STOPPING CROSS SECTIONS IN CARBON FOR LOW-ENERGY ATOMS WITH

1963 ◽  
Vol 41 (9) ◽  
pp. 1424-1442 ◽  
Author(s):  
J. H. Ormrod ◽  
H. E. Duckworth
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Atomic Number ◽  
Cross Sections ◽  
Monte Carlo Calculation ◽  
Low Energy ◽  
Energy Interval ◽  
Nuclear Scattering

The electronic stopping cross sections in carbon for atomic projectiles with [Formula: see text] have been determined in the energy interval from 10 to 140 kev. In doing so a Monte Carlo calculation was used to subtract from each experimentally observed cross section the contribution which arises from nuclear scattering. The trend of the results thus obtained agrees well with theory. In addition, however, a periodic dependence of Sε on the atomic number of the projectile is observed.

The Generation of Few-Group Constants for Fast Reactor Analysis

2016 ◽  
Author(s):  
Xianan Du ◽  
Liangzhi Cao ◽  
Youqi Zheng
Keyword(s):  
Monte Carlo ◽  
Cross Section ◽  
Cross Sections ◽  
Fast Reactor ◽  
Monte Carlo Calculation ◽  
Anisotropic Scattering ◽  
Slowing Down ◽  
Nodal Method ◽  
Reactor Calculation ◽  
Broad Energy

A way to generate the few-group cross sections for fast reactor calculation is presented in this paper. It is based on the three steps computational scheme. In the first step, the ultrafine method is used to solve the slowing down equation based on the ultrafine group cross section generated by NJOY. Optional 0D or 1D calculation is used to collapse energy group into broad energy groups. In the second step, the 2D RZ calculation using SN method is performed to obtain the space dependent neutron spectra to collapse broad energy groups into few groups. The anisotropic scattering is well handled by the direct SN calculation. Finally, the full core calculation is performed by using the 3D SN nodal method. The results are compared with continuous energy Monte-Carlo calculation. Both the cross section generated in the first step and the final keff in the last step are compared. The results match well between the three steps calculation and Monte-Carlo calculation.

Low-energy electronic stopping cross sections in nitrogen and argon

1968 ◽  
Vol 46 (6) ◽  
pp. 497-502 ◽  
Author(s):  
J. H. Ormrod
Keyword(s):  
Energy Loss ◽  
Energy Dependence ◽  
Cross Section ◽  
Atomic Number ◽  
Cross Sections ◽  
Collision Frequency ◽  
Gas Pressure ◽  
Low Energy ◽  
Nuclear Stopping ◽  
Gas Targets

The rate of energy loss in nitrogen and argon targets for ions with [Formula: see text] and E < 200 keV has been measured. The contribution to the energy loss from nuclear stopping was calculated using Fastrup's method, and was subtracted from the observed stopping cross section to give the electronic stopping cross section. Over the energy interval studied, the electronic stopping cross sections obtained are below the theoretical values and the energy dependence in argon is much greater than [Formula: see text].A target gas pressure of ~10 μ was used. This reduces the collision frequency eight orders of magnitude below that in a solid. The periodic dependence of the electronic stopping cross section on the atomic number of the incident projectile, previously observed in solid targets, occurs also for such low-pressure gas targets; it is concluded that this dependence is not affected by the collision frequency.

SOME LOW-ENERGY ATOMIC STOPPING CROSS SECTIONS

1965 ◽  
Vol 43 (2) ◽  
pp. 275-284 ◽  
Author(s):  
J. H. Ormrod ◽  
J. R. Macdonald ◽  
H. E. Duckworth
Keyword(s):  
Atomic Number ◽  
Cross Sections ◽  
Reasonable Agreement ◽  
Low Energy ◽  
Energy Interval

The electronic stopping cross sections for protons in aluminum are reported in the energy interval 10 < E < 70 keV. Stopping cross sections below 150 keV in carbon targets for projectiles with [Formula: see text], and in aluminum targets for [Formula: see text] are reported also. The results are compared with theory and show reasonable agreement. The previously reported periodic dependence of Se on the atomic number of the projectile is also evident in the present results.

scholarly journals Quest for precision in hadronic cross sections at low energy: Monte Carlo tools vs. experimental data

2010 ◽  
Vol 66 (3-4) ◽  
pp. 585-686 ◽  
Author(s):  
S. Actis ◽  
◽  
A. Arbuzov ◽  
G. Balossini ◽  
P. Beltrame ◽  
...  
Keyword(s):  
Experimental Data ◽  
Monte Carlo ◽  
Cross Sections ◽  
Low Energy

Note on the production of positron-electron pairs during the passage of β-particles through matter

1938 ◽  
Vol 34 (3) ◽  
pp. 435-441 ◽  
Author(s):  
N. Feather ◽  
J. V. Dunworth
Keyword(s):  
Cross Section ◽  
Atomic Number ◽  
Cross Sections ◽  
High Energy ◽  
Coincidence Counting ◽  
Electron Pairs ◽  
Radioactive Substances

The method of coincidence counting has been applied to an investigation of the possible production of positron-electron pairs by the high energy β-particles from a source of uranium X in absorbers of aluminium, brass and lead. The results are not inconsistent with the high values recently reported for atomic cross-sections for the effect, nor with the suggestion that the atomic cross-section is proportional to the first power of the atomic number rather than the second. Suggestions are made for the use of the β-particles from artificially radioactive substances in an attempt to increase the sensitivity of the method.

Total-to-K-shell photoelectric cross-section ratios in some rare-earth and high-Z elements

1989 ◽  
Vol 67 (2-3) ◽  
pp. 139-142 ◽  
Author(s):  
S. Chandra Lingam ◽  
K. Suresh Babu ◽  
V. Prakash Kumar ◽  
D. V. Krishna Reddy
Keyword(s):  
Rare Earth ◽  
Cross Section ◽  
Atomic Number ◽  
Cross Sections ◽  
Cross Section Ratio ◽  
Section Ratio ◽  
Photoelectric Cross Section ◽  
Normal Transmission ◽  
Experimental Values ◽  
Good Agreement

The total photoelectric cross-sections in the elements gadolinium, dysprosium, erbium, lutetium, tantalum, tungsten, gold, and lead have been obtained by using the normal transmission experiments, and the results are reported. Using these total photoelectric cross sections, we have found the K-shell photoelectric cross sections, the K-jump ratios, and the total-to-K-shell photoelectric cross-section ratios at the K edges for the above elements. These values are compared with the available theoretical and experimental values. The results are in good agreement with the Storm and Israel results and the Scofield theoretical values, within the limits of experimental uncertainties. Furthermore, the variation of the total-to-K-shell photoelectric cross-section ratio with energy and atomic number is discussed.

Sign in / Sign up

Export Citation Format

Share Document