bluuebunny/crossref_metadata_2025_split huggingface dataset:
Collisions between cold molecules in a superconducting magnetic trap
Authors: Pitzer M , Segev Y , Karpov M , Akerman N , Narevicius J , Narevicius E 
Published: June 2020

Synopsis
We decelerate and trap molecular oxygen using time-dependent magnetic fields and superconducting magnets. The density-dependent, non-exponential decay in particle number provides a clear proof of molecule-molecule collisions within the trapped ensemble. The spatial distribution of molecules in the trap is found to change over time, allowing to set limits on the ratio between the elastic and inelastic collision cross sections. Our experimental scheme opens up new possibilities for studying quantum effects in chemistry as well as for evaporative cooling of molecules.
A traveling wave Zeeman decelerator
Authors: Damjanovic T , Vanhaecke N , Cromiéres J , Haak H , Meijer G , willitsch S , Zhang D 
Published: June 2020

Synopsis
We developed a new-concept Zeeman decelerator which produces a traveling magnetic trap. Atoms and molecules possessing a magnetic dipole moment, in so-called low field seeking states, are trapped around a node of a propagating wave provided that the initial velocity of the wave matches a velocity populated in the supersonic beam. In addition, three dimensional confinement is achieved by controlling the radial orientation of the trap, which can be done fully independently from its longitudinal motion.
Calculations of long-range three-body interactions for Li(2 2S )-Li(22 S )-Li+(1 1S)
Authors: Yan P G , Tang L Y , Yan Z C , Babb J F 
Published: June 2020

Synopsis
Using perturbation theory for energies, we evaluate the additive and nonadditive interaction co-efficients C4, C6
, C7
, C8
and C9 for the Li(22S)-Li(22S)-Li+(11S) system. The obtained coefficients Cn are evaluated with highly accurate variationally-generated nonrelativistic wave functions in Hylleraas coordinates. The nonadditive interaction coefficients depend on the geometrical configurations of this three-body system and on the different position of the ion for each configuration. Our calculations may be of interest for the study of three-body recombination and for constructing precise potential energy surfaces.
Development of a cryogenic ion mobility spectrometer for an isomer-selected photoexcitation and reaction studies
Authors: Shiina Y , Takaya K , Ueta H , Hirayama T , Nakano Y 
Published: June 2020

Synopsis
A new development aiming experimental studies of isomer-selected gas-phase reactions and photoexcitation processes is being conducted. The experiment is based on isomer separation by an ion mobility spectrometry and ion accumulation in a temperature-variable radiofrequency ion trap. The laser plasma light source at Rikkyo University is currently under an upgrade for providing ultraviolet light at the wavelength region from 90 to 200 nm. We report on the details of the experimental setup and current status of the development.
Formation of

H3−

molecular ions by Three-Body Recombination
Authors: Silva H da , Dulieu O , Raoult M 
Published: June 2020

Synopsis
The simplest triatomic molecular ion

H
3
−

, is predicted to be stable, but has not yet been directly observed experimentally. He we model its formation via Three-Body Recombination of cold and trapped H− ions colliding with H2 molecules in the presence of a buffer gas of He atoms.
Molecular Auger Interferometry
Authors: Khokhlova M , Cooper B , Ueda K , Prince K C , Kolorenč P , Ivanov M , Averbukh V 
Published: June 2020

Synopsis
We propose a theory of interferometric measurement of a normal Auger decay width in molecules. Molecular Auger interferometry is based on the coherent phase control of Auger dynamics in a two-colour (ω/2ω) laser field. We show that, in contrast to atoms, in oriented molecules of certain point groups (e.g. CH3F) the relative ω/2ω phase modulates the total ionisation yield. A simple analytical formula is derived for the extraction of the widths of Auger-active states from a molecular Auger interferogram, avoiding the need of either attosecond or high-resolution spectroscopy.
Near-saddle-point-energy single- and two-photon Stark spectra of Sr
Authors: Spasopoulos D , Kalaitzis P , Cohen S 
Published: June 2020

Synopsis
We present single-photon ionization Stark spectra of Sr as a function of static electric field strength and just above the saddle-point-energy. The spectra exhibit a significant number of avoided crossings between Stark resonances, superimposed on an ionization background due to the continuum excitation. The latter may be avoided by employing single- and two-photon ionization in conjunction with phase sensitive coherent control techniques. This scheme will lead to the isolation of the resonances in differential ionization cross section measurements.
Combined MCDHF-CI and MBPT calculations for n=4 to n=3 x-ray transitions in Ni-like tungsten
Authors: Kozioł K , Rzadkiewicz J 
Published: June 2020

