F. Paoletti
A5049921906- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Geophysics and Gravity Measurements
- Magnetic confinement fusion research
- Geophysics and Sensor Technology
- Astrophysics and Cosmic Phenomena
- Astrophysical Phenomena and Observations
- Seismic Waves and Analysis
- Cosmology and Gravitation Theories
- Advanced Frequency and Time Standards
- Ionosphere and magnetosphere dynamics
- Particle accelerators and beam dynamics
- Radio Astronomy Observations and Technology
- Superconducting Materials and Applications
- Particle Detector Development and Performance
- High-pressure geophysics and materials
- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Solar and Space Plasma Dynamics
- Plasma Diagnostics and Applications
- Astronomical Observations and Instrumentation
- Fusion materials and technologies
- Laser-Plasma Interactions and Diagnostics
- Particle Accelerators and Free-Electron Lasers
- Statistical and numerical algorithms
Istituto Nazionale di Fisica Nucleare, Sezione di Pisa
2015-2024
University of Pisa
2004-2022
European Gravitational Observatory
2011-2022
Institut National de Physique Nucléaire et de Physique des Particules
2004-2022
Université Paris-Saclay
2022
Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2022
Centre National de la Recherche Scientifique
2010-2022
University of Naples Federico II
2022
Istituto Nazionale di Geofisica e Vulcanologia
2022
University of Antwerp
2022
The National Spherical Torus Experiment (NSTX) is being built at Princeton Plasma Physics Laboratory to test the fusion physics principles for spherical torus concept MA level. NSTX nominal plasma parameters are R0 = 85 cm, a 67 R/a ⩾ 1.26, Bt 3 kG, Ip 1 MA, q95 14, elongation κ ⩽ 2.2, triangularity δ 0.5 and pulse length of up 5 s. heating/current drive tools high harmonic fast wave (6 MW, s), neutral beam injection (5 80 keV, s) coaxial helicity injection. Theoretical calculations predict...
We report on the status of Virgo detector, under commissioning. will focus last year's activity. The two commissioning runs performed during 2005 allowed us to reach a sensitivity h ∼ 6 × 10 −22 . data obtained were used test few analysis algorithms, namely coalescing binaries and burst searches. main improvements made detector this year be described, as well plans activities foreseen in coming years.
We report correlations in underground seismic measurements with horizontal separations of several hundreds meters to a few kilometers the frequency range 0.01Hz 40Hz. These could threaten science goals planned interferometric gravitational-wave detectors such as Einstein Telescope well atom interferometers MIGA and ELGAR. use from four different sites, i.e. former Homestake mine (USA) two candidate sites for Telescope, Sos Enattos (IT) Euregio Maas-Rhein (NL-BE-DE) site housing detector,...
Research in NSTX has been conducted to establish spherical torus plasmas be used for high β, auxiliary heated experiments. This device a major radius R0 = 0.86 m and midplane halfwidth of 0.7 m. It operated with toroidal magnetic field B0 ⩽ 0.3 T Ip 1.0 MA. The evolution the plasma equilibrium is analysed between discharges an automated version EFIT code. Limiter, double null lower single diverted configurations have sustained several energy confinement times. stored reached 92 kJ (βt 17.8%)...
Correlated magnetic noise from Schumann resonances threatens to contaminate the observation of a stochastic gravitational-wave background in interferometric detectors. In previous work, we reported on first effort eliminate global correlated using Wiener filtering, demonstrating as much factor two reduction coherence between magnetometers different continents. this present results dedicated magnetometer measurements at Virgo and KAGRA sites, which are for subtraction data detector sites. We...
By incorporating parametric instabilities of lower hybrid (LH) waves into a ray-tracing Fokker-Planck code, accurate simulations the LH deposition profiles are provided, which useful for interpreting long-lasting internal transport barriers (ITBs) sustained by current drive (LHCD) on JET (Joint European Torus). Utilizing new model, simulation $q$-profile evolution results in agreement with that provided motional Stark effect reconstructed equilibria. Low magnetic shear...
In order to explain the results of non-inductive current produced in lower hybrid drive (LHCD) experiments, a broadening radiofrequency (RF) power spectrum coupled tokamak plasma needs occur. The presented modelling, supported by diagnostic measurements, shows that parametric instability (PI) driven ion sound quasimodes, which occur scrape-off layer located near antenna mouth, produces significant launched LH spectrum. Considering parameters LHCD experiments JET (Joint European Torus), and...
