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Neutron Activation Analysis, NAA

犖犖犖迦犖園犢仰犖犖犢犖犢犖ム権犖朽姑┯巌硯犢犖犖ム元犖∇牽犢犢犖犢犖犖犖迦犖
犖犖犖迦犖園犢仰犖犖犢犖犢犖ム権犖朽姑┯巌硯犢犖犖ム元犖∇牽犢犢犖犢犖犖犖迦犖

Neutron activation analysis of Thailand Institute of Nuclear Technology (TINT), Thailand

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Neutron Activation Analysis 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犖 犢犖о権犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th
Neutron capture reaction Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th Thermal neutron Target nucleus Compound nucleus Radioactive nucleus Prompt gamma ray Delay gamma ray Beta particle Product nucleus 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖蹩巌犖巌牽犖巌権犖迦犖園犖犖巌硯犖犖犖犖 (Neutron capture) 犖犖巌硯犢犖犖ム元犖∇肩犖犖犖犖犖迦犖伍犖園犢犖犖犖犢犖÷険犖ム犖巌硯犖犖犖犖犖犖迦犖 犢犖犖ム顕犖∇犖犢犖犖犖巌硯犢犖犖ム元犖∇肩犖犖園検犖÷険犖犖犖犖園犖犖 犖犖犖劇賢犢犖犢犖犢犖犖犖犖園犖犖 犖犖朽犖犖ム犖犖ム犖犖∇牽犖園犖犖朽犖朽犖÷元犖犖ム険犖犖犖迦犖犖迦犖犖迦鍵犖犖犖犢犖犢犖ム鍵犢犖犢犖犢犖犖犖犖犖犖÷顕
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 (Activation rate) 犖 犢犖迦検犖 犖犖巌硯犖犖犖犖犖犖ム険犖犖犢 (Flux) 犖犖犖劇賢犖犖о顕犖÷犖 犢犖 F n cm-2 s-1 犖犖迦犖蹩巌犖巌牽犖巌権犖迦犖園犖犖迦犖伍犖迦犖о NT 犖犖萎犖犖 犖÷元犖犖犖犖犢犖犖犖犖園 (Cross section) s barn 犖犖犖劇賢犖犖園検犖犖犖萎肩犖巌犖犖巌犖犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 ( 1 barn = 10-24 cm2) A = s N F s-1 F + NT N* (1) 犖÷元犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 :
N* = N0* e-lt Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 (Decay rate) 犖犖巌硯犢犖犖ム元犖∇肩犖犖犖劇賢犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖犖犖迦犖о N* 犖犖萎犖犖 犖÷元犖犢犖迦犖犖犖朽犖犖迦牽犖犖ム顕犖∇犖園硯 (Decay constant) l s-1 犖犖萎見犖о犖迦犖犖朽犖犖迦犖犖巌硯犖犖犖犖犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖犖÷元犖犖迦牽犖犖ム顕犖∇犖園硯 犖犖迦犖 犢犖犖迦犖о犢犖犢犖犢犖犖犖犖園犖犖 犖ム犖ム犖犖迦検犢犖о献犖迦犖犖∇検犖朽賢犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 dN* = -l N* s-1 dt (3) (2)
Production rate = Activation rate Decay rate Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犢犖犖巌犢犖犢犖犢犖犖犖犖園犖犖 (Production rate) 犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖 犢犖犢犖迦犖園 犖犖ム犢犖迦犖犖犖犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖迦犖園犖犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 dN* = sFN - l N* dt N* = sFN(1 - e-lt) l (7) (6) (5)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 (Induced radioactivity) 犖犖園検犖÷険犖犖犖犖迦犖犖犖犢犖犢犖犢犖犖犖犖園犖犖 犢犖÷厳犢犖犖犖迦犖犖巌硯犖犖犖犖 (Irradiation) 犖 犢犖о権犢犖о献犖 ti A0 = sFN(1 - e-lti) l