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Determination of experimental cross-sections by activation method Pierre-Jean Viellenave Tutor: Dr. Vladimir Wagner Nuclear Physics Institute, Academy.

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Presentation on theme: "Determination of experimental cross-sections by activation method Pierre-Jean Viellenave Tutor: Dr. Vladimir Wagner Nuclear Physics Institute, Academy."— Presentation transcript:

1 Determination of experimental cross-sections by activation method Pierre-Jean Viellenave Tutor: Dr. Vladimir Wagner Nuclear Physics Institute, Academy of Sciences of Czech Republic

2 Contents Introduction Spectrum analysis with DEIMOS32 Cross-sections calculation Statistical analysis (incertainty calculation) Results

3 Introduction My work consists: In analysing gamma spectrums from experiment with DEIMOS32… Experiment = measurement of radioactive sample (activated by activation method in a cyclotron) with different configurations …To get experimental cross-sections

4 Spectrum analysis with DEIMOS32 Gamma lines peak analysis with the software DEIMOS 32

5 Spectrum analysis with DEIMOS32 We’re able to plan possible reactions and isotopes produced

6 Spectrum analysis with DEIMOS32 Comparison between the result tables from DEIMOS 32 analysis and the internet data base (decay data search) on gamma lines to identify the isotopes

7 Spectrum analysis with DEIMOS32 4 isotopes found from (n,2n) to (n,4n) reactions and 1 isotope (198Au) found from (n,gamma) reaction.

8 Cross-sections calculation Nyield calculation: Peak areaSelf-absorption correction Beam correction Dead time correctionDecay during cooling and measurement γline intensity Detector efficiency Correction for coincidences Square-emitter correction Weight normalization Decay during irradiation

9 Cross-sections calculation Detector efficiency (given): Nyield approximation:

10 Cross-sections calculation Nyield calculation: Sp: peak area I γ: gamma line intensity (in %) T real & T live: datas from exp. λ: decay constant T irr: irradiation time T 0: beam end – start of measurement

11 Cross-sections calculation Cross-section calculation: N n: neutrons number (depends on experiment) m foil: foil mass S: foil size (in cm 2) A: mass number (197 for Au) N A: Avogadro’s number ( 6, {mol -1 })

12 Statistical analysis N yield_average calculation for each isotope => to increase the precision: Aerr: incertainty of peak area (data from DEIMOS) So =>

13 Statistical analysis N yield_average calculation for each isotope => to increase the precision: Aerr: incertainty of peak area (data from DEIMOS) So =>

14 Statistical analysis Finally: With:

15 Results 197 Au (n, 2n) 196 Au

16 Results 197 Au (n, 4n) 194 Au

17 Results 197 Au (n, 2n) 196m2 Au

18 Results Comments: Fluctuations are purely systematical N yield-average isn’t depending on the configuration But the difference of N yield-average (calculated for each gamma line and isotope) is bigger than the uncertainty of weighted average. It comes from the systematic uncertainty of efficiency determination.

19 Thank you for your attention !!!


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