Synopsis
The 4d → 3p, 4p → 3s, and 4f → 3p x-ray transitions in Ni-like tungsten ions have been studied theoretically. The Multiconfiguration Dirac–Hartree–Fock method and the large-scale relativistic Configuration Interaction and Many Body Perturbation Theory methods have been employed in order to take into account electron correlation effects on the lines wavelengths.
Photodetachment Studies of Ir− Ions at DESIREE
Authors: Kristiansson M K , Sundberg J , Hanstorp D , Eklund G , Cederquist H , Zettergren H , Schmidt H T 
Published: June 2020

Synopsis
Anions of iridium were stored in the cryogenic storage ring, DESIREE [1, 2, 3] and investigated using laser photodetachment. The ions were stored for up to 2000 seconds and the relaxation of several metastable states were studied by selecting different photon energies. The threshold of the previously not observed 3P2 level is located and the lifetime of this sate is found to be longer than the storage time of the ion beam. We also find that a state exists higher in energy than the previously known level with a lifetime in the range of hundreds of milliseconds.
Determination of the electron affinity of astatine
Authors: Leimbach D , Rothe S , Sundberg J , Hanstorp D 
Published: June 2020

Synopsis
Astatine is a promising candidate for targeted alpha therapy in nuclear medicine. However, due to its scarce nature, some of its fundamental properties that determine its chemical characteristics such as the electron affinity, the binding erergy of the additional electron in a negative ion, are still unknown. Here we present the method and results of the first measurement of the electron affinity of astatine, performed with the Gothenburg ANion Detector for Affinity measurements by Laser PHotodetachment (GANDALPH) at CERN-ISOLDE.
Photodissociation processes of O2
+(H2O) studied by ion imaging experiments
Authors: Nakashima Y , Nakano M , Okutsu K , Ito Y , Misaizu F 
Published: June 2020

Synopsis
Photodissociation processes in the visible and ultraviolet region of water-oxygen molecular complex ion, O2
+(H2O), were studied by ion imaging experiments and theoretical calculations. Two fragment ions, H2O+ and O2
+, were observed in the experiment; the former fragment ion was produced by direct dissociation after excitation, whereas the latter was generated by nonadiabatic transitions from the initially excited states to the lower electronic states.
Investigating the CO trimer geometry using Coulomb imaging technique
Authors: Fléchard X , Méry A , Gervais B , Guillous S , Kumar V , Matsumoto J , Rangamma J , Ropars F , Shiromaru H , Cassimi A 
Published: June 2020

Synopsis
The Coulombic explosion of multi-charged (CO)3q+ molecular ions produced in low energy collisions with Ar9+ projectiles was investigated using recoil ion momentum spectrometry (RIMS). A preliminary analysis of the data clearly shows a dominant triangular cyclic structure. Events that may correspond to a linear chain are also observed, but the latter could as well originate from false coincidences, associated to the fragmentation of dimers. A careful analysis of this source of background is proposed to disentangle trimer fragmentation events from false coincidences.
Formation of positive and negative ions in the gas phase of D-ribose by low-energy electrons
Authors: Chernyshova I , Kontros J , Shpenik O , Demes S 
Published: June 2020

Synopsis
Using a hypocycloidal electron spectrometer the total dissociative electron attachment cross section and the ionization cross section for D-ribose molecule were studied in the E<30 eV energy range. A clear structure near zero energy and in the 6.0-9.5 eV range is observed in the dissociative electron attachment cross section. These features appear due to the formation of negative ion fragments of the molecule. The ionization potential of the D-ribose molecule was determined at 9.74 ± 0.02 eV. In the total ionization cross section weak features are observed, which most likely due to the formation of positive ion fragments of the initial molecule.
K α1,2α3
and K
hα1,2 satellite transition energies and rates for Ar and Ca
Authors: Kozioł K , Rzadkiewicz J 
Published: June 2020

Synopsis
The calculations of radiative energies and transition rates for Kα 1,2α3
and Khα1,2
satellite (Mi, M2,3, and N1
spectator holes) lines for Ar and Ca have been carried out by using the GRASP2K and AMBIT codes. The influence of electron correlation on transition rates has been studied.
The generalized two-photon excitation cross-section of Xe revisited
Authors: Blondel C , Alkhoury J , Jannaud T , Drag C 
Published: June 2020

