The nuclear scattering of electrons and positrons at 0·7 and 1·4 MeV

1955 ◽  
Vol 229 (1177) ◽  
pp. 260-271 ◽  
Keyword(s):  
Incident Beam ◽  
Fast Response ◽  
Nuclear Scattering ◽  
Dirac Theory ◽  
Good Energy Resolution ◽  
Hollow Cone ◽  
Experimental Accuracy ◽  
Vertical Angle ◽  
Electrons And Positrons ◽  
Good Energy

An experiment is described in which electrons and positrons are scattered, under identical conditions, at energies of 0·7 and 1·4 MeV by foils of aluminium, silver and gold. Both the incident and scattered particles are counted by making use of the fast response and good energy resolution of anthracene crystals. The incident beam, which is in the form of a divergent hollow cone of semi-vertical angle of near 10°, and of 5% energy spread, is provided by using radioactive sources in a β-ray spectrometer. Effective angles of scattering of 22·8, 34·5 and 47·5° are employed. It is concluded that, within the experimental accuracy of about ±5% , the results are in accordance with predictions of the Dirac theory.

High Efficiency of Lutetium Silicate Scintillators, Ce-Doped LPS and LYSO Crystals for Medical Applications

2007 ◽  
Vol 555 ◽  
pp. 371-376 ◽  
Author(s):  
L. Pidol ◽  
Bruno Viana ◽  
Aurelie Bessière ◽  
A. Galtayries ◽  
P. Dorenbos ◽  
...  
Keyword(s):  
High Efficiency ◽  
Growth Parameters ◽  
Energy Levels ◽  
Light Yield ◽  
Fast Response ◽  
Good Energy Resolution ◽  
Scintillation Light ◽  
Time Resolved ◽  
Good Energy ◽  
Czochralski Process

The paper presents two cerium doped lutetium silicate crystals: pyrosilicate Ce:Lu2Si2O7 (LPS) and Ce: Lu2(1-x)Y2xSiO5 (LYSO). These two crystals exhibit the expected requirements for gamma detection: high density and high atomic number, high scintillation light yield, good energy resolution and fast response. LPS and LYSO crystals doped with cerium were grown by the Czochralski process. The crystal growth parameters were studied and optimized. Development of scintillators requires good understanding of the scintillation process. The location within the forbidden band gap of the localized lanthanide energy levels is analyzed by time resolved spectroscopy and thermoluminescence studies.

A small rugged imaging X-ray spectrometer: A lixiscope with good energy resolution

1980 ◽  
Vol 172 (3) ◽  
pp. 471-477 ◽  
Author(s):  
Lo I Yin ◽  
Jacob I. Trombka ◽  
Stephen M. Seltzer
Keyword(s):  
Energy Resolution ◽  
Good Energy Resolution ◽  
X Ray ◽  
Good Energy

scholarly journals Scintillating bolometers: A key for determining WIMP parameters

2014 ◽  
Vol 29 (19) ◽  
pp. 1443009 ◽  
Author(s):  
D. G. Cerdeño ◽  
C. Marcos ◽  
M. Peiró ◽  
M. Fornasa ◽  
C. Cuesta ◽  
...  
Keyword(s):  
Cross Section ◽  
Direct Detection ◽  
Massive Particle ◽  
Thermal Quenching ◽  
Good Energy Resolution ◽  
Discrimination Capability ◽  
Good Energy ◽  
Excellent Tool ◽  
Nuclear Structure Functions

In the last decade direct detection Dark Matter (DM) experiments have increased enormously their sensitivity and ton-scale setups have been proposed, especially using germanium and xenon targets with double readout and background discrimination capabilities. In light of this situation, we study the prospects for determining the parameters of Weakly Interacting Massive Particle (WIMP) DM (mass, spin-dependent (SD) and spin-independent (SI) cross-section off nucleons) by combining the results of such experiments in the case of a hypothetical detection. In general, the degeneracy between the SD and SI components of the scattering cross-section can only be removed using targets with different sensitivities to these components. Scintillating bolometers, with particle discrimination capability, very good energy resolution and threshold and a wide choice of target materials, are an excellent tool for a multitarget complementary DM search. We investigate how the simultaneous use of scintillating targets with different SD-SI sensitivities and/or light isotopes (as the case of CaF 2 and NaI ) significantly improves the determination of the WIMP parameters. In order to make the analysis more realistic we include the effect of uncertainties in the halo model and in the spin-dependent nuclear structure functions, as well as the effect of a thermal quenching different from 1.

