Evolution of the shape of fission fragment energy spectrum with absorber thickness in two different media and effective charge correction

2022 ◽  
Author(s):  
Rajkumar Santra ◽  
V. G. Vamaravalli ◽  
Ankur Roy ◽  
Balaram Dey ◽  
Subinit Roy
Keyword(s):  
Energy Spectrum ◽  
Energy Loss ◽  
Effective Charge ◽  
Correction Term ◽  
Stopping Power ◽  
Absorber Thickness ◽  
Shape Parameters ◽  
Bohr Theory ◽  
Present Simulation ◽  
Charge Formula

The energy loss behavior of fission fragments (FFs) from [Formula: see text]Cf(sf) in thin Mylar [Formula: see text] and Aluminium absorber foils has been revisited. The aim is to investigate the observed change in the well-known asymmetric energy of spontaneous fission of [Formula: see text]Cf as the fragments pass through increasingly thick absorber foils. Two different types of absorbers have been used: one elemental and the other an organic compound. The stopping powers have been determined as a function of energy for three fragment mass groups with average masses having [Formula: see text], 141.8, 125.8 corresponding to light, heavy and symmetric fragments of [Formula: see text]Cf. The energy loss data have been compared with the predictions of SRIM 2013 code. The best representations of the data have been achieved using the effective Z correction term in the stopping power relation from the classical Bohr theory. Using the effective charge ([Formula: see text]) in the stopping power relation in the classical Bohr theory best describes the stopping power data. Spectrum shape parameters, subsequently, have been extracted from the energy spectra of FFs for different foil thicknesses. The effective charge ([Formula: see text]) correction term determined from the stopping power data is then used in the simulation for the absorber thickness dependence of the shape parameters of the energy spectrum. The present simulation results are compared with the TRIM prediction. The trends of the absorber thickness dependence of the spectrum shape parameters, for both Mylar and Aluminium, are well reproduced with the present simulation.

scholarly journals Energy loss and effective charge of low-energy oxygen ions in partially ionized plasma

2000 ◽  
Vol 18 (4) ◽  
pp. 639-646
Author(s):  
K. NISHIGORI ◽  
U. NEUNER ◽  
M. TAKIZAWA ◽  
M. KOJIMA ◽  
T. SAGAMI ◽  
...  
Keyword(s):  
Energy Loss ◽  
Charge Distribution ◽  
Effective Charge ◽  
Low Energy ◽  
Stopping Power ◽  
Oxygen Ions ◽  
Power Equation ◽  
Slow Ions ◽  
Partially Ionized ◽  
Peak Value

This article reports on the interaction between slow ions and a partially ionized plasma. Temporal evolutions of energy loss and charge distribution of 2.4 MeV oxygen beams in the laser-induced polyethylene plasma were measured. The charge distribution showed strong stripping ability in the early phase of the plasma. Stopping power deduced from the experimental energy loss was 1.9 times larger than that for the solid. The effective charge of the projectile ion was estimated from the yields of 4+ and 6+ states. The peak value of the effective charge was 1.4 times larger than that of the solid. The stopping power equation given by Sigmund was extended for the partially ionized plasma and it could reproduce the measured energy loss.

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).

scholarly journals Strain/Damage in Crystalline Materials Bombarded by MeV Ions: Recrystallization of GaAs by High-Dose Irradiation

1984 ◽  
Vol 35 ◽  
Author(s):  
C. R. Wie ◽  
T. Vreeland ◽  
T. A. Tombrello
Keyword(s):  
Surface Layer ◽  
Energy Loss ◽  
Ion Irradiation ◽  
Stopping Power ◽  
High Dose ◽  
Double Crystal ◽  
Saturation Phenomenon ◽  
Nuclear Stopping ◽  
X Ray ◽  
Dose Irradiation

ABSTRACTMeV ion irradiation effects on semiconductor crystals, GaAs(100) and Si (111) and on an insulating crystal CaF2 (111) have been studied by the x-ray rocking curve technique using a double crystal x-ray diffractometer. The results on GaAs are particularly interesting. The strain developed by ion irradiation in the surface layers of GaAs (100) saturates to a certain level after a high dose irradiation (typically 1015/cm2), resulting in a uniform lattice spacing about 0.4% larger than the original spacing of the lattice planes parallel to the surface. The layer of uniform strain corresponds in depth to the region where electronic energy loss is dominant over nuclear collision energy loss. The saturated strain level is the same for both p-type and n-type GaAs. In the early stages of irradiation, the strain induced in the surface is shown to be proportional to the nuclear stopping power at the surface and is independent of electronic stopping power. The strain saturation phenomenon in GaAs is discussed in terms of point defect saturation in the surface layer.An isochronal (15 min.) annealing was done on the Cr-doped GaAs at temperatures between 200° C and 700° C. The intensity in the diffraction peak from the surface strained layer jumps at 200° C < T ≤ 300° C. The strain decreases gradually with temperature, approaching zero at T ≤ 500° C.The strain saturation phenomenon does not occur in the irradiated Si. The strain induced in Si is generally very low (less than 0.06%) and is interpreted to be mostly in the layers adjacent to the maximum nuclear stopping region, with zero strain in the surface layer. The data on CaF2 have been analysed with a kinematical x-ray diffraction theory to get quantitative strain and damage depth profiles for several different doses.

