Limiting fragmentation of target nucleus at high energy

2013 ◽  
Vol 91 (9) ◽  
pp. 737-743 ◽  
Author(s):  
M.S. El-Nagdy ◽  
A. Abdelsalam ◽  
Z. Abou-Moussa ◽  
B.M. Badawy
Keyword(s):  
Cross Section ◽  
System Size ◽  
High Energy ◽  
Simulation Code ◽  
Target Region ◽  
Geometrical Cross Section ◽  
Fragmentation Cross Section ◽  
Wide Range ◽  
Limiting Fragmentation ◽  
Nuclear Multifragmentation

This study discusses features suggestive of a nuclear multifragmentation in the target. A wide range of projectile masses are used (AProj = 1–207) over a large energy region (Elab = 1A–200A GeV). In particular, the validity of the nuclear limiting fragmentation hypothesis is focused in the target region. The probability that the target is fragmented forms about 90% from the total inelastic geometrical cross section. The dependence of the target fragmentation cross section on the system size and on the incident energy is presented. The results are analyzed in the framework of the modified FRITIOF simulation code.

QCD JETS AT HERA I.: O(αs) RADIATIVE CORRECTIONS TO ELECTROWEAK CROSS SECTIONS AND JET RATES

1989 ◽  
Vol 04 (07) ◽  
pp. 1781-1825 ◽  
Author(s):  
JÜRGEN G. KÖRNER ◽  
ERWIN MIRKES ◽  
GERHARD A. SCHULER
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Neutral Current ◽  
High Energy ◽  
Coupling Constant ◽  
Bjorken Scaling ◽  
Born Cross Section ◽  
Wide Range ◽  
Lepton Polarization ◽  
Jet Cross Sections

We present the complete O(αs) corrections to the electroweak cross sections of both neutral current and charged current deep inelastic e±p scattering including lepton polarization effects. Changes in the cross section due to the inclusion of next-to-leading-log (NLL) effects are parametrized by K factors, which are defined as the ratio of the NLL O(αs) cross sections and the Born cross section. Using the standard redefinition scheme of the parton densities, we find that the K factors deviate substantially from unity for small values of the Bjorken-Scaling variable x. We also elaborate on problems that arise when defining jet cross sections in ep scattering and present numerical results for the O(αs) 3-jet and 2-jet rates. We observe that the Q2-dependence of the 3-jet rate is dominated by the running strong coupling constant αs(Q2) allowing for its determination over a wide range in Q2 at high energy ep colliders.

Microfabrication research at the National Submicron Facility

1983 ◽  
Vol 41 ◽  
pp. 86-89
Author(s):  
E.D. Wolf
Keyword(s):  
Integrated Circuits ◽  
Particle Physics ◽  
High Speed ◽  
New Technology ◽  
High Energy ◽  
High Energy Particle ◽  
New Science ◽  
Wide Range ◽  
Intermediate Domain ◽  
Circuit Function

Most microelectronics devices and circuits operate faster, consume less power, execute more functions and cost less per circuit function when the feature-sizes internal to the devices and circuits are made smaller. This is part of the stimulus for the Very High-Speed Integrated Circuits (VHSIC) program. There is also a need for smaller, more sensitive sensors in a wide range of disciplines that includes electrochemistry, neurophysiology and ultra-high pressure solid state research. There is often fundamental new science (and sometimes new technology) to be revealed (and used) when a basic parameter such as size is extended to new dimensions, as is evident at the two extremes of smallness and largeness, high energy particle physics and cosmology, respectively. However, there is also a very important intermediate domain of size that spans from the diameter of a small cluster of atoms up to near one micrometer which may also have just as profound effects on society as “big” physics.

