Search results for "width [Lambda(1405)]"
showing 10 items of 330 documents
Grating compensated dispersion-managed systems incorporating nonlinear optical loop mirrors
2006
In this work, we investigate the use of nonlinear optical loop mirrors (NOLMs) in DM fiber systems compensated by CFGs with GDR by launching a 128-bit Gaussian-shaped pseudo-random bit sequence having pulse width of 5 ps for simulating a 40 Gb/s system. The dispersion map contains a fiber segment of length 10.3 km and a CFG with dispersion of -15.6 ps/nm. We consider a lossless grating and the GDR is modeled by a sinusoidal function for simplicity. We have shown that the use of NOLMs can substantially improve the transmission performance in a grating-compensated DM fiber system even with presence of amplifier noise and random variations of GDR, parameters in CFGs along the propagation dista…
Design of a double-gap Hughes-type coupled-cavity for a Ka-band Extended Interaction Klystron
2020
In this paper, the design of a Ka-band Extended-Interaction Klystron (EIK) working at 2$\pi$ mode. The interaction structure is a three-gap Hughes-type coupled-cavity. Based on the results obtained with the 3D model developed by using CST, “cold electrical parameters” have been calculated, necessary to measure the interaction with the electron beam. The structure stability and the synchronization with the electron beam are analyzed The large-signal analysis is performed by 1D software AJDISK. Under the beam voltage and current of 19.55 kV and 0.95 A, respectively, an RF output power value of 3.86 kW and a bandwidth gain value of 37. 06 dB have been obtained
Design of a Compact Dual Circular-Polarized Antenna for L-Band Satellite Applications
2020
In this paper, we propose the design of a dual circular-polarized antenna for L-band applications (1.1-1.6 GHz). The designed antenna has been developed by considering crossed-dipoles on top of which a circular patch has been placed to properly act on the mutual coupling between the dipoles. The dual circular polarization is achieved by feeding dipoles in quadrature. Moreover, to increase the antenna gain and polarization purity at high elevation angles, a fence of passive monopoles has been added. The proposed antenna can profitably used as primary feed of a low-frequency parabolic reflector.
An FPGA based demonstrator for a topological processor in the future ATLAS L1-Calo trigger “GOLD”
2012
Abstract: The existing ATLAS trigger consists of three levels. The level 1 (L1) is an FPGAs based custom designed trigger, while the second and third levels are software based. The LHC machine plans to bring the beam energy to the maximum value of 7 TeV and to increase the luminosity in the coming years. The current L1 trigger system is therefore seriously challenged. To cope with the resulting higher event rate, as part of the ATLAS trigger upgrade, a new electronics module is foreseen to be added in the ATLAS Level-1 Calorimeter Trigger electronics chain: the Topological Processor (TP). Such a processor needs fast optical I/O and large aggregate bandwidth to use the information on trigger…
Self-referenced phase reconstruction proposal of Ghz bandwidth non-periodical optical pulses by in-fiber semi-differintegration
2011
Abstract We propose two new techniques able to retrieve the phase profile of a given temporal optical pulse based on the use of in-fiber semi-differintegral operators, where by semi-differintegration we mean either a 0.5th-order differentiation or integration. In both cases, the signal's temporal phase can be obtained by simple dividing two temporal intensity profiles, namely the intensities of the input and output pulses of a spectrally shifted semi-differintegral operator. In both cases, we obtained simple analytical expressions for the phase profile. The techniques are self-referenced and well-suited for real-time applications. We numerically prove the viability of these proposals.
Efficient control of the energy exchange due to the Manakov vector-soliton collision
2003
By examining the concept of energy exchange among the orthogonally polarized components of each of two colliding (Manakov-like) vector solitons it is observed that a maximum or an efficient energy-exchange process is possible only for an appropriate choice of the initial physical parameters (namely, frequency separation, polarizations, time delay, and pulse-width separation between the colliding solitons) for which L(W) (walk-off length) >>L(NL) (nonlinear length). However, in this case only, the amount of energy-exchange can be considerably increased or decreased by appropriately changing the phases of colliding solitons without altering the walk-off length and the initial energy distribut…
A two-detector spectrometer for measurements of Doppler broadened positron annihilation spectra
2004
Abstract A two-detector spectrometer for measurements of Doppler broadened positron annihilation spectra has been constructed and tested. The energy difference of the annihilation quanta is measured in the analogue, not in the digital manner. The peak to background ratio in the measured spectra is of the order of 10 6 , the FWHM representing the energy resolution, equals to 1.1 keV , thus enabling the very subtle physical effects to be revealed. Some information on electronic structure of the investigated 3-d metals (Ti, V, Cr, Fe, Ni, Cu and Zn) has been determined using this spectrometer. It has been shown that the apparatus permits to detect the impurity-vacancy pairs in dilute nickel al…
Improving the Performance of Quasi-Hemispherical CdZnTe Detectors Using Infrared Stimulation
2012
The influence of monochromatic optical stimulation with wavelengths from 400 to 1100 nm on the characteristics of CdZnTe quasi-hemispherical detectors was studied. It was found that illumination with infrared (IR) light with wavelengths of 870-900 nm close to the absorption edge of the CdZnTe significantly improves the performance of the detector at room temperature. Improvement can be achieved with low-intensity IR illumination at 1-300 μW depending on the chosen wavelength of illumination. Higher intensity illumination was observed to lead to the degradation of the detector's spectrometric characteristics. IR radiation was noted to influence the detector's sensitivity, changing the equili…
A broad iron line in the Chandra/HETG spectrum of 4U 1705-44
2004
We present preliminary results from a Chandra 30 ks observation of the atoll sourco 4U 1705 44. In particular we concentrate on the study of the iron Kα line, using the HEG spectrometer. The iron Kα line at ~ 6.6 keV is found to be intrinsically broad (FWHM ~ 1.7 keV); its width can be explained by reflection from a cold accretion disk extending down to ~ 17 km from the neutron star center or by Compton broadening in the hotter (~ 3 – 4 keV) corona.
In-beam tests of scintillating fibre detectors at MAMI and at GSI
2008
The performance of scintillating fibre detectors was studied with electrons at the spectrometer facility of the Mainz microtron MAMI, as well as in a C-12 beam of 2 AGeV energy and in a beam of different particle species at GSI. Multi-anode photomultipliers were used to read out one or more bundles of 128 fibres each in different geometries. For electrons a time resolution of FWHM = 1 ns was measured in a single detector plane with a detection efficiency epsilon > 99%. A time resolution of 310 ps (FWHM) between two planes of fibres was achieved for carbon ions, leading to a FWHM = 220 ps for a single detector. The hit position residual was measured with a width of FWHM = 0.27 mm. The var…