NEUTRINO ENERGY LOSS AT MATTER-RADIATION DECOUPLING PHASE

2009 ◽  
Vol 24 (11n13) ◽  
pp. 1051-1054
Author(s):  
UNGKU FERWANI SALWA UNGKU IBRAHIM ◽  
NOR SOFIAH AHMAD ◽  
NORHASLIZA YUSOF ◽  
HASAN ABU KASSIM
Keyword(s):  
Energy Loss ◽  
Neutrino Energy ◽  
Electron Neutrino ◽  
Stopping Power ◽  
Power Equation ◽  
Electron Positron ◽  
Extra Energy ◽  
Expansion Of The Universe ◽  
Current Interaction ◽  
The Universe

Neutrinos are produced copiously in the early universe. Neutrinos and antineutrinos ceased to be in equilibrium with radiation when the weak interaction rate becomes slower than the rate expansion of the universe. The ratio of the temperature of the photon to the temperature of the neutrino at this stage is Tγ/Tν = (11/4)1/3. We investigate the neutrino energy loss due to the oscillation of the electron neutrino into a different flavor in the charged-current interaction of νe-e- based on the work of Sulaksono and Simanjuntak. The energy loss from the neutrinos ΔEν during the decoupling of the neutrinos with the rest of the matter would be a gain in the energy of the electrons and can be obtained from the integration of stopping power equation ΔEν = (dEν/dT-1)dT-1 where Eν and T are the energy of the neutrinos and the temperature respectively. When the universe expands and matter-radiation decouples, an extra energy will be transferred to the photons via the annihilation of the electron-positron pairs, e++e-→γ+γ. This consequently will increase the temperature of the photons. The net effect to the lowest order is an increase in the ratio of the photon temperature to the neutrino temperature. The magnitude of energy loss of the neutrino is ∼10-4-10-5 MeV for the probability of conversion of νe → νi (i = μ,τ) between 0 to 1.0.

Large-scale correction and thermal properties of holographic dual background of an adaptive graphene model

2020 ◽  
Vol 17 (09) ◽  
pp. 2050135
Author(s):  
Z. Zali ◽  
J. Sadeghi
Keyword(s):  
Thermal Properties ◽  
Energy Spectrum ◽  
Large Scale ◽  
Correction Term ◽  
Gaussian Function ◽  
Beltrami Equation ◽  
Additional Term ◽  
Order Equation ◽  
Small Scale ◽  
Corrected Entropy

In this paper, we consider the particle on curved graphene space-time. In that case, we calculate the geometric form of potential which is known as Gaussian function. Here, we introduce the metric background which completely corresponds to curved graphene space-times. This metric leads us to obtain the geometry potential and we make the Laplace Beltrami equation in the mentioned metric background. We also rearrange such relation in terms of the second-order equation. By using the known polynomial, we solve the particle equation of motion in graphene background. In that case, we arrive the energy spectrum which has three terms. We take advantage from energy spectrum and investigate the thermal properties of system. The additional terms give us an opportunity to obtain the corrected entropy and free energy. So, we show that the additional term comes from geometry potential. This correction is important for the large scale. Hence, we show that correction term is logarithmic as well as small scale corrections.

Energy Loss for Swift Heavy Ions in Different Elemental Absorbers: A Different Approach for Effective Charge Parameterization

2015 ◽  
Vol 238 ◽  
pp. 196-205
Author(s):  
B. Rani ◽  
Kalpana Sharma ◽  
Neetu ◽  
Anupam ◽  
Shyam Kumar ◽  
...  
Keyword(s):  
Experimental Data ◽  
Energy Loss ◽  
Effective Charge ◽  
Heavy Ions ◽  
Close Agreement ◽  
Input Parameter ◽  
Quantum Mechanical ◽  
Swift Heavy Ions ◽  
Calculated Energy ◽  
Semi Empirical

The energy loss for swift heavy ions, covering Z=3-29(~0.2 - 5.0MeV/n), has been calculated in the elemental absorbers like C, Al and Ti. The present calculations are based on Bohr’s approach applicable in both classical and quantum mechanical regimes. The major input parameter, the effective charge, has been calculated in a different way without any empirical/semi-empirical parameterization. The calculated energy loss values have been compared with the available experimental data which results in a close agreement.

scholarly journals Simulations of the energy loss of ions at the stopping-power maximum in a laser-induced plasma

2016 ◽  
Vol 688 ◽  
pp. 012009 ◽  
Author(s):  
W. Cayzac ◽  
A. Frank ◽  
A. Ortner ◽  
V. Bagnoud ◽  
M.M. Basko ◽  
...  
Keyword(s):  
Energy Loss ◽  
Stopping Power ◽  
Laser Induced Plasma
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