F. Basti

Bio: F. Basti is an academic researcher from Sapienza University of Rome. The author has contributed to research in topics: Gravitational-wave observatory & Payload. The author has an hindex of 1, co-authored 1 publications receiving 2 citations.

Research Facilities for Europe’s Next Generation Gravitational-Wave Detector Einstein Telescope

Abstract: The Einstein Telescope is Europe’s next generation gravitational-wave detector. To develop all necessary technology, four research facilities have emerged across Europe: The Amaldi Research Center (ARC) in Rome (Italy), ETpathfinder in Maastricht (The Netherlands), SarGrav in the Sos Enattos mines on Sardinia (Italy) and E-TEST in Liége (Belgium) and its surroundings. The ARC pursues the investigation of a large cryostat, equipped with dedicated low-vibration cooling lines, to test full-scale cryogenic payloads. The installation will be gradual and interlaced with the payload development. ETpathfinder aims to provide a low-noise facility that allows the testing of full interferometer configurations and the interplay of their subsystems in an ET-like environment. ETpathfinder will focus amongst others on cryogenic technologies, silicon mirrors, lasers and optics at 1550 and 2090 nm and advanced quantum noise reduction schemes. The SarGrav laboratory has a surface lab and an underground operation. On the surface, the Archimedes experiment investigates the interaction of vacuum fluctuations with gravity and is developing (tilt) sensor technology for the Einstein Telescope. In an underground laboratory, seismic characterisation campaigns are undertaken for the Sardinian site characterisation. Lastly, the Einstein Telecope Euregio meuse-rhine Site & Technology (E-TEST) is a single cryogenic suspension of an ET-sized silicon mirror. Additionally, E-TEST investigates the Belgian–Dutch–German border region that is the other candidate site for Einstein Telescope using boreholes and seismic arrays and hydrogeological characterisation. In this article, we describe the Einstein Telescope, the low-frequency part of its science case and the four research facilities.

Calculation of thermal radiation input via funneling through a duct shield with baffles for KAGRA

Abstract: Many studies worldwide are currently developing interferometric methods for detecting gravitational waves and one of the challenges in such methods has been to sufficiently cool the mirror in interferometric detectors in order to reduce thermal noise. Although the mirror is surrounded by a radiation shield, a hole in the shield is necessary to allow the laser beam to pass. To reduce the thermal radiation caused by the presence of the hole, we will install a duct shield with baffles. To calculate the heat input through the duct shield, we applied a ray trace model whose results were consistent with those of an experiment without baffles. As an application of our model, the heat input in the case of KAGRA (a Japanese cryogenic gravitational wave detector project) was calculated. Our analysis suggests that baffles in the duct shield can considerably reduce the heat input in KAGRA.

Computational Modelling of Amorphous mirror coatings for use in Advanced Gravitational wave detectors

Abstract: Albert Einstein in 1916 predicted the existence of a Gravitational Wave in his General Theory of Relativity. These waves, which propagate at the speed of light transmit gravitational information through the Universe. Since its prediction by Einstein, astronomers and physicists have searched for them and developed method to detect them. Though so far unsuccessful, the search of Gravitational waves goes on and great efforts are being made to develop the most sensitive detectors yet in the hope of that first detection. Currently ground based detectors are limited by coating Brownian thermal noise due to excitation of the reflective coatings applied to the test masses. Through measurement of mechanical loss of a material the magnitude of the Brownian thermal noise can be determined. It is necessary to determine the root cause of mechanical loss in current coatings (Ta2O5¬ and SiO2). Work towards this goal is taking place on multi paths, directly, through characterisation of mechanical loss and indirectly through microscopy studies to determine the structural cause. In this thesis, the effect of TiO2 doping and heat treatment of Ta2O5 has been investigated. It has been previously shown that a TiO2 doping of Ta2O5 reduces the mechanical loss and that, that reduction is at a maximum at 30% TiO2. It has been determined through Electron Diffraction experiments that the structure of TiO2 doped Ta2O5 becomes more homogenous up to 30% doping. Through computation modelling of these structures using Density Functional Theory it has also been determined that the abundance of TiTaO2 ring formations also maximises at 30% doping. Further modelling has also determined that the TiTaO2 rings are more flexible that their counter parts of Ta2O2 and Ti2O2. From this it has been hypothesised that the overall flexibility of a structure is a strong component of the mechanical response of the structure. Hence by increasing the flexibility through TiO2 doping the mechanical loss (as Thermal Noise) is decreased similarly and this response would also be expected using similarly flexibility improving dopants.

Cryogenic payloads for the Einstein Telescope - Baseline design with heat extraction, suspension thermal noise modelling and sensitivity analyses

Abstract: The Einstein Telescope (ET) is a third generation gravitational wave detector that includes a room-temperature high-frequency (ET-HF) and a cryogenic low-frequency laser interferometer (ET-LF). The cryogenic ET-LF is crucial for exploiting the full scientific potential of ET. We present a new baseline design for the cryogenic payload that is thermally and mechanically consistent and compatible with the design sensitivity curve of ET. The design includes two options for the heat extraction from the marionette, based on a monocrystalline high-conductivity marionette suspension fiber and a thin-wall titanium tube filled with static He-II, respectively. Following a detailed description of the design options and the suspension thermal noise (STN) modelling, we present the sensitivity curves of the two baseline designs, discuss the influence of various design parameters on the sensitivity of ET-LF and conclude with an outlook to future R&D activities.