Project C4;     (2003 - 2014)

 Project List   Abstracts   All Publications 

A1  A2  A4  A5  A7  B1  B2  B3  B4  B5  B6  B7  B8  B9  B10  C1  C2  C3  C4  C5  C6  C7  C8  C9  C10  Ö

 

Quality Factor Measurements at Cryogenic Temperatures

    Principal Investigators: R. Nawrodt, P. Seidel, A. Tünnermann

One of the fundamental sensitivity limits of gravitational wave detectors is the thermal noise of the test masses. An extensive improvement would be achieved by decreasing the operating temperature down to cryogenic temperatures while using test masses with high quality factors in this region. Therefore, measurements of the Q-factor of promising materials are done in project C4 in a temperature range from 300 K down to 5 K. These measurements reveal different kinds of damping mechanisms. In conjunction with the theoretical interpretation this contribution to the understanding of mechanical losses in solids leads to a controlled lowering of thermal noise.

Gravitational wave detectors currently in use are limited by different kinds of noise. One fundamental noise of these detectors will be its thermal noise arising from statistical motion of the optical components.

By the use of resonant systems (e.g. test masses suspended as pendulums) it is possible to shape the spectral density of the thermal energy in a way that most of it is stored around the resonances of the system. These resonances lie out of the detection band of the gravitational wave detector. Therefore, all spectral components around the resonances does not influence the measurement. To store as much energy at the resonances as possible high-Q materials are needed. In addition, cooling will also decrease the thermal noise in the detection band. To gain the maximum sensitivity materials with a high Q-factor at low temperatures need to be found.

Until now only insufficient information about the dependence of the Q-factor on different properties exists. Only three groups in the world (the Tokyo group, the Glasgow group, and the project C4 of this SFB) are performing these Q-measurements at low temperatures focusing on different materials.

Surface roughness, doping or crystal orientation strongly influence the mechanical Q. By changing the temperature new fundamental relaxation processes occur. The project C4 investigates the dependence of the Q-factor on the properties given above in regard to the sample temperature. This enables the researchers to identify the internal processes which lead to internal damping.

To form an optical component the low-loss material has to be provided with optical coatings to form a mirror or beam-splitter. These layers are strongly contributing to thermal noise as well. Only first preliminary measurements exist about the influence of coatings to the mechanical Q-factor of a test sample. The project C4 experimentally investigates the dependence of the layer's Q-factor on the coating parameters and the coating/bulk material surface. In collaboration with the project C3 the influence of specific surface structuring on the noise properties at low temperatures is researched.

Accompanying theoretical research in solid state physics to interpret the measurements provides a better understanding of the loss mechanisms in solids and therefore the thermal noise.

Additionally, other thermal and mechanical properties are analyzed, e.g. thermal conductivity or breaking strength at cryogenic temperatures of suspension fibers. This contributes to the development of high-Q low temperature optics which will be used in the third generation of gravitational wave detectors.

Because thermal noise is one of the fundamental sensitivity limits of gravitational wave detectors any type of future detector concept will benefit from these results.

Researchers

  Ronny Nawrodt   Postdoc, 2005 PI 2010
  Paul Seidel   Professor, PI 2003
  Rene Glaser   Student, 2013
  Daniel Heinert   Postdoc, 2007
  Gerd Hofmann   PhD Student, 2008
  Philip Pastrik   Student, 2014
  Christian Schwarz   Postdoc, 2006
  Brian Seyfarth   Student, 2013

Former Associates
  Ellen Butz   Student, 2012-2013
  Tina Clauss   Student, 2003-2004
  Inga-Maria Eichentopf   Student, 2004
  Andreas Falk   Student, 2008
  Veit Grosse   PhD Student, 2008
  Reschad Habibi   Student, 2010
  Christoph Heilmann   Student, 2009-2010
  Matthias Hudl   Student, 2007
  Thomas Kiefer   Student, 2003-2004
  Anika Kirschstein   Student, 2005-2006
  Torsten Koettig   PhD Student, 2003-2007
  Julius Komma   Student, 2008-2010
  Stefanie Kroker   Student, 2006-2009
  Sandor Nietzsche   Postdoc, 2003-2006
  Stefan Noack   Student, 2011
  Paul Petruck   Student, 2004
  Torsten Pliewischkies   Student, 2009
  Anja Schröter (geb. Zimmer)   PhD Student, 2003-2007
  Frederik Tuitje   Student, 2013
  Albrecht Töpfer   Student, 2013-2014
  Wolfgang Vodel   Senior, PI 2003-2009
  Bastian Walter   Student, 2012-2014
  Charlotte Weiss   Student, 2007