N* = sFN(1 - e-lti) (8) (9)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犢犖÷厳犢犖犖犖∇幻犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Irradiation) 犢犖犢犖犢犖犖犖犖園犖犖朽犖萎犖÷犢犖犖巌犖÷犖謹犖犢犖ム鍵犖犖萎肩犖ム顕犖∇犖園硯犖犖迦犖 犢 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽献犖犖ム犖犖迦検犢犖о献犖迦犖朽犖犖ム顕犖∇犖園硯 (Decay time), td A = sFN(1 - e-lti) e-ltd A = A0 e-ltd (10) (11)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽肩犖項犖犖謹犖犖犖迦検犢犖о献犖迦犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Irradiation time), ti 犢犖ム鍵犖ム犖ム犖犖迦検犢犖о献犖迦犖犖犖迦牽犖犖ム顕犖∇犖園硯 (Decay time), td 0 20 40 60 80 100 120 0 5 10 15 20 25 Radioactivity of neutron irradiated sample Irradiation time Decay timeEnd of irradiation Radioactivity A0
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦犖о犖犖萎犖犖÷犖犖犖犖迦犖 犖犖迦検犖迦牽犖犖犖迦犖 犢犖犖迦犖犖迦牽犖о険犖犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 A 犢犖÷厳犢犖犖犖犖迦犖犢犖迦犖ム険犖犖犢犖犖犖犖犖巌硯犖犖犖犖 F 犖犖犖犖犢犖犖犖犖園犖犖犖犖犖犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 s 犢犖о献犖迦犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 犢犖ム鍵犢犖о献犖迦犖犖犖迦牽犖犖ム顕犖∇犖園硯 N = A (12) sF(1 - e-lti) e-ltd N = A eltd sF(1 - e-lti) (13)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖巌硯犢犖犖ム犢 (Nuclides) 犖犖犖犖犖迦犖
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦見犖犖園犖犖迦犖伍犖犖犖園硯犖犖∇犖迦犖犖朽犖÷元犖犢犖迦見犖犖園 w 犖犖犖園検 犢犖ム鍵犖÷元 Isotope abundance q 犖÷元犖犖迦犖о犖犖萎犖犖 w = A0M eltd sF NAq(1 - e-lti) N = w NAq M (14) NA = Avogrados number, M = atomic weight 犢犖犖犖犢犖 N 犢犖犖犖÷犖迦牽 (13)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦見犖犖園犖犖迦犖伍犖犖犖園硯犖犖∇犖迦犖犖朽犖÷元犖犢犖迦見犖犖園 w 犖犖犖園検 犢犖ム鍵犖÷元 Isotope abundance q 犖÷元犖犖迦犖о犖犖萎犖犖 NA = Avogrados number, M = atomic weight w = A0 M eltd sF NAq(1 - e-lti) N = w NAq M (16) (15)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Gamma ray spectrometer 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽犖迦犢犖犢犖犢犖犖犖犖朽犢犖犖巌犖犖謹犖 犖犖迦検犖迦牽犖犖о険犖犢犖ム鍵犖о鹸犢犖犖犖迦鍵犖犢犖 犢犖о権犖犖萎犖犖о険犖犖犖園犖犖朽犖犖÷検犖 犖犖園硯犖о険犖犖犖園犖犖朽犖犖÷検犖迦犖犖犖犖迦牽犖犖謹犖犖犖園硯犖犖迦犖犖巌肩犖伍犖犖巌犖犖項 (High Purity Germanium detector) HPGe 犢犖ム鍵犖犖萎犖犖о鹸犢犖犖犖迦鍵犖犢犖犖園犖犖迦 犖犖迦検犖迦牽犖犢犖 犢犖о険犖i犖犖園犖犖朽犖犖÷検犖迦犖犖∇犖犖犖犖犖ム犖犢犖犖犢犖迦犖園犖о険犖 (Count) 犖犖犖犖犖園犖犖朽犖犢犖ム鍵犖犖ム険犖犖犖迦犖犖朽犖犖犖о犖о険犖犢犖 犢犖犖犖犢犖犖犖犖犖園検犖犖園犖犖朽犖犖÷検犖 (Gamma ray spectrum)
