Violin Modes S 2 violin team F Raab

Violin Modes S 2 violin team F. Raab, R. Berkowitz (LHO) N. Zotov (LLO) J. Castiglione, S. Klimenko, M. Rakhmanov (UF) G. Cagnoli (Glasgow) M. Diaz (UTB) presented by S. Klimenko l Outline Ø Measurement of violin resonances. Ø Thermal noise Ø Plans LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

S 2 violin measurements l Measurement of PSD spectra with high resolution Ø UF (J. Castiglione, S. Klimenko) : Ø average of 10 one hour long stretches of lock data (Df=0. 28 m. Hz) Ø frequency and Q for L 1, H 2 test masses (72 modes) Ø LHO (F. Raab, M. Landry, R. Berkowitz): Ø H 1 PSD (5000 sec X 10, Df=0. 2 m. Hz) Ø multi-parameter fit of H 1 violin resonances (24 modes) l Tracking of violin amplitudes with Line. Monitor (UF) Ø Independent measurement of all 72 modes Ø Integration time 1 min Ø Separation of thermal and external excitations LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

S 2 violin frequencies 1 http: //www. phys. ufl. edu/LIGO/LINE H 1 3 2 1 1 H 2 2 3 S 1 343. 754 343. 814 344. 051 344. 110 349. 201 349. 245 349. 282 349. 659 LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003 3 2 S 2 L 1 measurement accuracy 0. 5 m. Hz

Violin Frequencies and Q for H 1 landry_m: LHO e-log 8/12/03 1 2 3 good agreement with UF measurements frequency, Hz Q LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

H 1 first modes LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

Anharmonicity Gonzalez, Saulson H 1 Castiglione et al. LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

Deviation from n 3 Jason’s law: d, Hz d error ~5 m. Hz L 1 LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003 H 1 H 2

violin amplitudes l Measured with the Line. Monitor L 1: 346. 6499 Hz thermal excitation LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

Average square amplitude l l P(a) – Rayleigh distribution P(a 2) – exponential Ø slope s gives <a 2> work in progress at UF: run LM on 72 modes do the amplitude analysis LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

Modeling of Thermal Noise l A. Gillespie and F. Raab, Phys. Lett. A 178 (1993) 357, Gillespie’s PHD phenomenological model based on anelastic oscillator. l G. Gonzalez and P. Saulson, J. Acoust. Soc. Am. 96(1994) 207. l M. Barton (model for LIGO LOS); V. Sannibale and G. Cella l 4 th order beam equation for suspension wire. Predicts anharmonicity and thermal noise. time-domain model of the LIGO (Advanced) suspension l G. Cella and A. Vicere (Urbino Summer School, 1999). Mechanical Simulation Environment - allows modeling of arbitrarily complex mechanical suspensions. l S. Mohanty, LIGO T 990014 -E of LIGO Suspension based on Green functions l G. Cagnoli and N. Robertson, Class. Quant. Grav. 19 (2002) 4043 model for advanced LIGO suspension (modified by M. Rakhmanov for LIGO-I) LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003 model

H 1 violin thermal noise model: A. Gillespie, F. Raab Berkowitz, Landry, Raab LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

L 1 violin thermal noise Fluctuation dissipation theorem: H(w) obtained from Glasgow model: G. Cagnoli, M. Rakhmanov UF, Glasgow thermal noise for L 1 first four modes very preliminary LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003

Plans l Complete data analysis for all three interferometers l Interpretation of the experimental results & comparison with theory Ø deviation from n 3 Ø mode splitting Ø effects of calibration and servo Ø distribution of violin amplitudes (Line. Monitor) Ø ……. . l Estimation of LIGO thermal noise l Look at large outliers detected by Line. Monitor. LIGO-G 030457 -00 -Z S. Klimenko, LSC meeting, August 2003