Conveners
Instrument Science (ISB)
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Instrument Science (ISB)
- There are no conveners in this block
Instrument Science (ISB)
- There are no conveners in this block
Instrument Science (ISB)
- There are no conveners in this block
Instrument Science (ISB)
- There are no conveners in this block
Instrument Science (ISB)
- Jan Harms
- Stefan Hild
Instrument Science (ISB)
- There are no conveners in this block
E-TEST is a low-frequency suspension prototype developed for the Einstein Telescope, featuring a 100-kg test mass cooled to cryogenic temperatures (20โ25 K) through radiative cooling techniques. The prototype is designed to provide compact seismic isolation at low frequencies (<10 Hz) while minimizing thermal noise, addressing the critical noise sources for next-generation gravitational-wave...
The 3rd generation instrument era is approaching, and the Einstein Telescope giant interferometer is becoming a reality with the possibility to install the detector in an underground site where seismic noise is 100 times smaller than on surface. Moreover, new available technologies and the experience acquired in operating advanced detectors are the key points to further extend the detection...
The CAOS (Center for Applications on Gravitational Waves and Seismology) laboratory, part of the ETIC (Einstein Telescope Infrastructure Consortium) project, represents a significant Italian initiative designed for advancing third-generation gravitational wave detector technologies. CAOS has been envisioned as a hub for collaborative innovation and testing, particularly focusing on the...
Current gravitational wave detectors are limited at frequencies below 10 Hz by sensing and control noise related to the active seismic isolation systems and their local displacement sensors.
In order to overcome these limitations, the use of new, more accurate local displacement sensors, has been proposed.
In this talk I present our current design for a compact local displacement sensor...
Fused silica fibres used in current ground-based gravitational wave detectors, such as Advanced LIGO, sustain loads of 40 kg with stresses reaching up to ~780 MPa in their thinnest regions. Reducing fibre diameter and increasing stress improves suspension thermal noise performance by improving damping dilution. In addition, the resonant modes are shifted to more favourable frequency ranges...
To reach higher sensitivities in the frequency band below 10 Hz in third generation terrestrial gravitational wave detectors, such as the Einstein Telescope, the individual noise sources must be addressed and their impact on the system reduced. One of these noise sources is thermal noise, to be addressed through operating ET at cryogenic temperatures.
The cooling of the detector will...
This study focuses on optimizing crystalline silicon triangular blade springs for the vertical suspension system of the Einstein Telescope (ET) to enhance cryogenic performance. By leveraging siliconโs high Q-factor and thermal conductivity, the design minimizes thermal noise and ensures efficient heat dissipation at low temperatures. Structural integrity is improved through material selection...
The test-masses for ET-LF present one of the most complex hardware design challenges in the whole project. We propose a conceptual design for the towers that is capable in principle of addressing several concerns: rigid mounting of the suspension system; interfaces with the cryogenic and cryogentic vacuum systems; and clean installation and access. The design simplifies the...
The Superattenuator has played a pivotal role in enabling the detection of gravitational wave signals in current generation interferometers down to an unprecedented 10 Hz, attenuating the ground motion at that frequency by many orders of magnitude. For next-generation gravitational wave detectors, aiming at improving the sensitivity by more than one order of magnitude and extending the...
Future gravitational wave observatories require significant advances in all aspects of their seismic isolation; inertial sensors being a pressing example. Inertial sensors using gram-scale, high Q factor, glass mechanical resonators combined with compact interferometric readout are promising alternatives to kilogram-scale conventional inertial sensors. We have developed a novel technique for...
We present the design and performance requirements of GEMINI, the first underground R&D facility dedicated to active seismic isolation and interplatform control for next-generation gravitational-wave observatories. The GEMINI site is located 1.4 km deep at the National Laboratories of Gran Sasso (LNGS). The facility consists of two actively isolated platforms operating in a vacuum, designed to...
Magnetic noise will pose a significant limitation on the sensitivity of future Gravitational Wave (GW) detectors, such as the Einstein Telescope (ET), especially at low frequencies from a few Hz to approximately 100 Hz. This noise primarily originates from two sources: the natural terrestrial component (Schumann Resonances) and the environmental noise associated with the interferometer...
Angular sensing and control (ASC) noise will play a crucial role in designing the low-frequency interferometer of the Einstein Telescope (ET). We have to ensure at an early design stage of the project that we can achieve tolerable levels of ASC noise that won't limit the target sensitivity of ET. ASC noise arises at the interface of the optical and mechanical systems and sets requirements on...
