43 research outputs found
Dressed projectile charge state dependence of differential electron emission from Ne atom
We study the projectile charge state dependence of doubly differential electron emission cross section (DDCS) in ionization of Ne under the impact of dressed and bare oxygen ions. Experimental DDCS results measured at different angles are compared with the calculations based on a CDW-EIS approximation using the GSZ model potential to describe projectile active-electron interaction. This prescription gives an overall very good agreement. In general a deviation from the q2-law was observed in the DDCS. The observations crudely identify the dominance of different projectile electron loss mechanisms at certain electron energy range.Fil: Biswas, S.. Tata Institute of Fundamental Research; IndiaFil: Monti, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Tribedi, L. C.. Tata Institute of Fundamental Research; Indi
Extension of charge-state-distribution calculations for ion-solid collisions towards low velocities and many-electron ions
Knowledge of the detailed evolution of the whole charge-state distribution of projectile ions colliding with targets is required in several fields of research such as material science and atomic and nuclear physics but also in accelerator physics, and in particular in regard to the several foreseen large-scale facilities. However, there is a lack of data for collisions in the nonperturbative energy domain and that involve many-electron projectiles. Starting from the etacha model we developed [Rozet, Nucl. Instrum. Methods Phys. Res., Sect. B 107, 67 (1996)10.1016/0168-583X(95)00800-4], we present an extension of its validity domain towards lower velocities and larger distortions. Moreover, the system of rate equations is able to take into account ions with up to 60 orbital states of electrons. The computed data from the different new versions of the etacha code are compared to some test collision systems. The improvements made are clearly illustrated by 28.9MeVu-1Pb56+ ions, and laser-generated carbon ion beams of 0.045 to 0.5MeVu-1, passing through carbon or aluminum targets, respectively. Hence, those new developments can efficiently sustain the experimental programs that are currently in progress on the "next-generation" accelerators or laser facilities.Fil: Lamour, E.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Fainstein, Pablo Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas; Argentina. ComisiĂłn Nacional de EnergĂa AtĂłmica. Centro AtĂłmico Bariloche; ArgentinaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Prigent, C.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Ramirez, C. A.. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rozet, J. P.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Trassinelli, M.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; FranciaFil: Vernhet, D.. Centre National de la Recherche Scientifique; Francia. Universite de Paris; Franci
Young-type interference effects in heavy-ion collisions with diatomic molecules
We present the theoretical and experimental progress in the field of coherent electron emission from simple molecules by the impact of energetic charged particles. In particular, we outline the different theoretical approaches to tackle the single ionization of diatomic molecules by the impact of heavy-ions. Furthermore, a comparison with experimental measurements, where available, is made. Throughout our contribution we emphasize the phenomenology behind these molecular processes and discuss the advantages and drawbacks of the different theoretical approaches.Fil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, IngenierĂa y Agrimensura; ArgentinaFil: Tachino, Carmen Alejandra. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, IngenierĂa y Agrimensura; ArgentinaFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentina. Universidad Nacional de Rosario. Facultad de Ciencias Exactas, IngenierĂa y Agrimensura; ArgentinaFil: Ciappina, Marcelo Fabián. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentina. Czech Academy of Sciences; RepĂşblica Chec
Electron emission in ionization of He and Ne by fast dressed oxygen ions and projectile-charge-state dependence
The double-differential cross sections (DDCS) of low-energy electrons emitted at forward, backward, and perpendicular directions are reported for collisions of 3.75 MeV/u Oq+ (q=5, 6, 7, 8) projectiles with He and Ne targets. The measured DDCS are found to be deviating from the q2 dependence throughout the entire energy region. The effect of projectile electrons, for the dressed ions, as a function of the impact parameter is clearly noticeable for large as well as low-impact parameter collisions. We also present a theoretical calculation based on the prior form of the continuum distorted wave-eikonal initial state approximation, in which the projectile-active electron interaction is modeled with the Green-Sellin-Zachor potential. This particular representation of the potential has been proven to give good qualitative results for projectiles with residual electrons. In addition to the total DDCS, the individual contributions from target ionization, projectile electron loss, and simultaneous ionization processes are also calculated. The total DDCS obtained from these calculations are shown to be in excellent agreement with the experimental observations.Fil: Biswas, Shubhadeep. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Kasthurirangan, S.. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; España. Institute of Chemical Technology; IndiaFil: Misra, D.. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; EspañaFil: Monti, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Fainstein, Pablo Daniel. ComisiĂłn Nacional de EnergĂa AtĂłmica. Centro AtĂłmico Bariloche; Argentina. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Patagonia Norte; ArgentinaFil: Tribedi, L.C.. International Centre Of Theoretical Science. Tata Institute Of Fundamental Research; Españ
Electron emission in collisions between dressed Alq+ ions with He targets
Experimental and theoretical results are presented for electron emission in collisions between dressed Alq+ ions and atomic He targets. The experimental data are compared with a four-body CTMC model and two distorted wave models, namely the CDW and CDW-EIS. The contribution to total electron emission spectra from the ionisation of each collision center and as well as the simultaneous ionisation can be assessed separately.Fil: Monti, Juan Manuel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Fiol, Juan. ComisiĂŁÂłn Nacional de EnergĂŁÂa AtĂŁÂłmica. Gerencia del Area InvestigaciĂŁÂłn y Aplicaciones No Nucleares. Gerencia de FĂŁÂsica (centro AtĂŁÂłmico Balseiro). DivisiĂŁÂłn Colisiones AtĂŁÂłmicas; Argentina. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Area de InvestigaciĂłn y Aplicaciones No Nucleares. Gerencia de FĂsica (Centro AtĂłmico Bariloche); ArgentinaFil: Fregenal, Daniel Eduardo. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Area de InvestigaciĂłn y Aplicaciones No Nucleares. Gerencia de FĂsica (Centro AtĂłmico Bariloche); ArgentinaFil: Fainstein, Pablo Daniel. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Area de InvestigaciĂłn y Aplicaciones No Nucleares. Gerencia de FĂsica (Centro AtĂłmico Bariloche); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Wolff, W.. Universidade Federal do Rio de Janeiro; BrasilFil: E. Horsdal. University Aarhus; DinamarcaFil: Bernardi, Guillermo Carlos. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Area de InvestigaciĂłn y Aplicaciones No Nucleares. Gerencia de FĂsica (Centro AtĂłmico Bariloche); ArgentinaFil: Suarez, Sergio Gabriel. ComisiĂłn Nacional de EnergĂa AtĂłmica. Gerencia del Area de InvestigaciĂłn y Aplicaciones No Nucleares. Gerencia de FĂsica (Centro AtĂłmico Bariloche); Argentin
