bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of pulse selectors for the synchrotron radiation pulses from the Photon Factory 2.5 GeV ring to study multiple photoionization
Authors: Adachi J , Tanaka H , Kosuge T , Ishii H , Suzuki I H , Kaneyasu T , Taniguchi T , Odagiri T , Ohtaki S , Tsuji Y , Soejima K , Lablanquie P , Hikosaka Y 
Published: June 2020

Synopsis
We have developed three pulse selectors to obtain soft x-ray pulses with repetition rates suitable for electron coincidence measurements. The devices enable us to pick out the light pulse from the solo bunch located in the center of the 364-ns dark gap of the hybrid-filling operation. We report the development status and show some typical results of the coincidence measurements with the pulse selectors.
Electron emission from fluorene molecule in collisions with 3.5 MeV/u Si8+ ions
Authors: Bagdia C , Roychowdhury M , Mandal A , Champion C , Tribedi L C 
Published: June 2020

Synopsis
We present measured absolute double differential cross section (DDCS) of electron emission from fluorene (C13H10) molecule upon 3.5 MeV/u Si8+ ion impact. We have compared the energy and angular distributions of the DDCS with CB1 (Ist Born with correct boundary conditions) calculations. The e-DDCS shows an indication of collective excitation peak in low energy part of the spectrum at a few backward angles. The shape of the distribution has also been compared with that for a smaller molecule i.e. CH4.
Photoionization microscopy: linear polarization rotation effects
Authors: Kalaitzis P , Danakas S , Lépine F , Bordas C , Cohen S 
Published: June 2020

Synopsis
Photoionization microscopy (PM) aims at imaging the flux of slow (meV) electrons released by atomic photoionization in the presence of a static electric field. We discuss the rotation of the linear light polari-zation with respect to the electric field direction. Two-photon ionization out of an m=0 initial state allows for the population of |m|=0,1,2 Stark states. The resulting |m|-beating effects in the PM images are demonstrated theoretically (in hydrogen atom) and experimentally (in Mg atom). Implications on the applicability of tomographic techniques for slow electrons are also discussed.
Cross section scaling for the ionization of H2O by highly charged ions
Authors: Bachi N , Otranto S , Olson R E 
Published: June 2020

Synopsis
A classical trajectory Monte Carlo model that explicitly considers the ten electrons of the H2O molecule is used to study electron production in collisions involving bare ions. Present results are contrasted to the reported experimental data and to other theoretical results obtained by means of distorted wave models. Focus is made on the energy range 100 (keV/amu)/ZP-1000 (keV/amu)/ZP along which a simple scaling for the net cross section is introduced.
Electron correlation in simultaneous electron transfer and excitation: results of new 2eAOCC calculations and comparison to experiment in 50-500 keV He+ + H/H2 collisions
Authors: Dubois A , Zouros T J M 
Published: June 2020

Synopsis
New two-electron semiclassical atomic orbital coupled channel calculations (2eAOCC) are compared to experiment and to older coupled channel calculations. Progress in these type of calculations is assessed in an effort to investigate the effect of electron correlations in this fundamental collision system.
Dissociative Electron Attachment to MgCN
Authors: Orel A , Larson Å 
Published: June 2020

Synopsis
Dissociative electron attachment (DEA) to the molecule MgCN and its isomer MgNC have been proposed as possible sources of CN− in the interstellar media. We have carried out electron scattering calculations using the Complex Kohn Variational Method as a function of the internal degrees of freedom to obtain the resonance energy surfaces and autoionization widths. We use this data as input to form the Hamiltonian relevant to the nuclear dynamics. The multidimensional wave equation is solved using the MultiConfiguration Time-Dependent Hartree (MCTDH) approach. We compute the DEA cross sections.
Low-energy electron scattering from methylene radicals: multichannel-coupling effects
Authors: Wang K D , Zhang H X 
Published: June 2020

Synopsis
We reported elastic and excitation cross sections for electron collisions with methylene radical using R-matrix method for electron energies ranging from 0.01 to 15 eV in close-coupling (CC) approximation. We discuss the multi-channel-coupling effects on the calculated cross sections and resonances, and how the number of excited states included in the target state impacts the convergence of the elastic and the X3B1 → 11A1 and X3B1 → 11B1 excitation cross sections, especially at higher impact energy. Finally, we estimate the accuracy of the 11A1and 11B1 excitation cross sections.
Integral cross sections for elastic electron scattering by methane molecule
Authors: Maljković J B , Vuković J , Tökési K , Predojević B , Marinković B P 
Published: June 2020

