"Thermal Spike" model applied to thin targets irradiated with swift heavy ion beams at few MeV/u

International audienceHigh electronic excitations in radiation of metallic targets with swift heavy ion beams at the coulomb barrier play a dominant role in the damaging processes of some metals. The inelastic thermal spike model was developed to describe tracks in materials and is applied in this paper to some systems beams/targets employed recently in some nuclear physics experiments. Taking into account the experimental conditions and the approved electron-phonon coupling factors, the results of the calculation enable to interpret the observation of the fast deformation of some targets

Modification of Fe-B based metallic glasses using swift heavy ions

We report on small-angle x-ray scattering (SAXS) measurements of amorphous Fe80B20, Fe85B15, Fe 81B135Si35C2, and Fe 40Ni40B20 metallic alloys irradiated with 11.1 MeV/u 132Xe, 152Sm, 197Au, and 8.2 MeV/u 238U ions. SAXS experiments are nondestructive an

Etude des défauts surfaciques et volumiques induits par les ions lourds dans les isolants

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Temperature and pressure spikes in ion-beam cancer therapy

International audienceThe inelastic thermal spike model is applied to liquid water in relation to high-energy 12C6+ beams (hundreds of MeV/u) used for cancer therapy. The goal of this project is to calculate the heat transfer in the vicinity of the incident-ion track. Thermal spike calculations indicate a very large temperature increase in the vicinity of ion tracks near the Bragg peak during the time interval from 10−15 to 10−9 s after the ion's passage and an increase in pressure, as large as tens of MPa, can be induced during that time. These effects suggest a possibility of thermomechanical pathways to disruption of irradiated DNA. An extension of the model for hydrogen, beryllium, argon, krypton, xenon, and uranium ions around the Bragg peak is presented as well

SiO2 sur silicium (comportement sous irradiation avec des ions lourds)

CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Investigation of initial stage of chemical etching of ion tracks in polycarbonate

International audienceChemical track etching and the growth of nanochannels in ion-irradiated polycarbonate foils were investigated by loss of weight measurements and IR-spectroscopy. The data provided by both methods are in good agreement and allow us to shed light on the early stage of pore formation including times where the breakthrough of the pores has not yet occurred. Clear evidence is shown that the pore growth as a function of etching time depends on the irradiation fluence. For fixed etching parameters, foils containing 7 X 109 tracks/cm2 exhibit much smaller pores than samples with 2 X 108 tracks/cm2. This effect is independent of the etching temperature and appears for irradiations with Pb ions as well as for Ca–ion tracks sensitized by UV exposure. Model calculations for different etching times and fluences show that the data for low track densities can be fitted quite well by describing the radial etching rate by the track etch rate changing into the bulk etch rate with a Gaussian-shaped transition

Dislocation mobility study of heavy ion induced track damage in LiF crystals

International audienceThe track damage created in LiF crystals by swift U, Xe and Kr ions with a specific energy of 11.1 MeV/u was studied using dislocation mobility measurements, track etching, SEM, AFM and optical microscopy. The results demonstrate high sensitivity of dislocation mobility to track core damage. The relationship between the energy loss of ions, dislocation mobility and track structure is discussed