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Author(s):  
Amol Holkundkar ◽  
Felix Mackenroth

Abstract We present a novel approach to analyzing phase-space distributions of electrons ponderomotively scattered off an ultra-intense laser pulse and comment on implications for thus conceivable in-situ laser-characterization schemes. To this end, we present fully relativistic test particle simulations of electrons scattered from an ultra-intense, counter-propagating laser pulse. The simulations unveil non-trivial scalings of the scattered electron distribution with the laser intensity, pulse duration, beam waist, and energy of the electron bunch. We quantify the found scalings by means of an analytical expression for the scattering angle of an electron bunch ponderomotively scattered from a counter-propagating, ultra-intense laser pulse, also accounting for radiation reaction (RR) through the Landau-Lifshitz (LL) model. For various laser and bunch parameters, the derived formula is in excellent quantitative agreement with the simulations. We also demonstrate how in the radiation-dominated regime a simple re-scaling of our model's input parameter yields quantitative agreement with numerical simulations based on the LL model.


Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7511
Author(s):  
Jonathan Chuah ◽  
Anjam Khursheed

This paper presents the design of a reflection electron energy spectrometer (REELS) attachment for low voltage scanning electron microscopy (LVSEM) applications. The design is made by carrying out a scattered electron trajectory ray paths simulation. The spectrometer attachment is small enough to fit on the specimen stage of an SEM, and aims to acquire nanoscale spatially resolved REELS information. It uses a retarding field electrostatic toroidal sector energy analyzer design, which is able to lower the kinetic energies of elastically backscattered electrons to pass energies of 10 eV or less. For the capture of 1 keV BSEs emitted in the polar angular range between 40 to 50°, direct ray-tracing simulations predict that the spectrometer attachment will have an energy resolution of around 0.4 eV at a pass energy of 10 eV, and 0.2 eV at a pass energy of 5 eV. This predicted performance will make it a suitable REELS attachment for SEMs that use field emission electron sources.


Biology ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1242
Author(s):  
Oimahmad Rahmonov ◽  
Jerzy Cabała ◽  
Robert Krzysztofik

Post-mining waste from Zn-Pb ore exploitation undergoes processes of spontaneous succession and changes in soil chemical composition. The Zakawie area was industrially transformed by historical mining activity, ore enrichment, and the metallurgical processing of Zn-Pb ore. The subject of the study was to analyse the rate of vegetation succession (from 1999 to 2019), soil chemistry, and the relationships between them in an anthropogenic habitat with high concentrations of potentially toxic metals. Ecological and geochemical studies were carried out in an area contaminated with waste from a disused Zn-Pb ore-washing plant. Between 1999 and 2019, the transformation of grassland and meadow vegetation into scrub and forest–grassland communities was observed. This transformation led to a decrease in the area of Molinietum caeruleae meadow (from 25.8% in 1999 to 10.7% in 2019), whose place was taken by Prunus spinosa and Rhamnus cathartica. The community of xerothermic limestone grasslands completely disappeared, being replaced in favour of the Diantho-Armerietum and Prunus spinosa community. In this period, the share of lifeforms of plants and species composition (46 and 60, respectively) also changed. The Shannon and Simpson biodiversity index reached high values in the second investigation period, and it was 0.893 and 0.86, respectively. The anthrosols had a high content of Zn—85,360 mg kg−1, Pb—28,300 mg kg−1, Cd—340 mg kg−1, and As—1200 mg kg−1. Carbonates, clay minerals, and fe-oxides are predominant in the mineral composition of the rhizosphere; the metal-bearing phases are stable; and hardly soluble minerals include smithsonite, cerussite, monheimite, hemimorphite, and oxides of Fe and Fe-Mn. Mineralisation/crust processes formed on the epidermis, and their influences on root development were found. Scanning electron microscopy and energy-dispersive X-ray spectroscopy studies on rhizosphere soil components provide information on the type of minerals and their susceptibility to heavy metals release. The identification of some biotic and mineral structures in rhizospheres can be an interesting source of information on pedogenic processes identified in back-scattered electron images.


