Low-energy electron dose-point kernel simulations using new physics models implemented in Geant4-DNA

AbstractIn light of the excess in the low-energy electron recoil events reported by XENON1T, many new physics scenarios have been proposed as a possible origin of the excess. One possible explanation is that the excess is a result of a fast moving dark matter (DM), with velocity $$v\sim $$ v ∼ 0.05–0.20 and mass between 1 MeV and 10 GeV, scattering off an electron. Assuming the fast moving DM-electron interaction is mediated by a vector particle, we derive collider constraints on the said DM-electron interaction. The bounds on DM-electron coupling is then used to constrain possible production mechanisms of the fast moving DM. We find that the preferred mass of the vector mediator is relatively light ($$\lesssim $$ ≲ 1 GeV) and the coupling of the vector to the electron is much smaller than the coupling to the fast moving DM.

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Low-energy electron dose-point kernels and radial dose distributions around gold nanoparticles: Comparison between MCNP6.1, PENELOPE2014 and Geant4-DNA

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/j.nimb.2018.06.001 ◽

2018 ◽

Vol 430 ◽

pp. 18-22 ◽

Cited By ~ 2

Author(s):

Seongmoon Jung ◽

Wonmo Sung ◽

Sung-Joon Ye

Keyword(s):

Gold Nanoparticles ◽

Low Energy ◽

Energy Electron ◽

Electron Dose ◽

Dose Distributions ◽

Low Energy Electron ◽

Radial Dose

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Electron Beam Induced Degradation of 2Deg in AlGaAs/GaAs Heterostructure

MRS Proceedings ◽

10.1557/proc-325-67 ◽

1993 ◽

Vol 325 ◽

Cited By ~ 1

Author(s):

T. Wada ◽

T. Kanayama ◽

S. Ichimura ◽

Y. Sugiyama ◽

M. Komuro

Keyword(s):

Electron Irradiation ◽

Room Temperature ◽

Low Energy ◽

Energy Electron ◽

Two Dimensional ◽

Electron Gases ◽

Electron Dose ◽

Gaas Buffer Layer ◽

Core Electrons ◽

Low Energy Electron

AbstractThe effects of low-energy electron irradiation on the two-dimensional electron gases (2DEG's) in AlGaAs/GaAs heterostructures have been investigated. Not only the electron mobility of the 2DEG's but also the two-dimensional (2D) carriers are found to be reduced by the electron irradiation with the incident energies between 3.5 k and 8 keV and the electron dose of 1×1016 and 1×1017 /cm2. The degraded mobility and the removed carriers by the low-energy electron irradiation are shown to recover by isochronal annealing to some extent, but not completely below 400°C. It is also found that considerable amount of scatterers which are created by an electron irradiation at room temperature are also created by an irradiation at 90 K. Comparing the experimental results with the Monte Carlo simulation, we speculate that the mobility degradation and the 2D carrier compensation are partly caused by the formation of complex defects in the GaAs buffer layer which are due to the excitations of core electrons of As, and that the mobility is further degraded by the formation of short-range scatterers in the heterointerface.

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Monte Carlo calculations of low-energy electron dose-point-kernels in water using different stopping power approximations

Nuclear Instruments and Methods in Physics Research Section B Beam Interactions with Materials and Atoms ◽

10.1016/j.nimb.2010.10.016 ◽

2011 ◽

Vol 269 (14) ◽

pp. 1650-1654 ◽

Cited By ~ 3

Author(s):

Christos Bousis ◽

Dimitris Emfietzoglou ◽

Panagiotis Hadjidoukas ◽

Hooshang Nikjoo ◽

Anand Pathak

Keyword(s):

Monte Carlo ◽

Low Energy ◽

Energy Electron ◽

Stopping Power ◽

Electron Dose ◽

Monte Carlo Calculations ◽

Low Energy Electron

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A Study of the DII Defect after Electron Irradiation and Annealing of 4H SiC

Materials Science Forum ◽

10.4028/www.scientific.net/msf.556-557.319 ◽

2007 ◽

Vol 556-557 ◽

pp. 319-322 ◽

Cited By ~ 3

Author(s):

W. Sullivan ◽

John W. Steeds

Keyword(s):

High Temperature ◽

Electron Irradiation ◽

Low Energy ◽

Energy Electron ◽

Vibrational Modes ◽

Electron Dose ◽

Low Energy Electron ◽

Local Vibrational Modes ◽

First Time ◽

Dose Variation

The high-temperature persistent PL defect known as DII is commented on within this study, seen for the first time in low-energy electron irradiated 4H SiC. The local vibrational modes associated with the defect have been identified and the temperature dependence, spatial variation and electron-energy/electron-dose variation of this defect have all been investigated.

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

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100180525 ◽

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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