Synopsis
We have performed a combined experimental and theoretical study of electron elastic differential and integral cross sections from methane molecule (CH4) in the intermediate energy range. Data have been compared with available data sets in the literature as well as with recommended data set [Song et al J. Phys. Chem. Ref.Data
44 023101 (2015)].
Dissociation of furan-2-carboxylic acid by low energy electrons
Authors: Zawadzki M , Kočišek J , Fedor J 
Published: June 2020

Synopsis
Electron attachment to molecular target can lead to a variety of negative fragment ions. We experimentally probe the main dissociative electron attachment channels in furan-2-carboxylic acid (C3H3O2 – COOH) - a molecular target composed of two important structural units: a furan ring and a carboxylic group. In our studies we utilise nearly mono-energetic electrons at electron energies from 0 eV up to 15 eV. Our detection setup is based on extraction lens system and quadrupole mass spectrometer, that enables measurement of the energy dependent mass-selected yields of newly formed stable anions.
Investigation of electron scattering asymmetries in halocamphors
Authors: Ruivo J C , Kossoski F , Varella M T do N 
Published: June 2020

Synopsis
We present a study on the electron transmission and dissociative electron attachment asymmetries in halocamphor species. Our results consist in their anion state spectra, applied in a model for the spin-polarized electron scattering problem under the influence of a low energy resonance.
Spectroscopic investigations of YAG-laser-driven microdroplet-tin plasma sources of extreme ultraviolet radiation for nanolithography
Authors: Versolato O , Bayerle A , Bayraktar M , Behnke L , Bekker H , Bouza Z , Colgan J , Crespo López-Urrutia J R , Deuzeman M J , Hoekstra R , Kurilovich D , Liu B , Meijer R , Neukirch A , Poirier L , Rai S , Ryabtsev A , Scheers J , Schupp R , Sheil J , Torretti F , Ubachs W , Witte S 
Published: June 2020

Synopsis
Highly charged tin ions are the sources of extreme ultraviolet (EUV) light at 13.5-nm wavelength in laser-produced transient plasmas for next-generation nanolithography. Generating this EUV light at the required power, reliability, and stability however presents a formidable task that combines industrial innovations with challenging scientific questions. We will present work on the spectroscopy of tin ions in and out of YAG-laser-driven plasma and present a surprising answer to the key question: what makes that light?
Base damages induced in DNA by 10 eV electrons: contribution to the radiosensitization mechanism of platinum chemotherapeutic drugs
Authors: Liu W , Gao Y , Lemelin V , Zheng Y , Sanche L 
Published: June 2020

Synopsis
Binding of Pt-drugs to DNA significantly enhaces base damages, crosslinks, double strand breaks (DSBs) and non-DSB cluster lesions induced by 10 eV electrons. This enhancement of potentially lethal lesions is due to a modification of electron-DNA interactions, which contributes to the synergy between chemo- and radio-therapy, when these modalities are administered in concomitance during cancer treatments.
Solar wind sputtering of lunar analogue material
Authors: Szabo P S , Biber H , Weichselbaum D , Brenner M , Stadlmayr R , Mayer D , Mutzke A , Nenning A , Doppler M , Sauer M , Jäggi N , Galli A , Fleig J , Foelske-Schmitz A , Lammer H , Mezger K , Wurz P , Aumayr F 
Published: June 2020

Synopsis
Sputtering by solar wind ions is investigated on thin films of the mineral wollastonite (CaSiO3) as an analogue material for the lunar surface. Sputtering yields are measured with a Quartz Crystal Microbalance (QCM) using H and He ions as well as multiply charged Ar ions at different incidence angles. The results of these irradiations show that kinetic sputtering can be very well reproduced using SDTrimSP, while potential sputtering significantly increases the expected erosion of airless bodies in the solar system.
The role of contaminations on the interaction of highly charged ions with 2D materials
Authors: Niggas A , Schwestka J , Creutzburg S , Aumayr F , Wilhelm R A 
Published: June 2020