2021 ◽  
Author(s):  
◽  
Kartika Palupi Savitri

<p>Tompaso geothermal system is a typical volcanic arc geothermal system in North Sulawesi, Indonesia. Although situated close to the Tondano caldera, subsurface lithologies and structures do not show any evidence for caldera-related features and the system is inferred to be related to the andesitic Soputan volcano. The subsurface geology of Tompaso consists of Tuff B unit, Rhyolite unit, Andesite B unit, Pitchstone unit, Pyroclastic Breccia unit,Andesite A unit, Pumice unit, and Tuff A unit, respectively, from the oldest penetrated unit. The silicic Pitchstone and Rhyolite units are presumed to be sourced from the same magma chamber. Petrological and mineralogical observations using binocular and petrographic microscopy, short-wave infrared (SWIR) analysis, and back-scattered electron (BSE) imaging combined with energy dispersive X-ray spectroscopy (EDS) have been applied to cuttings and limited core material from three boreholes: LHD-26, LHD-27, and LHD-32. Age dating has not been undertaken and, thus, conclusions on correlations between subsurface geology inferred here with surface formation groupings from previous works cannot be drawn.  Tompaso geothermal system is characterised primarily by variations in the fracturing within the reservoir. Secondary mineralogy and the structure of present-day temperature of the system suggest that the movement of hydrothermal fluids at Tompaso is controlled by faults: the Soputan, Tempang, and A-A’ faults, the last defined for the first time in this thesis. Soputan Fault controls the outflow of the system. On the other hand, the influence of Tempang and A-A’ faults is dominant only in the upper portion of the system. The A-A’ fault likely acts as a channel for cooler meteoric surface water, while the Tempang Fault is inferred to have experienced self-sealing and appears to be an impermeable structure in the system. The self-sealing process of the Tempang Fault and/or the introduction of meteoric water through the A-A’ fault may be related to the cooling of the northern and western part of the system.  The challenges in identifying protoliths in active geothermal areas is addressed here through studies of the influence of andesite textures on the preferences of hydrothermal alteration processes. Wairakei andesites were chosen for comparison to Tompaso andesites, especially because of its different geological setting and geothermal reservoir structure. The results suggest that mineral composition and arrangement affect the preference of hydrothermal alteration on andesites.</p>


2021 ◽  
Author(s):  
◽  
Kartika Palupi Savitri

<p>Tompaso geothermal system is a typical volcanic arc geothermal system in North Sulawesi, Indonesia. Although situated close to the Tondano caldera, subsurface lithologies and structures do not show any evidence for caldera-related features and the system is inferred to be related to the andesitic Soputan volcano. The subsurface geology of Tompaso consists of Tuff B unit, Rhyolite unit, Andesite B unit, Pitchstone unit, Pyroclastic Breccia unit,Andesite A unit, Pumice unit, and Tuff A unit, respectively, from the oldest penetrated unit. The silicic Pitchstone and Rhyolite units are presumed to be sourced from the same magma chamber. Petrological and mineralogical observations using binocular and petrographic microscopy, short-wave infrared (SWIR) analysis, and back-scattered electron (BSE) imaging combined with energy dispersive X-ray spectroscopy (EDS) have been applied to cuttings and limited core material from three boreholes: LHD-26, LHD-27, and LHD-32. Age dating has not been undertaken and, thus, conclusions on correlations between subsurface geology inferred here with surface formation groupings from previous works cannot be drawn.  Tompaso geothermal system is characterised primarily by variations in the fracturing within the reservoir. Secondary mineralogy and the structure of present-day temperature of the system suggest that the movement of hydrothermal fluids at Tompaso is controlled by faults: the Soputan, Tempang, and A-A’ faults, the last defined for the first time in this thesis. Soputan Fault controls the outflow of the system. On the other hand, the influence of Tempang and A-A’ faults is dominant only in the upper portion of the system. The A-A’ fault likely acts as a channel for cooler meteoric surface water, while the Tempang Fault is inferred to have experienced self-sealing and appears to be an impermeable structure in the system. The self-sealing process of the Tempang Fault and/or the introduction of meteoric water through the A-A’ fault may be related to the cooling of the northern and western part of the system.  The challenges in identifying protoliths in active geothermal areas is addressed here through studies of the influence of andesite textures on the preferences of hydrothermal alteration processes. Wairakei andesites were chosen for comparison to Tompaso andesites, especially because of its different geological setting and geothermal reservoir structure. The results suggest that mineral composition and arrangement affect the preference of hydrothermal alteration on andesites.</p>


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xinnan Peng ◽  
Harshitra Mahalingam ◽  
Shaoqiang Dong ◽  
Pingo Mutombo ◽  
Jie Su ◽  
...  

