scholarly journals Optimization of the combined proton acceleration regime with a target composition scheme

2016 ◽  
Vol 23 (1) ◽  
pp. 013107 ◽  
Author(s):  
W. P. Yao ◽  
B. W. Li ◽  
C. Y. Zheng ◽  
Z. J. Liu ◽  
X. Q. Yan ◽  
...  
Keyword(s):  
Proton Acceleration ◽  
Target Composition

Effect of target composition on proton acceleration in ultraintense laser-thin foil interaction

2012 ◽  
Vol 19 (9) ◽  
pp. 093108 ◽  
Author(s):  
Qingcao Liu ◽  
Meng Liu ◽  
Tongpu Yu ◽  
Pengji Ding ◽  
Zuoye Liu ◽  
...  
Keyword(s):  
Thin Foil ◽  
Proton Acceleration ◽  
Target Composition

scholarly journals Effect of target composition on proton acceleration by intense laser pulses in the radiation pressure acceleration regime

2011 ◽  
Vol 29 (1) ◽  
pp. 11-16 ◽  
Author(s):  
K.H. Pae ◽  
I.W. Choi ◽  
J. Lee
Keyword(s):  
Energy Spectrum ◽  
Radiation Pressure ◽  
Laser Pulses ◽  
High Energy ◽  
Intense Laser ◽  
Carbon Ions ◽  
Proton Acceleration ◽  
Acceleration Mechanism ◽  
Target Composition ◽  
Intense Laser Pulses

AbstractThe characteristics of high energy protons generated from thin carbon-proton mixture targets via circularly polarized intense laser pulses are investigated using two-dimensional particle-in-cell simulations. It is found that the density ratio n between protons and carbon ions plays a key role in determining the acceleration dynamics. For low n values, the protons are mainly accelerated by the radiation pressure acceleration mechanism, resulting in a quasi-monoenergetic energy spectrum. The radiation pressure acceleration mechanism is enhanced by the directed-Coulomb-explosion of carbon ions which gives a high proton maximum energy, though a large energy spread, for high n values. From a proton acceleration point of view, the role of heavy ions is very important. The fact that the proton energy spectrum is controllable based on the target composition is especially useful in real experimental environments.

Effect of the electron heating transition on the proton acceleration in a strongly magnetized plasma

2019 ◽  
Vol 26 (10) ◽  
pp. 103101
Author(s):  
Chong Lv ◽  
Bao-Zhen Zhao ◽  
Feng Wan ◽  
Hong-Bo Cai ◽  
Xiang-Hao Meng ◽  
...  
Keyword(s):  
Magnetized Plasma ◽  
Electron Heating ◽  
Proton Acceleration

scholarly journals Phase Stability of Iron Nitride Fe4N at High Pressure—Pressure-Dependent Evolution of Phase Equilibria in the Fe–N System

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 3963
Author(s):  
Marius Holger Wetzel ◽  
Tina Trixy Rabending ◽  
Martin Friák ◽  
Monika Všianská ◽  
Mojmír Šob ◽  
...  
Keyword(s):  
High Pressure ◽  
Phase Equilibria ◽  
Phase Stability ◽  
Polymorphic Transition ◽  
Ex Situ ◽  
Stable Phase ◽  
Iron Nitride ◽  
Phase System ◽  
Target Composition ◽  
Heat Treated