Correlated seismic noise and the resulting Newtonian noise (NN), pose a significant challenge for future gravitational-wave detectors like the Einstein Telescope (ET), especially for low-frequency gravitational-wave background (GWB) searches.
The body-wave-induced NN could significantly impact ET's sensitivity to GWB by orders of magnitude in its most sensitive frequency band.
This study...
The increasing power levels injected into interferometric gravitational wave detectors have highlighted the impact of localized defects on the high-reflectivity (HR) surfaces of the main optics. These defects, originating from coating inhomogeneities, substrate imperfections, or localized absorbers, can degrade detector performance by introducing aberrations in the optical wavefront, leading...
At the Department of Physics and Earth Sciences at the University of Ferrara we have a sensitive polarimeter for birefringence measurements of both substrates and coatings. In the configuration for substrate measurements the polarimeter is based on two co-rotating half-wave plates with the sample between them. The induced time dependent ellipticity signal is then extracted using a heterodyne...
We present an updated estimation of the noise induced by scattered light inside the main arms of the Einstein Telescope (ET) gravitational wave detector. Both ET configurations for high- and low-frequency interferometers are considered. The new studies include the cryotrap areas close to the main mirrors, consider both 10km and 15km arms, and explore possible mis-alignments of the laser beam...
As straylight is an important limitation for the sensitivity of gravitational wave detectors, we investigate new laser operation concepts and interferometer topologies for a more straylight-resilient detector configuration.
Our main focus is the use of tunable coherence realized by phase modulation following a pseudo-random-noise (PRN)-sequence on the interferometer laser. This breaks the...
Quantum noise is one of the main limitations to sensitivity in both the low- and high-frequency interferometers of ET. Reaching the design sensitivity requires the use of frequency-dependent squeezing, which relies on long filter cavities and minimizing losses throughout the entire interferometer. Achieving this is challenging, both technologically and fundamentally. However, considering the...
Quantum Noise (QN) limits the sensitivity of ground-based Gravitational Wave (GW) interferometers (ITF) across all the frequency bandwidth (10Hz - 10kHz) [1]. Current detectors are designed to achieve broadband QN Reduction (QNR) via frequency-dependent squeezing (FDS) generated in reflection of a 300 m long detuned filter cavity (FC) that is coupled with a frequency-independent squeezing...
Increasing the optical circulating power in gravitational-wave detectors is a straightforward way of increasing detection sensitivity. However, current detectors are limited in the amount of achievable circulating power far below the design values. Optical absorption in the test masses and main optics leads to thermal effects that shift the eigenmodes of the optical cavities and cause control...
The CAOS facility in Perugia serves as a specialized lab for testing mechanical and optical systems for the Einstein Telescope (ET). It will host a seismic-isolated Fabry-Perot cavity. The current research and development efforts include testing ET's full-sized Super Attenuators, creating integration tools and procedures for lateral-entry payload access at the base of the tower, and evaluating...
In the upcoming third generation of gravitational wave (GW) detectors, the unavoidable build-up of a frost layer on cryogenically cooled mirrors and their electrostatic charging may represent two potentially critical showstoppers for GW detection. We already proposed a possible mitigation solution for both such issues, relying on irradiation with low energy electrons (from 20 to few hundreds...
The Amaldi Research Center (ARC), located at Sapienza University of Rome, will host the first experiment of a cooling system designed for a full-scale cryogenic payload. Following the solid conduction cooling approach, two refrigeration lines, each driven by two Pulse Tube cryocoolers, will be used to cool down a cryogenic payload housed in a specially designed 3-meter-tall cryostat.
The...
A significant challenging feature of the ET vacuum system is the requirement on the hydrocarbon partial pressure ($p_{hy}$) for molecules heavier than 100 atomic mass unit (amu), as explained in the ET design report
\begin{equation}
p_{hy}\le1\cdot10^{-14}\,mbar
\end{equation}
In order to reach such an ambitious result, both the non volatile and volatile residue of hydrocarbons should...
The Glasgow Cryogenic Interferometer Facility (GCIF) is one of the prototype facilities working in the ET Collaboration to develop technology, demonstrate integration and prove the concepts and validate the technology readiness of critical elements for the cryogenic Einstein Telescope LF detector.
We report here on the progress of the instrument science program of the GCIF, including the...
