Measuring light elements (e. g Measuring light elements (e.g. H, B, Cl) and REE with neutron activation techniques Katalin Gméling Hungarian Academy of Sciences, Centre for Energy Research, Nuclear Analysis and Radiograhpy Department Budapest, Hungary 03. September 2012.

All using neutrons served by the Budapest Research Reactor (BRR) Neutron Activation Techniques in our maintenance Prompt gamma activation analysis (PGAA) Neutron activation analysis (NAA) Low-level counting facility (DÖME) Neutron induced prompt gamma-ray spectrometry (NIPS) can be used with an imaging and position-sensitive element analyser (NORMA) All using neutrons served by the Budapest Research Reactor (BRR)

The physical basis of Neutron Activation Techniques The irradiative neutron capture PGAA 10-17 – 10-14 s NAA T1/2=1s – years The gamma energy is characteristic for the element or isotope The gamma-ray intensity is characteristic for the quantity of the element or isotope

Neutron activation analysis (NAA) Irradiating the samples in BRR off-line counting of activated samples in a low-level counting chamber (e.g. DÖME)

Automated Sample Changer Prompt gamma activation analysis (PGAA) Sample: cca. 1 g or less Sample preparation: no or PTFE bag Irradiation: cold neutrons, few times 10’ or hours Detection: on-line, during the measurement Spectrum: 100 – 5000 peaks, 50keV – 12MeV Results: some hours Detection limits: >ppm, % Radioactivity remained: cca. 1 – 2 days Sample preparation Automated Sample Changer ‘Multielemental’ BULK composition No matrix effect Non-destructive (negligible residual radioactivity, no mechanical damage) k0-method, no standard needed

Carbonaceous Chondrites measuered with PGAA Comparison between the PGAA values obtain at FRM II and Budapest and literature values on the Allende meteorite obtained by Jarosewich (1990) and Kallemeyn and Wasson (1981). Advantages of PGAA, compared to NAA: the shorter irradiation times, easy preparation of the samples, a complete analysis within one day, possible to determine light elements for example H, B

NAA and PGAA sensitive elements

Low-level counting chamber (DÖME) 8/18 For off-line counting of activated samples Environmental samples 7 t of pre-WW2 iron no man-made radioactivity 15 cm wall thickness graded shielding inside (Cd and Cu layers) Background suppression: [8 – 3200 keV] ~ 200 Room background: 1.116 cps

Neutron Optics and Radiography for Material Analysis (NORMA) PGAI (prompt-gamma activation imaging) collimating the neutron beam and the gamma detection 3D PGAA, pointwise scanning, 2-3 mm resolution already reached very time consuming (requires high neutron flux to shorten it) Radiography/Tomography- driven PGAI visualize and locate the interesting regions first prompt-g measurement only where it is needed can save substantial beam time

Carbonaceous Chondrites measuered with NORMA Mg 2D distribution Radiography Si 2D distribution Fe 2D distribution 2D distribution of the main elements Fe, Si and Mg obtained with PGAI. . Reconstructed image of the Allende meteorite fragment obtained with neutron tomography at the PGAA station.

Facility access programs We are a member of the Budapest Neutron Centre (BNC) PGAA and NIPS are partly operated as user facilities NMI3 - Integrated Infrastructure Initiative for Neutron Scattering and Muon Spectroscopy It supports research proposals that can be solved using the facilities of BNC CHARISMA EU FP7 – Cultural heritage It supports research proposals in the field of archaeometry on the FixLab facilities ERINDA EURATOM FP7 – Nuclear data It supports nuclear data measurements on actinides and related topics on the PGAA- NIPS facility

A bright view from NORMAFA, Budapest Thank you! A bright view from NORMAFA, Budapest