TY  - JOUR
AU  - Nešković, Nebojša B.
AU  - Telečki, Igor N.
AU  - Bojović, Boško
AU  - Petrović, Srđan M.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4269
AB  - The subject of this paper is the transmission of protons through a square electrostatic rainbow lens, which is similar to a quadrupole electrostatic lens and analogous to a crystal channel. The potential of the electrodes is chosen to be 10, 20, 50 and 100 kV. The initial proton kinetic energy is 10 keV. It is shown that the interaction potential between the proton and lens is purely anharmonic. We explore the spatial distributions of transmitted protons inside the lens and in the drift space after its exit. It is demonstrated that the evolution of the spatial distribution is determined by the evolution of the corresponding rainbow pattern. The proton beam after passing through the lens is clearly separated into the bright and dark components, which correspond to the bright and dark sides of the rainbow, respectively. All the focused protons are confined within the rainbow line. This effect is called the catastrophic ion beam focusing. We also explore the angular distributions of transmitted protons at the lens exit. The corresponding rainbow patterns appear only when the potential is 50 and 100 kV. In these cases almost all the focused protons are confined within the rainbow line. This means that the lens enables one to create a proton beam core, which includes the protons focused in both the transverse position plane and the transmission angle plane. The evolutions of the focused and defocused groups of protons are analyzed quantitatively via three parameters - the focusing coefficient of the lens, and the confining coefficients of the lens for the focused and defocused protons. Finally, we discuss the possible applications of the lens.
T2  - Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment
T1  - A square electrostatic rainbow lens: Catastrophic ion beam focusing
VL  - 635
IS  - 1
SP  - 1
EP  - 7
DO  - 10.1016/j.nima.2010.12.126
ER  - 

@article{
author = "Nešković, Nebojša B. and Telečki, Igor N. and Bojović, Boško and Petrović, Srđan M.",
year = "2011",
abstract = "The subject of this paper is the transmission of protons through a square electrostatic rainbow lens, which is similar to a quadrupole electrostatic lens and analogous to a crystal channel. The potential of the electrodes is chosen to be 10, 20, 50 and 100 kV. The initial proton kinetic energy is 10 keV. It is shown that the interaction potential between the proton and lens is purely anharmonic. We explore the spatial distributions of transmitted protons inside the lens and in the drift space after its exit. It is demonstrated that the evolution of the spatial distribution is determined by the evolution of the corresponding rainbow pattern. The proton beam after passing through the lens is clearly separated into the bright and dark components, which correspond to the bright and dark sides of the rainbow, respectively. All the focused protons are confined within the rainbow line. This effect is called the catastrophic ion beam focusing. We also explore the angular distributions of transmitted protons at the lens exit. The corresponding rainbow patterns appear only when the potential is 50 and 100 kV. In these cases almost all the focused protons are confined within the rainbow line. This means that the lens enables one to create a proton beam core, which includes the protons focused in both the transverse position plane and the transmission angle plane. The evolutions of the focused and defocused groups of protons are analyzed quantitatively via three parameters - the focusing coefficient of the lens, and the confining coefficients of the lens for the focused and defocused protons. Finally, we discuss the possible applications of the lens.",
journal = "Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment",
title = "A square electrostatic rainbow lens: Catastrophic ion beam focusing",
volume = "635",
number = "1",
pages = "1-7",
doi = "10.1016/j.nima.2010.12.126"
}

Nešković, N. B., Telečki, I. N., Bojović, B.,& Petrović, S. M.. (2011). A square electrostatic rainbow lens: Catastrophic ion beam focusing. in Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment, 635(1), 1-7.
https://doi.org/10.1016/j.nima.2010.12.126

Nešković NB, Telečki IN, Bojović B, Petrović SM. A square electrostatic rainbow lens: Catastrophic ion beam focusing. in Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment. 2011;635(1):1-7.
doi:10.1016/j.nima.2010.12.126 .

