UID:
kobvindex_GFZ1700304968
Format:
xxix, 177 Seiten
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Illustrationen, Diagramme
ISSN:
0174-1454
Series Statement:
Wissenschaftliche Arbeiten der Fachrichtung Geodäsie und Geoinformatik der Leibniz Universität Hannover Nr. 351
Note:
Dissertation, Gottfried Wilhelm Leibniz Universität Hannover, 2019
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Contents
1. Introduction
1.1. Motivations and background
1.2. Research hypotheses and aims
1.3. Outline of this work
2. Fundamentals and theory of seismic noise
2.1. Fundamentals of mechanical vibration
2.1.1. Theory of oscillation
2.1.1.1. Oscillation and waves
2.1.1.2. Standing waves and resonance
2.1.1.3. Types of noise
2.1.1.4. Signal-to-Noise Ratio
2.1.2. The oscillatory systems
2.1.2.1. Mass-Spring-Damper model
2.1.2.2. Equation of motion
2.1.2.3. Free damped oscillation
2.1.2.4. Forced damped oscillation
2.1.3. Modal analysis
2.1.3.1. Fourier transform
2.1.3.2. Windowing
2.1.3.3. Averaging and overlapping
2.1.4. Data evaluation
2.1.4.1. Presenting spectra and spectral densities
2.1.4.2. RMS value in the frequency domain
2.1.4.3. Transfer function
2.1.4.4. Spectrogram
2.2. Seismic noise sources
2.2.1. Natural sources
2.2.1.1. Geodynamical aspects
2.2.1.2. Geological aspects at Hamburg, DESY
2.2.2. Human-made sources
2.2.2.1. Impact by stationary objects
2.2.2.2. Impact by traffic on site, machines and human work
2.2.2.3. Technical devices in the laboratory
2.3. Methods of seismic isolation
2.3.1. Passive constructions
2.3.1.1. Principle of a simple pendulum
2.3.1.2. Principle of a spring pendulum
2.3.1.3. The inverted pendulum concept
2.3.1.4. The anti-spring concept
2.3.1.5. The harmonic oscillator as transfer function
2.3.2. Control theory
2.3.2.1. Simple controller
2.3.2.2. Feed-forward controller
2.3.2.3. Feedback controller
2.3.2.4. Combined controller
3. The Any Light Particle Search experiment
3.1. ALPS and its seismic noise requirements
3.1.1. The physics of ALPS
3.1.2. Optical resonators
3.1.3. Control loop design
3.1.4. Frequency region and absolute length requirements
3.1.5. Infrastructure and status
3.2. Tools and techniques used for seismicmeasurements, analyses, and isolations
3.2.1. Seismic measuring instruments
3.2.1.1. Seismometers
3.2.1.2. Acquisition devices
3.2.1.3. Selected measurement chain
3.2.2. Data management and analyses
3.2.2.1. Notations for documentation
3.2.2.2. Analysing procedure
3.2.3. Finite Element Method simulation
3.2.3.1. Simple isolation simulations
3.2.3.2. Over-determined isolation systems
3.2.3.3. Selected FEM tools
4. Seismic noise analysis 57
4.1. Method of frequency-weighted and averaged FFT
4.1.1. Problem definition and motivation
4.1.2. The solution approaches
4.1.2.1. Stitching
4.1.2.2. LPSD
4.1.2.3. New solution approach
4.1.3. The MfwaFFT algorithm
4.1.3.1. Data preparation
4.1.3.2. FFT generation
4.1.3.3. Windowing of the iteration steps
4.1.3.4. Weighting
4.1.3.5. Summing up
4.1.4. Advantages and disadvantages
4.1.5. Discussion in the field of geodesy
4.2. Measurement Preparation
4.2.1. Calibration of seismic devices
4.2.1.1. Single instruments
4.2.1.2. Cross-calibration
4.2.2. Accuracy analysis
4.2.2.1. Measuring device accuracy and precision
4.2.2.2. Digital uncertainties and errors
4.3. Seismic measurements on-site
4.3.1. On-site noise conditions (HERA)
4.3.1.1. ALPS IIa laboratory (HERA West)
4.3.1.2. ALPS IIc site (HERA North)
4.3.1.3. Reference (HERA South)
4.3.2. Optic-related components of the ALPS II experiment
4.3.2.1. Optical tables
4.3.2.2. CBB and mirror mountings
4.3.3. Associated noise sources
4.3.3.1. Dipole magnet girders
4.3.3.2. Filter Fan Units
4.4. Filtering of signal
4.4.1. Spatial transfer functions
4.4.2. Low-pass filter due to the cavity pole frequency
4.4.3. Filter by the control loop
4.5. Data evaluation
4.5.1. Specifications for the ALPS IIa isolation
4.5.2. Specifications for an ALPS IIc isolation
4.5.3. Specifications for a JURA isolation
5. Development of seismic isolation systems
5.1. Procedure for handling seismic noise and isolation problems
5.2. State-of-the-art seismic isolation concepts
5.2.1. The LIGO system
5.2.2. The VIRGO system
5.3. Development of a seismic isolation system
5.3.1. CAD draft of a test model
5.3.2. FEM simulations
5.3.3. Design drawing
5.3.4. Evaluation and validation
5.4. Seismic isolation concept for ALPS IIc and JURA
6. Conclusion
6.1. Summary
6.2. Outlook
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Sprache der Zusammenfassungen: Englisch, Deutsch
In:
Wissenschaftliche Arbeiten der Fachrichtung Geodäsie und Geoinformatik der Leibniz Universität Hannover, Nr. 351
Language:
English
Keywords:
Hochschulschrift
URL:
https://www.repo.uni-hannover.de/handle/123456789/9921