Comparative Studies of the Light Yield Non-Proportionality and Energy Resolution of CsI(Tl), LYSO and BGO Scintillation Crystals

2016 ◽  
Vol 872 ◽  
pp. 266-270
Author(s):  
Pruittipol Limkitjaroenporn ◽  
Narong Sangwaranatee ◽  
Wuttichai Chaiphaksa ◽  
Jakrapong Kaewkhao
Keyword(s):  
Energy Resolution ◽  
Comparative Studies ◽  
Gamma Ray ◽  
Light Yield ◽  
Good Energy Resolution ◽  
Intrinsic Resolution ◽  
Scintillation Crystals ◽  
Good Energy ◽  
Better Than

This article, for comparison, the non-proportionality of light yield and energy resolution of BGO, LYSO and CsI(Tl) scintillators couple to the R1306 PMT readouts were investigated. At 662 keV from 137Cs source, the good energy resolution of 7.13% for CsI(Tl) superior than LYSO and BGO scintillators. The energy resolution on gamma-ray energy was also evaluated to expose the scintillator intrinsic resolution parameters. For non-proportionality of light yield, the study showed a light yield non-proportionality 0.35% of LYSO, the value is better than 4.82 % for CsI(Tl) and 1.53 % of BGO scintillators.

scholarly journals A Search for Levels of 7Li Between 9·0 and 9·55 MeV Excitation

1959 ◽  
Vol 12 (3) ◽  
pp. 231 ◽  
Author(s):  
KH Purser
Keyword(s):  
Cross Section ◽  
Energy Resolution ◽  
Resonance Structure ◽  
Good Energy Resolution ◽  
Good Energy ◽  
The Cross

The cross section of the reaction 6Li(n,3H)'He has been measured, with good energy resolution, over the neutron range 2�0--2�65 MeV. This corresponds to an excitation of 7Li from 9� 0 to 9� 55 MeV, a region in which photodisintegration experiments indicate the presence of one or more levels. No resonance structure was observed in this experiment and possible reasons for this are discussed.

scholarly journals NEUTRINOS FROM ICARUS

2013 ◽  
Vol 53 (A) ◽  
pp. 776-781
Author(s):  
Christian Farnese
Keyword(s):  
3D Imaging ◽  
Sterile Neutrino ◽  
Rare Event ◽  
Liquid Argon ◽  
Good Energy Resolution ◽  
Time Projection Chambers ◽  
Event Reconstruction ◽  
The Status ◽  
Good Energy ◽  
Time Projection

Liquid Argon Time Projection Chambers are very promising detectors for neutrino and astroparticle physics due to their high granularity, good energy resolution and 3D imaging, allowing for a precise event reconstruction. ICARUS T600 is the largest liquid Argon (LAr) TPC detector ever built (~600 ton LAr mass) and is presently operating underground at the LNGS laboratory. This detector, internationally considered as the milestone towards the realization of the next generation of massive detectors (~tens of ktons) for neutrino and rare event physics, has been smoothly running since summer 2010, collecting data with the CNGS beam and with cosmics. The status of this detector will be shortly described together with the intent to adopt the LAr TPC technology at CERN as a possible solution to the sterile neutrino puzzle.

Hollow-cone illumination in simulated ADF STEM

1989 ◽  
Vol 47 ◽  
pp. 124-125
Author(s):  
R. F. Loane ◽  
J. Silcox
Keyword(s):  
Stationary Phase ◽  
Spherical Aberration ◽  
Image Interpretation ◽  
Incident Beam ◽  
Bragg Angle ◽  
Hollow Cone ◽  
Fringe Contrast ◽  
Convergence Angle ◽  
Probe Size ◽  
Overlap Region

The overlap regions between CBED disks are a source of lattice fringe contrast in ADF STEM images of crystals. For sufficiently small lattice spacings, the Scherzer focus convergence angle is too small for the CBED disks to overlap, and the lattice is not visible. By increasing the convergence angle beyond the Scherzer angle to create an overlap region, and by using stationary phase defocus, smaller lattices can be imaged However, with larger convergence angles, lens aberrations spread the incident beam and small aperiodic structures, such as adatoms, become difficult to image. If the specimen Bragg angle is known, an annular objective aperture can be designed to pass the overlap regions of the incident beam, while blocking the central, non-overlap region which produces a large constant background. The annular probe size is minimized by choosing an annulus width and defocus which balance the spherical aberration across the annulus (close to stationary phase defocus). Simulations indicate hollow cone illumination may allow both adatoms and smaller lattices to be imaged simultaneously. This approach presumes knowledge of the specimen, and must be used in conjunction with standard methods for correct image interpretation. An incorrectly applied annulus will produce image artifacts.

scholarly journals ROSAT Observations of Active Galactic Nuclei

1994 ◽  
Vol 159 ◽  
pp. 53-62 ◽  
Author(s):  
W. Brinkmann
Keyword(s):  
Active Galactic Nuclei ◽  
Spectral Properties ◽  
Galactic Nuclei ◽  
High Sensitivity ◽  
Good Energy Resolution ◽  
Ongoing Research ◽  
X Ray ◽  
Sky Survey ◽  
Good Energy ◽  
First Time

The large number of Active Galactive Nuclei detected for the first time through their X-ray emission in the ROSAT All Sky Survey as well as the first measurements of the X-ray emission of many previously known AGN provide a new unprecedented large basis for the statistical and morphological exploration of these objects.The soft energy range of the X-Ray Telescope, the good energy resolution of the PSPC detector, and the high sensitivity of the instrument further allows an investigation of the spectral properties of sources in this energetically important energy band.A short overview is given of the actual ongoing research concentrating on the study of the soft X-ray class properties of the various types of AGN.

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