Density changes in the atmosphere produce a fluctuating gravity field that affect strainmeters or gradiometers used for detection of gravitational-waves and geophysical applications. This work addresses impact atmospheric local noise on such detectors, extending previous analyses. In particular we present effect introduced by building housing analyze gravity-noise suppression constructing detector underground. We also new sound spectra correlations measurements. The results obtained are...
Fast radio bursts (FRBs) are short (millisecond) pulses originating from enigmatic sources at extragalactic distances so far lacking a detection in other energy bands. Magnetized neutron stars (magnetars) have been considered as the powering FRBs, but connection is controversial because of differing energetics and lack X-ray detections with similar characteristics two classes. We report here by AGILE satellite on April 28, 2020 an burst coincidence very bright Galactic magnetar SGR...
Below a few tens of hertz interferometric detection gravitational waves is masked by seismic vibrations the optical components. In order to isolate mirrors VIRGO interferometer, sophisticated suspension system, called superattenuator, has been developed. Its working principle based on multistage pendulum acting as chain second mechanical low-pass filters. A complete superattenuator built and tested. This apparatus allows extending band down Hz. detailed description attenuation system its...
Global magnetohydrodynamic (MHD) stability limits in the National Spherical Torus Experiment (NSTX) have increased significantly recently due to a combination of device and operational improvements. First, more routine H-mode operation with broadened pressure profiles allows access higher normalized β lower internal inductance. Second, correction poloidal field coil induced error-field has largely eliminated locked tearing modes during normal maximum achievable β. As result these...
The design of a new preisolator stage for the VIRGO superattenuator is presented. device essentially 6 m high inverted pendulum with horizontal resonant frequency 30 mHz. An isolation 65 dB at 1 Hz has been achieved. Very low forces are needed to move whole acting on pendulum. For this reason, system suitable platform active control mirror suspension.
VIRGO interferometer commissioning started in September 2003. The complete lock of the was achieved October 2004 via several steps. main activity deals with improvements stability and sensitivity. status advancement short-term plans are discussed here.
The important goal of adding to the bootstrap current a more flexible tool, capable producing and controlling steady-state profiles with high fraction non-inductive plasma current, could be reached using lower hybrid drive (LHCD) effect. Experiments performed on FTU (Frascati Tokamak Upgrade) demonstrated that LHCD can occur at reactor-graded density, provided parametric instability (PI)-produced broadening spectrum launched by antenna is reduced under proper operating conditions, relatively...
The first twenty years of operation gravitational-wave interferometers have shown that these detectors are affected by physical disturbances from the surrounding environment. These seismic, acoustic, or electromagnetic mainly produced experiment infrastructure itself. Ambient noise can limit interferometer sensitivity potentially generate transients non-astrophysical origin. Between 1 April 2019 and 27 March 2020, network second generation interferometers—LIGO, Virgo GEO—performed third...
Coaxial Helicity Injection (CHI) on the National Spherical Torus Experiment (NSTX) has produced 240kA of toroidal current without use central solenoid.Values multiplication ratio (CHI / injector current) up to 10 were obtained, in agreement with predictions.The discharges which lasted for 200ms, limited only by programmed waveform are more than an order magnitude longer duration that any CHI previously a Spheromak or (ST).
Application of Ion Bernstein Wave Heating (IBWH) into the Princeton Beta Experiment-Modification (PBX-M) [Phys. Fluids B 2, 1271 (1990)] tokamak stabilizes sawtooth oscillations and generates peaked density profiles. A transport barrier, spatially correlated with IBWH power deposition profile, is observed in core IBWH-assisted neutral beam injection (NBI) discharges. precursor to fully developed barrier seen soft x-ray data during edge localized mode (ELM) activity. Sustained operation...
Research on the stability of spherical torus plasmas at and above no-wall beta limit is being addressed National Spherical Torus Experiment [M. Ono et al., Nucl. Fusion 40, 557 (2000)], that has produced low aspect ratio plasmas, R/a∼1.27 plasma current exceeding 1.4 MA with high energy confinement (TauE/TauE_ITER89P>2). Toroidal normalized have exceeded 25% 4.3, respectively, in q∼7 plasmas. The observed to increase then saturate increasing li. factor βN/li reached 6, limited by...
In this paper we analyse the noise level induced by changes in mass density distribution around Virgo interferometric antenna. These stochastic fluctuations generate a gravitational field which couples directly to mirrors of optical apparatus, and it could be relevant if planned final sensitivity interferometer is reached.
The commissioning of the Virgo gravitational wave detector has restarted after several major hardware upgrades carried out during winter 2005. Now is fully operative and its sensitivity greatly improved continually improving. A program short scientific data taking already started moving towards a period continuous taking, which should start at end May 2007. actual status reported, describing as well limiting noises mid-term plans.