Synopsis
Contaminations on two dimensional materials can influence electronic, optical or mechanical material properties or even dominate them. We perform ion beam spectroscopy with highly charged ions as projectiles transmitted through freestanding 2D materials to study fundamental charge exchange processes between the ion and the samples under extreme conditions. Various in situ cleaning techniques to remove contaminations such as laser annealing and sample heating are employed. Their influence on our spectroscopy results is discussed here.
Influence of surface plasmon polaritons on heating of gold
Authors: Terekhin P N , Ndione P D , Weber S T , Rethfeld B 
Published: June 2020

Synopsis
We present a detailed investigation of periodic heating of gold and periodic structures formation on a surface induced by surface plasmon polaritons (SPP) after irradiation with ultrashort laser pulses. Conditions of the SPP excitation and influence of the angle of incidence and wavelength of the laser field on the resulting structured heating are analysed in detail.
Charge-transfer dynamics in anion collisions with vicinal nanostepped surfaces
Authors: Shaw J , Monismith D , Zhang Y , Doerr D , Chakraborty H S 
Published: June 2020

Synopsis
We investigate the electron dynamics at various monocrystalline metal surfaces with stepped vicinal nanostructures. The unoccupied bands of the surface superlattice are resonantly excited via the charge transfer interaction of the surface with a H− ion which flies by at grazing angles. The ion survival exhibits modulations as a function of the vicinal-terrace size and shows peaks at energies that access the image state subbands.
The missing single-scattering peak in tin ion collisions on Mo and Ru targets
Authors: Rai S , Deuzemann M J , Noordam W , Holleman E , Versolato O O , Hoekstra R 
Published: June 2020

Synopsis
We report the absence of single-scattering peaks in collisions of tin ions on Mo and Ru targets. For these systems standard simulation packages as e.g. SRIM predict prominent single-scattering peaks. To identify the potential cause of the single-scattering peak missing, we changed charge state, energy, and species of the projectiles, detected ions and neutrals separately and studied collisions of Kr on Cu which has a similar mass ratio of projectie and target particles.
Modelling interactions of alkali-cation dimers in He clusters
Authors: Alharzali N , Berriche H , Villarreal P , Prosmiti R 
Published: June 2020

Synopsis
Doped He droplets constitute an important environment as ultracold homogeneous matrices for spectroscopic studies. Alkali metal dopants have a series of interesting properties due to their unusual bonding behavior. Neutral atoms attached to the surface of the droplet, forming eventually cold molecules via collisions, while charged dopants form solvation shells, related with the low mobility of the ions in experiments. So, investigations on the underlying intermolecular, markedly orientational ionic, forces, and on the miscoscopic structures of alkali-cation-He complexes is essential.
Simulations of proton beam propagation in matter using entropic moment method
Authors: Olivier E , Nguyen-Bui T H , Champion C , Dubroca B 
Published: June 2020

Synopsis
Atomic interactions of ions with the penetrated medium lead to a strong evolution of ion charge-state fractions as a function of the target thickness. In this paper, we present a fast and accurate method in order to simulate the slowing-down of ions in matter. Our model relies on the averaging of the transport equation leading to fast simulations of the deposited dose by particles beam. Simulations have been performed for the case of proton beams propagating through water. Results have been compared with Monte Carlo simulations.
Screened independent atom model calculations for electron emission from biologically relevant molecules by proton impact
Authors: Lüdde H J , Horbatsch M , Kirchner T 
Published: June 2020

Synopsis
Screened independent atom model calculations for the net ionization of complex biomolecules bom-barded by energetic protons are presented. Scaling relations are examined and a simple parametrization of the cross section results in terms of an analytical formula is suggested.
Elastic and inelastic scattering of positrons from neon
Authors: Babij T , Cheong Z , Machacek J , McEachran R P , Buckman S J , Sullivan J P 
Published: June 2020

Synopsis
Data will be presented for positron scattering from neon. As a “simple” target, neon provides a useful target for the testing and exploration of our fundamental understanding of scattering processes. The low-energy, high-resolution positron beamline based at the Australian National Universitywas used to measure elastic differential cross sections and total electronic and ionization cross sections for low energy scattering of positrons from neon. The experimental data presented will be compared to several recent theoretical calculations.
Four-body calculation of energy levels of muonic molecule dtμe in muon catalyzed fusion
Authors: Niiyama M , Yamashita T , Kino Y 
Published: June 2020

