Event 

Title:
Seminars at the Accelerator - Comparative study of high energy ion beam-irradiation effects ...
When:
16.10.2014 - 16.10.2014
Where:
CMAM - Madrid
Category:
Informal seminars at the Accelerator

Description

Speaker: Ovidio Peña Rodriguez

Title: Comparative study of high energy ion beam-irradiation effects on α-quartz and silica based on in-situ optical measurements and MD simulations

Abstract: In this talk we review our recent work, experimental and theoretical, with the aim of understanding the high energy ion irradiations effects on both SiO2 phases: silica and α-quartz. In particular, we will focus on in-situ optical measurements of the optical reflectance (to obtain the refractive index), transmittance (information about the point defects), and ionoluminescence spectra (recombination centers).

Extremely detailed (in terms of fluence step), those kinetics curves have been obtained for a wide range of ions and energies in order to change the values of the electronic stopping power (Se) from about 2 keV/nm (near the threshold) to 10 keV/nm, well above the threshold. For α-quartz this extensive dataset has been compared the damage obtained by standard RBS/C at some particular fluences, in equivalent samples.

Finally, we compare those results with MD and FDTD simulations to correlate the changes in the optical properties with the microscopic changes in the structures. We find that MD provides a reasonable quantitative agreement with experiments in terms of track radii and defect concentration.

Moreover, FDTD simulations are able to provide a similar correlation with the evolution of the optical response in the irradiated samples. Combined use of experimental and theoretical tools provides very good understanding of the irradiation effects on both materials. Moreover, the employed techniques are general enough to be used in a large number of materials.

Venue

CMAM
Venue:
CMAM   -   Website
Street:
Faraday 3, Campus de Cantoblanco
ZIP:
28049
City:
Madrid
Country:
Country: es

Description

The seminar takes place at the meeting room of the CMAM