1. 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.

2. 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)

3. The physical basis of Neutron Activation Techniques
The irradiative neutron capture
PGAA
10-17 – 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

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

5. 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

6. 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

7. NAA and PGAA sensitive elements

8. 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: cps

9. 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

10. 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.

11. 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

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