Study on the optimal incident proton energy of ^(7)Li(p,n)^(7)Be neutron source for boron neutron capture therapy

Boron neutron capture therapy(BNCT)is recognized as a precise binary targeted radiotherapy technique that effectively eliminates tumors through the^(10)B(n,α)^(7)Li nuclear reaction.Among various neutron sources,accelerator-based sources have emerged as particularly promising for BNCT applications.The^(7)Li(p,n)^(7)Be reaction is highly regarded as a potential neutron source for BNCT,owing to its low threshold energy for the reaction,significant neutron yield,appropriate average neutron energy,and additional benefits.This study utilized Monte Carlo simulations to model the physical interactions within a lithium target subjected to proton bombardment,including neutron moderation by an MgF_(2)moderator and subsequent BNCT dose analysis using a Snyder head phantom.The study focused on calculating the yields of epithermal neutrons for various incident proton energies,finding an optimal energy at 2.7 MeV.Furthermore,the Snyder head phantom was employed in dose simulations to validate the effectiveness of this specific incident energy when utilizing a^(7)Li(p,n)^(7)Be neutron source for BNCT purposes.

Study of Differential Cross-Section and S-Matrix Using Volkov Function and Taylor Series Expansion for Elastic Scattering

This paper deals with S-matrix, born first approximation, amplitude, and differential cross-section (DCS), using Volkov function and Taylor series expansion in laser field, scattering. Equation (30) copes-with DCS and Equation (36) deals with S-matrix, with different parameters, moreover, both equations contain real and imaginary parts. The DCS increases with increasing angle and polarizabilities, constant with dipole distance for both emission and absorption of single-photon. The DCS for both emission and absorption is responded to low incidence energy (30 eV - 60 eV) and photon energy (15 eV) while at high energy only emission and absorption are responded for DCS. The DCS between absorption and emission of a photon with angle variation, dipole distance, and atomic polarizabilities was found 1.098 a.u.2 and at high incidence, energies were found 0.1 a.u.2.

B3Y-FETAL effective interaction in the folding analysis of elastic scattering of ^(16)O+^(16)O

In this paper,a new M3Y-type effective nucleon–nucleon interaction,derived based on the lowest order constrained variational approach(LOCV)and termed B3Y-Fetal,has been used in DDM3Y1,BDM3Y1,BDM3Y2,and BDM3Y3 density-dependent versions in a heavy ion(HI)optical potential based on four types of a real folded potential and a phenomenological Woods–Saxon imaginary potential to study the elastic scattering of the^(16)O+^(16)O nuclear system within the framework of the optical model(OM)by computing the associated differential cross sections at various incident energies.The results of the folding analyses have shown the DDB3Y1-Fetal and BDB3Y1-Fetal,out of the four folded potentials,give a reasonably better description of the elastic data of the nuclear system.These best-fit folded potentials are followed,in performance,by the BDB3Y2-Fetal,with the BDB3Y3-Fetal potential coming last.This performance trend was also demonstrated by the optical potentials based on the M3Y-Reid interaction.Furthermore,the best-fit folded potentials,renormalized by a factor NRof approximately 0.9,have been shown to reproduce the energy dependence of the real optical potential for^(16)O scattering found in previous optical model analyses creditably well.In excellent agreement with previous works,they have also been identified in this work to belong to the family of deep refractive potentials because they have been able to reproduce and consistently describe the evolution of Airylike structures,at large scattering angles,observed in the^(16)O scattering data at different energies.Finally,a comparison of the performances of B3Y-Fetal and M3Y-Reid effective interactions undertaken in this work has shown impressive agreement between them.

Etching Mechanisms of CF_3 Etching Fluorinated Si:Molecular Dynamics Simulation

Molecular dynamics simulations are performed to investigate CF3 continuously bom- barding the amorphous silicon surface with energies of 10 eV, 50 eV, 100 eV and 150 eV at normal incidence and room temperature. The improved Tersoff-Brenner potentials were used. The simulation results show that the steady-state etching rates are about 0.019, 0.085 and 0.1701 for 50 eV, 100 eV and 150 eV, respectively. With increasing incident energy, a transition from C-rich surface to F-rich surface is observed. In the region modified by CF3, SiF and CF species are dominant.

Effect of Woods-Saxon Potential on the ^16O＋^20Ne Reaction Cross Section

The excitation function and angular distributions for the ^16O+^20Ne system have been explained using the distorted wave Born approximation (DWBA) calculations. The real and imaginary Woods Saxon optical potentials are assumed to be energy-dependent. The gross resonant structures observed in the ^20Ne(^16O,^16O)^20 Ne excitation function are well described by the present DWBA calculations. Although the elastic and elastic-transfer analyses introduce a qualitative description of the experimental data, the coherent sum of the two reaction processes exhibit a much better result for both forward and large-angle data.

Effects of incident energy and angle on carbon cluster ions implantation on silicon substrate:a molecular dynamics study

Carbon cluster ion implantation is an important technique in fabricating functional devices at mi- cro/nanoscale. In this work, a numerical model is constructed for implantation and implemented with a cutting- edge molecular dynamics method. A series of simulations with varying incident energies and incident angles is performed for incidence on silicon substrate and correlated effects are compared in detail. Meanwhile, the behav- ior of the cluster during implantation is also examined under elevated temperatures. By mapping the nanoscopic morphology with variable parameters, numerical formalism is proposed to explain the different impacts on phrase transition and surface pattern formation. Particularly, implantation efficiency （IE） is computed and further used to evaluate the performance of the overall process. The calculated results could be properly adopted as the theoretical basis for designing nano-structures and adjusting devices＇ properties.