Synopsis
Two-photon absorption laser-induced fluorescence (TALIF) is a technique commonly used for density and/or temperature diagnostics, mainly of oxygen atoms, in flames and plasmas. Usually, density measure-ments are based on the comparison with the signal obtained, at a similar wavelength, in pure xenon. The cross-section of xenon thus appears a key parameter, the measure of which has not been consolidated by independent measurements. The present experiment is a direct measurement of this two-photon cross-section.
Relation between the spatial shape of excited molecular orbital and molecular-frame electron scattering cross section
Authors: Watanabe N , Yamada S , Takahashi M 
Published: June 2020

Synopsis
We report the molecular-frame electron scattering cross sections of the 2σg→1πg excitation in O2 and N2, obtained using an electron-ion coincidence technique. The vector correlation between the scattered electron and the fragment ion has been measured at incident electron energy of 1.4 keV. The results exhibit clear molecular-orientation dependence reflecting the nodal structure of the 1πg orbital. It strongly suggests that the electron-ion coincidence technique can provide a powerful tool to investigate spatial shapes of unoccupied molecular orbitals.
Complex scaling in relativistic calculations of cross sections for electron-ion recombination processes
Authors: Bondarev A I , Zaytsev V A , Shabaev V M , Ma X 
Published: June 2020

Synopsis
We present an approach to calculate cross sections for electron-ion recombination processes. It is based on the combination of relativistic many-body perturbation theory and complex scaling method. A preliminary comparison between measured and calculated spectra for the electron-ion recombination rate coefficients for Be-like Ca will be given.
Electron induced excitation of Furfural (C5H4O
2)
Authors: Modak P , Singh A , Antony B 
Published: June 2020

Synopsis
The present study reports excitation cross section for three low-lying excited states of furfural (C5
H4
O2). These states have a significant contribution to the elastic channel as well as dissociation processes. R-matrix method is used to study the e-C5H4O2 problem under configuration interaction (CI) approximation. The ground state geometry is considered for the construction of Hamiltonian of the problem. Results show resonances for these sates.
Photoionization of Ti3+: β parameter and Momentum Transfer
Authors: Eissner W , Vo Ky L 
Published: June 2020

Synopsis
Key issue is the presentation of the unpublished 4 angular factors arising from the 4 paths when momentum transfer induces asymmetry β in photoionization calculations. They require functional expansions such as the frozen cores approach which are not bedevilled by the prior-post dilemma. It is essential to consider all magnetic 2-body terms in the Breit-Pauli hamiltonian that contribute to finestructure.
Atomic diagnostics of ultrahigh laser intensities
Authors: Ciappina M F , Popruzhenko S V , Korn G , Ditmire T , Bulanov S V , Weber S 
Published: June 2020

Synopsis
We suggest and discuss a method for precise measurement of ultrahigh laser intensities in the 1020 – 1024W/cm2 range of intensities. The method is based on the observation of multiple sequential tunneling ionization of heavy atoms in the focus of an intense laser beam. It can be of use for probing electromagnetic fields of record power expected to achieve at new multi-petawatt laser facilities.
Target dependence of post-collision effects in ionization by proton impact
Authors: Silvus A , Dhital M , Bastola S , Buxton J , Klok Z , Ali E , Ciappina M F , Madison D H , Schulz M 
Published: June 2020

Synopsis
Double differential cross sections (DDCS) for ionization in p + Ne, Ar collisions were measured and calculated for a broad range of projectile energy losses as a function of scattering angle. PCI effects in the DDCS were found to be become increasingly prominent with increasing ionization potential I probably due to a greater importance of the nucleus-nucleus interaction when I becomes larger.
First experimental results from a new high-power electron gun: Electron-impact ionisation of multiply charged xenon ions
Authors: Döhring B M , Ebinger B , Borovik A , Huber K , Müller A , Schippers S 
Published: June 2020

Synopsis
During recent years we have developed a new high-current electron gun for the Giessen electron-ion crossed-beams experiment aiming at an extension of the previously available collision-energy range of 1–1000 eV to 3500 eV. Here, we report on the first measurements of absolute cross sections for electron-impact ionisation of multiply charged xenon ions employing the new electron gun. Comparisons with available experimental and theoretical data from the literature provide convincing evidence that the new electron gun can be operated reliably over the entire design energy-range.
Role of the variable charge in (e,3e) processes on argon
Authors: Herbadji A , Mansouri A , Dal Cappello C , Kada I , Houamer S 
Published: June 2020