Nešković, Nebojša B., Telečki, Igor N., Bojović, Boško, Petrović, Srđan M., "A square electrostatic rainbow lens: Catastrophic ion beam focusing" in Nuclear Instruments and Methods in Physics Research. Section A: Accelerators, Spectrometers, Detectors, and Associated Equipment, 635, no. 1 (2011):1-7,
https://doi.org/10.1016/j.nima.2010.12.126 . .

TY  - JOUR
AU  - Šiljegović, Milorad
AU  - Kačarević-Popović, Zorica M.
AU  - Krklješ, Aleksandra N.
AU  - Stojanović, Zoran A.
AU  - Jovanović, Zoran M.
PY  - 2011
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4263
AB  - Ion bombardment is a suitable tool to modify the optical properties of polymers. In the present study the effect of ion bombardment on the optical absorption of ethylene-norbornene copolymer (TOPAS) was studied using ultraviolet-visible (UV-Vis) and Raman spectroscopy. Polymer samples were bombarded with 60 key C4+ and N4+ ion beams to various fluences ranging from 1.0 x 10(13) to 1.0 x 10(16) cm(-2). The indirect and direct band gaps have been determined. The values of direct band gaps have been found to be greater than the corresponding values of the indirect band gaps. Activation energy has been investigated as the function of ion fluences. The number of carbon atoms per conjugated length is determined according to modified Taucs equation. The correlation between the optical band gap, activation energy for optical transition and the number of carbon atoms per conjugated length as well as chemical structure changes induced by ion beams irradiation have been discussed in the case of ethylene-norbornene copolymer. (C) 2011 Elsevier B.V. All rights reserved.
T2  - Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
T1  - Effect of N4+ and C4+ ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS)
VL  - 269
IS  - 7
SP  - 708
EP  - 715
DO  - 10.1016/j.nimb.2011.01.134
ER  - 

@article{
author = "Šiljegović, Milorad and Kačarević-Popović, Zorica M. and Krklješ, Aleksandra N. and Stojanović, Zoran A. and Jovanović, Zoran M.",
year = "2011",
abstract = "Ion bombardment is a suitable tool to modify the optical properties of polymers. In the present study the effect of ion bombardment on the optical absorption of ethylene-norbornene copolymer (TOPAS) was studied using ultraviolet-visible (UV-Vis) and Raman spectroscopy. Polymer samples were bombarded with 60 key C4+ and N4+ ion beams to various fluences ranging from 1.0 x 10(13) to 1.0 x 10(16) cm(-2). The indirect and direct band gaps have been determined. The values of direct band gaps have been found to be greater than the corresponding values of the indirect band gaps. Activation energy has been investigated as the function of ion fluences. The number of carbon atoms per conjugated length is determined according to modified Taucs equation. The correlation between the optical band gap, activation energy for optical transition and the number of carbon atoms per conjugated length as well as chemical structure changes induced by ion beams irradiation have been discussed in the case of ethylene-norbornene copolymer. (C) 2011 Elsevier B.V. All rights reserved.",
journal = "Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms",
title = "Effect of N4+ and C4+ ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS)",
volume = "269",
number = "7",
pages = "708-715",
doi = "10.1016/j.nimb.2011.01.134"
}

Šiljegović, M., Kačarević-Popović, Z. M., Krklješ, A. N., Stojanović, Z. A.,& Jovanović, Z. M.. (2011). Effect of N4+ and C4+ ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS). in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 269(7), 708-715.
https://doi.org/10.1016/j.nimb.2011.01.134

Šiljegović M, Kačarević-Popović ZM, Krklješ AN, Stojanović ZA, Jovanović ZM. Effect of N4+ and C4+ ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS). in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms. 2011;269(7):708-715.
doi:10.1016/j.nimb.2011.01.134 .

Šiljegović, Milorad, Kačarević-Popović, Zorica M., Krklješ, Aleksandra N., Stojanović, Zoran A., Jovanović, Zoran M., "Effect of N4+ and C4+ ion beam bombardment on the optical and structural characteristics of ethylene-norbornene copolymer (TOPAS)" in Nuclear Instruments and Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms, 269, no. 7 (2011):708-715,
https://doi.org/10.1016/j.nimb.2011.01.134 . .

