Download - GEO 600 Simulation Group
Andreas FreiseILIAS WG1 MeetingCERN (29-Mar-07)
GEO 600 Simulation Group
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 2
Simulation Work in GEO GEO in this sense is not GEO 600 but the people in
GEO related research groups Simulation work consists of:
Theoretical understanding of the physics Coding the physics (algorithm development) Coding, maintaining, documenting software Using simulations to produce modelled data
(commissioning, detector design, table-tops, … Understand more about the modelled experiment from the
modelled data
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 3
The GEO Collaboration
Suspension Development
Laser Development
Squeezed Light R+D
GW Source Modelling
Detector Commissioning
Laser Development
Data Analysis
LISA Instrument Development
Design of future GW Detectors
Interferometer Prototypes
New Materials R+D
InterferometryR+D
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 4
The GEO Collaboration Relatively small collaboration Entangled with several large projects Subgroups develop automatically
Possible Remedy: Create topic based groups Members are contact points to the various activities Strengthen and develop a GEO 'identity' Test in progress: the simulation group
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 5
The GEO Simulation Group Members (as of 22.01.07): Andreas Freise, Stefan Hild,
Kentaro Somiya, Sabina Huttner, Roland Schilling, Paul Cochrane, Jan Harms, Gudrun Diederichs, Simon Chelkowski, Antonio Perreca, Jonathan Hallam, Oliver Bock
Meetings : 16.01.07 (Hannover), 13.03.07 (Hannover) Resources: Website (Wiki), mailing list, svn repositories
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 6
The GeoSim Website www.sr.bham.ac.uk/dokuwiki/doku.php?id=geosim:home A public Wiki with restricted write access Hosts
Meeting dates Talks of past meetings References to GEO experiments Links to simulation programs and software tools Summaries of current or open tasks ….
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 7
Code from the good old days OptoCad
2D CAD program that traces Gaussian beams through an optical layout (GEO, VIRGO, LISA)
WaveProp FFT propagtion code (somewhat like DarkF)
(GEO) LISO
Numerical electronic circuit simulator, specialised tool for building electronic filters
Finesse Numerical Interferometer Simulation, uses Hermite-Gauss
modes in the frequency domain (GEO, LIGO, VIRGO, TAMA)
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 8
OptoCad: Alignement tolerancing of the LISA Pathfinder optical bench (Gudrun Diederichs)
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 9
OptoCad: Alignement tolerancing for LISA Pathfinder
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 10
OptoCad and Finesse
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 11
Simple Two-Mirror Cavity
Finesse output
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 12
Finesse: Current Activities GEO commissioning
Using Finesse to 'debug' GEO by matching simulations to experimental results
Maintain a configuration file which is in sync with GEO reality Quantum noise extension
For the design and commissioning of future detectors we need a proper description of quantum noise
Implementation of quantum noise is 50% complete Adding new features
Phasemaps, Matlab interface, New detector types Testing and code documentation
Unit tests, Code cleaning, Doxygen documentation
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 13
GEO Commissioning
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 14
GEO Commissioning
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 15
Shotnoise
New Finesse command 'qshot'
New algorithm to compute shotnoise for N carrier/ modulation fields and M demodulations (paper submitted)
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 16
The missing factor of two
The modelled shotnoise did not match the measuredsensitivity. Often we were apparently missing a factorof two or sqrt(2). Do we understand why? YES
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 17
Adding Phasemaps to Finesse
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 18
Finesse with Phasemaps
Analyse the effectsof mirror surfacedefects
Study aperture effects(clipping)
Simulate flat beams
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 19
The Finesse Code
Code is being re-organised and cleaned (Paul Cochrane) It is now hosted in a svn repository and is currenlty
changed regularly by three developers Extensive code documentation via Doxygen Manual (also extensive) is supplemented by in-depth
explanations of GEO input files Started to introduce unit tests of single functions:
about 50% of the code base (43000 lines) is testednightly
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 20
New Activities
LISA BBO Simulator (Jan Harms) Thermal effects via FFT simulations (Jerome Degallaix) Non-linear cavity simulator (Nico Latzka) Simulating mirrors as elastic deformable objects
(Yanbei Chen) AdLIGO, Optickle (Kentaro Somiya) ….
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 21
Conclusion
New GEO Simulation Group has been started So far it works very well and has initiated or vitalised
several activities related to GEO 600 and/or simulations The group aims at forming a communication hub inside
the GEO collaboration This will also benefit the links between GEO and other
projects Link of the GeoSim meetings with LSC meetings planned
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 22
end
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 23
GEO Commissioning GEO optical layout with OptoCad
Stores the location of the optics (lengths, angles) Is used to understand spurious beams, etc.
Finesse input file for GEO Computes control signals and transfer functions Used to compute noise couplings and the detector sensitivity
WaveProp for thermal lensing Is used only for special task which require a time-domain or FFT
approch LISA is a mission to detect and observe gravitational
waves
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 24
The GEO Collaboration LISA is a mission to detect and observe gravitational
waves
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 25
The GEO Collaboration LISA is a mission to detect and observe gravitational
waves
A. Freise ILIAS WG1 - CERN - 29/03/2007 Slide 26
The GEO Collaboration LISA is a mission to detect and observe gravitational
waves