Hydrogen analysis by p-p scattering in geological material

Research output: Contribution to journalArticle

Abstract

It has been concluded by geologists that a significant amount of hydrogen is stored as point defects in nominally anhydrous minerals. Determination of the amount of hydrogen bound in these minerals is a step towards determining the total water content of the earth mantle as well as comprehending its internal water cycle. The possibility to measure hydrogen in thin geological samples by elastic p-p scattering has been investigated at the Lund Nuclear Microprobe. In this work the development of the experimental procedure and standardisation of data analysis is described. Special emphasis has been put into doing the data analysis as simple as possible and at the same time applicable to all sorts of thin samples, even those of unknown nature. A special annular surface barrier detector composed of two insulated detector halves, which are read out simultaneously, is used to detect the recoiled proton and the scattered proton in coincidence. Conditions on the difference in time and energy of the detected particles, enables us to distinguish true hydrogen events from false or random ones. Homogeneous Mylar foils with known hydrogen content are used as reference material and enables determination of the total amount of hydrogen in the bulk of the geological samples as well as depth profiling, in order to separate contaminations in the surface front the bulk concentrations. The method has been tested with a 2.8 MeV proton beam on thin samples of both Muscovite, which is known to have a natural hydrogen concentration of about 0.5 wt%, and Pyroxene, which is a nominally anhydrous mineral.

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Authors
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Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Subatomic Physics

Keywords

  • hydrogen, coincidence, p-p scattering, depth profiling, geology
Original languageEnglish
Pages (from-to)550-554
JournalNuclear Instruments & Methods in Physics Research. Section B: Beam Interactions with Materials and Atoms
Volume219-20
Publication statusPublished - 2004
Publication categoryResearch
Peer-reviewedYes

Bibliographic note

The information about affiliations in this record was updated in December 2015. The record was previously connected to the following departments: Nuclear Physics (Faculty of Technology) (011013007)