Synopsis
We investigate dtμe (= d + t + μ + e) four-body system which includes the most important bound states (dtμ)11 in muon catalyzed fusion (μCF). We directly estimate the energy shift more accurately than the previous perturbation calculation. The shift found to be one order of magnitude larger than previous calculation and to be more significant in the calculation of the μCF reaction rate.
Production of cold molecular ions in superfluid helium droplets
Authors: Iguchi A , Otani H , Kuma S , Tanuma H , Azuma T 
Published: June 2020

Synopsis
The capability of helium droplets to isolate cryogenic molecular ions at a temperature of 0.4 K is exploited to observe ultracold molecular processes in the RIKEN Cryogenic Electrostatic (RICE) storage ring. The development of a pulsed droplet beam consisting of extremely large helium droplets up to 1011 atoms is a promising step to apply this unique and robust cooling method to a wide variety of molecular ions. Production of ions by photoionization of neutral species inside helium droplets will provide internally cold ions below the ring temperature of 4 K.
Vibrational autodetachment from hot copper dimer anions: breakdown of the Born-Oppenheimer approximation
Authors: Anderson E K , Schmidt-May A F , Najeeb P K , Eklund G , Rosén S , Stockett M H , Chartkunchand K , Kaminska M , Hansen K , Cederquist H , Zettergren H , Schmidt H T 
Published: June 2020

Synopsis
The decay of hot copper dimer anions is studied in a cryogenic storage ring. We detect atomic anion and neutral products and determine the fragmentation and vibrational autodetachment (VAD) rates separately. For short storage times the dimer anions predominantly decay by fragmentation of highly rotationally excited ions by tunneling through the rotational barrier. For storage times exceeding 100 ms, however, VAD is dominating. This process is driven by the very weak direct coupling between nuclear and electronic degrees of freedom.
An electrospray ionisation apparatus for gas phase study of biomolecules
Authors: Chiarinelli J , Bolognesi P , Ramillon J M , Rousseau P , Domaracka A , Castrovilli M C , Avaldi L 
Published: June 2020

Synopsis
A set-up to study large biomolecules in the gas phase based on an ElectroSpray Ionisation source has been installed at CNR-ISM in Rome, and it is currently under commissioning. Accurate ion optics simulation provide crucial feedback in the understanding and optimisation of its performance.
DNA damage in Thymidyl(3’-5’)thymidine (TpT) induced by very low energy electrons
Authors: Khorsandgolchin G , Lemelin V , Cloutier P , Sanche L , Wagner J R 
Published: June 2020

Synopsis
The interaction of high-energy radiation with the biological matter produces copious amounts of non-thermal secondary low energy electrons (LEEs; 0-30 eV). Several studies have shown that 5-15 eV electrons induce different types of DNA damage by the formation of transient negative ions (TNIs), decaying into the dissociative elec-tron attachment (DEA) process [1,2]. Here, our main focus is to understand the chemical mechanism of damage by very low energy electrons (vLEEs∼1.8 eV) by using TpT as a simple model of DNA, solid-state LEE irradiation methods and LC-MS/MS analysis of the degradation products.
Measurement of proton microbeam profiles in atmosphere produced by single tapered glass capillary optics with an end window
Authors: Ikeda T , Ikekame M , Hikima Y , Mori M , Kawamura S , Minowa T , Jin W-G 
Published: June 2020

Synopsis
Profiles of 2.8 MeV H+ microbeam extracted from a single tapered glass capillary optics were meas-ured by two methods for a future irradiation to an outer organ of insect target. The halo component was analyzed to be 575 μm in full width at half maximum (FWHM) at a plastic tracking detector CR-39 located 1 mm down-stream of the capillary. The core component was examined by knife-edge method according to the ion energies. The profiles consisting of more energy-loss events have wider FWHM, which can be reduced by Al thin layers.
Real-time trajectory control on a deterministic ion source
Authors: Lopez C , Trimeche A , Comparat D , Picard Y J 
Published: June 2020

Synopsis
The major challenge to improve deterministic single ion sources is to control the position and momentum of each ion. Based on the extra information given by the electron created in a photoionization process, the trajectory of the correlated ion can be controlled and corrected using a fast real time feedback system. In this work, we report on a proof-of-principle experiment that demonstrates the performance of this feedback control with individual cesium ions.
Absolute cross sections for production of molecular dications by electron impact
Authors: Sigaud L , Montenegro E C 
Published: June 2020

Abstract
Molecular dications are important metastable species present in a variety of environments including, but not restricted to, planetary atmospheres and the human body when submitted to radiation. On the other hand, symmetric molecular dications cannot be separated from the cation corresponding to the molecule broken in half (e.g.