Ionization induced by protons on isolated molecules of adenine: theory, modelling and experiment
We here report a comparison between semi-empirical and theoretical predictions in terms of differential and total cross sections for proton-induced ionization of isolated adenine molecules. Whereas the first ones are provided by existing analytical models, the second ones are based on two quantum-mechanical models recently developed within the 1st Born and the continuum distorted wave approximation, respectively. Besides, a large set of experimental data is also reported for comparisons. In all kinematical conditions here investigated, we have observed a very good agreement between theory and experiment whereas strong discrepancieswere reported with the semi-empirical models in particular when doubly-differential cross sections are analysed.Fil: Champion, C.. Universite de Bordeaux; FranciaFil: Galassi, Mariel Elisa. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Weck, P. F.. University of Nevada Las Vegas. Department of Chemistry and Harry Reid Center for Environmental Studies; Estados UnidosFil: Abdallah, C.. University Saint Joseph. Faculty of Sciences. Department of Physics; LĂbanoFil: Francis, Z.. University Saint Joseph. Faculty of Sciences. Department of Physics; LĂbano. The Open University. Faculty of Science. Department of Physical Sciences; Reino UnidoFil: Quinto, M. A.. Universite de Bordeaux; FranciaFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Hanssen, Jocelyn. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Iriki, Y.. Kyoto University. Department of Nuclear Engineering; JapĂłnFil: Itoh, A.. Kyoto University. Department of Nuclear Engineering; JapĂł
Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study
Summary
Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally.
Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies
have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of
the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income
countries globally, and identified factors associated with mortality.
Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to
hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis,
exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a
minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical
status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary
intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause,
in-hospital mortality for all conditions combined and each condition individually, stratified by country income status.
We did a complete case analysis.
Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital
diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal
malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome
countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male.
Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3).
Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income
countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups).
Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome
countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries;
p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients
combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11],
p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20
[1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention
(ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety
checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed
(ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of
parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65
[0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality.
Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome,
middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will
be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger
than 5 years by 2030
Fully differential cross sections for ionization of H2 + by ion impact: Classical and quantum effects
Single ionization of H2 + molecular ions by impact of bare ions is theoretically studied. Fully differential cross sections are calculated by employing the prior version of the continuum distorted wave-eikonal initial state model within an independent electron approximation. It is shown in this work that, under certain conditions there can exist a competition between classical and quantum mechanisms in the ionization reaction that gives rise to the suppression of characteristic classical structures, namely the binary and recoil peaks, from the ionization angular spectra. The existence of destructive quantum interferences due to the coherent emission of electrons from the neighbourhood of both molecular centres may be held as the responsible for the suppression of these classical signatures. Different behaviours are observed depending on whether the ground (gerade) or the first excited (ungerade) states of the H2 + target are analysed. Different values of the projectile nuclear charge and collision geometries are considered when alculating FDCS.Fil: Tachino, Carmen Alejandra. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentin
Electron capture to the continuum manifestation in fully differential cross sections for ion impact single ionization
We present theoretical calculations of single ionization of He atoms by protons and multiply charged ions. The kinematical conditions are deliberately chosen in such a way that the ejected electron velocity matches the projectile impact velocity. The computed fully differential cross sections (FDCS) in the scattering plane using the continuum-distorted wave-eikonal initial state show a distinct peaked structure for a polar electron emission angle θ k = 0°. This element is absent when a first order theory is employed. Consequently, we can argue that this peak is a clear manifestation of a three-body effect, not observed before in FDCS. We discuss a possible interpretation of this new feature.Fil: Ciappina, Marcelo Fabián. Czech Academy of Sciences. Institute of Physics; RepĂşblica ChecaFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Rosario. Instituto de FĂsica de Rosario. Universidad Nacional de Rosario. Instituto de FĂsica de Rosario; Argentin
Coherent electron emission from simple molecules by impact of energetic charged particles
We review the theoretical and experimental progress in the field of coherent electron emission from simple molecules by the impact of energetic charged particles. We describe in detail the different theoretical approaches to tackle the single ionization of diatomic molecules by the impact of ions and electrons. Furthermore, we compare with experimental measurements, where available. The case of photon impact is also considered, in order to obtain a deeper understanding of the physics involved. An attempt is made to emphasize the phenomenology behind these molecular processes and to discuss the advantages and drawbacks of the different theoretical approaches. Additionally, we highlight the differences and similarities between the particular projectiles which initiate the process, namely ions, electrons or photons.Fil: Ciappina, M. F.. Institut de Ciences Fotòniques; España. Auburn University. Department of Physics; Estados UnidosFil: Fojon, Omar Ariel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); ArgentinaFil: Rivarola, Roberto Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Rosario. Instituto de FĂsica de Rosario (i); Argentin