Transcript Instrumental Neutron Activation Analysis (INAA)

Frank Laboratory of Neutron Physics
Summer school in Dubna 5.7.-25.7.2010
Prepared by:
B. Andel (SVK), E. Govor (BLR), K. V. Mareš (CZE), M. Mazánová (SVK), A.
Moravcsík (SVK), V. Voronova (BLR)
Supervisor :
prof. M. V. Frontasyeva, FLNP
The founders of FLNP
Introduction
 Neutron Activation Analysis (NAA) is a sensitive
multi-element analytical technique used for both
qualitative and quantitative analysis of major, minor,
trace and rare elements
 NAA was discovered in 1936 by G. Hevesy
(Hungary) and H. Levi (Denmark)
Forms of NAA
 Destructive ( radiochemical ) - the resulting radioactive
sample is chemically decomposed, and the elements are
chemically separated
 Nondestructive ( instrumental ) - the resulting
radioactive sample is kept intact
Principle
Detection
 Irradiated samples are analyzed by gamma-spectrometry
Neutron sources
 Isotopic neutron sources (252Cf, 242Am)
 Neutron generators
 Nuclear reactors
 At FLNP the pulsed fast
reactor IBR-2 is used
Neutrons
 Thermal 0.025 eV-0.5 eV
 Epithermal 0.5 eV-100 keV
 Fast 100 keV-25 MeV
Characteristics of INAA
 Non-destructive analysis
 The chemical form and physical state of the elements do
not influence the activation and decay process
 Multi-element analytical technique
 C, H, N, O and Si do not activate well
 Suitable even for determination of masses in the order of
10–6–10–9 g and less
Applications of INAA at FLNP
 Environmental studies (migration of pollutants in
ecosystems, air pollution studies using moss-biomonitors)
 Biotechnology for medicine (development of new
pharmaceuticals and sorbents)
 Material Science (high purity materials, nanoparticles
and objects of national heritage)
Dependence of counts on distance
between detector and gamma-source
24000
1600
22500
152
1500
Eu 121,8keV
152
Eu 1408keV
1400
19500
1300
18000
1200
counts in peak (time 7 min)
counts in peak (time 7 min)
21000
16500
15000
13500
12000
10500
9000
7500
6000
4500
1100
1000
900
800
700
600
500
400
300
200
3000
100
4
5
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8
9
10
11
distance (cm)
12
13
14
15
16
0
4
5
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9
10
11
distance (cm)
12
13
14
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16
References
 P. Bode: Instrumental and organizational aspects of a
neutron activation analysis laboratoty
 http://www.sciner.com/Neutron/naa.html
 http://reactor.engr.wisc.edu/naa/
 http://tin.er.usgs.gov/geochem/doc/inaa.htm
 http://reactor.engr.wisc.edu/naa/UWNRNAA.htm
 http://www.reak.bme.hu/Wigner_Course/WignerManuals/
Budapest/NEUTRON_ACTIVATION_ANALYSIS.htm
 http://archaeometry.missouri.edu/naa_overview.html
Foto by Kamil Vavrinec Mares
Thank you for your attention