Ion beam processing of DNA origami nanostructures.

DNA origami nanostructures are emerging as a bottom-up nanopatterning approach. Direct combination of this approach with top-down nanotechnology, such as ion beams, has not been considered because of the soft nature of the DNA material. Here we demonstrate that the shape of 2D DNA origami nanostructures deposited on Si substrates is well preserved upon irradiation by ion beams, modeling ion implantation, lithography, and sputtering conditions.

Infrared Spectroscopic Study on Swift-Ion Irradiation of Solid NO-HO Samples: Synthesis of N-O Bearing Species in Astrophysical Ices.

As of early 2022, only six species bearing an N-O bond have been detected toward cold molecular clouds and regions of star formation. It is not clear yet if the small number of N-O bond species found in the interstellar medium so far stems from physical and technological limitations of astronomical detection techniques, or whether in fact molecules that bear an N-O bond are for some reason rare in these objects of the interstellar medium. Astronomical N-O bearing molecules are important because they are part of astrochemical models which propose that they are precursors of hydroxylamine (NHOH), a species linked to the formation of prebiotic amino acids in space.

Valine Radiolysis by H, He, N, and S MeV Ions.

Radiolysis of biomolecules by fast ions has interest in medical applications and astrobiology. The radiolysis of solid D-valine (0.2-2 μm thick) was performed at room temperature by 1.

Infrared complex refractive index of N-containing astrophysical ices free of water processed by cosmic-ray simulated in laboratory.

Several nitrogen-containing molecules have been unambiguously identified in the Solar System and in the Interstellar Medium. It is believed that such a rich inventory of species is a result of the energetic processing of astrophysical ices during the interaction with ionizing radiation. An intrinsic parameter of matter, the complex refractive index, stores all the "chemical memory" triggered by energetic processing, and therefore might be used to probe ice observations in the infrared.

Production of Hydronium Ion (HO) and Protonated Water Clusters (HO)H after Energetic Ion Bombardment of Water Ice in Astrophysical Environments.

Water ice exists on many objects in space. The most abundant icy species, among them water, are present in the icy satellites of the outer Solar System giant planets. The nuclei of comets, which are mainly composed of water ice, give another example of its abundance.

IGLIAS: A new experimental set-up for low temperature irradiation studies at large irradiation facilities.

We designed and built a mobile experimental set-up for studying the interaction of ion beams with solid samples in a wide temperature range from 9 to 300 K. It is either possible to mount up to three samples prepared ex situ or to prepare samples by condensation of molecules from gases or vapours onto IR or Visible-ultraviolet (Vis-UV) transparent windows. The physico-chemical evolution during irradiation can be followed in situ with different analysis techniques including Fourier transform infrared spectroscopy, Vis-UV, and quadrupole mass spectrometry.

Radiolysis of N-rich astrophysical ice by swift oxygen ions: implication for space weathering of outer solar system bodies.

In order to investigate the role of medium mass cosmic rays and energetic solar particles in the processing of N-rich ice on frozen moons and cold objects in the outer solar system, the bombardment of an N : HO : NH : CO (98.2 : 1.5 : 0.

Ion irradiation of pure and amorphous CH ice relevant for astrophysical environments.

This work presents a physicochemical study of frozen amorphous methane (at 16 K) under bombardment by medium-mass ions (15.7 MeV O) with implications for icy bodies in the outer Solar System exposed to the action of cosmic rays and energetic particles. The experiment was performed at the Grand Accélérateur National d'Ions Lourds (GANIL) located in Caen, France.

Radioresistance of Adenine to Cosmic Rays.

The presence of nucleobases in carbonaceous meteorites on Earth is an indication of the existence of this class of molecules in outer space. However, space is permeated by ionizing radiation, which can have damaging effects on these molecules. Adenine is a purine nucleobase that amalgamates important biomolecules such as DNA, RNA, and ATP.

Thermal and energetic processing of ammonia and carbon dioxide bearing solid mixtures.

We present new experimental results on thermal and ion irradiation processing of frozen ammonia-carbon dioxide mixtures. Some mixtures were deposited at low temperatures (T ≈ 16 K). Upon warming up to 160 K, complex chemical reactions occur leading to the formation of new molecules and, in particular, of ammonium carbamate.

Radiolysis of astrophysical ice analogs by energetic ions: the effect of projectile mass and ice temperature.

An experimental study of the interaction of highly charged, energetic ions (52 MeV (58)Ni(13+) and 15.7 MeV (16)O(5+)) with mixed H(2)O : C(18)O(2) astrophysical ice analogs at two different temperatures is presented. This analysis aims to simulate the chemical and the physicochemical interactions induced by cosmic rays inside dense, cold astrophysical environments, such as molecular clouds or protostellar clouds as well at the surface of outer solar system bodies.

Three-electron auger process from beam-foil excited multiply charged ions.

Electron emission from collisions of C3+ ions (22.7 A MeV) with carbon foils (21, 49 and 90 microg/cm(2)) was studied by the time-of-flight method. Two prominent emission patterns can be readily identified as "binary encounter" electrons and "cusp" electrons.

Radiative electron capture to the continuum and the short-wavelength limit of electron-nucleus bremsstrahlung in 90A MeV U88 + ((1s2)(2s2))+N2 Collisions.

We have measured the continuum momentum distribution for radiative electron capture to the continuum (RECC) cusp electrons in 90A MeV U88+ + N2-->U88+ + N2 +* + ecusp(0 degrees ) + hnu (RECC) collisions. We demonstrate that x rays coincident with RECC cusp electrons originate from the short-wavelength limit of the electron-nucleus bremsstrahlung and explain the asymmetric cusp shape by comparison with theory within the relativistic impulse approximation.

Track formation and electron emission in swift ion collisions with condensed matter.

Electron ejection from target atoms is one of the basic processes when ionizing radiation interacts with matter. The primary electrons and their subsequent secondary interactions lead to the deposition of energy around the ion trajectory. The detailed knowledge of the structure of these ion tracks is a key issue for our understanding of radiation effects in condensed matter, an important example being calculations of the RBE of heavy particles, where doubly differential electron ejection cross sections are a key input parameter.