N
2

+
+

and N+) in stantard mass spectrometers. The DETOF technique allows one to identify the symmetric molecular dication, obtaining absolute cross sections related to their production. Results for dications of molecular nitrogen, molecular oxygen, ethylene and benzene are discussed here, giving emphasis on the mechanisms behind their production. It is seen that, while most metastable molecular dications result from a combination of direct double ionization and Auger-like processes,

N
2

+
+

and

O
2

+
+

represent so-called pure cases, where the dication is produced only by, respectively, double direct ionization or post-collisional Auger-like decay.
Role of methylation in electron scattering on X(CH3)4 (X= C, Si, Ge) molecules
Authors: Stefanowska-Tur Sylwia , Szmytkowski Czesław , Ptasińska-Denga Elżbieta , Możejko Paweł 
Published: June 2020

Abstract
To investigate how replacement of H atom with methyl group (CH3) – in tetrahedral compounds of carbon, silicon and germanium – affects electron scattering process, total cross sections (TCS) for electron scattering from C(CH3)4, Si(CH3)4 and Ge(CH3)4 molecules have been compared with data for CH4, SiH4 and GeH4 molecules. All examined data have been obtained with the same experimental setup. The shape of all discussed TCS energy dependences is very similar and is characterized by a dominant maximum peaked below 10 eV. For methylated compounds a gentle structure is also visible on high energy slope of main enhancement, between 10 – 20 eV. A simple formula for TCS evaluation for partially methylated carbon, silicon and germanium compounds is also proposed.
Atomic processes with twisted electrons
Authors: Zaytsev V A , Surzhykov A , Serbo V G , Kosheleva V P , Groshev M E , Yerokhin V A , Shabaev V M , Stöhlker Th 
Published: June 2020

Abstract
The present status of the fully-relativistic nonperturbative calculations of the fundamental atomic processes with twisted electrons is presented. In particular, the elastic (Mott) scattering, the radiative recombination, and for the very first time, the Bremsstrahlung processes are considered. The electron-ion interaction is accounted for in a nonperturbative manner, that allows obtaining reliable results for heavy systems. We investigate the influence of the “twistedness” of the incoming electron on the angular and polarization properties of the emitted electrons and photons for the elastic and inelastic scattering, respectively. It is found that these properties exhibit a strong dependence on the opening angle of the vortex electron beam in all processes considered.
Collisional cooling of trapped ions with cold atoms: results and insights
Authors: Dutta Sourav , Sawant Rahul , Rangwala S A 
Published: June 2020

Abstract
We present a series of recent experimental and numerical results which allow us to propose and explain the mechanisms for collisional cooling of a trapped ion by sequential binary collisions with atoms. Our experiments in hybrid atom-ion traps study the cooling of ions when the reservoir of the coolant atoms is spatially localized at the centre of the ion trap. Under these conditions the widely and long held expectation that for the ion to collisionally cool, the atom must be of lighter mass (i.e. mI
> mA
) is overturned. Instead we show ion cooling for mI
⩽ mA
in addition to mI
> mA
, and explain why earlier work establishing mass ratios does not apply to the experiments in hybrid traps. Further, for cooling of an ion A+ by the parent atom A, the mechanism of resonant charge exchange (RCE) allows for extremely efficient cooling of the ion A+. This mechanism is demonstrated by comparing the cooling rate of an ion with a localized ensemble of its parent atoms and with a lighter atomic species, where in the latter case the RCE mechanism does not exist. The difference in measured cooling rates for a given number density of the atoms and the theoretically calculated difference between elastic and RCE cross sections are used to show that the cooling efficiency per collision with RCE is much greater than the cooling by elastic collision. We conclude with some perspectives and prospects of future experiments.
Abnormal photoelectron angular distribution of Ar atoms in pulsed XUV and IR laser fields
Authors: Tong XM , Toshima N 
Published: June 2020

Synopsis
We calculated the photoelectron angular distribution of Ar atoms in pulsed XUV and IR laser fields by solving the time-dependent Schrödinger equation and found that the angular distributions of sidebands are not always straight lines in the energy-angle plot as predicted by the strong field approximation. Further study shows that the abnormality is attributed to the photoelectron-nucleus Coulomb interaction. The abnormality depends on the IR intensity, IR pulse duration, XUV photon energy and the time-delay between the two pulses.