In situ irradiation effects studies in medium- and high-voltage TEM

1995 ◽  
Vol 53 ◽  
pp. 234-235
Author(s):  
Charles W. Allen
Keyword(s):  
Cross Section ◽  
Particle Flux ◽  
Threshold Value ◽  
High Energy ◽  
Irradiation Damage ◽  
Defect Complexes ◽  
Lattice Position ◽  
Electrons And Ions ◽  
The Masses

With respect to structural consequences within a material, energetic electrons, above a threshold value of energy characteristic of a particular material, produce vacancy-interstial pairs (Frenkel pairs) by displacement of individual atoms, as illustrated for several materials in Table 1. Ion projectiles produce cascades of Frenkel pairs. Such displacement cascades result from high energy primary knock-on atoms which produce many secondary defects. These defects rearrange to form a variety of defect complexes on the time scale of tens of picoseconds following the primary displacement. A convenient measure of the extent of irradiation damage, both for electrons and ions, is the number of displacements per atom (dpa). 1 dpa means, on average, each atom in the irradiated region of material has been displaced once from its original lattice position. Displacement rate (dpa/s) is proportional to particle flux (cm-2s-1), the proportionality factor being the “displacement cross-section” σD (cm2). The cross-section σD depends mainly on the masses of target and projectile and on the kinetic energy of the projectile particle.

Compact back-scattered electrons' energy analyzer for standard SEM

1994 ◽  
Vol 52 ◽  
pp. 488-489
Author(s):  
S. Likharev ◽  
A. Kramarenko ◽  
V. Vybornov
Keyword(s):  
Depth Resolution ◽  
High Energy ◽  
Primary Beam ◽  
Layer By Layer ◽  
Energy Analyzer ◽  
High Energy Part ◽  
Small Window ◽  
Energy Part ◽  
Wide Range ◽  
High Voltage Supply

At present time the interest is growing considerably for theoretical and experimental analysis of back-scattered electrons (BSE) energy spectra. It was discovered that a special angle and energy nitration of BSE flow could be used for increasing a spatial resolution of BSE mode, sample topography investigations and for layer-by layer visualizing of a depth structure. In the last case it was shown theoretically that in order to obtain suitable depth resolution it is necessary to select a part of BSE flow with the directions of velocities close to inverse to the primary beam and energies within a small window in the high-energy part of the whole spectrum.A wide range of such devices has been developed earlier, but all of them have considerable demerit: they can hardly be used with a standard SEM due to the necessity of sufficient SEM modifications like installation of large accessories in or out SEM chamber, mounting of specialized detector systems, input wires for high voltage supply, screening a primary beam from additional electromagnetic field, etc. In this report we present a new scheme of a compact BSE energy analyzer that is free of imperfections mentioned above.

scholarly journals Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

2021 ◽  
Vol 22 (15) ◽  
pp. 7879
Author(s):  
Yingxia Gao ◽  
Yi Zheng ◽  
Léon Sanche
Keyword(s):  
Condensed Phase ◽  
Genetic Material ◽  
High Energy ◽  
Dna Lesions ◽  
Low Energy ◽  
Experimental Investigations ◽  
Experimental Conditions ◽  
Strand Breaks ◽  
Sequence Of Events ◽  
Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

scholarly journals Optically transparent and very thin structure against electromagnetic pulse (EMP) using metal mesh and saltwater for shielding windows

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Duy Tung Phan ◽  
Chang Won Jung
Keyword(s):  
Electromagnetic Pulse ◽  
Low Cost ◽  
High Energy ◽  
Metal Plate ◽  
Optical Transparency ◽  
Shielding Effectiveness ◽  
Concrete Wall ◽  
Metal Mesh ◽  
Wide Range ◽  
Optically Transparent

AbstractAn electromagnetic pulse (EMP) with high energy can damage electronic equipment instantly within a wide range of thousands of kilometers. Generally, a metal plate placed inside a thick concrete wall is used against an EMP, but it is not suitable for an EMP shielding window, which requires not only strong shielding effectiveness (SE) but also optical transparency (OT). In this paper, we propose a very thin and optically transparent structure with excellent SE for EMP shielding window application. The proposed structure consists of a saltwater layer held between two glass substrates and two metal mesh layers on the outside of the glass, with a total thickness of less than 1.5 cm. The SE and OT of the structure are above 80 dB and 45%, respectively, which not only meet the requirement of EMP shielding for military purposes but also retain the procedure of good observation. Moreover, the OT of the structure can be significantly improved using only one metal mesh film (MMF) layer, while the SE is still maintained high to satisfy the required SE for home applicants. With the major advantages of low cost, optical transparency, strong SE, and flexible performance, the proposed structure can be considered a good solution for transparent EMP shielding windows.