Synopsis
The differential fivefold cross section for the double ionization of argon by electron impact is calculated taking into account the variations of the effective charges describing each ejected electron during the reaction; the energy of the electron projectile is fixed in the intermediate range, and the ejected electrons have low energies. The initial state is described by the Clementi wavefunction, and the ejected electrons in the final state by Coulomb waves. A comparison is made with the measurements of Jia et al [1].
Electron-impact ionisation of Wq+ ions with 1 ⩽ q ⩽ 19
Authors: Schury D , Becker A , Borovik A , Ebinger B , Gharaibeh M F , Hellhund J , Huber K , Rausch J , Spruck K , Jin F , Schippers S , Müller A 
Published: June 2020

Synopsis
Electron-impact ionisation cross sections of tungsten ions in the energy range from the ionisation threshold to 1000 eV were measured. The experimental cross sections are compared with results from sub-configuration averaged distorted wave calculations. Derived plasma rate coefficients are provided for convenient use in plasma modelling.
Tracing inter-Coulombic decay of molecular dimers
Authors: Iskandar W , Gatton A S , Gaire B , Sturm F P , Larsen K A , Champenois E G , Shivaram N , Moradmand A , Williams J B , Berry B , Severt T , Ben-Itzhak I , Metz D , Sann H , Weller M , Jahnke T , Dörner R , Slaughter D , Weber Th 
Published: June 2020

Synopsis
We have conducted an experimental study on the photo double ionization (PDI) of carbon dioxide dimers and oxygen dimers, while focusing on the dissociation dynamics upon single photon absorption. The results in terms of the kinetic energy and angular distributions of the charged particles show unambiguous experimental evidence of intermolecular Coulombic decay (ICD) in carbon dioxide dimers. In the oxygen dimer, the results show that ICD is accompanied by knock-off ionization mechanisms.
Effect of SOIAIC on photoionization time delay of the Xe 3d subshell
Authors: Banerjee S , Deshmukh P C , Manson S T 
Published: June 2020

Synopsis
The effect of spin-orbit activated interchannel coupling (SOIAIC) has been studied on the time delay spectrum of 3d photoionization in xenon. The relativistic-random-phase-approximation with relaxation (RRPA-R) has been used to calculate the Wigner-Eisenbud-Smith (WES) time delay in photoionization. SOIAIC has a strong influence on the WES time delay for all ejection angles of the photoelectrons with respect to the incident direction and the polarization vector of the photon absorbed.
Outer-shell photodetachment of Li− near inner-shell thresholds
Authors: Gorczyca T W , Manson S T 
Published: June 2020

Synopsis
The effect of inner-shell excited channels on outer-shell photodetachment is investigated using a correlated and coupled-channel R-matrix method. The simplest multishell negative ion of Li− is treated near the 1s ionization threshold to determine strong”hole-state” continuum coupling with the direct photodetachment channels.
Using ‘dressed’ convoluted quasi-Sturmian functions as a basis for Coulomb three-body continuum problems
Authors: Zaytsev A S , Zaytseva D S , Ancarani L U , Zaytsev S A 
Published: June 2020

Synopsis
We present an ab initio approach to the two electron continuum problem based on an expansion on convoluted quasi Sturmian functions (CQS) equipped with an appropriately built electron-electron phase factor. Such’dressed’ CQS functions constitute a suitable basis to solve Coulomb three-body scattering problems as illustrated through numerical applications to double ionization processes on Helium. They put in evidence, once more, the importance of electron-electron correlation over the whole space.
Energy dependent relative cross sections in carbon 1s photoionization
Authors: Travnikova O , Patanen M , Söderström J , Lindblad A , Kas J J , Vila F D , Céolin D , Nicolas C , Marchenko T , Goldsztejn G , Journel L , Guillemin R , Carroll T X , Børve K J , Decleva P , Rehr J J , Mårtensson N , Simon M , Svensson S , Sæthret L J 
Published: June 2020

Synopsis
We demonstrate that the possibility of monitoring relative photoionization cross sections over a large photon energy range extending to hard x-rays allows studying and disentangling shake processes and intramolecular inelastic scattering effects. An “EXAFS”-type of oscillatory behaviour of the relative C 1s cross sections is observed in a wide photon energy range up to 1 keV due to multiple intramolecular elastic scattering of the photoelectron. These effects are also present in solids and constitute a significant part of all elastic and inelastic scattering effects occurring in solids.
Photodissociation dynamics of the diamondoid adamantane induced by attosecond XUV pulses
Authors: Maclot S , Peschel J , Lahl J , Wikmark H , Rudwaski P , Coudert-Alteirac H , Rousseau P , Indrajith S , Huber B A , Díaz-Tendero S , Johnsson P 
Published: June 2020

