Search results for "temperature measurement."
showing 10 items of 120 documents
Coulomb blockade-based nanothermometry in strong magnetic fields
1998
We have performed experiments to test for the susceptibility to strong magnetic fields of electron tunneling in normal metal -based nanostructures for Coulomb blockade primary thermometry. We have confirmed that, to within our accuracy of about ±1%, the single electron charging -induced zero bias differential resistance maximum is unaffected by the field up to 23 T at temperatures of 0.4–4.2 K. We discuss the simple theoretical basis of this immunity. We also report on the practical limitation at low temperatures imposed by superconductivity of aluminium in small magnetic fields.
High-resolution multichannel Time-to-Digital Converter core implemented in FPGA for ToF measurements in SiPM-PET
2013
In this contribution, Coincidence Resolving Time (CRT) results with the developed multichannel FPGA-TDC are showed as a function of different configurations for both, the sensor bias voltage and the digitizer threshold. The dependence of the CRT with the sensor matrix temperature, the amount of SiPM active area and the crystal type are also analyzed. Preliminary measurements carried out with a crystal array of 2 mm pixel size and 10 mm height have shown time resolutions for the entire 144 SiPM two-detectors ensemble as good as 800 ps.
Investigation on pixellated CZT detectors coupled with a low power readout ASIC
2008
In this work, we investigated on the spectroscopic performances of two pixellated CZT detectors coupled with a custom low noise and low power readout ASIC. The detectors (10 x 10 x 1 mm3 and 10 x 10 x 2 mm3 single crystals) consist of an array of 256 pixels with a geometric pitch of 0.5 mm. The ASIC, fabricated in 0.8 μm BiCMOS technology, is equipped with eight independent channels (preamplifier and shaper) characterized by a dynamic range from 10 keV to 100 keV, low power consumption (0.5 mW/channel) and low noise (150–500 electrons r.m.s.). The spectroscopic results point out the good energy resolution of both detectors at room temperature (5.8 % FWHM at 59.5 keV for the 1 mm thick detec…
A methodology for obtaining the crop temperature from NOAA-9 AVHRR data
1991
Abstract In this paper a methodology for obtaining the crop temperature from NOAA-9 AVHRR data has been developed, which is based on a theoretical model that permits interpreting the remote sensing temperature measurement in heterogeneous and rough surfaces. This procedure determines the crop temperature by evaluating prsviously: (1) the temperature difference between crop and ground, (2) the atmospheric and emissivity corrections, (3) the ground and vegetation emissi-vities in the AVHRR bands 4 (10-3-11-3 μm) and 5 (11 -5-12-5 μm), and (4) the proportion of ground in each pixel. We have applied this method to obtain a map of orange-tree temperatures for the Valencian region and satisfactor…
Optical diagnostic of temperature in rocket engines by coherent Raman techniques
2004
Abstract This article reviews the study of Raman line shapes of molecular species involved in reactive media, such flames or engines, at high temperature and high pressure. This study is of interest from a fundamental as well as from a practical point of view with regards to the CARS temperature diagnostic of GH2–LOX combustion systems. We will particularly draw attention to recent investigations by means of Stimulated Raman Spectroscopy (SRS) in H2–H2O mixtures at temperature up to 1800 K. Whereas H2–X systems usually exhibit large inhomogeneous effects, due to the speed dependence of the collisional parameters, the absence of such apparent inhomogeneous signatures in the H2–H2O system all…
Calculated helium-broadened line parameters in the nu4 band of 13CH4
1998
International audience; Helium line-broadening coefficients for transitions in the nu4 band of 13CH4 have been calculated using a semi-classical model. This model is analogous to the one that we have used in a previous study on argon line-broadening coefficients for transitions in the nu3 band of 12CH4. For the present study, over 270 room temperature measurements were considered. The J, symmetry and fine structure dependences of the data are satisfactorily reproduced, although deficiencies of the semi-classical model are evidenced.
Application of a radiative cooling model to daily minimum temperature prediction
1985
A model of exponential decrease of temperature is applied to the study of night cooling in an agricultural area of citrus orchards located near the Valentian Coast (Spain). A set of annual average parameters which determine that cooling is obtained by using temperature measurements at different levels during two years. These parameters appear to be representative of the thermal behaviour of the area of study. The attainment of such parameters allows a prediction of the minimum temperatures of the area to an accuracy of £1.5 K, knowing the temperature at sunset and some time later.
Charge carrier transport mechanisms in CdZnTe detectors grown by the vertical Bridgman technique
2016
In this work, we report on the results of electrical characterization of CdZnTe (CZT) detectors, with gold electroless contacts, grown by the boron oxide encapsulated vertical Bridgman technique (B-VB), currently produced at IMEM-CNR (Parma, Italy). The detectors, with different thicknesses (1 and 2.5 mm), have the same electrode layout: the anode is a central electrode (2 x 2 mm(2)) surrounded by a guard ring electrode. The cathode is a planar electrode covering the detector surface (4.1 x 4.1 mm(2)). Current-voltage (I-V) characteristics were measured at different temperatures in order to study the charge transport and the electrical properties. These detectors were compared with the trav…
Emissitivity spectra obtained from field and laboratory measurements using the temperature and emissivity separation algorithm.
2006
Surface emissivities play an important role in thermal remote sensing, since knowledge of them is required to estimate land surface temperature with enough accuracy. They are also important in other environmental or geological studies. We show the results obtained for the emissivity spectra of different natural surfaces (water, green, and senescent vegetation) by applying the temperature and emissivity separation (TES) algorithm to ground-based measurements collected at the field with a multiband thermal radiometer. The results have been tested with data included in spectral libraries, and rms errors lower than 0.01 have been found, except for senescent vegetation. Two methods are also prop…
Effects of radiation and hydrogen-loading on the performances of raman-distributed temperature fiber sensors
2015
International audience; The integration of Raman-distributed temperature fiber-based sensors (RDTS) into the envisioned French deep geological repository for nuclear wastes, called Cigéo requires evaluating how the performances of RDTS evolve in harsh environments, more precisely in presence of H2 or γ-rays. Both H2 and radiations are shown to affect the temperature measurements made with the single-ended RDTS technology. The amplitudes of the observed effects depend on the different classes of multimode fibers varying in terms of composition and coatings. By selecting the most tolerant fiber structure for the sensing, we could maintain the RDTS performances for such application. A hardeni…