Search results for "Linearity"

El tipo de cambio real dólar-euro y el diferencial de intereses reales

2006

This paper investigates whether threshold effects exist in the relationship between dollar-euro real exchange rate and real interest differential, over the period January 1984 to December 2004. We specify a three-regime threshold model and the results provide evidence that there is no threshold effect in the short term, but the nonlinear behaviour of real exchange rate implies threshold effect in the long term. On the other hand, the nonlinearity into the behaviour of real exchange rates can be modelled by a Band-TAR which implies a symmetric response to the real interest differential outside the bank. Finally, into the threshold band the behaviour of real exchange rate is near to follow a …

Time of flight measurements based on FPGA using a breast dedicated PET

2014

In this work the implementation of a Time-to-Digital Converter (TDC) using a Nutt delay line FPGA-based and applied on a Positron Emission Tomography (PET) device is going to be presented in order to check the system’s suitability for Time of Flight (TOF) measurements. In recent years, FPGAs have shown great advantages for precise time measurements in PET. The architecture employed for these measurements is described in detail. The system developed was tested on a dedicated breast PET prototype, composed of LYSO crystals and Positive Sensitive Photomultipliers (PSPMTs). Two distinct experiments were carried out for this purpose. In the first test, system linearity was evaluated in order to …

A laser-based system for a fast and accurate measurement of gain and linearity of photomultipliers

2018

This paper describes a method for the measurement of gain and linearity of photomultipliers (PMTs). Gain and linearity are two fundamental parameters to use properly a PMT in several physics experiments. In the developed system light is laser generated and adressed to the PMT through a set of optical fibers. The data acquisition system consists in a commercial 16 channel digitizer coupled to a custom front-end board. With the chosen digitizer the system is scalable to test up to 16 PMTs, with the aid of a light distribution system and a multi-channel version of the front-end board. Data analysis is performed by a custom acquisition software. A 1.5» Hamamatsu PMT is used to validate the syst…

Electron performance measurements with the ATLAS detector using the 2010 LHC proton-proton collision data

2012

Acknowledgements We thank CERN for the very successful operation of the LHC, as well as the support staff from our institutions without whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; BMWF, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq and FAPESP, Brazil; NSERC, NRC and CFI, Canada; CERN; CONICYT, Chile; CAS, MOST and NSFC, China; COLCIENCIAS, Colombia; MSMT CR, MPO CR and VSC CR, Czech Republic; DNRF, DNSRC and Lundbeck Foundation, Denmark; ARTEMIS, European Union; IN2P3-CNRS, CEA-DSM/IRFU, France; GNAS, Georgia; BMBF, DFG, HGF, MPG and AvH Foundation, Germany; GSRT, Greece; ISF, MINERVA, GIF, DIP and Benoziyo…

Inelastic scattering and interactions of three-wave parametric solitons.

2006

We study the interactions of velocity-locked three-wave parametric solitons in a medium with quadratic nonlinearity and dispersion. We reveal that the inelastic scattering between three-wave solitons and linear waves may be described in terms of analytical solutions with dynamically varying group velocity, or boomerons. Moreover, we demonstrate the elastic nature of three-wave soliton-soliton collisions and interactions.

A large-area modular electromagnetic shower detector for the CERN intersecting storage rings

1979

The authors describe the design and performances large-area (13 m/sup 2/) shower detector built for an experiment at the CERN ISR to detect electrons and gamma rays with energies up to 4 GeV. The main characteristics of the detector are: a) linearity of the energy response from 0.5 to 4 GeV; b) good energy, time and space resolutions; c) modularity of the mechanical assembly; d) low cost of construction. (3 refs).

Measurement of the Th229 Isomer Energy with a Magnetic Microcalorimeter

2020

We present a measurement of the low-energy (0-60 keV) γ-ray spectrum produced in the α decay of ^{233}U using a dedicated cryogenic magnetic microcalorimeter. The energy resolution of ∼10  eV, together with exceptional gain linearity, allows us to determine the energy of the low-lying isomeric state in ^{229}Th using four complementary evaluation schemes. The most precise scheme determines the ^{229}Th isomer energy to be 8.10(17) eV, corresponding to 153.1(32) nm, superseding in precision previous values based on γ spectroscopy, and agreeing with a recent measurement based on internal conversion electrons. We also measure branching ratios of the relevant excited states to be b_{29}=9.3(6)%…

Pulse Generation and Shaping Using Fiber Nonlinearities

2017

Construction, Commissioning and First Results of a Highly Granular Hadron Calorimeter with SiPM-on-Tile Read-out

2018

The CALICE collaboration is developing a highly granular Analogue Hadron sampling CALorimeter (AHCAL) for a future electron-positron collider. Very small detection units are required for the AHCAL due to an optimized design for the Particle Flow Algorithm. This is realized with scintillator tiles each wrapped in reflector foil and individually read out by a silicon photomultiplier (SiPM). These scintillator tiles and SiPMs are assembled on readout boards (HCAL Base Unit, HBU) which are integrated later on in the AHCAL detector stack. With this design a higher energy resolution is achievable, but also a large quantity of components (around 8,000,000 scintillator tiles and SiPMs) are needed t…

Stabilization of 1D solitons by fractional derivatives in systems with quintic nonlinearity

2022

AbstractWe study theoretically the properties of a soliton solution of the fractional Schrödinger equation with quintic nonlinearity. Under “fractional” we understand the Schrödinger equation, where ordinary Laplacian (second spatial derivative in 1D) is substituted by its fractional counterpart with Lévy index $$\alpha$$ α . We speculate that the latter substitution corresponds to phenomenological account for disorder in a system. Using analytical (variational and perturbative) and numerical arguments, we have shown that while in the case of Schrödinger equation with the ordinary Laplacian (corresponding to Lévy index $$\alpha =2$$ α = 2 ), the soliton is unstable, even infinitesimal diffe…