1. Detector calibration R&D - 1 Elastic deformation of test masses »R. Savage with Pablo Daveloza (LIGO fellowship) and Mario Diaz – UTB and Mahmuda Afrin Badhan – SURF (with M. Landry and P. Willems) Goal: compensation for calibration errors due to TM distortions caused by actuation and calibration forces Results: »accounts for more than 90% of observed actuation discrepancy at high frequencies »found optimum location for photon calibrator beams to minimize calibration errors due to elastic deformation »Future: analysis of aLIGO ETMs with electrostatic drive 1 H1 actuation discrepancy

2. Detector calibration R&D - 2 Photon calibrator development »R. Savage, J. Berliner, and M. Sakosky with Roberto Grosso – UTB, Matt West – Syracuse, Ryan DeRosa – LSU, and Alberto Sottile – U of Pisa Goal: development of technique, hardware, and analysis methods for aLIGO calibration Results: »Design, fabrication, installation, and operation of eLIGO Pcals »Continued investigation of accuracy and stability of Gold and Working standards (absolute power) 2 LLO Pcal swept sine Continuous Pcal calibration lines in both H1 and L1 during all of S6

3. Detector calibration R&D - 3 Photon calibrator data characterization Discovery of long-term stability of voice coil and photon calibrator actuation chains, and photon calibrator analysis method 3 Alberto Sottile, senior thesis U of Pisa (with R. Gross and J. Berliner)

4. aLIGO PSL table legs Design of table legs and scheme for mounting and interfacing with PSL table »R. Savage and M. Rodruck with Demetrio Corralez – UTEP, Robert Schofield – U of O, and Riccardo DeSalvo – CIT Goal: reduction of table (periscope) motion by optimum location of legs and improved design of legs and interface with LVEA floor and table surface Results: »factor of ten improvement in RMS displacement over iLIGO legs 4

5. On-line RFAM monitoring development of technique for monitoring RFAM downstream of the suspended modecleaner »R. Savage with Volker Quetschke – UTB Goal: characterize RFAM downstream of the MC as a function of operating laser power Results: »hardware designed, fabricated, and installed on H1. Both quadratures being recorded in the DAQ (2 kHz channels) for all of S6. »assessment of results in progress »development of DMT monitor planned – with R. Grosso - UTB 5 S6 data 20 W

6. PMC loss characterization Measurement of optical losses and mode distortion at high power »R. Savage with Malik Rakhmanov, Volker Quetschke, and Sergio Cantu – UTB Goal: tracking of long term optical losses with few- ppm resolution and understanding impact of PMC contamination at aLIGO circulating power levels Results: »fabrication of spare PMCs for eLIGO (lowest losses of any PMCs) »improvement of characterization method – few-ppm level achieved »10-W laser on loan to UTB now operating in lab; PMC characterization set-up under construction 6