Search results for "Mathematical physics"
showing 10 items of 2687 documents
The manipulation of ions using electromagnetic traps
1992
Electromagnetic traps, in addition to providing very clean and gentle confinement for very precise and sensitive observation of charged particles, are very versatile devices for collecting and preparing charged particles from outside sources for observation by devices which are also outside, devices which may in themselves be other electromagnetic traps. This paper introduces the basic principles of using electromagnetic traps for collecting and cooling and presents some preliminary test results from using Paul traps for these purposes. Specifically, in relatively modest Paul traps with 28 mm between end electrodes a collection efficiency of 0.2% was achieved for a 60 keV DC beam of 132Xe i…
Detection of deuterium retention by LIBS at different background pressures
2017
ITER plans foresee the quantitative diagnostics of fuel retention in reactor walls at near-atmospheric pressures. Using laser induced breakdown spectroscopy (LIBS) for this purpose assumes a reliable resolving of Balmer α-lines of hydrogen isotopes in spectra of plasma produced by focused laser radiation onto the target surface. To develop LIBS for quantitative diagnostics of fuel retention during the maintenance breaks of ITER, the effect of background gas pressure on the laser-induced plasma characteristics has been studied. The background pressure limits the expansion rate of plasma and as a result it leads to higher plasma concentrations. At the same time the limiting factor of the reso…
Single-Element Reflective Digital Holographic Microscopy
2021
Digital holographic microscopy (DHM) is a well-known microscopy technique using an interferometric architecture for quantitative phase imaging (QPI) and it has been already implemented utilizing a large number of interferometers. Among them, single-element interferometers are of particular interest due to its simplicity, stability, and low cost. Here, we present an extremely simple common-path interferometric layout based on the use of a single one-dimensional diffraction grating for both illuminating the sample in reflection and generating the digital holograms. The technique, named single-element reflective digital holographic microscopy (SER-DHM), enables QPI and topography analysis of r…
Programmable Supercontinuum Laser Spectrum Generator Based on a Liquid-Crystal on Silicon Spatial Light Modulator
2021
Supercontinuum (SC) lasers combine a broadband light spectrum with the unique properties of single-mode lasers. In this work we present an optical system to spectrally filter a SC laser source using liquid-crystal on silicon (LCoS) spatial light modulators (SLM). The proposed optical system disperses the input laser and the spectrally separated components are projected onto the LCoS-SLM, where the state of polarization of each wavelength is separately modulated. Finally, recombining the modulated spectral components results in an output laser source where the spectrum can be controlled dynamically from a computer. The system incorporates two branches to independently control the visible (VI…
Uniform Carbon and Carbon/Cobalt Nanostructures by Solid-State Thermolysis of Polyphenylene Dendrimer/Cobalt Complexes
2005
Benson, J. Am. Chem. Soc. 1962, 84, 3374. b) D. L. Jeanmaire, R. P. van Duyne, J. Am. Chem. Soc. 1976, 98, 4029. c) J. P. Gong, Y. Osada, Appl. Phys. Lett. 1992, 61, 2787. d) S. Liu, Y. Liu, D. Zhu, Thin Solid Films 1996, 280, 271. e) S. Liu, Y. Liu, P. Wu, D. Zhu, H. Tian, K. Chen, Thin Solid Films 1996, 289, 300. f) S. Liu, Y. Liu, P. Wu, D. Zhu, Chem. Mater. 1996, 8, 2779. [6] a) R. S. Potember, T. O. Poehler, D. O. Cowan, F. L. Carter, P. I. Brant, in Molecular Electronic Devices (Ed: F. L. Carter), Marcel Dekker, New York 1982. b) I. Ikemoto, J. M. Thomas, H. Kuroda, Bull. Chem. Soc. Jpn. 1973, 46, 2237. [7] a) A. M. Rao, D. Jacques, R. C. Haddon, W. Zhu, C. Bower, S. Jin, Appl. Phys. …
Partially Coherent Optical Diffraction Tomography Toward Practical Cell Study
2021
Optical diffraction tomography (ODT) is a computational imaging technique based on refractive index (RI) contrast. Its application for microscopic imaging of weakly absorbing and scattering samples has been demonstrated by using a specially designed holographic microscope with angular scanning of the coherent sample illumination direction. Recently, an alternative low cost technique based on partially coherent sample illumination (PC-ODT), which is compatible with the conventional wide-field transmission microscope, has been established. In this case, the 3D refractive index distribution of the sample is obtained by deconvolution from a single stack of through-focus intensity images. The pe…
SiPMs coated with TPB: coating protocol and characterization for NEXT
2012
[EN] Silicon photomultipliers (SiPM) are the photon detectors chosen for the tracking readout in NEXT, a neutrinoless \bb decay experiment which uses a high pressure gaseous xenon time projection chamber (TPC). The reconstruction of event track and topology in this gaseous detector is a key handle for background rejection. Among the commercially available sensors that can be used for tracking, SiPMs offer important advantages, mainly high gain, ruggedness, cost-effectiveness and radio-purity. Their main drawback, however, is their non sensitivity in the emission spectrum of the xenon scintillation (peak at 175 nm). This is overcome by coating these sensors with the organic wavelength shifte…
Limits on the release of Rb isotopes from a zeolite based 83mKr calibration source for the XENON project
2011
The isomer 83mKr with its half-life of 1.83 h is an ideal calibration source for a liquid noble gas dark matter experiment like the XENON project. However, the risk of contamination of the detector with traces of the much longer lived mother isotop 83Rb (86.2 d half-life) has to be ruled out. In this work the release of 83Rb atoms from a 1.8 MBq 83Rb source embedded in zeolite beads has been investigated. To do so, a cryogenic trap has been connected to the source for about 10 days, after which it was removed and probed for the strongest 83Rb gamma-rays with an ultra-sensitive Germanium detector. No signal has been found. The corresponding upper limit on the released 83Rb activity means tha…
Simulations of single-fluid flow in porous media
1998
Several results of lattice-gas and lattice-Boltzmann simulations of single-fluid flow in 2D and 3D porous media are discussed. Simulation results for the tortuosity, effective porosity and permeability of a 2D random porous medium are reported. A modified Kozeny–Carman law is suggested, which includes the concept of effective porosity. This law is found to fit well the simulated 2D permeabilities. The results for fluid flow through large 3D random fibre webs are also presented. The simulated permeabilities of these webs are found to be in good agreement with experimental data. The simulations also confirm that, for this kind of materials, permeability depends exponentially on porosity over…
Investigation of E0 Transition in 74Kr
2000
The N = Z+2 nucleus 74Kr has been investigated by in-beam conversion electron (CE) and γ ray spectroscopy. The electric-monopole (E0) decay was examined in order to confirm the evidence for a low-lying isomeric 0+2 state and to give insight into the mixing between the predicted coexisting prolate and oblate shapes.