Technical Progress Planned/Needed in FY07

1. Technical Progress Planned/Needed in FY07 Advanced LIGO Program Advisory Panel meeting, 30 November – 1 December 2006, MIT Dennis Coyne, Caltech

2. Technical Progress:Planned/Needed in FY07 • state of development -- advise on triage or prioritization to ensure readiness • Subsystems without significant start-of-project, readiness concerns: • PSL – 35W front-end MOPA for enhanced LIGO will be installed 2007 • IO – high power component technology & subsystem design well developed; components to be tested in Enhanced LIGO • AOS –low-risk engineering, with the exception of AOS/Thermal Compensation System (TCS) • Data and Computing Systems (DCS) – design based on off-the-shelf hardware (in the future) • FMP/INS – minimal preparation for contracted items; mostly not schedule critical • 40m – responsive to ISC needs

3. Systems:Planned/Needed FY07 Progress • Conduct a Systems Preliminary Design Review (1st Qtr 2007) • Effort lags plan • Risk of improper requirements flowdown – Systems Scientist & Engineer involved in most subsystem meetings & decisions • Distraction of key staff -- hiring & setting priorities • Decision: Stable vs Nearly-Unstable Signal &/or Power Recycling Cavities • Modulation scheme & frequencies chosen (ISC) • Definitive optical layout for the Core Optics • Preliminary (but complete) opto-mechanical layout for all LVEA systems • Finalize all generic design & fabrication guidance (EMI/EMC, UHV, QA/QC, etc.) • Interface Control Documents established for all subsystems • Contamination Control Plan/Design (with COC) • Simulation • Demonstrate angular stability at high power • Sensitivity of optical design to optical figure, thermal lensing • Likely defer till Final Design Phase (FY08): • Suspension Point Interferometer (SPI) • Simulation • Determine if parametric instability (coupled acoustic & optical modes) are to be mitigated by COC design (ITM transmission, coating aperture) • Improved lock acquisition approaches

4. Interferometer Sensing & Control (ISC):Planned/Needed FY07 Progress • Hold a Design Requirements Review (1st Qtr 2007) • Preliminary Design progress through 2007 (review late 07 or early 08) • In-vacuum, suspended Output Mode Cleaner (OMC) and photodection to be demonstrated • LASTI testing starts May 2007; currently in preliminary design • DC read-out and OMC performance in an interferometer • 40m Lab experiment: non-suspended prototype under test • Enhanced LIGO: to be installed Nov 2007 • Length, Alignment and modulation scheme chosen • Required to definitize the optics layout & COC parameters (COC polishing starts CY08) • Modeling underway • Lock acquisition scheme • demonstrated in End-to-End (E2E) simulation (possibly) • Demonstrated in 40m experiment

5. Control & Data Systems (CDS):Planned/Needed FY07 Progress • Conduct a Data Acquisition, Networking & Supervisory Control (DAQ) Requirements Review (early 2007) • Preliminary Design progress through 2007 (review late 07 or early 08) • Install & Test at LASTI (PCIX & EPICS architecture): • FrameBuilder, RealTime Network (Myranet) & Quad Suspension controls (PCI-X) have been installed & are under test • Install/test of HAM-SAS prototype controls has begun (to be completed Jan) • BSC-ISI prototype controls • OMC Length & Alignment Controls, OMC SUS Controls & antisymmetric optical port Read-out electronics • DC Power distribution system • EMI/EMC and thermal management approach to be defined • Install & Test at 40m Lab: • OMC Length & Alignment Controls & Read-out electronics & software are nearing completion (based on new architecture) • Concerns: • QA & QC (including proper & timely definition of requirements) • Thermal management for front-end systems – liquid cooled?

6. Core Optic Components (COC):Planned/Needed FY07 Progress • Preliminary Design efforts through 3Q 2007 • ‘Polishing Pathfinder’ RFP • Achieve Advanced LIGO requirements on full scale optics (better figure & tighter Radius Of Curvature tolerance) • Hope to contract 3 polishers soon • Coating R&D continues to reduce thermal noise & absorption • coatings good enough, but improvements help performance • Prepare production polishing RFP package (ready for FY2008 funds) • Concerns: • Understanding & Controlling loss due to point scatter • Currently installed test masses indicate 30-40 ppm of scatter loss • R&D continues to identify source/cause (substrate, coating) • Polishing Pathfinder is late – COC is a (near) critical path effort • Single Source for Test Mass Coatings (LMA/Lyon)

7. Compensation plate might be a –dn/dT material mask external heating beam Ring heater Thermal Compensation System (TCS):Planned/Needed FY07 Progress • Thermal compensation strategy is still evolving (conceptual design last Aug) • Compensation plate dimensions changed to improve radiative coupling to the test mass • Proposed addition of low emissivity coating on the test mass barrel (to mitigate radial gradients) • Considering removal of compensation plate ring heater • … • All of these considerations effect suspension and COC design details • Testing • Hartmann sensors at Gin Gin • Initial and Enhanced LIGO (CO2 heating beam) • Ring heater at LASTI (temperature fields only) • Full scale performance via simulation alone • Concern is late development compared to need to finalize the COC optics and Suspension design details

8. Seismic Isolation (SEI):Planned/Needed FY07 Progress • HAM Isolation • ISI (baseline, “stiff”) or SAS (alternate, “soft”) Decision (4/2007) • HAM-ISI (“stiff”) single stage prototype design & revised costing • HAM-SAS (“soft”) prototype test at LASTI • HAM prototype fabrication (Enhanced & Advanced LIGO) • 1st unit ready for install at LLO by Oct • 2nd & 3rd units ready for install at LHO & LASTI by Dec • BSC-ISI prototype • Complete clean assembly & installation • Performance testing: • Stand-alone • With quadruple, ETM suspension (test dynamic coupling, control re-allocation, etc.) • System Diagnostics & Control Synthesis Tool Development • Essential for rapid control system tuning after installation • Stanford’s on-going ETF Technology Demonstration effort supports the control synthesis • Concerns: • HAM-SEI is critical path and development schedule has risk – contractor hired • LIGO SEI is understaffed – looking for personnel now • Dual HAM-ISI & HAM-SAS effort may have significant payoff but saps critical resources & is divisive – hold to April 2007 decision date

9. Suspensions (SUS):Planned/Needed FY07 Progress • Suspensions – 11 Types: • BSC Chamber Suspensions (UK): • Paced by UK Funding • Proceeding ahead of project need dates • Stressing LASTI integrated test plan • HAM Chamber Suspensions (US): • Efforts are delayed by lack of personnel – in hiring mode now • US suspension focus is Output Mode Cleaner (OMC) suspension for ISC and Enhanced LIGO • Prototyping for FY07 dependent on LASTI integrated test replan • Electrostatic Charging Issues • R&D to understand charge generation, transfer and mitigation has been slow • Testing new earthquake stop design intended for Enhanced LIGO use

10. LIGO Advanced System Test Interferometer (LASTI):Planned/Needed FY07 Progress • LASTI planning has undergone very significant changes over the years to accommodate HEPI development and late R&D schedules for SUS & SEI • LASTI oversight committee is charged with advising on a replan • Does the deployment of adv. LIGO elements into Enhanced LIGO obviate the need for LASTI system-level, optical-cavity testing? (HAM-SEI, OMC, PSL)? • Should we consider any system-level testing at LASTI to be risk reduction alone and not tie to development/fabrication schedules? Original two test-cavity layout for LASTI