Gamma ray spectrometry 犖犖園犖犖朽犖犖÷検犖迦犖犢犖ム鍵犖犖ム険犖犖犖迦 犢犖犖犖 犖 犢犖о権犢犖犢犖犖犖朽犖犖犖犢犖犖犖犖犖園検 犢犖犖∇検犖朽賢犖園犖犖迦犖迦牽犖犖園犖о険犖 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 犖犖迦犖о犢犖 犢犖犖迦 犖犖園犖犖迦犖迦牽犖犖園犖о険犖犖犖園犖犖朽犢犖犖犖犖萎肩犖巌犖犖巌犖迦 Count rate = peak area counting time Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Efficiency, e = Count rate Activity Activity = Count rate e (17)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Absolute method NAA 犖犖犖巌検犖迦犖犖迦犖伍犖朽犖 犢犖犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢 犖犖迦検犖迦牽犖犖犖迦犖о犢犖 犢犖犖迦犖犢犖迦犖園犖о険犖犖犖園犖犖朽犖犖÷検犖 犢犖犖∇犖犖犖犢犖 犖犖÷犖迦牽犖犖朽 (17) 犢犖犖犖÷犖迦牽犖犖朽 (16) Absolute method NAA 犢犖犢犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖犖迦犖犢犖迦犖園硯犢犖犖犖犖園犖犖犖÷ w = count rate M eltd sF NAq e (1 - e-lti) (18)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Comparative method NAA 犢犖 犢犖犖迦牽犖 犢犖迦犖犖巌 (Reference material) 犖犖朽犖犖犖迦犖犖犖巌検犖迦犖犖迦犖伍犖朽犖 犢犖犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢 犖犖迦犖犖巌硯犖犖犖犖 犖犖 犢犖犖÷犖園犖犖園硯犖犖∇犖迦 (Sample) 犖犖÷犖迦牽 NAA 犖犖迦見犖犖園犖犖迦牽犖 犢犖迦犖犖巌 (R) 犖犖÷犖迦牽 NAA 犖犖迦見犖犖園犖犖園硯犖犖∇犖迦 (S) w(R) = count rate (R) M eltd(R) sF NAq e (1 - e-lti) w(S) = count rate (S) M eltd(S) sF NAq e (1 - e-lti) (19) (20)
Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Comparative method NAA 犖犖÷犖迦牽犖犖朽 (20) 犖犖迦牽犖 犢犖о権犖犖÷犖迦牽犖犖朽 (19) w(R) count rate (R) eltd(R) w(S) count rate (S) eltd(S) (21) (22) = count rate (R) w(R) count rate (S) el(td(S) - td(R)) w(S) =

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Neutron Activation Analysis, NAA

  • 1. Neutron Activation Analysis 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犖 犢犖о権犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th
  • 2. Neutron capture reaction Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th Thermal neutron Target nucleus Compound nucleus Radioactive nucleus Prompt gamma ray Delay gamma ray Beta particle Product nucleus 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖蹩巌犖巌牽犖巌権犖迦犖園犖犖巌硯犖犖犖犖 (Neutron capture) 犖犖巌硯犢犖犖ム元犖∇肩犖犖犖犖犖迦犖伍犖園犢犖犖犖犢犖÷険犖ム犖巌硯犖犖犖犖犖犖迦犖 犢犖犖ム顕犖∇犖犢犖犖犖巌硯犢犖犖ム元犖∇肩犖犖園検犖÷険犖犖犖犖園犖犖 犖犖犖劇賢犢犖犢犖犢犖犖犖犖園犖犖 犖犖朽犖犖ム犖犖ム犖犖∇牽犖園犖犖朽犖朽犖÷元犖犖ム険犖犖犖迦犖犖迦犖犖迦鍵犖犖犖犢犖犢犖ム鍵犢犖犢犖犢犖犖犖犖犖犖÷顕
  • 3. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 (Activation rate) 犖 犢犖迦検犖 犖犖巌硯犖犖犖犖犖犖ム険犖犖犢 (Flux) 犖犖犖劇賢犖犖о顕犖÷犖 犢犖 F n cm-2 s-1 犖犖迦犖蹩巌犖巌牽犖巌権犖迦犖園犖犖迦犖伍犖迦犖о NT 犖犖萎犖犖 犖÷元犖犖犖犖犢犖犖犖犖園 (Cross section) s barn 犖犖犖劇賢犖犖園検犖犖犖萎肩犖巌犖犖巌犖犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 ( 1 barn = 10-24 cm2) A = s N F s-1 F + NT N* (1) 犖÷元犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 :
