Ionization of uracil in collisions with highly charged carbon and oxygen ions of energy 100 keV to 78 MeV

Agnihotri, A. N.; Kasthurirangan, S; Nandi, Saikat; Kumar, Ajay; Galassi, M E; Rivarola, R D; Fojón, O A; Champion, C.; Hanssen, J.; Lekadir, H.; Weck, Philippe F.; Tribedi, Lokesh C.

doi:10.1103/physreva.85.032711

Cited by 52 publications

(54 citation statements)

References 32 publications

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“…The post and prior versions of the transition amplitude for the reactions above mentioned may be written as † In the current work, the cross sections for electron capture are computed within prior version whereas for electron ionization the post version is used for simplicity (Champion et al 2010, 2012.…”

Section: Cross Section Calculationmentioning

confidence: 99%

Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

et al. 2015

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Water is a common surrogate of DNA for modelling the charged particle-induced ionizing processes in living tissue exposed to radiations. The present study aims at scrutinizing the validity of this approximation and then revealing new insights into proton-induced energy transfers by a comparative analysis between water and realistic biological medium. In this context, a self-consistent quantum mechanical modelling of the ionization and electron capture processes is reported within the continuum distorted wave-eikonal initial state framework for both isolated water molecules and DNA components impacted by proton beams. Their respective probability of occurrence-expressed in terms of total cross sections-as well as their energetic signature (potential and kinetic) are assessed in order to clearly emphasize the differences existing between realistic building blocks of living matter and the controverted water-medium surrogate. Consequences in radiobiology and radiotherapy will be discussed in particular in view of treatment planning refinement aiming at better radiotherapy strategies.

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Section: Cross Section Calculationmentioning

confidence: 99%

Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

et al. 2015

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“…Experiments: proton impact on △ uracil[19], ▽ pyrimidine[23] and THF[25]. Impact of ⊖ C 4+ , ⊕ C 6+ , O 6+ , F 6+ , and ⊗ O 8+ , F 8+ on uracil[20,21]. Symbols ⊳[24], ⊲[26], and[27] for electron impact with equivelocity conversion.…”

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confidence: 99%

Ionization of biological molecules by multicharged ions using the stoichiometric model

Mendez

Montanari

Miraglia

2020

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

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In the present work, we investigate the ionization of molecules of biological interest by the impact of multicharged ions in the intermediate to high energy range. We performed full non-perturbative distorted-wave calculations (CDW) for thirty-six collisional systems composed by six atomic targets: H, C, N, O, F and S -which are the constituents of most of the DNA and biological molecules-and six charged projectiles (antiprotons, H, He, B, C, and O). On account of the radiation damage caused by secondary electrons, we inspect the energy and angular distributions of the emitted electrons from the atomic targets. We examine seventeen molecules: DNA and RNA bases, DNA backbone, pyrimidines, tetrahydrofuran (THF), and CnHn compounds. We show that the simple stoichiometric model (SSM), which approximates the molecular ionization cross sections as a linear combination of the atomic ones, gives reasonably good results for complex molecules. We also inspect the extensively used Toburen scaling of the total ionization cross sections of molecules with the number of weakly bound electrons. Based on the atomic CDW results, we propose new active electron numbers, which improves significantly scaling for all the targets and ions studied here in the intermediate to the high energy region. The new scaling describes well the available experimental data for proton impact, including small molecules. We perform full molecular calculations for five nucleobases and test a modified stoichiometric formula based on the Mulliken charge of the composite atoms. The difference introduced by the new stoichiometric formula is less than 3%, which indicates the reliability of the SSM to deal with this type of molecules. The results of the extensive ion-target examination included in the present study allow us to assert that the SSM and the CDW-based scaling will be useful tools in this area.

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“…Lately, studies involving ionization of large biomolecules from the biomedical therapy point of view, have become an important topic of research. For instance, the dependence of total ionization cross sections of uracil molecules on the projectile energy as well as charge state has been reported by Agnihotri et al [3], using keV to MeV energy heavy ions. Similar studies with protons having different energies were reported earlier by many research groups [4][5][6].…”

Section: Introductionmentioning

confidence: 84%

Double-differential cross sections for ionization of H2O by fast bare O ions: Comparison with continuum-distorted-wave eikonal-initial-state calculations in prior and post forms

et al. 2013

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We have measured the double-differential cross sections (DDCS) for electron emission in ionization of H 2 O molecules under the impact of 4.5-MeV/u O 8+ ions. The data were collected between 1 and 600 eV, in an angular range of 20 • -150 • by using an electrostatic hemispherical analyzer. In the experiment we used the H 2 O vapor in a static gas condition which allowed us to deduce the absolute value of the cross sections. The single-differential cross sections (SDCS) and the total cross sections have also been obtained. The DDCS as well as the SDCS spectra are compared with the continuum-distorted-wave eikonal-initial-state (CDW-EIS) calculations for both the prior as well as the post forms of the scattering matrix. The initial state is represented within the complete neglect of differential overlap approximation, where the molecular orbitals are expressed in terms of atomic orbitals of the atomic constituents. The overall agreement with the CDW-EIS model is quite good as far as the energy dependence is concerned. The prior form of the model is found to provide a better understanding of the

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Ionization of uracil in collisions with highly charged carbon and oxygen ions of energy 100 keV to 78 MeV

Cited by 52 publications

References 32 publications

Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

Water versus DNA: new insights into proton track-structure modelling in radiobiology and radiotherapy

Ionization of biological molecules by multicharged ions using the stoichiometric model

Double-differential cross sections for ionization of H2O by fast bare O ions: Comparison with continuum-distorted-wave eikonal-initial-state calculations in prior and post forms

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