Search results for "spectrometer"
showing 10 items of 751 documents
Rock paintings from Minas Gerais, Brasil, investigated by in-situ Mössbauer spectroscopy
2002
The archaeological site of Santana do Riacho is located at about 90 km northeastern of Belo Horizonte, in the “Serra do Cipo” region. The recent development of a miniaturised Mossbauer spectrometer opened the possibility of making in-situ measurements of the rock paitings, and the results of such pioneer work is presented in this contribution. The spectrometer MIMOS II operates in backscattering geometry measuring the scattered 14.41 keV Mossbauer radiation and the 6.4 keV Fe X-rays. The dimensions of the whole instrument are approximately 110 mm (long) × 80 mm (diameter). The paintings were selected based on their colours and apparent thickness, and six spots were measured. The analysis of…
On-Line and In-Situ Identification of Air Pollution
2002
The elemental, iron-phase, and oxidation state analysis of urban aerosol samples, collected from different sites in Vitoria metropolitan region, ES, Brazil, was carried out using Mossbauer (MB) Spectroscopy (MBS) and X-ray fluorescence (XRF) techniques. A portable XRF spectrometer for elemental analysis from Na to Fe, and the miniaturized MB spectrometer MIMOS-II have been installed together using a 100 mCi 57 Co(Rh) MB source for XRF excitation. Both measurements can be performed simultaneously. For continuous and fast characterization purposes a software package was developed for Mossbauer and XRF analysis. The software is based on genetic algorithm, fuzzy logic and artificial neural netw…
A new cell for the study of in situ chemical reactions using X-ray absorption spectroscopy
2005
An in situ cell for reductive and oxidative treatments at different temperatures that allows the possibility of recording data as a function of temperature has been designed and constructed for X-ray absorption experiments at the GILDA beamline BM08 of ESRF. The cell is linked to a mass quadrupole spectrometer providing control of the reaction gases and monitoring of the products. The apparatus allows measurements to be performed both in transmission and fluorescence geometry. The cell was tested by studying the CO oxidation reaction promoted by a Pt/ceria-zirconia-supported catalyst. The CO(2) yield is correlated with the structural results confirming the existence of a strong metal-suppor…
The Land Surface Temperature Synergistic Processor in BEAM: A Prototype towards Sentinel-3
2016
Land Surface Temperature (LST) is one of the key parameters in the physics of land-surface processes on regional and global scales, combining the results of all surface-atmosphere interactions and energy fluxes between the surface and the atmosphere. With the advent of the European Space Agency (ESA) Sentinel 3 (S3) satellite, accurate LST retrieval methodologies are being developed by exploiting the synergy between the Ocean and Land Colour Instrument (OLCI) and the Sea and Land Surface Temperature Radiometer (SLSTR). In this paper we explain the implementation in the Basic ENVISAT Toolbox for (A)ATSR and MERIS (BEAM) and the use of one LST algorithm developed in the framework of the Syner…
Methane and carbon monoxide infrared emissions observed at the Canada-France-Hawaii Telescope during the collision of comet SL-9 with Jupiter
1995
Observations with the Fourier Transform Spectrometer were conducted in spectral ranges from 1.6 to 4.7 µm from July 17 to 21 (UT) on the hot plumes appearing on the limb as well as hours or days after the impacts. We present here an analysis of the methane emission observed at 3.3 µm some 10 min after the C impact, indicating the presence of a very small (less than 100 km wide) hot region with temperatures in the 750–1500 K range within the 0.1- to 0.01-mbar region. We also report the detection of CO emission at 4.7 µm 4.5 hrs after the L impact, indicative of a temperature of 274±10 K at the ∼1016 CO molec cm−2 level. The observations suggest that the stratospheric temperature decreases wi…
High resolution study of AsHD2: Ground state and the three bending fundamental bands v(3), v(4), and v(6)
2006
International audience; For the first time the infrared spectrum of the AsHD2 molecule has been measured in the region of the bending fundamental bands v(3), v(4), and v(6) on a Fourier transform spectrometer with a resolution of 0.0024 cm(-1) and analyzed. More than 5500 transitions with J(max) = 26 have been assigned and used both to obtain "ground state combination differences" and for the determination of upper state ro-vibrational energies of the triad (001000), (000100), and (000001). Rotational parameters including centrifugal distortion coefficients up to octic terms of the ground vibrational state were calculated by fitting more than 500 "ground state combination differences" with …
Optimized integral imaging display by global pixel mapping
2006
Integral imaging systems are imaging devices that provide 3D images of 3D objects. When integral imaging systems work in their standard configuration the provided reconstructed images are pseudoscopic; that is, are reversed in depth. In this paper we present a technique for formation of real, undistorted, orthoscopic integral images by direct pickup. The technique is based on a global mapping of pixels of an elemental-images set. Simulated imaging experiments are presented.
A mass-independent expanded Dunham analysis of aluminum monoxide and aluminum monosulfide
2018
Abstract Pure rotational transitions of 27Al16O, 27Al18O, 27Al32S, and 27Al34S are recorded in the vibrational ground state and singly excited vibrational state using a mm-wavelength supersonic jet spectrometer in combination with a laser ablation source. In total 275 rotational transitions have been assigned. For the first time, mass-independent expanded Dunham analyses are performed using isotopologues of aluminum monoxide and aluminum monosulfide. The breakdown of the Born-Oppenheimer approximation is observed. Based on these mass-independent analyses, frequency positions of pure rotational transitions of the rare radioactive isotopologues 26AlO and 26AlS are predicted with uncertainties…
Kompakti automatisoitu laser-ionisointijärjestelmä
2011
In an experimental nuclear physics off-line systems are often used in situations where acceleration energies are relatively small. Main benefits are low price and meager radiated laboratory enviroments. In this master’s thesis I discuss mostly about automation which was used in our off-line system. The system was built at the Ion Guide Separator On-Line facility (IGISOL) in Jyväskylä University. The automation set up was made with the Phoenix Contacts inline terminals, which were programmed by using the Labview program. The system consists of thermistor, skimmer handling, mirror handling, gasline parts per billion (ppb) mixing and quadrupole mass spectrometer measurement. There were major p…
Experimental investigations of the hypernucleus $_Λ^4$H
2015
International audience; Negatively charged pions from two-body decays of stopped _Lambda^4H hypernuclei were studied in 2012 at the Mainz Microtron MAMI, Germany. The momenta of the decay-pions were measured with unprecedented precision by using high-resolution magnetic spectrometers. A challenge of the experiment was the tagging of kaons from associated K^+∧ production off a Be target at very forward angles. In the year 2014, this experiment was continued with a better control of the systematic uncertainties, with better suppression of coincident and random background, improved particle identification, and with higher luminosities. Another key point of the progress was the improvemen…