1. Neutron activation analysis in Mongolia
DAMDINSUREN Gantumur
Nuclear Research Center
National University of Mongolia

2. History 1964, neutron generator was installed at NUM
1979, neutron activation analysis facility with 252Cf source was installed. It is being used for education till now.
1982, 2 researchers were sent to Hungary, at laboratory, neutron activation analysis with neutron generator
1992, Microtron MT-22 electron cycle accelerator was installed an NRC

3. Neutron isotopic sources
Code
Source name
Half life, year
First year
First activity, Bq
Neutron current, n/sec 1
238Pu-Be
87.74
2.4x1011
1.04x107 2
1.2x1012
4.76x107 3
239Pu-Be
24119 -
5.36x106 4
252Cf
2.645
5.67x108
2.13x109 5
1.50x108
0.56x109

4. Pu-Be
Cf-252

5. Pu-Be
Cf-252

6. NA-4 neutron generator
Т(d,n)He
En=14MeV
But under repair

7. NA-4
Neutron generator

8. Microtron MT-22 electron cycle accelerator
Converter U, Bi, Pb

9. Microtron MT-22

10. Thermal neutron current
238U(γ,n)237U Ee=22MeV Eγ=0÷22MeV
Graphite of neutron decelerator     
Thermal neutron current
Ф=108÷109 neutron/(cm2×sec)

11. (homogenization, weighing)
Steps of analysis
sample preparation
(homogenization, weighing)
irradiation
cooling (different times)
measurement by gamma spectrometry
evaluation

12. Measurement
Gamma spectrometer (HpGe) with channels.

13. Detection
Irradiated samples are analyzed by gamma-spectrometry

14. Detection ability
Ln() = 0,08 [Ln()]3 - 1,51 [Ln()]2 + 8,69Ln() - 20,34

15. Quantifacation Absolute A – isotope of personal activity, Bq/kg
S(Ei) – gamma intensity field
Sfon(Ei) – Fon field
Ki – Absolute intensity, %
ε(Ei) – detection ability
ω(Ei ) – gamma coefficient
t – measure time, sec
m – sample mass

16. Quantifacation Relative Сstand – standard sample content
Ssample , Sstand – standard and sample of gamma intensity field
Мstand , Мsample – standard and sample of mass

17. Application examples
Geological samples: trace elements that could be usable such as REE, transition metal in copper ore (Erdenet, Oyutolgoi), coal deposits (Baganuur, Tavantolgoi), uranium ore (Mardai etc), industrial waste
To determine environmental pollutants: heavy metal pollution, air, water, soil, biomonitoring
Agriculture, biological samples: fertility, food products, trace elements in human and animal tissue
Archeological samples

18. Application examples Biomedicine
Ultra trace elements in pure materials
Quality assurance and reference materials
Forensic samples
Molecular activation analysis to determine chemical state of target elements

19. Requirements for NAA
app analyses per year for external customer
app analyses for internal customer
Short and intermediate half-life radionuclides
Number of samples to be irradiated once: 20 samples including flux monitors, control samples and blanks
Amount of the sample: 500 mg- 3g

20. Comparison of the detection limit of the analytical techniques at CGL to NAA (geological sample)
Element
XRF,
ppm
NAA, As 5
0.1-1 Pb
10-100 Bi Ta 6 Co Th Cr U Ga 3 W 8 Ge
1-10 Y Hg - Zn Mo Zr Nb Ba 20

21. Summary and future project
Further with research reactor
TRIGA-II with neutron current ≈1011neutron/(cm2sec)
Isotope production
Nuclear cross section
Training
Research etc

22. Isotope production in Mongolia

23. Isotopes using in Mongolia
1982, started using radioisotope in diagnosis and therapy
Nuclear Diagnosis Laboratory, State central clinic, Ulaanbaatar
Not be produced in Mongolia, export from outside, Intermediate half-life radioisotopes

24. 131I (T1/2 =8 days) thyroid cancer, for therapy and diagnosis
from the company High Tech China, Beijing
Order using internet, pay, receive
mCu one time
Buy 6 times a year
For thyroid disease 20-30mCu ( ₮)
For Cancer therapy, mCu ~100000₮

25. 125I (T1/2 59.4 days) Diagnosis kidneys,
99mTc (99Mo, T1/2=65.94h) diagnosis
188Re (experience in therapy for liver cancer )

26. Isotope production Medical (99mTc, 131I,125I )
Lung, liver, heart disease
Short and intermediate half-life radioisotopes (possible)

27. Further Biological study (protein study Se-75)
Zinc-65 & Manganese-54: Used to predict the behaviour of heavy metal components in effluents from mining waste water.
Industrial (Yb-169, Ir-192)

28. Thank you for your attention !