Publications

[1] Database of Bulk Material Properties
D. Heinert, C. Schwarz, G. Hofmann, J. Komma, R. Nawrodt, ET technical report ET-0001A-14

[2] Thermal noise of folding mirrors
D. Heinert, K. Craig, H. Grote, S. Hild, H. Lück, R. Nawrodt, D. A. Simakov, D. V. Vasilyev, S. P. Vyatchanin, H. Wittel, Phys. Rev. D 90 (2014) 042001

[3] Silicon mirror suspensions for gravitational wave detectors
A. V. Cumming, L. Cunningham, G. D. Hammond, K. Haughian, J. Hough, S. Kroker, I. W. Martin, R. Nawrodt, S. Rowan, C. Schwarz, A. A. van Veggel, Class. Quantum Grav. 31 (2014) 025017

[4] Evaluation of heat extraction through sapphire fibers for the GW observatory KAGRA
A. Khalaidovski, G. Hofmann, D. Chen, J. Komma, C. Schwarz, C. Tokoku, N. Kimura, T. Suzuki, A. O. Scheie, E. Majorana, R. Nawrodt, K. Yamamoto, Class. Quantum Grav. 31 (2014) 106004

[5] Measurement of the mechanical loss of prototype GaP/AlGaP crystalline coatings for future gravitational wave detectors
A. Cumming, K. Craig, I. Martin, R. Bassiri, L. Cunningham, M. Fejer, J. Harris, K. Haughian, D. Heinert, B. Lantz, A. Lin, A. Markosyan, R. Nawrodt, R. Route, S. Rowan, accepted at Class. Quantum Grav. (2014)

[6] Fluctuation-Dissipation at Work: Thermal Noise in Reflective Optical Coatings for GW Detectors
D. Heinert, G. Hofmann, R. Nawrodt, IEEE proceeding (2014), Metrology for Aerospace (MetroAeroSpace)

[7] The Einstein Telescope
S. Kroker, R. Nawrodt, IEEE proceeding (2014), Metrology for Aerospace (MetroAeroSpace)

[8] Mechanical loss in bulk materials
R. Nawrodt, D. Heinert, G. Hofmann, P. Murray, C. Schwarz, ET technical report ET-0002A-13

[9] Investigation of mechanical losses of thin silicon flexures at low temperatures
R. Nawrodt, C. Schwarz, S. Kroker, I. W. Martin, R. Bassiri, F. Brückner, L. Cunningham, G. D. Hammond, D. Heinert, J. Hough, T. Käsebier, E. B. Kley, R. Neubert, S. Reid, S. Rowan, P. Seidel, A. Tünnermann, Class. Quantum Grav. 30 (2013) 115008

[10] Calculation of thermal noise in grating reflectors
D. Heinert, S. Kroker, D. Friedrich, S. Hild, E.-B. Kley, S. Leavey, I. W. Martin, R. Nawrodt, A. Tünnermann, S. P. Vyatchanin, K. Yamamoto, Phys. Rev. D 88 (2013) 042001

[11] Scientific objectives of Einstein Telescope
B. Sathyaprakash et al. (including D. Heinert, R. Nawrodt, C. Schwarz, P. Seidel), Class. Quantum Grav. 29 (2013) 124013

[12] Mechanical spectroscopy of silicon as a low loss material for high precision mechanical and optical experiments
C. Schwarz, D. Heinert, K. Haughian, G. Hofmann, J. Komma, I. W. Martin, P. Murray, S. Rowan, P. Seidel, R. Nawrodt, Solid State Phenomena 184 (2012) 443-8

[13] Reduction of coating thermal noise by using an etalon
K. Somiya, A. G. Gurkovsky, D. Heinert, S. Hild, R. Nawrodt, S. P. Vyatchanin, Phys. Lett. A 375 (2011) 1363

[14] Reducing thermal noise in future gravitational wave detectors by employing Khalili etalons
A. G. Gurkovsky, D. Heinert, S. Hild, R. Nawrodt, K. Somiya, S. P. Vyatchanin, H. Wittel, Phys. Lett. A 375 (2011) 4147

[15] Thermorefractive noise of finite-sized cylindrical test masses
D. Heinert, A. G. Gurkovsky, R. Nawrodt, S. P. Vyatchanin, K. Yamamoto, Phys. Rev. D 84 (2011) 062001

[16] The effect of a laser beam displacement on parametric oscillatory instabilities for Advanced LIGO
D. Heinert, S. Strigin, Phys. Lett. A 375 (2011) 3804

