Instrumental Neutron Activation Analysis (INAA) by R5B6GI

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									           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
                               21000                                  Eu 121,8keV                                                  1400
                                                                                                                                                                        152
                                                                                                                                                                              Eu 1408keV
                               19500                                                                                               1300
 counts in peak (time 7 min)




                               18000                                                                                               1200




                                                                                                     counts in peak (time 7 min)
                               16500                                                                                               1100
                               15000                                                                                               1000
                               13500                                                                                               900
                               12000                                                                                               800
                               10500                                                                                               700

                               9000                                                                                                600
                                                                                                                                   500
                               7500
                                                                                                                                   400
                               6000
                                                                                                                                   300
                               4500
                                                                                                                                   200
                               3000                                                                                                100
                                       4   5   6   7   8    9    10    11   12   13   14   15   16                                   0
                                                                                                                                          4   5   6   7   8    9   10   11     12   13   14   15   16
                                                           distance (cm)
                                                                                                                                                              distance (cm)
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

								
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