AbstractCreating atomically precise quantum architectures with high digital fidelity and desired quantum states is an important goal in a new era of quantum technology. The strategy of creating these quantum nanostructures mainly relies on atom-by-atom, molecule-by-molecule manipulation or molecular assembly through non-covalent interactions, which thus lack sufficient chemical robustness required for on-chip quantum device operation at elevated temperature. Here, we report a bottom-up synthesis of covalently linked organic quantum corrals (OQCs) with atomic precision to induce the formation of topology-controlled quantum resonance states, arising from a collective interference of scattered electron waves inside the quantum nanocavities. Individual OQCs host a series of atomic orbital-like resonance states whose orbital hybridization into artificial homo-diatomic and hetero-diatomic molecular-like resonance states can be constructed in Cassini oval-shaped OQCs with desired topologies corroborated by joint ab initio and analytic calculations. Our studies open up a new avenue to fabricate covalently linked large-sized OQCs with atomic precision to engineer desired quantum states with high chemical robustness and digital fidelity for future practical applications.


Author(s):  
Junu Jeong ◽  
Jihn E. Kim ◽  
Sungwoo Youn

In this paper, we consider the effects of bound atomic electrons scattered by solar neutrinos due to the electromagnetic properties of neutrinos. This necessitates considering the recoil of atomic nucleus, which should be considered in the momentum conservation, but the effect to the energy conservation is negligible. This effect changes the kinematic behavior of the scattered electron compared to that scattered on free electrons. We apply this effect to the recent XENON1T data, but the bounds obtained from this are not very restrictive. We obtained the bounds: the (transition) magnetic moment [Formula: see text] (times the electron Bohr magneton) and the charge radius [Formula: see text] cm. For a nonvanishing millicharge [Formula: see text], the allowed bound is shown in the [Formula: see text] plane.


Author(s):  
Virendra Sharma ◽  
Piyush Kumar Choubey ◽  
Amit Kumar ◽  
Lata Gidwani

<p>This paper presents an approach for optimal generation capacity mix to fulfill future power demand using a micro-grid model which is operated in both the on-grid and off-grid modes. This is achieved using the solar photovoltaic (PV) system, fuel-cell, and battery energy storage system (BESS) with and without the grid-connected mode. Different control approaches and optimal size of the generators are presented. Proposed micro grid with solar PV system, solid oxide fuel cell (SOFC) and back scattered electron detector (BESD) is tested for different operational scenarios of loads. Comparative index of performance (CIP) is introduced to indicate effectiveness of the micro-grid operations in the off-grid mode. This is based on difference in the total harmonic distortions (THD) in both the on-grid and off-grid modes. This is established that CIP indicates that the micro-grid works efficiently in the both the on-grid and off- grid modes during the simulated events of the switching ON/OFF the loads at different test conditions. The optimal generation mix successfully met the load demand with and without grid having conventional generatio.</p>


2021 ◽  
Vol 81 (8) ◽  
Author(s):  
A. van Hameren ◽  
P. Kotko ◽  
K. Kutak ◽  
S. Sapeta ◽  
E. Żarów

AbstractWe propose a novel way of studying the gluon number density (the so-called Weizsäcker–Williams gluon distribution) using the planned Electron Ion Collider. Namely, with the help of the azimuthal correlations between the total transverse momentum of the dijet system and the scattered electron, we examine an interplay between the effect of the soft gluon emissions (the Sudakov form factor) and the gluon saturation effects. The kinematic cuts are chosen such that the dijet system is produced in the forward direction in the laboratory frame, which provides an upper bound on the probed longitudinal fractions of the hadron momentum carried by scattered gluons. Further cuts enable us to use the factorization formalism that directly involves the unpolarized Weizsäcker–Williams gluon distribution. We find this observable to be very sensitive to the soft gluon emission and moderately sensitive to the gluon saturation.


Universe ◽  
2021 ◽  
Vol 7 (7) ◽  
pp. 210
Author(s):  
Georgii K. Sizykh ◽  
Sergei P. Roshchupkin ◽  
Victor V. Dubov

The process of resonant high-energy electron–positron pairs production by electrons in an X-ray pulsar electromagnetic field is studied theoretically. Under the resonance conditions, the second-order process under consideration effectively reduces into two sequential first-order processes: X-ray-stimulated Compton effect and X-ray–stimulated Breit–Wheeler process. The kinematics of the process is studied in detail: the dependencies of the energy of the scattered electron on its outgoing angle and the energies of the particles of the pair on the outgoing angle of the scattered electron and the opening angle of the pair are obtained. The analysis of the number of different possible particles energies values in the entire range of the angles is also carried out, according to which the energies of the particles of the pair can take up to eight different values at a fixed outgoing angle of the scattered electron and opening angle of the pair. The estimate of the resonant differential probability per unit time of the process, which reaches the maximum value of 24 orders of the value of the non-resonant differential probability per unit time, is obtained. The angular distribution of the differential probability per unit time of the process is analyzed, particularly for the case of high-energy positrons presenting in pulsar radiation.


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