Effective energy loss per electron-ion pair in proton aurora

1994 ◽  
Vol 12 (10/11) ◽  
pp. 1071-1075 ◽  
Author(s):  
B. V. Kozelov ◽  
V. E. Ivanov
Keyword(s):  
Energy Loss ◽  
Cross Sections ◽  
Proton Transport ◽  
Average Energy ◽  
Initial Energy ◽  
Ion Pair ◽  
Effective Energy ◽  
Transport Parameters ◽  
Secondary Electrons ◽  
Proton Aurora

Abstract. Effective energy loss per electron-ion pair produced, <xi>(E0), as a function of a particle's initial energy has been obtained for proton transport in the atmosphere. The influence of some transport parameters on the shape of <xi>(E0) has been studied. Comparisons with the case of electron transport and with other results were made. It has been shown that: 1. for E0>1 keV, <xi>(E0) varies within the range 30-36 eV; 2. as E0 increases the value of <xi>(E0) tries to attain an asymptotic value that is the same as for electrons (≈35 eV); 3. <xi>(E0) strongly depends on the average energy of secondary electrons, but the energy distribution of secondary electrons is not as important. The range of possible changes in <xi>(E0) associated with discrepancies in cross sections has been obtained.

Effective energy loss per electron-ion pair in proton aurora

1994 ◽  
Vol 12 (10) ◽  
pp. 1071
Author(s):  
B. V. Kozelov ◽  
V. E. Ivanov
Keyword(s):  
Energy Loss ◽  
Ion Pair ◽  
Effective Energy ◽  
Proton Aurora

scholarly journals Contribution of Outer Electron and Inner-Shell Electron to Proton Energy Loss in Liquid Water and DNA

2015 ◽  
Vol 60 ◽  
pp. 25-34
Author(s):  
Bashier Sabty Faris ◽  
Riaybd K.A. Al-Ani
Keyword(s):  
Energy Loss ◽  
Liquid Water ◽  
Average Energy ◽  
Electron Shell ◽  
Stopping Power ◽  
Outer Electron ◽  
Secondary Electrons ◽  
Strand Breaks ◽  
Biological Damage ◽  
Good Agreement

In the present work Drude-dielectric formalism has been used to calculate the effects of contribution of inner and outer-electron shell to energy-loss of protons liquid water H2O and DNA. The results show that the incident protons with energy between (T = 0.05, 0.25, 1, 2, 2.5 MeV) are very efficient in producing secondary electrons in dry DNA, which are able to produce strand breaks and could be very effective for the biological damage of malignant cells. The PSPEC, Stopping power, average energy transfer, ∆E and ionization energy have been calculated taking in the consideration the Sub-shells of each elements in DNA and H2O, Fourier energy density ρ (q), Charge exchange and Screening effects ᴧ. Good agreement achieved with the previous work [1].

scholarly journals Monte Carlo model for electron degradation in xenon gas

2016 ◽  
Vol 472 (2187) ◽  
pp. 20150727 ◽  
Author(s):  
Vrinda Mukundan ◽  
Anil Bhardwaj
Keyword(s):  
Monte Carlo ◽  
Energy Loss ◽  
Cross Sections ◽  
Input Data ◽  
Monte Carlo Model ◽  
Ion Pair ◽  
Two Dimensional ◽  
Excitation Process ◽  
Volume Production ◽  
Inelastic Processes

We have developed a Monte Carlo model for studying the local degradation of electrons in the energy range 9–10 000 eV in xenon gas. Analytically fitted form of electron impact cross sections for elastic and various inelastic processes are fed as input data to the model. The two-dimensional numerical yield spectrum (NYS), which gives information on the number of energy loss events occurring in a particular energy interval, is obtained as the output of the model. The NYS is fitted analytically, thus obtaining the analytical yield spectrum (AYS). The AYS can be used to calculate electron fluxes, which can be further employed for the calculation of volume production rates. Using the yield spectrum, mean energy per ion pair and efficiencies of inelastic processes are calculated. The value for mean energy per ion pair for Xe is 22 eV at 10 keV. Ionization dominates for incident energies greater than 50 eV and is found to have an efficiency of approximately 65% at 10 keV. The efficiency for the excitation process is approximately 30% at 10 keV.

scholarly journals Leading jets and energy loss

2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
Duff Neill ◽  
Felix Ringer ◽  
Nobuo Sato
Keyword(s):  
Energy Loss ◽  
Cross Sections ◽  
Evolution Equations ◽  
Average Energy ◽  
Longitudinal Momentum ◽  
Longitudinal Momentum Fraction ◽  
Inclusive Jets ◽  
Jet Energy ◽  
The Difference ◽  
Additional Reference

