MTA Centre for Energy Research Budapest MTA EK

MTA Centre for Energy Research, Budapest (MTA EK) 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.

MTA Centre for Energy Research, Budapest (MTA EK) 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)

MTA Centre for Energy Research, Budapest (MTA EK) The physical basis of Neutron Activation Techniques The irradiative neutron capture 10 -17 – 10 -14 s T 1/2=1 s – 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

MTA Centre for Energy Research, Budapest (MTA EK) Neutron activation analysis (NAA) Irradiating the samples in BRR off-line counting of activated samples in a low-level counting chamber (e. g. DÖME)

MTA Centre for Energy Research, Budapest (MTA EK) Prompt gamma activation analysis (PGAA) Sample: Sample preparation: Irradiation: cca. 1 g or less no or PTFE bag cold neutrons, few times 10’ or hours Detection: on-line, during the measurement Spectrum: 100 – 5000 peaks, 50 ke. V – 12 Me. V Results: some hours Detection limits: >ppm, % Radioactivity remained: cca. 1 – 2 days ‘Multielemental’ BULK composition No matrix effect Non-destructive (negligible residual radioactivity, no mechanical damage) k 0 -method, no standard needed Sample preparation Automated Sample Changer

MTA Centre for Energy Research, Budapest (MTA EK) 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

MTA Centre for Energy Research, Budapest (MTA EK) NAA and PGAA sensitive elements

Low-level counting chamber (DÖME) MTA Centre for Energy Research, Budapest (MTA EK) 8/18 For off-line counting of activated samples Environmental samples 7 t of pre-WW 2 iron no man-made radioactivity 15 cm wall thickness graded shielding inside (Cd and Cu layers) Background suppression: [8 – 3200 ke. V] ~ 200 Room background: 1. 116 cps

MTA Centre for Energy Research, Budapest (MTA EK) Neutron Optics and Radiography for Material Analysis (NORMA) PGAI (prompt-gamma activation imaging) collimating the neutron beam and the gamma detection 3 D 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

MTA Centre for Energy Research, Budapest (MTA EK) Carbonaceous Chondrites measuered with NORMA Radiography . Si 2 D distribution of the main elements Fe, Si and Mg obtained with PGAI. Fe 2 D distribution Mg 2 D distribution Reconstructed image of the Allende meteorite fragment obtained with neutron tomography at the PGAA station.

MTA Centre for Energy Research, Budapest (MTA EK) Facility access programs We are a member of the Budapest Neutron Centre (BNC) PGAA and NIPS are partly operated as user facilities NMI 3 - Integrated Infrastructure Initiative for Neutron Scattering and Muon Spectroscopy It supports research proposals that can be solved using the facilities of BNC CHARISMA EU FP 7 – Cultural heritage It supports research proposals in the field of archaeometry on the Fix. Lab facilities ERINDA EURATOM FP 7 – Nuclear data It supports nuclear data measurements on actinides and related topics on the PGAANIPS facility

MTA Centre for Energy Research, Budapest (MTA EK) Thank you! A bright view from NORMAFA, Budapest