise injections
– Tapping/hammering tests

Noise reduction techniques:
–
–
–
–
New optical layouts for auxiliary beams
Larger/higher quality optics
AR-coated windows on photodiodes
Beam dumps
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
14/19
The joint noise hunting project
A 9 months post-doc fellowship granted.
J.Smith (GEO) spent 25% of time at Virgo site
Common noise investigations
–
–
–
–
–
Virgo alignment noise projections
Virgo laser power noise investigations
GEO noise transfer functions simulation
General noise hunting at both sites
Knowledge exchange
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
Common algos/Software exchange
– GEO algo for glitch parameterization
implemented at Virgo
– GEO data viewer used at Virgo to
listen to “dark fringe music” and for offline analysis of data
G.Losurdo – INFN Firenze
15/19
The joint noise hunting project
How much is the alignment noise coupled with the GW channel?

Answer the questions by measuring noise projections

Method frequently discussed in WG1, now widely used on both detectors
J. Smith - G. Vajente
Virgo sensitivity
Alignment noise
contributions
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
16/19
The joint noise hunting project
GEO glitch monitor available at Virgo. Precious “commissioning
oriented” tool for understanding detector noise
Every point is a glitch: an
excess of power for some
short period of time (tens of
ms) and a narrow frequency
band (tens of Hz)
―
data quality
detector noise
characterization
―
―
J. Smith - G. Vajente
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
vetoing
HACR at Virgo
G.Losurdo – INFN Firenze
17/19
The Windmills project

Costruction of two windmills stations near Virgo proposed. Concern
for seismic disturbance

The wind park next to GEO600: chance to study the windmills seismic
wave field in a soft soil similar to the Virgo one.
–
–
Seismic survey on GEO600 site using two stations run in coincidence
A model of noise spectral composition and soil attenuation was done
and used to predict effects of the wind parks at Virgo. A safety
distance of 5km from Virgo buildings was defined.

Positive reaction of both windmill companies, which modified projects
layout to comply with our request.

Joint VIRGO-GEO600 document: VIR-NOT-PIS-1390-317 (I.Fiori
L.Giordano S.Hild G.Losurdo E.Marchetti G.Mayer F.Paoletti)
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
18/19
Conclusion
WG1: intense activity linked to the commissioning of Virgo and GEO
– Frequent face-to-face meetings
– Parallel projects on defined topics
– Joint noise hunting effort
The networking activity N5-WG1 is having a real impact
on the commissioning of Virgo and GEO600
Today: a real collaboration among a
group of young physicists has been
established
Tomorrow: the grown-up WG1
fellows may continue to collaborate
and lead the effort for a new
EUROPEAN detector
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
19/19
Spare slides
WG1: 4-years execution plan
MILESTONES
YEAR 1
04-05
Working group set-up
GEO/Virgo noise sources comparison
DELIVERABLES
Annual report
Annual report
Recommandations report for
short term improvements
YEAR 2
05-06
GEO/Virgo joint noise characterization
Development of common
characterization algorithms
YEAR 3
06-07
GEO/Virgo joint noise characterization
Implementation of common
characterization algorithms
Annual report
GEO/Virgo joint noise characterization
Annual report
Recommandations report for
short term improvements
YEAR 4
07-08
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
21/19
The beam centering project

Centering of beam used for wavefront sensing on the quadrants is
essential for the robustness of the alignment system

Virgo quadrants are centered with a low bandwidth (<0.3 Hz) control
– Not enough to reduce rms considerably
– Noisy system

GEO uses a commercial galvanometer scanner with custom mechanics
and electronics.

Succesfully tested on Virgo: very good suppression of beam fluctuations
Galvo off
Galvo on
R.De Rosa, L. Di Fiore, H.Grote,
H.Heitmann, J.Marque,
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
22/19
The alignment optimization project

A.Freise, M.Mantovani
Sensing matrix optimization
– Use the distribution of the matrix’ row vectors in the system's parameter
space. Compute the separation of the diode signals in the space of
the mirror angular movements.

Controllability:
– Study of the dependence of the controllability of a simple system (a FP
cavity using the Ward and the Anderson technique) on the
parameters of the optical readout in order to validate and check the
performance the chosen test method

Alignment noise propagation in Virgo under study
VIRGO configuration: Result of the study on the
controllability on a complex configuration as the
VIRGO alignment system. The minimum separation
between the 'best' sub-set of signal vectors is shown as
a function of Gouy and demodulation phase (for the
NE diodes). The chosen alignment control system can
thus control all the required degrees of freedom and it
can improved by tuning the parameters of the optical
readouts.
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
23/19
LIGO
Challenging…
but feasible
Long
commissioning
needed
Commissioning started in 1999.
Design sensitivity achieved.
Detector technology demonstrated
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
24/19
Virgo, GEO, LIGOs
ILIAS Annual Meeting - Chambery, Feb. 27th, 2007
G.Losurdo – INFN Firenze
25/19