Search Results

You are looking at 1 - 8 of 8 items for

  • Author or Editor: P. Trocellier x
  • Refine by Access: All Content x
Clear All Modify Search

Abstract  

In the first part of this work, we show the basic principle of the Rutherford backscattering method and follow the possibilities and performance allowed. We also discuss how to choose the best experimental configuration to provide most significant spectrum in the case of glass surface analysis.

Restricted access

Abstract  

In this second part, examples of glass pieces submitted to a leaching process are analyzed. A discussion is undertaken to show how to prevent secondary effects. It is pointed out how the near-surface region of the glass sample interacts with the surrounding aqueous solution, by testing three different glass compositions and various leaching solutions, and different leaching time and temperature. An increasing rate of the heaviest components of the glassy matrix, which is observed in almost all cases, is connected with the glass composition as well as with the solution composition. The strong leaching solution's pH value depends on ion-exchange and redox equilibria as main phenomena.

Restricted access

Determination de la fonction d'excitation de la reaction nucleaire1H(15N, α γ)12C entre 6 et 14 MeV

Application a la mesure du profil de concentration de l'hydrogene dans la region superficielle des solides

Journal of Radioanalytical and Nuclear Chemistry
Authors:
P. Trocellier
and
Ch. Engelmann

Abstract  

Thick targets (mica) and thin hydrogen layers obtained by ionic implantation of protons in silica are used to establish the excitation function of the nuclear resonant reaction1H (15N, α γ)12C. Two main resonances in the energy gap explored were observed. Their FWHM and the cross section at ER are specified. The experimental conditions required and the performances allowed, using this reaction to determine hydrogen depth profiles in the near surface region of solids, are presented. Examples concerning borosilicates, leached in aqueous medium, are given.

Restricted access

Abstract  

Thin targerts obtained by sodium implantation in a layer of silica were used to establish the true excitation functions of the nuclear reactions in question. Many resonances are observed in the energy range explored and their half-widths and the cross-section values at the maxima have been evaluated. The potential performances allowed by these resonant nuclear reactions are examined from the viewpoint of their application to measurements of sodium concentration profiles in the surface region of solids.

Restricted access

Abstract  

The main resonant nuclear reactions which permit hydrogen determination in the near-surface region of solids, and particularly to determine its concentration depth profile by a non-destructive procedure, are presented and compared. More specifications are given about the three reactions we have studied:1H(15N, )12C;1H(7Li,)8Be;1H(13O,)15N; which seem to be the most interesting for the above purpose.

Restricted access

Elastic recoil detection analysis

Theoretical analysis of scattering cross section and basic parameters

Journal of Radioanalytical and Nuclear Chemistry
Authors:
J. Tirira
and
P. Trocellier

Abstract  

This work briefly describes the basic principle of Elastic Recoil Detection Analysis. From a theoretical analysis of the physical process, we discuss the choice of the best experimental configuration for solid surface examination and particularly the advantages of the transmission geometry. Then, we propose a new calculation procedure for the collision cross section1H(4He,4He)1 H between 0.5 and 8 MeV helium ions energy, and finally we analyze in more detail the cross section results in the low energy range (1 to 2.5 MeV).

Restricted access

Abstract  

We have developed an absolute, quantitative procedure to determine the hydrogen content and to describe its concentration profile in the near-surface region of solids. The experimental technique used is the Elastic Recoil Detection Analysis of protons induced by helium-4 beam bombardment in the energy range 1.8 MeV. The deconvolution of the recoil spectra is obtained by means of a computer program which simulates all the physical processes of4He/1H interaction. The hydrogen content is calculated using a new recoil cross section expression. The analyses are performed in silicon crystals implanted with hydrogen at 10 keV. The implantation dose is evaluated with an accuracy of 10% and the hydrogen depth profile is given with an accuracy of ±10 nm around 200 nm.

Restricted access

Abstract  

A polycrystalline silicon specimen, cut off from an ingot directionally solidified from upgraded metallurgical grade silicon /UMG-Si/ has been examined using a 1.45 MeV deuteron microbeam. The superficial distributions of carbon and oxygen were determined by direct observation of nuclear reactions. Several carbon concentration ranges were identified. Oxygen is always strongly correlated with carbon, but the nature of this correlation has to be specified. The presence of iron was shown inside areas with strong carbon precipitation.

Restricted access