Zobrazeno 1 - 10
of 58
pro vyhledávání: '"M.M.F.R. Fraga"'
Autor:
D.G. Beasley, P. Fonte, M.M.F.R. Fraga, Ana C. Marques, Luís Alves, Carlos Manuel Neves da Cruz, R.C. da Silva
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 348:100-105
A cylindrical gas flow ionization chamber has been developed for measuring particle energy in Scanning Transmission Ion Microscopy Tomography (STIM-T) experiments due to its ability to withstand the direct beam. The response of a He-iso-C 4 H 10 fill
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 306:104-108
A gas flow ionization chamber for use with on-axis scanning transmission ion microscopy tomography (STIM-T) has been developed. The entrance window is composed of a square silicon nitride membrane 100 nm thick and 1 mm2 in area. The use of this type
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 695:425-428
The effect of gas contamination on light emission properties of CF 4 is presented. The study was performed in the UV (220–450 nm) and visible (450–800 nm) wavelength ranges and the relative light emission intensity and effective decay times were
Autor:
A. Morozov, S.T.G. Fetal, F.A.F. Fraga, Bruno Guerard, L.M.S. Margato, M.M.F.R. Fraga, L. Pereira, G. Manzin
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 628:360-363
The effect of an electric field on the primary scintillation from CF4 in the ultraviolet and visible wavelength regions (200–800 nm) is reported. The study was performed in the pressure range from 1 to 5 bar and at electric fields of up to 2 kV/cm.
Autor:
M.M.F.R. Fraga, A. Morozov, Bruno Guerard, L.M.S. Margato, G. Manzin, L. Pereira, F.A.F. Fraga, S.T.G. Fetal
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms. 268:1456-1459
Carbon tetrafluoride (CF4) photon yield, defined as the number of photons emitted per 1 MeV of energy deposited in the gas is reported for the ultraviolet (220–500 nm) and visible (500–800 nm) emission in the pressure range from 0.5 to 5 bar. An
Publikováno v:
The European Physical Journal D. 56:325-334
The temperature dependences of the quenching rate constants of the states N2 (\({\rm C} \ {^{3}{ \rm \Pi }_{u}}\) v′=0,1) by N2 (X) and of the state N2 (\({\rm C} \ {^{3}{ \rm \Pi }_{u}} \ v^{\prime}=0\)) by O2 (X) are studied. Time-resolved light
Autor:
N. Castro, L. Pereira, M.M.F.R. Fraga, Filipe Veloso, A. Onofre, M. Pimenta, A.J.P.L. Policarpo, R. Ferreira Marques, F.A.F. Fraga
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 597:75-82
The detection of fluorescence radiation produced in the atmosphere by the extensive air showers (EAS) generated by the interaction of incoming ultra high energy cosmic rays (UHECR) with the air molecules, is a technique that is being used by several
Autor:
S.T.G. Fetal, A.J.P.L. Policarpo, F.A.F. Fraga, R. Ferreira Marques, M.M.F.R. Fraga, L.M.S. Margato, Stéfanie Pereira
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 581:202-205
We report the first results on the operation of an optical double GEM TPC, read out by four photomultipliers in a square array. The detector, operated with Ar + 5 % CF 4 at atmospheric pressure, was tested with 241Am alpha particles emitted in variou
Publikováno v:
IEEE Transactions on Nuclear Science. 54:276-279
In this Paper we describe the performance of a rad-hard diode (Al/p+/n/n+/Al), developed in the framework of research and development programs for the future CMS experiment at LHC, for detection and spectrometry of X-and gamma-rays envisaging its use
Autor:
M.M.F.R. Fraga, R. Ferreira Marques, F.A.F. Fraga, S.T.G. Fetal, A.J.P.L. Policarpo, L.M.S. Margato
Publikováno v:
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 504:88-92
Light emitted during the development of electron avalanches in a gas electron multiplier (GEM) can be efficiently used for optical readout of the detector. We report on measurements of total light yields in Ar/CF 4 , He/CF 4 , Ar/TEA and Xe/TEA mixtu