Measurements of mechanical Q in levitated paramagnetic crystals

Augst, S. J.; Drever, R. W. P.
June 2000
AIP Conference Proceedings;2000, Vol. 523 Issue 1, p338
Academic Journal
Thermal noise from test masses, arising both from internal noise in the test mass material and from losses in the suspension wires and their attachments, is a significant factor limiting sensitivity of interferometric gravity-wave detectors. To investigate ways of reducing these noise sources we are using magnetic levitation in place of suspension wires. A search for high-Q crystals with magnetic properties allowing tests in moderate field strengths has led us to paramagnetic crystals, and we report preliminary results with small levitated samples of Gadolinium Gallium Garnet (GGG) and Terbium Gallium Garnet (TGG). The technique seems the first to allow Q measurements with no mechanical contact, and may facilitate work aimed at reducing thermal noise. © 2000 American Institute of Physics.


Related Articles

  • Construction and performance of a low noise inductive transducer for the Louisiana State University gravitational wave detector. Solomonson, N.; Hamilton, W. O.; Johnson, W.; Xu, B. // Review of Scientific Instruments;Jan1994, Vol. 65 Issue 1, p174 

    The design, fabrication, and performance of an inductive transducer for a two-mode resonant mass gravitational radiation detector is described. The design of the transducer is based on a detailed noise model of the detector. The transducer combines a large dynamic mass, a large loaded quality...

  • Measurement of position and orientation of optical elements in interferometric gravity wave... Heitmann, Henrich; Drezen, Christine // Review of Scientific Instruments;Aug1997, Vol. 68 Issue 8, p3197 

    Describes the measurement of position and orientation of optical elements in interferometric gravity wave detectors. Description of the VIRGO interferometer; Fine and coarse measurement scheme; Imaging system; Calculation of the mass coordinates.

  • Aspects of the suspension system for GEO 600 Plissi, M.V.; Plissi, M. V.; Strain, K.A.; Strain, K. A.; Torrie, C. I.; Robertson, N. A.; Killbourn, S.; Rowan, S.; Twyford, S. M.; Ward, H.; Skeldon, K. D.; Hough, J. // Review of Scientific Instruments;Aug1998, Vol. 69 Issue 8, p3055 

    Examines several aspects of the design, modeling and testing of a gravitational wave detector. Features of the isolation stack; Effects of seismic isolation on the sensitivity of the detector; Information on how the level of isolation is achieved; Details on the uses of the double pendulum.

  • Mechanical quality factor of large mirror substrates for gravitational waves detectors. Amico, P.; Bosi, L.; Carbone, L.; Gammaitoni, L.; Marchesoni, F.; Punturo, M.; Travasso, F.; Vocca, H. // Review of Scientific Instruments;Jan2002, Vol. 73 Issue 1, p179 

    Thermal noise in the mirror substrates sets a most severe limit to the low-frequency sensitivity of the interferometric gravitational wave detectors presently under construction. The mechanical quality of the mirror substrates and the geometry of their suspension are shown to affect markedly the...

  • Toward gravitational wave detection. Finn, L. S.; Gonzalez, G.; Hough, J.; Huq, M. F.; Mohanty, S.; Romano, J.; Rowan, S.; Saulson, P. R.; Strain, K. A. // AIP Conference Proceedings;2000, Vol. 523 Issue 1, p451 

    An overview of some tools and techniques being developed for data conditioning (regression of instrumental and environmental artifacts from the data channel), detector design evaluation (modeling the science “reach” of alternative detector designs and configurations), noise...

  • Validation of data in operating resonant detectors. Prodi, G. A.; Baggio, L.; Cerdonio, M.; Visconti, V. Crivelli; Martinucci, V.; Ortolan, A.; Taffarello, L.; Vedovato, G.; Vitale, S.; Zendri, J. P. // AIP Conference Proceedings;2000, Vol. 523 Issue 1, p345 

    Assessing the confidence of detection for candidate signals of gravitational waves is a particularly subtle matter. A fundamental step toward this achievement is the validation of the output data of the detectors involved. Here we present how this is accomplished in the operating resonant...

  • Bars in action. Coccia, Eugenio // AIP Conference Proceedings;2000, Vol. 523 Issue 1, p32 

    We report on the status of the five resonant-mass detectors of gravitational waves operating today in Australia, Italy and USA. These bar detectors are in continuous observational mode with burst sensitivity h=4×10[sup -19], or, in spectral units, 2×10[sup -22] Hz[sup -1/2] over...

  • Suspension design for GEO 600—an update. Robertson, N. A.; Cagnoli, G.; Hough, J.; Husman, M. E.; McIntosh, S.; Palmer, D.; Plissi, M. V.; Robertson, D. I.; Rowan, S.; Sneddon, P.; Strain, K. A.; Torrie, C. I.; Ward, H. // AIP Conference Proceedings;2000, Vol. 523 Issue 1, p313 

    The GEO 600 gravitational wave detector (1) is currently under construction at Ruthe, near Hannover in Germany. The design of the suspension system for the main mirrors in the detector has been chosen such that thermal noise due to the internal modes of the mirrors is expected to set the...

  • Active seismic isolation for enhanced LIGO detectors. Giaime, Joseph; Lantz, Brian; DeBra, Daniel; How, Jonathan; Hardham, Corwin; Richman, Sam; Stebbins, Robin // AIP Conference Proceedings;2000, Vol. 523 Issue 1, p300 

    The levels of seismic isolation needed for LIGO II will require a dramatic technological shift from the systems used in the initial LIGO detector. To take advantage of the improved thermal noise of a 30 kg test mass made of high-Q material and suspended with fused silica fibers, one must...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics