Search results for "Instrument"
showing 10 items of 5652 documents
ATHENA X-IFU thermal filters development status toward the end of the instrument phase-A
2018
Copyright 2018 Society of Photo-Optical Instrumentation Engineers (SPIE). One print or electronic copy may be made for personal use only. Systematic reproduction and distribution, duplication of any material in this paper for a fee or for commercial purposes, or modification of the content of the paper are prohibited. The X-ray Integral Field Unit (X-IFU) is one of the two instruments of the Athena astrophysics space mission approved by ESA in the Cosmic Vision 2015-2025 Science Programme. The X-IFU consists of a large array of transition edge sensor micro-calorimeters that will operate at 100 mK inside a sophisticated cryostat. A set of thin filters, highly transparent to X-rays, will be m…
Thin plastic foil X-ray optics with spiral geometry
2007
Winding a plastic foil ribbon into spiral cylinder or spiral cones we can design and build single or multiple reflection X-ray grazing incidence focusing optics with potential applications in Astronomy as well as experimental physics. The use of thin plastic foils from common industrial applications and of a mounting technique which does not require the construction of mandrels make these optics very cost effective. A spiral geometry focusing optic produces an annular image of a point source with the angular size of the annulus depending mainly on the pitch of the winding and the focal length. We use a ray-tracing code to evaluate the performances of cylindrical, and double conical spiral g…
EBIT diagnostics using X-ray spectra of highly ionized Ne
2003
We have carried out a detailed analysis of highly ionized neon spectra collected at the NIST EBIT using an NTD germanium X-ray microcalorimeter developed at the Harvard-Smithsonian Center for Astrophysics [Nucl. Instr. and Meth. A 444 (2000) 156]. Our attention was focused especially on the Ne IX He-like triplet to check electron density diagnostics through the intercombination/forbidden line ratio. We have investigated possible effects of the ion dynamics on the plasma emission line intensities, looking at the dependence of the count-rate and the charge state distribution on the electron beam energy and current. The temperature and spatial distribution of the neon ions, and hence the overl…
The LOFT mission concept: a status update
2016
The Large Observatory For x-ray Timing (LOFT) is a mission concept which was proposed to ESA as M3 and M4 candidate in the framework of the Cosmic Vision 2015-2025 program. Thanks to the unprecedented combination of effective area and spectral resolution of its main instrument and the uniquely large field of view of its wide field monitor, LOFT will be able to study the behaviour of matter in extreme conditions such as the strong gravitational field in the innermost regions close to black holes and neutron stars and the supra-nuclear densities in the interiors of neutron stars. The science payload is based on a Large Area Detector (LAD, >8m2 effective area, 2-30 keV, 240 eV spectral resolut…
IBIS: The Imager on-board INTEGRAL
2003
The IBIS telescope is the high angular resolution gamma-ray imager on-board the INTEGRAL Observatory, successfully launched from Baikonur (Kazakhstan) the 17th of October 2002. This medium size ESA project, planned for a 2 year mission with possible extension to 5, is devoted to the observation of the gamma-ray sky in the energy range from 3 keV to 10 MeV (Winkler 2001). The IBIS imaging system is based on two independent solid state detector arrays optimised for low ( 15-1000 keV) and high ( 0.175-10.0 MeV) energies surrounded by an active VETO System. This high efficiency shield is essential to minimise the background induced by high energy particles in the highly excentric out of van All…
Science case study and scientific simulations for the enhanced X-ray Timing Polarimetry mission, eXTP
2022
The X-ray astronomy mission eXTP (enhanced X-ray Timing Polarimetry) is designed to study matter under extreme conditions of density, gravity and magnetism. Primary goals are the determination of the equation of state (EoS) of matter at supranuclear density, the physics in extremely strong magnetic fields, the study of accretion in strong-field gravity (SFG) regime. Primary targets include isolated and binary neutron stars, strong magneticfield systems like magnetars, and stellar-mass and supermassive black holes. In this paper we report about key observations and simulations with eXTP on the primary objectives involving accretion under SFG regimes and determination of NS-EoS.
A database for historical pigments through handheld instrumentation
2020
Portable instrumentation is largely used in archaeometry for in-field measurements at museums and archaeological sites. The historic evolution of pigments is closely related to the technology developments in past cultures and provides relevant clues regarding their knowledge advancement. Here, a systematic study of 26 historical powdered pigments was carried out through a combined handheld instrumentation for X-ray Fluorescence. Chemical identification was carried out through a set of instrumentation produced by different manufacturers. Their performances are compared on the same set of samples to identify best practices for the study of historical pigments. A database of organic and inorga…
First Dark Matter Search Results from the XENON1T Experiment
2017
We report the first dark matter search results from XENON1T, a ∼2000-kg-target-mass dual-phase (liquid-gas) xenon time projection chamber in operation at the Laboratori Nazionali del Gran Sasso in Italy and the first ton-scale detector of this kind. The blinded search used 34.2 live days of data acquired between November 2016 and January 2017. Inside the (1042±12)-kg fiducial mass and in the [5,40] keVnr energy range of interest for weakly interacting massive particle (WIMP) dark matter searches, the electronic recoil background was (1.93±0.25)×10-4 events/(kg×day×keVee), the lowest ever achieved in such a dark matter detector. A profile likelihood analysis shows that the data are consisten…
Study of optical absorbance and MR relaxation of Fricke xylenol orange gel dosimeters
2017
Abstract Studies on the optical absorbance spectra of Fricke xylenol orange gel dosimeters were performed, in the wavelength range from 300 nm to 800 nm, in order to highlight some particular characteristics that can affect the achievable precision. The spectra are different mainly due to the different types of xylenol orange that was used and to a lower extent due to the different gelling agents (agarose or gelatine). The characteristic of variation of absorbance spectra versus dose, however, are similar in the various cases and can explain some peculiarities, as apparent effects of dose threshold. Changes of spectral shapes appear over the time after irradiation. Magnetic resonance measur…
An experimental analysis of self-Q-switching via stimulated Brillouin scattering in an ytterbium doped fiber laser
2013
An experimental study of self-Q-switching (SQS) in an ytterbium doped fiber laser (YDFL) arranged using a twin-core GTWave assembly is reported. The main mechanisms that initiate, amplify, and limit SQS pulses in amplitude are revealed to be stimulated Brillouin and Raman scattering (SBS/SRS) and Yb3+ amplified spontaneous emission. The parameters featuring SQS oscillation in terms of efficiency and stability of pulsing are found to be intra-cavity loss and feedback strength. An analysis of the YDFL SQS regime?s features?pulsing time series, optical and RF spectra, amplitude and timing jitter?is provided for the two experimental situations: (i) when SQS pulsing stochastically intermits with…