Advanced VIRGO WG1: Status 14.06.2007 VIRGO, Cascina Andreas Freise University of Birmingham.
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Transcript of Advanced VIRGO WG1: Status 14.06.2007 VIRGO, Cascina Andreas Freise University of Birmingham.
Advanced VIRGO
WG1: Status
14.06.2007 VIRGO, Cascina
Andreas Freise
University of Birmingham
14.06.2007 A. Freise2
Group Status Organisation, Resources Man power, schedule
Group Status Organisation, Resources Man power, schedule
Overview
Technical Status Expected outputs Status of the R+D Some 'cost' estimates
Technical Status Expected outputs Status of the R+D Some 'cost' estimates
14.06.2007 A. Freise3
Expected Output (1)
Parameter for core optics (March 2006) parametrised formula for SR response (or sensitivity) mirror coating specification beam shape and position throughout the IFO substrate size and geometry
(i.e. the constrains on it from ray tracing) number and position of readout ports
(i.e. the impact on the outer geometry of the vacuum system and around it)
basic parameter set that can be used for various simulation input files
14.06.2007 A. Freise4
Advanced VIRGO Sensitivity
Optical readout noise: simple analytic computations (white paper), simulation codes are almost ready
Thermal noise: beam shape and size, under investigation
Control noise: no idea (no locking scheme,…)
14.06.2007 A. Freise5
Advanced VIRGO Test Layout
VIRGO note VIR-NOT-EGO-1390-330
14.06.2007 A. Freise6
Advanced VIRGO Simulations
Finesse: input file is available and is being used (Andreas, Maddalena, …), code currently being extended to include radiation pressure effects
New software by Courty and LeBars: should be available soon
Siesta: development should re-start now Various LIGO simulations could be adopted
14.06.2007 A. Freise7
14.06.2007 A. Freise8
Advanced VIRGO Working Area
14.06.2007 A. Freise9
Expected Output (2)
Evaluate benefits and costs for the different options
Signal Recycling (RSE) Flat beams, higher order LG modes
DC Readout Non-degenerate recycling cavities Wedges/no wedges in optical substrates
14.06.2007 A. Freise10
Cost Evaluation
Larger apertures (tubes, flanges, baffles, …)
New modulation-demodulation scheme (optics, electronics)
New input/output optics (telescopes, mode cleaners, benches,…)
High quality optics in output ports
14.06.2007 A. Freise11
Flat Beams
Special mirror substrates and coatings for core optics
Many special auxiliary optics Different suspension controls Complex input/ouput optics
for all ports (inlcuding pick-off beams)
See talks by J.Y. Vinet, M. Laval !
14.06.2007 A. Freise12
Higher Order LG Modes
LG mode generation and mode cleaning
Problems in main interferometer and read-out ports not yet clear (there arenone??)
14.06.2007 A. Freise13
Signal Recycling
Additional suspension, additional core mirror
Probably additional modulation-demodulation frequency (modulator, electronics)
Requires a more advanced lock-acquisition scheme
More complex calibration and reconstruction process
14.06.2007 A. Freise14
Non-Degenerate Recycling Cavities
New optics in vacuum system (tanks, tubes, suspensions, optics, …??) Might be required anyway, depends on input optics and requirements.
14.06.2007 A. Freise15
DC Readout
More advanced output mode-cleaner (high finesse, low-noise)
Better laser power stabilisation
14.06.2007 A. Freise16
Summary
Work underway towards a parameter set for the core optics
Currently based on a simple extension of VIRGO with Signal Recycling
Trade-off between this and other options is difficult, more R+D needed
Cost evaluation started but also lacks more accurate input data
14.06.2007 A. Freise17
… end of part 1.
14.06.2007 A. Freise18
Group Organisation
The group WG1 is currently a loose meeting of interested people
Several independent R+D activities are now linked together through WG1
New R+D activities are initiated by WG1
No-one is yet committed to any of the priority tasks
Some people seem more interested in R+D for 3rd generation detectors than in 'Advanced' VIRGO
14.06.2007 A. Freise19
Resources
All information is available in the EGO-VIRGO working area
Simulation codes must be made available (and advertised better)
Meetings and discussions not very regular nor frequent, mostly due to the lack of progress (see next slide)
14.06.2007 A. Freise20
Man Power
VIRGO and VIRGO+ have priorityBut: we have no direct link to discussions about either!
Most people hope to become more available now that VSR1 started
Birmingham should hire a 100% dedicated post-doc anytime now
No 'young' people with a long term perspective are active in this group
Time scales are very difficult without a more dedicated effort (see Rai's comment during the LSC meeting)
14.06.2007 A. Freise21
Length Sensing and Control
No volunteers for this topic yet This will limit the progress from now
on This should be the most interesting
topic: use what you learned from the design and commissioning of VIRGO!
14.06.2007 A. Freise22
Summary
WG1 has provided a good starting point for the collaboration
We probably need to link better with VIRGO and VIRGO+ activities
The R+D effort towards Advanced VIRGO is low compared to similar projects, thus the working group will be required to make decisions without having the data from R+D projects
14.06.2007 A. Freise23
… end.