Enabling highly reversible sodium metal cycling across a wide temperature range with dual-salt electrolytes

2021 ◽  
Author(s):  
Akila C. Thenuwara ◽  
Pralav P. Shetty ◽  
Neha Kondekar ◽  
Chuanlong Wang ◽  
Weiyang Li ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
High Energy ◽  
Liquid Electrolyte ◽  
Metal Cycling ◽  
Temperature Range ◽  
Sodium Metal ◽  
Wide Range

A new dual-salt liquid electrolyte is developed that enables the reversible operation of high-energy sodium-metal-based batteries over a wide range of temperatures down to −50 °C.

scholarly journals Total cross sections of eγ → $$ eX\overline{X} $$ processes with X = μ, γ, e via multiloop methods

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Roman N. Lee ◽  
Alexey A. Lyubyakin ◽  
Vyacheslav A. Stotsky
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Elliptic Integral ◽  
High Energy ◽  
Calculation Methods ◽  
Complete Elliptic Integral ◽  
Total Cross Sections ◽  
Multiloop Calculation ◽  
The Cross ◽  
Analytical Expressions

Abstract Using modern multiloop calculation methods, we derive the analytical expressions for the total cross sections of the processes e−γ →$$ {e}^{-}X\overline{X} $$ e − X X ¯ with X = μ, γ or e at arbitrary energies. For the first two processes our results are expressed via classical polylogarithms. The cross section of e−γ → e−e−e+ is represented as a one-fold integral of complete elliptic integral K and logarithms. Using our results, we calculate the threshold and high-energy asymptotics and compare them with available results.

scholarly journals Vector boson fusion at multi-TeV muon colliders

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Antonio Costantini ◽  
Federico De Lillo ◽  
Fabio Maltoni ◽  
Luca Mantani ◽  
Olivier Mattelaer ◽  
...  
Keyword(s):  
Cross Sections ◽  
Vector Boson ◽  
High Energy ◽  
New Physics ◽  
Vector Boson Fusion ◽  
Weak Boson ◽  
Wide Range ◽  
Lepton Colliders ◽  
Muon Colliders ◽  
New Phenomena

Abstract High-energy lepton colliders with a centre-of-mass energy in the multi-TeV range are currently considered among the most challenging and far-reaching future accelerator projects. Studies performed so far have mostly focused on the reach for new phenomena in lepton-antilepton annihilation channels. In this work we observe that starting from collider energies of a few TeV, electroweak (EW) vector boson fusion/scattering (VBF) at lepton colliders becomes the dominant production mode for all Standard Model processes relevant to studying the EW sector. In many cases we find that this also holds for new physics. We quantify the size and the growth of VBF cross sections with collider energy for a number of SM and new physics processes. By considering luminosity scenarios achievable at a muon collider, we conclude that such a machine would effectively be a “high-luminosity weak boson collider,” and subsequently offer a wide range of opportunities to precisely measure EW and Higgs couplings as well as discover new particles.

Ultrasmall Gd@Cdots as a Radiosensitizing Agent for Non-Small Cell Lung Cancer

Nanoscale ◽  
2021 ◽  
Author(s):  
Chaebin Lee ◽  
Xiangji Liu ◽  
Weizhong Zhang ◽  
M. A. Duncan ◽  
Fangchao Jiang ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Small Cell Lung Cancer ◽  
Cross Section ◽  
Cell Lung Cancer ◽  
High Energy ◽  
Small Cell ◽  
Small Cell Lung ◽  
High Energy Radiation ◽  
Energy Radiation

High-Z nanoparticles (HZNPs) afford high cross-section for high energy radiation and have attracted wide attention as a novel type of radiosensizers. However, conventional HZNPs are often associated with issues such...

Sign in / Sign up

Export Citation Format

Share Document