scholarly journals Experimental electronic stopping cross section of tungsten for light ions in a large energy interval

2021 ◽  
Vol 498 ◽  
pp. 1-8
Author(s):  
M.V. Moro ◽  
P.M. Wolf ◽  
B. Bruckner ◽  
F. Munnik ◽  
R. Heller ◽  
...  
Keyword(s):  
Cross Section ◽  
Energy Interval ◽  
Large Energy ◽  
Light Ions

scholarly journals Are Further Cross Section Measurements Necessary for Space Radiation Protection or Ion Therapy Applications? Helium Projectiles

2020 ◽  
Vol 8 ◽  
Author(s):  
John W. Norbury ◽  
Giuseppe Battistoni ◽  
Judith Besuglow ◽  
Luca Bocchini ◽  
Daria Boscolo ◽  
...  
Keyword(s):  
Radiation Protection ◽  
Cross Section ◽  
Cross Sections ◽  
Nuclear Reactions ◽  
Production Cross ◽  
Cosmic Ray ◽  
Space Radiation ◽  
Radiation Shielding ◽  
Light Ions ◽  
Ion Therapy

The helium (4He) component of the primary particles in the galactic cosmic ray spectrum makes significant contributions to the total astronaut radiation exposure. 4He ions are also desirable for direct applications in ion therapy. They contribute smaller projectile fragmentation than carbon (12C) ions and smaller lateral beam spreading than protons. Space radiation protection and ion therapy applications need reliable nuclear reaction models and transport codes for energetic particles in matter. Neutrons and light ions (1H, 2H, 3H, 3He, and 4He) are the most important secondary particles produced in space radiation and ion therapy nuclear reactions; these particles penetrate deeply and make large contributions to dose equivalent. Since neutrons and light ions may scatter at large angles, double differential cross sections are required by transport codes that propagate radiation fields through radiation shielding and human tissue. This work will review the importance of 4He projectiles to space radiation and ion therapy, and outline the present status of neutron and light ion production cross section measurements and modeling, with recommendations for future needs.

scholarly journals CHARGE INFLUENCE ON MINI BLACK HOLE'S CROSS SECTION

2010 ◽  
Vol 19 (08n10) ◽  
pp. 1265-1269
Author(s):  
R. S. CARAÇA ◽  
M. MALHEIRO
Keyword(s):  
Cross Section ◽  
Electric Charge ◽  
Mass Ratio ◽  
Horizon Radius ◽  
Maximum Charge ◽  
Light Ions ◽  
Ratio Condition ◽  
The Cross ◽  
Mini Black Holes ◽  
Section Production

In this work we study the electric charge effect on the cross section production of charged mini black holes (MBH) in accelerators. We analyze the charged MBH solution using the fat brane approximation in the context of the ADD model. The maximum charge–mass ratio condition for the existence of a horizon radius is discussed. We show that the electric charge causes a decrease in this radius and, consequently, in the cross section. This reduction is negligible for protons and light-ions but can be important for heavy-ions.

scholarly journals Irradiation Spectrum and Ionization-Induced Diffusion Effects in Ceramics

1996 ◽  
Vol 439 ◽  
Author(s):  
S. J. Zinkle
Keyword(s):  
Ionizing Radiation ◽  
Cross Section ◽  
The Other ◽  
Dislocation Loops ◽  
Defect Production ◽  
Transmission Electron ◽  
Diffusion Effects ◽  
Light Ions ◽  
Main Components ◽  
Atom Energy

AbstractThere are two main components to the irradiation spectrum which need to be considered inradiation effects studies on nonmetals, namely the primary knock-on atom energy spectrum and ionizing radiation. The published low-temperature studies on A12O3 and MgO suggest that the defect production is nearly independent of the average primary knock-on atom energy, in sharp contrast to the situation for metals. On the other hand, ionizing radiation has been shown to exert a pronounced influence on the microstructural evolution of both semiconductors and insulators under certain conditions. Recent work on the microstructure of ion-irradiated ceramics is summarized, which provides evidence for significant ionization-induced diffusion. Polycrystalline samples of MgO, A12O3, and MgAl2O4 were irradiated with various ions ranging from 1 MeV H+ to 4 MeV Zr+ ions at temperatures between 25 and 650°C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructure of the irradiated specimens. Dislocation loop nucleation was effectively suppressed in specimens irradiated with light ions, whereas the growth rate of dislocation loops was enhanced. The sensitivity to irradiation spectrum is attributed to ionization-induced diffusion. The interstitial migration energies in MgAl2O4 and A12O3 are estimated to be ≤0.4 eV and ≤0.8 eV, respectively for irradiation conditions where ionization-induced diffusion effects are expected to be negligible.

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.

scholarly journals Excitation Cross Section of the 11/2– Isomeric State of 137Ce Nucleus in (γ, n) Reaction in the 11–18-MeV Energy Interval of Gamma Quanta

2016 ◽  
Vol 61 (12) ◽  
pp. 1048-1052 ◽  
Author(s):  
V.M. Mazur ◽  
◽  
Z.M. Bigan ◽  
P.S. Derechkey ◽  
D.M. Symochko ◽  
...  
Keyword(s):  
Cross Section ◽  
Isomeric State ◽  
Excitation Cross Section ◽  
Energy Interval

Effect of Irradiation Spectrum on the Microstructure of Ion-Irradiated A120O3

1994 ◽  
Vol 373 ◽  
Author(s):  
S. J. Zinkle
Keyword(s):  
Cross Section ◽  
Diffusion Processes ◽  
Ion Irradiation ◽  
Defect Cluster ◽  
The Other ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Light Ions ◽  
Alpha Alumina

AbstractPolycrystalline samples of alpha-alumina have been irradiated with various ions ranging from 3.6 MeV Fe+ to 1 MeV H+ ions at 650°C. Cross-section transmission electron microscopy was used to investigate the depth-dependent microstructure of the irradiated specimens. The microstructure following irradiation was observed to be dependent on the irradiation spectrum. In particular, defect cluster nucleation was effectively suppressed in specimens irradiated with light ions such as I MeV H+ ions. On the other hand, light ion irradiation tended to accelerate the growth rate of dislocation loops. The microstructural observations are discussed in terms of ionization enhanced diffusion processes.

scholarly journals Reflection of keV light ions from solids at oblique and grazing incidence

2009 ◽  
Vol 24 (3) ◽  
pp. 188-194 ◽  
Author(s):  
Jovan Vukanic ◽  
Rodoljub Simovic
Keyword(s):  
Reflection Coefficient ◽  
Multiple Scattering ◽  
Cross Section ◽  
Scattering Theory ◽  
Grazing Incidence ◽  
Universal Functions ◽  
Light Ions ◽  
Analytical Formulae ◽  
Analytical Approaches ◽  
Good Agreement

The particle reflection coefficient of light keV ions backscattered from heavy targets has been determined by two different analytical approaches: by the single collision model in the case of nearly perpendicular incidence and by the small-angle multiple scattering theory in the case of glancing angles of incidence. The obtained analytical formulae are approximately universal functions of the scaled transport cross-section describing the reflection of all light ions from heavy targets. Going from perpendicular to grazing incidence, the transition from pure single to pure multiple scattering type of reflection is observed. For larger values of the scaling parameter the results of these theories cover the whole region of ion incident angles and the present estimates of the particle reflection coefficient are in good agreement with the results obtained from the empirical formula of Tabata et al.

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