scholarly journals CDMS Detector Fabrication Improvements and Low Energy Nuclear Recoil Measurements in Germanium

2015 ◽  
Author(s):  
Andrew Jastram
Keyword(s):  
Low Energy ◽  
Nuclear Recoil

scholarly journals Low energy electron and nuclear recoil thresholds in the DRIFT-II negative ion TPC for dark matter searches

2009 ◽  
Vol 4 (04) ◽  
pp. P04014-P04014 ◽  
Author(s):  
S Burgos ◽  
E Daw ◽  
J Forbes ◽  
C Ghag ◽  
M Gold ◽  
...  
Keyword(s):  
Dark Matter ◽  
Low Energy ◽  
Energy Electron ◽  
Nuclear Recoil ◽  
Negative Ion ◽  
Low Energy Electron

scholarly journals Direct dark matter research by observing electrons produced in neutralino-nucleus collisions

2019 ◽  
Vol 14 ◽  
pp. 19
Author(s):  
Ch. C. Moustakidis ◽  
J. D. Vergados ◽  
H. Ejiri
Keyword(s):  
Dark Matter ◽  
Elastic Scattering ◽  
Electron Energy ◽  
Ionization Rate ◽  
Low Energy ◽  
Nuclear Recoil ◽  
Important Process ◽  
Nuclear Collisions ◽  
Neutralino Mass ◽  
Direct Dark Matter

The most important process for directly detecting dark matter is the LSP-nucleus elastic scattering by measuring the energy of the recoiling nucleus. In the present work we explore a novel process that is the detection of the dark matter constituents by observing the low energy ionization electrons. We develop the formalism and apply it in calculating the ratio of the ionization rate to the nuclear recoil rate in a variety of atoms. The obtained ratios are essentially independent of all parameters of supersymmetry except the neutralino mass, but they crucially depend on the electron energy cut off. Based on our results it is both interesting and realistic to detect the LSP by measuring the ionization electrons following the-LSP nuclear collisions.

scholarly journals Low-Energy Physics Reach of Xenon Detectors for Nuclear-Recoil-Based Dark Matter and Neutrino Experiments

2019 ◽  
Vol 123 (23) ◽  
Author(s):  
B. G. Lenardo ◽  
J. Xu ◽  
S. Pereverzev ◽  
O. A. Akindele ◽  
D. Naim ◽  
...  
Keyword(s):  
Dark Matter ◽  
Low Energy ◽  
Nuclear Recoil ◽  
Neutrino Experiments ◽  
Energy Physics

scholarly journals Passive Low-Energy Nuclear-Recoil Detection with Color Centers

2021 ◽  
Vol 16 (6) ◽  
Author(s):  
Bernadette K. Cogswell ◽  
Apurva Goel ◽  
Patrick Huber
Keyword(s):  
Low Energy ◽  
Nuclear Recoil ◽  
Color Centers

Dissociated Σ=27 boundaries in silicon

1988 ◽  
Vol 46 ◽  
pp. 624-625
Author(s):  
A. Garg ◽  
W.A.T. Clark ◽  
J.P. Hirth
Keyword(s):  
Electron Diffraction ◽  
Local Minimum ◽  
Boundary Energy ◽  
Coincidence Site Lattice ◽  
Boundary Plane ◽  
Low Energy ◽  
Theoretical Understanding ◽  
Site Lattice ◽  
Kikuchi Pattern ◽  
Analysis Techniques

In the last twenty years, a significant amount of work has been done in the theoretical understanding of grain boundaries. The various proposed grain boundary models suggest the existence of coincidence site lattice (CSL) boundaries at specific misorientations where a periodic structure representing a local minimum of energy exists between the two crystals. In general, the boundary energy depends not only upon the density of CSL sites but also upon the boundary plane, so that different facets of the same boundary have different energy. Here we describe TEM observations of the dissociation of a Σ=27 boundary in silicon in order to reduce its surface energy and attain a low energy configuration.The boundary was identified as near CSL Σ=27 {255} having a misorientation of (38.7±0.2)°/[011] by standard Kikuchi pattern, electron diffraction and trace analysis techniques. Although the boundary appeared planar, in the TEM it was found to be dissociated in some regions into a Σ=3 {111} and a Σ=9 {122} boundary, as shown in Fig. 1.

Transfer optics for high spatial resolution electron spectroscopy

1988 ◽  
Vol 46 ◽  
pp. 666-667
Author(s):  
G. G. Hembree ◽  
Luo Chuan Hong ◽  
P.A. Bennett ◽  
J.A. Venables
Keyword(s):  
Magnetic Field ◽  
Scanning Transmission Electron Microscope ◽  
Low Energy ◽  
Objective Lens ◽  
State University ◽  
Arizona State University ◽  
Initial Field ◽  
Resolution Electron ◽  
Scanning Transmission ◽  
Low Energy Electrons

A new field emission scanning transmission electron microscope has been constructed for the NSF HREM facility at Arizona State University. The microscope is to be used for studies of surfaces, and incorporates several surface-related features, including provision for analysis of secondary and Auger electrons; these electrons are collected through the objective lens from either side of the sample, using the parallelizing action of the magnetic field. This collimates all the low energy electrons, which spiral in the high magnetic field. Given an initial field Bi∼1T, and a final (parallelizing) field Bf∼0.01T, all electrons emerge into a cone of semi-angle θf≤6°. The main practical problem in the way of using this well collimated beam of low energy (0-2keV) electrons is that it is travelling along the path of the (100keV) probing electron beam. To collect and analyze them, they must be deflected off the beam path with minimal effect on the probe position.

Performance Evaluation of a Novel Type of Low-Energy Electron Microscope

1990 ◽  
Vol 48 (1) ◽  
pp. 354-355
Author(s):  
Bertholdand Senftinger ◽  
Helmut Liebl
Keyword(s):  
Electron Microscope ◽  
High Resolution ◽  
Field Strength ◽  
Numerical Aperture ◽  
Low Energy ◽  
Energy Electron ◽  
High Resolution Imaging ◽  
Lens System ◽  
Resolution Imaging ◽  
Low Energy Electron

During the last few years the investigation of clean and adsorbate-covered solid surfaces as well as thin-film growth and molecular dynamics have given rise to a constant demand for high-resolution imaging microscopy with reflected and diffracted low energy electrons as well as photo-electrons. A recent successful implementation of a UHV low-energy electron microscope by Bauer and Telieps encouraged us to construct such a low energy electron microscope (LEEM) for high-resolution imaging incorporating several novel design features, which is described more detailed elsewhere.The constraint of high field strength at the surface required to keep the aberrations caused by the accelerating field small and high UV photon intensity to get an improved signal-to-noise ratio for photoemission led to the design of a tetrode emission lens system capable of also focusing the UV light at the surface through an integrated Schwarzschild-type objective. Fig. 1 shows an axial section of the emission lens in the LEEM with sample (28) and part of the sample holder (29). The integrated mirror objective (50a, 50b) is used for visual in situ microscopic observation of the sample as well as for UV illumination. The electron optical components and the sample with accelerating field followed by an einzel lens form a tetrode system. In order to keep the field strength high, the sample is separated from the first element of the einzel lens by only 1.6 mm. With a numerical aperture of 0.5 for the Schwarzschild objective the orifice in the first element of the einzel lens has to be about 3.0 mm in diameter. Considering the much smaller distance to the sample one can expect intense distortions of the accelerating field in front of the sample. Because the achievable lateral resolution depends mainly on the quality of the first imaging step, careful investigation of the aberrations caused by the emission lens system had to be done in order to avoid sacrificing high lateral resolution for larger numerical aperture.

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