1. The use of tantalum foil in the study of production and transport of neutrons in assemblies with lead target irradiated by high energy deuterons Autor: Ondřej Novák Konzultant: RNDr. Vladimír Wagner, CSc

2. Introduction • Problem of nuclear energy – long half – life of nuclear waste • Solution= Transmutation • Changing stability of radioisotope by interaction of neutron • Shorter half - life

3. Main goal: • To measure the quantity, spatial distribution and energy of neutrons in the transmutation system by tantalum foil

4. Thresholdenergy • Energy, which is the lowiest for special (n,xn) reaction

5. Spectra analysis • Fit of peaks by special (Gauss) function • Integral area

6. Data analysis • The measured amount of gamma-rays of special line was calculated to obtain the total number of radioisotope with specific line. • The total number of nuclei of specific isotope was calculated from these values by using the formula for the weighted average

7. Reaction181Ta (n,gama)182Ta

8. Reaction181Ta (n,2n)180Ta

9. Reaction181Ta (n,3n)179Ta • Half - life is too long or too short • 179mTa 9 ms => stable 179Hf • 179Ta 1,87 year

10. Raction181Ta (n,4n)178Ta

11. experiment - simulation • The total number of neutrons(indirect) • Simulation describe whole system • Experiment only few places

12. Experiment – simulation- Au

13. End 