[17] Sensitivity studies for third-generation gravitational wave observatories
S. Hild et al. (including D. Heinert, R. Nawrodt, C. Schwarz, P. Seidel), Class. Quantum Grav. 28 (2011) 094013

[18] Mechanical loss of calcium fluoride at cryogenic temperatures
C. Schwarz, D. Heinert, P. Seidel, A. Tünnermann, G. D. Hammond, R. Nawrodt, Phys. Status Solidi A 208 (2011) 2719

[19] Acoustic losses in a thick quartz plate at low temperatures
A. Grib, D. Heinert, R. Nawrodt, C. Schwarz, V. Grosse, P. Seidel, I. Martin, S. Rowan, J. Hough, J. Appl. Phys. 107 (2010) 013504

[20] The third generation of gravitational wave observatories and their science reach
M. Punturo et al. (including D. Heinert, R. Nawrodt, C. Schwarz, P. Seidel), Class. Quantum Grav. 27 (2010) 084007

[21] The Einstein Telescope: a third-generation gravitational wave observatory
M. Punturo et al. (including D. Heinert, R. Nawrodt, C. Schwarz, P. Seidel), Class. Quantum Grav. 27 (2010) 194002

[22] Potential mechanical loss mechanisms in bulk materials for future gravitational wave detectors
D. Heinert, A. Grib, K. Haughian, J. Hough, S. Kroker, P. Murray, R. Nawrodt, S. Rowan, C. Schwarz, P. Seidel, A. Tünnermann, Journal of Physics: Conference Series 228 (2010) 012032

[23] Effect of heat treatment on mechanical dissipation in Ta2O5 coatings
I. W. Martin et al. (including R. Nawrodt, C. Schwarz, P. Seidel), Class. Quantum Grav. 27 (2010) 225020

[24] Cryogenic Setup for Q-factor measurements on bulk materials for future gravitational wave detectors
R. Nawrodt, C. Schwarz, D. Heinert, M. Thuerk, R. Neubert, W. Vodel, A. Tuennermann, P. Seidel, Proceedings of ICEC22, The Korea Institute of Applied Superconductivity and Cryogenics 2009, 978-89-957138-2-2

[25] Comparison of the temperature dependence of the mechanical dissipation in thin films of Ta2O5 and Ta2O5 doped with TiO2
I. W. Martin, E. Chalkley, R. Nawrodt, H. Armandula, R. Bassiri, C. Comtet, M. M. Fejer, A. Gretarsson, G. Harry, D. Heinert, J. Hough, I. MacLaren, C. Michel, J.-L. Montorio, N. Morgado, S. Penn, S. Reid, R. Rout, S. Rowan, P. Seidel, W. Vodel, A. L. Woodcraft, Class. Quantum Grav. 26 (2009) 155012

[26] Mirror thermal noise in laser interferometric gravitational wave detectors operating at room and cryogenic temperature
J. Franc, N. Morgado, R. Flaminio, R. Nawrodt, I. Martin, L. Cunningham, A. Cumming, S. Rowan, J. Hough, ET technical report ET-021-09 (2009)

[27] Mirror thermal noise calculation for ET
R. Nawrodt, L. Cunningham, R. Flaminio, J. Franc, D. Heinert, J. Hough, I. Martin, N. Morgado, S. Rowan, C. Schwarz, P. Seidel, ET technical report ET-027-09 (2009)

[28] Measurements of a low-temperature mechanical dissipation peak in a single layer of Ta2O5 doped with TiO2
I. Martin, H. Armandula, C. Comtet, M. M. Fejer, A. Gretarsson, G. Harry, J. Hough, J.-M. M. Mackowski, I. MacLaren, C. Michel, J.-L. Montorio, N. Morgado, R. Nawrodt, S. Penn, S. Reid, A. Remillieux, R. Route, S. Rowan, C. Schwarz, P. Seidel, W. Vodel, A. Zimmer, Class. Quantum Grav. 25 (2008) 055005

[29] High mechanical Q-factor measurements on silicon bulk samples
R. Nawrodt, A. Zimmer, T. Koettig, C. Schwarz, D. Heinert, M. Hudl, R. Neubert, M. Thuerk, S. Nietzsche, W. Vodel, P. Seidel, A. Tuennermann, Journal of Physics: Conference Series 122 (2008) 012008

[30] High Mechanical Q-factor Measurements on Calcium Fluoride at Cryogenic Temperatures
R. Nawrodt, A. Zimmer, T. Koettig, S. Nietzsche, M. Thuerk, W. Vodel, P. Seidel, Eur. Phys. J. Appl. Phys. 38 (2007) 53