TY  - JOUR
AU  - Nešković, Nebojša B.
AU  - Borka, Duško
AU  - Šopić, Sandra
AU  - Petrović, Srđan M.
PY  - 2010
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/4238
AB  - In this work we investigate theoretically the spatial and angular distributions of protons channeled in a bent very short (11, 9) single-wall carbon nanotube. The initial proton kinetic energy is 1 GeV and the nanotube length 7 mu m. The nanotube bending angle is varied between 0 and 2 mrad. The calculations are performed employing the theory of crystal rainbows. The interaction of the proton and a nanotubes atom is described by the Molieres approximation of the Thomas-Fermi interaction potential. The spatial and angular distributions of transmitted protons are generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse position plane. They are explained by the rainbow patterns in the final transverse position and transmission angle planes, being the images of the spatial and angular rainbow patterns in the impact parameter plane, respectively. These patterns are also obtained numerically. We discuss the possibility of applying bent carbon nanotubes for guiding ion beams in accelerators.
T2  - International Journal of Nonlinear Sciences and Numerical Simulation
T1  - Rainbows in Channeling of 1 GeV Protons in a Bent Very Short (11,9) Single-wall Carbon Nanotube
VL  - 11
IS  - 12
SP  - 1131
EP  - 1143
DO  - 10.1515/IJNSNS.2010.11.12.1131
ER  - 

@article{
author = "Nešković, Nebojša B. and Borka, Duško and Šopić, Sandra and Petrović, Srđan M.",
year = "2010",
abstract = "In this work we investigate theoretically the spatial and angular distributions of protons channeled in a bent very short (11, 9) single-wall carbon nanotube. The initial proton kinetic energy is 1 GeV and the nanotube length 7 mu m. The nanotube bending angle is varied between 0 and 2 mrad. The calculations are performed employing the theory of crystal rainbows. The interaction of the proton and a nanotubes atom is described by the Molieres approximation of the Thomas-Fermi interaction potential. The spatial and angular distributions of transmitted protons are generated by the computer simulation method using the numerical solution of the proton equations of motion in the transverse position plane. They are explained by the rainbow patterns in the final transverse position and transmission angle planes, being the images of the spatial and angular rainbow patterns in the impact parameter plane, respectively. These patterns are also obtained numerically. We discuss the possibility of applying bent carbon nanotubes for guiding ion beams in accelerators.",
journal = "International Journal of Nonlinear Sciences and Numerical Simulation",
title = "Rainbows in Channeling of 1 GeV Protons in a Bent Very Short (11,9) Single-wall Carbon Nanotube",
volume = "11",
number = "12",
pages = "1131-1143",
doi = "10.1515/IJNSNS.2010.11.12.1131"
}

Nešković, N. B., Borka, D., Šopić, S.,& Petrović, S. M.. (2010). Rainbows in Channeling of 1 GeV Protons in a Bent Very Short (11,9) Single-wall Carbon Nanotube. in International Journal of Nonlinear Sciences and Numerical Simulation, 11(12), 1131-1143.
https://doi.org/10.1515/IJNSNS.2010.11.12.1131

Nešković NB, Borka D, Šopić S, Petrović SM. Rainbows in Channeling of 1 GeV Protons in a Bent Very Short (11,9) Single-wall Carbon Nanotube. in International Journal of Nonlinear Sciences and Numerical Simulation. 2010;11(12):1131-1143.
doi:10.1515/IJNSNS.2010.11.12.1131 .

Nešković, Nebojša B., Borka, Duško, Šopić, Sandra, Petrović, Srđan M., "Rainbows in Channeling of 1 GeV Protons in a Bent Very Short (11,9) Single-wall Carbon Nanotube" in International Journal of Nonlinear Sciences and Numerical Simulation, 11, no. 12 (2010):1131-1143,
https://doi.org/10.1515/IJNSNS.2010.11.12.1131 . .