Synopsis
Adamantane is the simplest of the diamondoid molecules, which due to their high stability are of high interest both in astrophysics and nanotechnology. This work investigates the molecular photodissociation after ionization by attosecond XUV pulses. The fragmentation dynamics is inferred by means of velocity map imaging spectrometry, covariance analysis techniques and quantum chemistry calculations.
Determination of energy-transfer distributions in ionizing ion-molecule collisions
Authors: Indrajith S , Erdmann E , Chiarinelli J , Domaracka A , Łabuda M , Avaldi L , Alcami M , Aguirre N F , Díaz-Tendero S , Bolognesi P , Rousseau P , Huber B A 
Published: June 2020

Synopsis
The main objective of this study is to determine the energy transfer occuring in ion-molecule collisions. In order to solve this problem, we followed two approaches; the first one by validating a purely experimental method and the second one by testing a new theoretical model M3C (Microcanonical Metropolis Monte Carlo).
Absolute cross section for electron emission from uracil upon ion collision using velocity map imaging technique
Authors: Sens N , Ryszka M , Méry A , Poully J-C , Chesnel J-Y , Vizcaino V 
Published: June 2020

Synopsis
Ion-induced electron emission from RNA base uracil has been measured using a newly developed experimental set-up based on velocity map imaging (VMI) technique. Electrons emitted in a solid angle of 4π steradians are extracted and analyzed in energy and angle by the multi-electrodes VMI spectrometer. By monitoring the target density, the projectile ion beam intensity and the beams overlap with the use of a quartz crystal micro balance and an ion beam profiler, we were able to estimate absolute singly- and doubly-differential cross sections for electron emission.
A new experimental setup to measure absolute cross section for electron emis-sion from atoms, molecules or nanoparticles upon ion collisions
Authors: Sens N , Ryszka M , Mery A , Poully J-C , Chesnel J-Y , Vizcaino V 
Published: June 2020

Synopsis
A newly developed crossed beam experimental setup that utilizes a velocity map imaging technique to simultaneously measure both emission energy and angle of electrons ejected from atoms, molecules or nano-particles upon ion collision will be presented. The incident ion beam is produced at the GANIL facility with incident energies from a few keV to a few MeV and the target beam density is monitored by a quartz crystal microbalance allowing for estimating absolute single or double differential cross sections.
Two-body dissociation of C3H4 isomers investigated by 50 keV/u Ne8+ impact
Authors: Li Y , Xu S , Guo D L , Jia S , Jiang X , Zhu X L , Ma X 
Published: June 2020

Synopsis
Fragmentation dynamics of two isomers of C3H4, propyne (CH3CCH) and allene (CH2CCH2), is in-vestigated by 50 keV/u Ne8+ impact. Isomerization processes are identified in two-body fragmentation channels of C3H4
2+ for both isomers. Besides, we observe two new dissociation channels of C3H4
3+ trications, H+ + C3H3
2+ and H2
+ + C3H2
2+. For CH2CCH2
3+, the peak and shoulder structures in the kinetic energy release spectrum of H+ + C3H3
2+ channel are attributed to different geometries of the C3H3
2+ products by comparing with theoretical cal-culation.
Coupled-channel calculations of ionisation of atomic hydrogen by multiply-charged bare ions
Authors: Abdurakhmanov I B , Massen-Hane K , Faulkner J , Alladustov Sh U , Kadyrov A S , Bray I 
Published: June 2020

Synopsis
The wave-packet convergent close-coupling method has been applied to calculate the total and fully differential cross sections for electron capture, excitation and ionisation processes in collisions between multiply-charged bare ions and atomic hydrogen.
Fragmentation of hydrocarbons by collision. AGAT@ANDROMEDE.
Authors: IdBarkach T , Chabot M , Béroff K , Della-Negra S , Lesrel J , Diaz-Tendero S 
Published: June 2020

Synopsis
We are studying small hydrocarbons produced in high velocity (3.4 a.u.) collision between

CH

y
+

cations and He atoms. During the collision those hydrocarbons gain some energy and release this energy doing fragmentation. Thanks to the detector AGAT we have been able to measure fragmentation branching ratios for

CH

y

q
+

(y=2-4, q=0-3). We also constructed semi-empirical breakdown curves for

CH

y

q
+

using these experimental branching ratios.