[31] Cryogenic resonant acoustic spectroscopy of bulk materials (CRA spectroscopy)
A. Zimmer, R. Nawrodt, T. Koettig, R. Neubert, M. Thuerk, W. Vodel, A. Tünnermann, P. Seidel, Rev. Sci. Instrum. 78 (2007) 063905 1

[32] Mechanical Q-factor measurements on a test mass with a structured surface
R. Nawrodt, A. Zimmer, T. Koettig, T. Clausnitzer, A. Bunkowski, E. B. Kley, R. Schnabel, K. Danzmann, S. Nietzsche, W. Vodel, A. Tuennermann, P. Seidel, New J. Phys. 9 (2007) 225

[33] Mechanical losses in low loss materials studied by Cryogenic Resonant Acoustic spectroscopy of bulk materials (CRA spectroscopy)
A. Zimmer, R. Nawrodt, D. Heinert, C. Schwarz, M. Hudl, T. Koettig, W. Vodel, A. Tuennermann, P. Seidel, Journal of Physics: Conference Series 92 (2007) 012095.

[34] High-sensitivity tool for studying phonon related mechanical losses in low loss materials
D. Heinert, A. Zimmer, R. Nawrodt, T. Koettig, C. Schwarz, M. Hudl, W. Vodel, A. Tuennermann, P. Seidel, Journal of Physics: Conference Series 92 (2007) 012183

[35] Cryogenic Q-factor measurement of optical substrate materials
S. Nietzsche, R. Nawrodt, A. Zimmer, M. Thuerk, W. Vodel, P. Seidel, Journal of Physics: Conference Series 32 (2006), 445

[36] Cryogenic Q-factor measurement of optical substrates for optimization of gravitational wave detectors
S. Nietzsche, R. Nawrodt, A. Zimmer, R. Schnabel, W. Vodel, P. Seidel, Supercond. Sci. Technol. 19 (2006), S293

[37] A new apparatus for mechanical Q-factor measurements between 5 and 300 K
R. Nawrodt, A. Zimmer, S. Nietzsche, M. Thuerk, W. Vodel, P. Seidel, Cryogenics 46 (2006), 718

[38] Proposed cryogenic Q-factor measurement of mirror substrates
S. Nietzsche, A. Zimmer, W. Vodel, M. Thürk, F. Schmidl, P. Seidel, Class. Quantum Grav. 21 (2004), 1133

[39] Kryotechnische Aspekte der Guetemessung an optischen Substraten fuer Gravitationswellendetektoren
R. Nawrodt, A. Zimmer, M. Thuerk, 31. Deutsche Kaelte-Klima-Tagung, Bremen 2004, DKV-Tagungsbericht 2004, ISBN 3-932-71536-5.

Theses

[40] Mechanische Verlustmessungen an Materialien füur die Präzisionsmesstechnik
C. Schwarz, PhD Thesis

[41] Thermisches Rauschen in interferometrischen Gravitationswellendetektoren
D. Heinert, PhD Thesis

[42] Kryogene Gütemessung an optischen Substratmaterialien für zukünftige Gravitationswellendetektoren
R. Nawrodt, PhD Thesis

[43] Mechanical losses in materials for future gravitational wave detectors
A. Schröter, PhD Thesis

[44] Mechanische Verluste in Festkörpern
D. Heinert, Diploma Thesis

[45] Untersuchung von mechanischen Dämpfungsvorgängen in dielektrischen Schichten
M. Hudl, Diploma Thesis

[46] Kryogene Gütemessung an optischen Substraten für Gravitationswellendetektoren
Ch. Schwarz, Diploma Thesis

[47] Charakterisierung mechanischer Verluste dielektrischer Schichten bei kryogenen Temperaturen
S. Kroker, Diploma Thesis

[48] Mechanische Spektroskopie an verlustarmen Materialien
C. Heilmann, Diploma Thesis

[49] Charakterisierung von Bulk-Materialien bei tiefen Temepraturen
G. Hofmann, Diploma Thesis

[50] Messung und Charakterisierung von optischen Schichten für die Präzisionsmesstechnik
J. Komma, Diploma Thesis

[51] Untersuchung des mechanischen Verlustes amorpher Tantalpentoxid-Schichten
B. Walter, BSc Thesis

[52] Herstellung und Charakterisierung von Si-Cantilevern
E. Butz, BSc Thesis

[53] Untersuchung des mechanischen Verlusts im thermischen Nichtgleichgewicht
R. Glaser, BSc Thesis

[54] Verlustuntersuchungen an dielektrischen Materialien
B. Walter, MSc Thesis