Although the general instability of the iron nitride γ′-Fe4N with respect to other phases at high pressure is well established, the actual type of phase transitions and equilibrium conditions of their occurrence are, as of yet, poorly investigated. In the present study, samples of γ′-Fe4N and mixtures of α Fe and γ′-Fe4N powders have been heat-treated at temperatures between 250 and 1000 °C and pressures between 2 and 8 GPa in a multi-anvil press, in order to investigate phase equilibria involving the γ′ phase. Samples heat-treated at high-pressure conditions, were quenched, subsequently decompressed, and then analysed ex situ. Microstructure analysis is used to derive implications on the phase transformations during the heat treatments. Further, it is confirmed that the Fe–N phases in the target composition range are quenchable. Thus, phase proportions and chemical composition of the phases, determined from ex situ X-ray diffraction data, allowed conclusions about the phase equilibria at high-pressure conditions. Further, evidence for the low-temperature eutectoid decomposition γ′→α+ε′ is presented for the first time. From the observed equilibria, a P–T projection of the univariant equilibria in the Fe-rich portion of the Fe–N system is derived, which features a quadruple point at 5 GPa and 375 °C, above which γ′-Fe4N is thermodynamically unstable. The experimental work is supplemented by ab initio calculations in order to discuss the relative phase stability and energy landscape in the Fe–N system, from the ground state to conditions accessible in the multi-anvil experiments. It is concluded that γ′-Fe4N, which is unstable with respect to other phases at 0 K (at any pressure), has to be entropically stabilised in order to occur as stable phase system. In view of the frequently reported metastable retention of the γ′ phase during room temperature compression experiments, energetic and kinetic aspects of the polymorphic transition γ′⇌ε′ are discussed.

scholarly journals Intense proton acceleration in ultrarelativistic interaction with nanochannels

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
L. A. Gizzi ◽  
G. Cristoforetti ◽  
F. Baffigi ◽  
F. Brandi ◽  
G. D'Arrigo ◽  
...  
Keyword(s):  
Proton Acceleration

Proton acceleration from magnetized overdense plasmas

2017 ◽  
Vol 24 (1) ◽  
pp. 013112 ◽  
Author(s):  
Deep Kumar Kuri ◽  
Nilakshi Das ◽  
Kartik Patel
Keyword(s):  
Proton Acceleration

ENERGETIC PROTON ACCELERATION BY ULTRAINTENSE LASER PULSES IN INHOMOGENEOUS PLASMA TARGETS

2007 ◽  
Vol 21 (03n04) ◽  
pp. 642-646 ◽  
Author(s):  
A. ABUDUREXITI ◽  
Y. MIKADO ◽  
T. OKADA
Keyword(s):  
Laser Pulse ◽  
Inhomogeneous Plasma ◽  
Laser Pulses ◽  
Proton Acceleration ◽  
Particle In Cell ◽  
Target Plasma ◽  
Plasma Target ◽  
Experimental Process ◽  
Foil Target ◽  
Proton Bunch

Particle-in-Cell (PIC) simulations of fast particles produced by a short laser pulse with duration of 40 fs and an intensity of 1020W/cm2 interacting with a foil target are performed. The experimental process is numerically simulated by considering a triangular concave target illuminated by an ultraintense laser. We have demonstrated increased acceleration and higher proton energies for triangular concave targets. We also determined the optimum target plasma conditions for maximum proton acceleration. The results indicated that a change in the plasma target shape directly affects the degree of contraction accelerated proton bunch.

scholarly journals Surface Analysis by MeV Ion Beams and Microscopy

2009 ◽  
Vol 15 (S3) ◽  
pp. 87-88
Author(s):  
José A. R. Pacheco de Carvalho ◽  
Cláudia F. F. P. R. Pacheco ◽  
António D. Reis
Keyword(s):  
Surface Analysis ◽  
Nuclear Reactions ◽  
Ion Beam ◽  
Ion Beams ◽  
Analysis Method ◽  
Analysis Techniques ◽  
Target Composition ◽  
Nuclear Techniques ◽  
Surface Analysis Techniques ◽  
Wide Range

AbstractMaterial analysis, specially surface analysis of materials, has been increasingly important. A wide range of surface analysis techniques is available. The techniques are, generally, complementary. There are nuclear and non-nuclear techniques, e.g. microscopy. Nuclear techniques, which are nondestructive, permit analysis for a few microns near the surface. They have been applied to areas such as scientific, technologic, industry, arts and medicine, using MeV ion beams. Nuclear reactions permit to achieve high sensitivities for detection of light elements in heavy substrates and also discrimination of isotopes. We use ion-ion nuclear reactions, elastic scattering and the energy analysis method, where an energy spectrum is obtained of ions from the target for a chosen energy of the incident ion beam. The target composition and concentration profile information contained in the spectrum is computationally obtained through a computer program that has been developed for predicting such energy spectra. Predicted spectra obtained for variations of target parameters are compared with experimental data, giving that information. SEM and TEM are also used.

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