  • 4. N* = N0* e-lt Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 (Decay rate) 犖犖巌硯犢犖犖ム元犖∇肩犖犖犖劇賢犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖犖犖迦犖о N* 犖犖萎犖犖 犖÷元犖犢犖迦犖犖犖朽犖犖迦牽犖犖ム顕犖∇犖園硯 (Decay constant) l s-1 犖犖萎見犖о犖迦犖犖朽犖犖迦犖犖巌硯犖犖犖犖犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖犖÷元犖犖迦牽犖犖ム顕犖∇犖園硯 犖犖迦犖 犢犖犖迦犖о犢犖犢犖犢犖犖犖犖園犖犖 犖ム犖ム犖犖迦検犢犖о献犖迦犖犖∇検犖朽賢犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 dN* = -l N* s-1 dt (3) (2)
  • 5. Production rate = Activation rate Decay rate Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園犖犖迦犖迦牽犢犖犖巌犢犖犢犖犢犖犖犖犖園犖犖 (Production rate) 犢犖犢犖犢犖犖犖犖園犖犖朽犖朽犢犖犖巌犖犖謹犖 犢犖犢犖迦犖園 犖犖ム犢犖迦犖犖犖犖犖園犖犖迦犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖迦犖園犖犖園犖犖迦犖迦牽犖犖ム顕犖∇犖園硯 dN* = sFN - l N* dt N* = sFN(1 - e-lt) l (7) (6) (5)
  • 6. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 (Induced radioactivity) 犖犖園検犖÷険犖犖犖犖迦犖犖犖犢犖犢犖犢犖犖犖犖園犖犖 犢犖÷厳犢犖犖犖迦犖犖巌硯犖犖犖犖 (Irradiation) 犖 犢犖о権犢犖о献犖 ti A0 = sFN(1 - e-lti) l N* = sFN(1 - e-lti) (8) (9)
  • 7. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犢犖÷厳犢犖犖犖∇幻犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Irradiation) 犢犖犢犖犢犖犖犖犖園犖犖朽犖萎犖÷犢犖犖巌犖÷犖謹犖犢犖ム鍵犖犖萎肩犖ム顕犖∇犖園硯犖犖迦犖 犢 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽献犖犖ム犖犖迦検犢犖о献犖迦犖朽犖犖ム顕犖∇犖園硯 (Decay time), td A = sFN(1 - e-lti) e-ltd A = A0 e-ltd (10) (11)
  • 8. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽肩犖項犖犖謹犖犖犖迦検犢犖о献犖迦犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Irradiation time), ti 犢犖ム鍵犖ム犖ム犖犖迦検犢犖о献犖迦犖犖犖迦牽犖犖ム顕犖∇犖園硯 (Decay time), td 0 20 40 60 80 100 120 0 5 10 15 20 25 Radioactivity of neutron irradiated sample Irradiation time Decay timeEnd of irradiation Radioactivity A0
  • 9. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦犖о犖犖萎犖犖÷犖犖犖犖迦犖 犖犖迦検犖迦牽犖犖犖迦犖 犢犖犖迦犖犖迦牽犖о険犖犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 A 犢犖÷厳犢犖犖犖犖迦犖犢犖迦犖ム険犖犖犢犖犖犖犖犖巌硯犖犖犖犖 F 犖犖犖犖犢犖犖犖犖園犖犖犖犖犖犖迦牽犢犖犖巌犖犖蹩巌犖巌牽犖巌権犖 s 犢犖о献犖迦犖犖犖迦牽犖犖迦犖犖巌硯犖犖犖犖 犢犖ム鍵犢犖о献犖迦犖犖犖迦牽犖犖ム顕犖∇犖園硯 N = A (12) sF(1 - e-lti) e-ltd N = A eltd sF(1 - e-lti) (13)
  • 10. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖巌硯犢犖犖ム犢 (Nuclides) 犖犖犖犖犖迦犖
  • 11. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦見犖犖園犖犖迦犖伍犖犖犖園硯犖犖∇犖迦犖犖朽犖÷元犖犢犖迦見犖犖園 w 犖犖犖園検 犢犖ム鍵犖÷元 Isotope abundance q 犖÷元犖犖迦犖о犖犖萎犖犖 w = A0M eltd sF NAq(1 - e-lti) N = w NAq M (14) NA = Avogrados number, M = atomic weight 犢犖犖犖犢犖 N 犢犖犖犖÷犖迦牽 (13)
