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

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

Neutron isotopic sources Code Source name Half life, year First year First activity, Bq Neutron current, n/sec 1 238Pu-Be 87.74 1980.05.15 2.4x1011 1.04x107 2 1985.04.26 1.2x1012 4.76x107 3 239Pu-Be 24119 1967.07.20 - 5.36x106 4 252Cf 2.645 1990.12.03 5.67x108 2.13x109 5 1979.01.23 1.50x108 0.56x109

Pu-Be Cf-252

Pu-Be Cf-252

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

NA-4 Neutron generator

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

Microtron MT-22

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)

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

Measurement Gamma spectrometer (HpGe) with 4096 channels.

Detection Irradiated samples are analyzed by gamma-spectrometry

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

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

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

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

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

Requirements for NAA app. 2000-2500 analyses per year for external customer app. 1000 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

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 0.01-0.1 Ge 1-10 Y 102-103 Hg - Zn Mo Zr Nb Ba 20

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

Isotope production in Mongolia

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

131I (T1/2 =8 days) thyroid cancer, for therapy and diagnosis from the company High Tech China, Beijing Order using internet, pay, receive 250-500 mCu one time Buy 6 times a year For thyroid disease 20-30mCu (40000- 60000₮) For Cancer therapy, 50-60 mCu ~100000₮

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

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

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)

Thank you for your attention !