Simulation of the time evolution of 1  MeV proton microbeam transmission through an insulating macrocapillary

Nagy, Gyula; Szilasi, S.Z.; Rajta, I.; Tőkési, K.

doi:10.1016/j.nimb.2017.02.025

Cited by 8 publications

(5 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, a few experiments with a microbeam of 1 MeV protons [27][28][29] provided evidence of MeV-ion guiding as they showed clear charge-up processes together with a high transmission, which could not be achieved by the atomic scatterings. Recently, several theoretical simulations [30][31][32] reproduced those experimental results. The pioneering simulation by Nagy etal [30,31] adopted two-dimensional (2D) model, where the charge patch deflections and atomic scatterings were both considered.…”

Section: Introductionmentioning

confidence: 73%

“…Recently, several theoretical simulations [30][31][32] reproduced those experimental results. The pioneering simulation by Nagy etal [30,31] adopted two-dimensional (2D) model, where the charge patch deflections and atomic scatterings were both considered. However, a three-dimensional (3D) model was used in our latest simulation [32], which only included the charge patch deflections.…”

Section: Introductionmentioning

confidence: 73%

See 1 more Smart Citation

Simulations of transmission of 1 MeV protons through an insulating macrocapillary

Liu

Zhao

2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

We report the simulated results of 1 MeV protons transmitted through a straight insulating macrocapillary with a diameter of 0.8 mm and a length of 50 mm. In the simulations, the atomic scattering due to collisions with atoms in the capillary bulk and the guiding caused by the charge patch are both considered. The simulation results indicated a charge-up process in the macrocapillary, leading to a guided transmission. Some transmitted protons suffered significant energy losses due to the atomic scatterings. A temporal evolution of the transmitted proton fraction is shown. The fractions with the tilt angle Ψ can be well described by the exponential function e −Ψ ξ . Altogether, the results reveal that the transmission of 1 MeV protons through a macrocapillary is determined by both the guiding and scattering. In the case of smaller angles, the MeV-ion transmission is mainly governed by the guiding. However, the scattering becomes more important as the tilt angle increases.

show abstract

Section: Introductionmentioning

confidence: 73%

Section: Introductionmentioning

confidence: 73%

Simulations of transmission of 1 MeV protons through an insulating macrocapillary

Liu

Zhao

2019

J. Phys. D: Appl. Phys.

View full text Add to dashboard Cite

show abstract

“…Here we note that we used a focused, microsized beam, since it was expected that it is much easier to obtain an efficient transmission and thus it is easier to detect and characterize. Later we started the construction of a twodimensional computer simulation [20,21], which, despite its simplicity, well reproduced our experimental results and, even more, it was capable to give predictions for observables. Some of them were experimentally confirmed later [18].…”

Section: Introductionmentioning

confidence: 72%

“…The blue dots are the simulated data points, while the red line is shown to guide the eye. over, this dominance is more pronounced at larger incident intensities, which is explained by the incident beam intensity dependence of the maximum achievable transmission: at larger incident beam intensity, the efficiency of transmission saturates at a higher value [20]. Inversely, in the case of lower incident current, the transmission saturates at a lower relative value due to the discharge and thus the weaker electric field of the formed charge patch.…”

Section: Spatial Distributions Of the Transmitted Beammentioning

confidence: 98%

Spatial and temporal distribution of a 1-MeV proton microbeam guided through a poly(tetrafluoroethylene) macrocapillary

et al. 2021

Self Cite

View full text Add to dashboard Cite

We present computer simulations about the spatial and temporal evolution of 1 MeV proton microbeam transmitted through an insulating macrocapillary with the length of 45 mm and with the inner diameter of 800 μm. The axis of the capillary was tilted to 1° relative to the axis of the incident beam, which ensured geometrical non-transparency. The simulation is based on the combination of stochastic (Monte-Carlo) and deterministic methods. It involves 1) random sampling of the initial conditions, according to distributions generated by the widely used and freely available computer software packages, SRIM and WinTRAX, 2) the numerical solution of the governing equations for following the classical trajectory of the projectiles, and 3) the description of the field-driven charge migration on the surface and in the bulk of the insulator material. We found that our simulation describes reasonably all of our previous experimental observations, indicating the functionality and reliability of the applied model. In addition, we found that at different phases of the beam transmission, different atomic processes result in the evolution of the beam distribution. First, in a scattering phase, the multiple small angle atomic scattering dominates in the beam transmission, resulting an outgoing beam into a wide angular range and in a wide energy window. Later, in a mixed phase, scattering and guiding happens simultaneously, with a continuously increasing contribution of the guiding. Finally, in the phase of the stabilized, guided transmission, a quadrupole-like focusing effect is observed, i.e. the transmitted beam is concentrated into a small spot, and the transmitted protons keep their initial kinetic energy.

show abstract

“…This strongly suggests that the beam transmission was governed by a self-organizing charge-up process. The group performed a classical trajectory Monte-Carlo simulation for the 1°tilt case based on the selforganizing charge-up mechanism, which reproduced their experimental results well [110].…”

Section: Straight Capillaries With Mev Ionsmentioning

confidence: 78%

Ion guiding in macro-size insulating capillaries: straight, tapered, and curved shapes

Kojima¹

2018

J. Phys. B: At. Mol. Opt. Phys.

View full text Add to dashboard Cite

When keV energy ions are injected into a tilted insulating capillary, a certain fraction of the injected ions are transported through the tilt angle of the capillary. This ion guiding phenomenon is considered to be caused by a self-organizing charge distribution, where the inner wall of the capillary becomes charged by initial incoming ions. The charge distribution, which is formed, can guide following ions toward the exit of the capillary. Since the initial discovery of this effect, studies of ion guiding by insulating capillaries have been extended to various materials, and different sizes and shapes of capillaries. In recent years, some investigations of the guiding effect of macro-size curved capillaries have also been reported. In this review, relevant studies in a history of ion guiding in curved capillaries are discussed and future directions in this field are considered.

show abstract

Simulation of the time evolution of 1 MeV proton microbeam transmission through an insulating macrocapillary

Cited by 8 publications

References 19 publications

Simulations of transmission of 1 MeV protons through an insulating macrocapillary

Simulations of transmission of 1 MeV protons through an insulating macrocapillary

Spatial and temporal distribution of a 1-MeV proton microbeam guided through a poly(tetrafluoroethylene) macrocapillary

Ion guiding in macro-size insulating capillaries: straight, tapered, and curved shapes

Contact Info

Product

Resources

About