  • 12. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) 犖犖迦見犖犖園犖犖迦犖伍犖犖犖園硯犖犖∇犖迦犖犖朽犖÷元犖犢犖迦見犖犖園 w 犖犖犖園検 犢犖ム鍵犖÷元 Isotope abundance q 犖÷元犖犖迦犖о犖犖萎犖犖 NA = Avogrados number, M = atomic weight w = A0 M eltd sF NAq(1 - e-lti) N = w NAq M (16) (15)
  • 13. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Gamma ray spectrometer 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖朽犖迦犢犖犢犖犢犖犖犖犖朽犢犖犖巌犖犖謹犖 犖犖迦検犖迦牽犖犖о険犖犢犖ム鍵犖о鹸犢犖犖犖迦鍵犖犢犖 犢犖о権犖犖萎犖犖о険犖犖犖園犖犖朽犖犖÷検犖 犖犖園硯犖о険犖犖犖園犖犖朽犖犖÷検犖迦犖犖犖犖迦牽犖犖謹犖犖犖園硯犖犖迦犖犖巌肩犖伍犖犖巌犖犖項 (High Purity Germanium detector) HPGe 犢犖ム鍵犖犖萎犖犖о鹸犢犖犖犖迦鍵犖犢犖犖園犖犖迦 犖犖迦検犖迦牽犖犢犖 犢犖о険犖i犖犖園犖犖朽犖犖÷検犖迦犖犖∇犖犖犖犖犖ム犖犢犖犖犢犖迦犖園犖о険犖 (Count) 犖犖犖犖犖園犖犖朽犖犢犖ム鍵犖犖ム険犖犖犖迦犖犖朽犖犖犖о犖о険犖犢犖 犢犖犖犖犢犖犖犖犖犖園検犖犖園犖犖朽犖犖÷検犖 (Gamma ray spectrum)
  • 14. Gamma ray spectrometry 犖犖園犖犖朽犖犖÷検犖迦犖犢犖ム鍵犖犖ム険犖犖犖迦 犢犖犖犖 犖 犢犖о権犢犖犢犖犖犖朽犖犖犖犢犖犖犖犖犖園検 犢犖犖∇検犖朽賢犖園犖犖迦犖迦牽犖犖園犖о険犖 犖犖園検犖÷険犖犖犖犖迦犖犖園犖犖 犖犖迦犖о犢犖 犢犖犖迦 犖犖園犖犖迦犖迦牽犖犖園犖о険犖犖犖園犖犖朽犢犖犖犖犖萎肩犖巌犖犖巌犖迦 Count rate = peak area counting time Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Efficiency, e = Count rate Activity Activity = Count rate e (17)
  • 15. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Absolute method NAA 犖犖犖巌検犖迦犖犖迦犖伍犖朽犖 犢犖犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢 犖犖迦検犖迦牽犖犖犖迦犖о犢犖 犢犖犖迦犖犢犖迦犖園犖о険犖犖犖園犖犖朽犖犖÷検犖 犢犖犖∇犖犖犖犢犖 犖犖÷犖迦牽犖犖朽 (17) 犢犖犖犖÷犖迦牽犖犖朽 (16) Absolute method NAA 犢犖犢犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖犖迦犖犢犖迦犖園硯犢犖犖犖犖園犖犖犖÷ w = count rate M eltd sF NAq e (1 - e-lti) (18)
  • 16. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Comparative method NAA 犢犖 犢犖犖迦牽犖 犢犖迦犖犖巌 (Reference material) 犖犖朽犖犖犖迦犖犖犖巌検犖迦犖犖迦犖伍犖朽犖 犢犖犖犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢 犖犖迦犖犖巌硯犖犖犖犖 犖犖 犢犖犖÷犖園犖犖園硯犖犖∇犖迦 (Sample) 犖犖÷犖迦牽 NAA 犖犖迦見犖犖園犖犖迦牽犖 犢犖迦犖犖巌 (R) 犖犖÷犖迦牽 NAA 犖犖迦見犖犖園犖犖園硯犖犖∇犖迦 (S) w(R) = count rate (R) M eltd(R) sF NAq e (1 - e-lti) w(S) = count rate (S) M eltd(S) sF NAq e (1 - e-lti) (19) (20)
  • 17. Thailand Institute of Nuclear Technology (Public Organization) www.tint.or.th 犖犖迦牽犖о鹸犢犖犖犖迦鍵犖犢犢犖犖∇犖迦牽犖犖迦犖犖巌硯犖犖犖犖 (Neutron Activation Analysis) Comparative method NAA 犖犖÷犖迦牽犖犖朽 (20) 犖犖迦牽犖 犢犖о権犖犖÷犖迦牽犖犖朽 (19) w(R) count rate (R) eltd(R) w(S) count rate (S) eltd(S) (21) (22) = count rate (R) w(R) count rate (S) el(td(S) - td(R)) w(S) =