Abstract The formation and evolution of leading jets can be described by jet functions which satisfy non-linear DGLAP-type evolution equations. Different than for inclusive jets, the leading jet functions constitute normalized probability densities for the leading jet to carry a longitudinal momentum fraction relative to the initial fragmenting parton. We present a parton shower algorithm which allows for the calculation of leading-jet cross sections where logarithms of the jet radius and threshold logarithms are resummed to next-to-leading logarithmic (NLL′) accuracy. By calculating the mean of the leading jet distribution, we are able to quantify the average out-of-jet radiation, the so-called jet energy loss. When an additional reference scale is measured, we are able to determine the energy loss of leading jets at the cross section level which is identical to parton energy loss at leading-logarithmic accuracy. We identify several suitable cross sections for an extraction of the jet energy loss and we present numerical results for leading subjets at the LHC. In addition, we consider hemisphere and event-wide leading jets in electron-positron annihilation similar to measurements performed at LEP. Besides the average energy loss, we also consider its variance and other statistical quantities such as the KL divergence which quantifies the difference between quark and gluon jet energy loss. We expect that our results will be particularly relevant for quantifying the energy loss of quark and gluon jets that propagate through hot or cold nuclear matter.

scholarly journals The rate of emission of γ -ray energy by radium B and radium C, and by thorium B and thorium C"

1937 ◽  
Vol 159 (897) ◽  
pp. 263-283 ◽  
Keyword(s):  
Total Energy ◽  
Unit Volume ◽  
Homogeneous Medium ◽  
Average Energy ◽  
Ion Pair ◽  
Secondary Electrons ◽  
Γ Ray

Consider a γ -ray source situated in an infinite homogeneous medium. If q r , is the γ -ray energy absorbed per unit volume of the medium at a distance r from the source, the total energy emitted by the source is Q = 4 π ∫ ∞ 0 q r r 2 dr . (1) If a small air-filled cavity is introduced at any point in such a medium, the number of pairs of ions per unit volume n produced in the air in the cavity is related to the γ -ray energy absorbed per unit volume of the medium q r by the equation q r = nWρ , (2) where W is the average energy lost by the secondary electrons per ion pair formed in the air, and ρ is the ratio of the rate of loss of energy by the secondary electrons in the medium and in air. Thus, in terms of the ionization per unit volume n r produced in a small air-filled cavity at a distance r from the source, equation (1) becomes Q = 4 πWρ ∫ ∞ 0 n r r 2 dr . (3) This paper describes a determination of Q in this way for the γ -radiation accompanying the disintegration of Ra B and Ra C in equilibrium with radium, and for the γ -radiation emitted by Th B and Th C" in equilibrium with radio-thorium.

Stopping-power determination for compound by EELS

1994 ◽  
Vol 52 ◽  
pp. 948-949 ◽  
Author(s):  
David C. Joy ◽  
Suichu Luo ◽  
John R. Dunlap ◽  
Dick Williams ◽  
Siqi Cao
Keyword(s):  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Average Energy ◽  
Stopping Power ◽  
Accurate Information ◽  
Power Calculation ◽  
Coulomb Collisions ◽  
Electron Energy Loss

In Physics, Chemistry, Materials Science, Biology and Medicine, it is very important to have accurate information about the stopping power of various media for electrons, that is the average energy loss per unit pathlength due to inelastic Coulomb collisions with atomic electrons of the specimen along their trajectories. Techniques such as photoemission spectroscopy, Auger electron spectroscopy, and electron energy loss spectroscopy have been used in the measurements of electron-solid interaction. In this paper we present a comprehensive technique which combines experimental and theoretical work to determine the electron stopping power for various materials by electron energy loss spectroscopy (EELS ). As an example, we measured stopping power for Si, C, and their compound SiC. The method, results and discussion are described briefly as below.The stopping power calculation is based on the modified Bethe formula at low energy:where Neff and Ieff are the effective values of the mean ionization potential, and the number of electrons participating in the process respectively. Neff and Ieff can be obtained from the sum rule relations as we discussed before3 using the energy loss function Im(−1/ε).

Information and Dose in the Scanning Transmission Ion Microscope

1980 ◽  
Vol 38 ◽  
pp. 232-233
Author(s):  
Fox T. R. ◽  
R. Levi-Setti
Keyword(s):  
Information Retrieval ◽  
Electron Microscope ◽  
Elastic Scattering ◽  
Energy Loss ◽  
Cross Sections ◽  
Previous Analysis ◽  
Single Scattering ◽  
Screening Length ◽  
Relative Damage ◽  
Scanning Transmission

At an earlier meeting [1], we discussed information retrieval in the scanning transmission ion microscope (STIM) compared with the electron microscope at the same energy. We treated elastic scattering contrast, using total elastic cross sections; relative damage was estimated from energy loss data. This treatment is valid for “thin” specimens, where the incident particles suffer only single scattering. Since proton cross sections exceed electron cross sections, a given specimen (e.g., 1 μg/cm2 of carbon at 25 keV) may be thin for electrons but “thick” for protons. Therefore, we now extend our previous analysis to include multiple scattering. Our proton results are based on the calculations of Sigmund and Winterbon [2], for 25 keV protons on carbon, using a Thomas-Fermi screened potential with a screening length of 0.0226 nm. The electron results are from Crewe and Groves [3] at 30 keV.

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