1. Seminární soustředění společného doktorského projektu UTEF ČVUT Praha a ÚJF AVČR Řež Transmutation studies on JINR Dubna Phasotron
Mitja Majerle

2. Transmutation studies on JINR Dubna Phasotron
Introduction
Accelerator Driven Systems are modified classic reactors – extra neutrons are added to the reactor
The design of ADS is complicated, simplified and minimized setups for testing – Dubna experiments
Experiments : protons (up to 1.5GeV), heavy metal target, activation detectors
Phasotron experiment : 660 MeV protons, intensive beam – 10 min, samples of 127I and 129I in neutron field, focus on production of short-lifetime isotopes
Analysis is long procedure, includes comparing results with computer simulated results
Transmutation studies on JINR Dubna Phasotron

3. Transmutation studies on JINR Dubna Phasotron

4. Transmutation studies on JINR Dubna Phasotron
Topics
Overview of the experiment
Analysis :
Number of protons
Neutron field – experiment, simulation
Iodine samples
Simulation codes
Transmutation studies on JINR Dubna Phasotron

5. Transmutation studies on JINR Dubna Phasotron

6. Experiment characteristics
Date and time: 14th of December 2003 at 16:33
Intensive beam (2,6·1013 protons/s) of protons with energy 660 MeV from Phasotron
Bare Pb target
The irradiation time : 10 minutes
Measurements of iodine samples and foils in HPGe detectors
Transmutation studies on JINR Dubna Phasotron

7. Transmutation studies on JINR Dubna Phasotron

8. Transmutation studies on JINR Dubna Phasotron

9. Transmutation studies on JINR Dubna Phasotron
Proton beam
Measured with two foils (Al,Cu – wider spectrum of reactions with protons) – 1,58·1015 protons with accuracy 6%
Beam displacement (Al, Au, Bi foils) : beam was shifted upwards, cca 1 cm c 1 2 3 4
Transmutation studies on JINR Dubna Phasotron

10. Transmutation studies on JINR Dubna Phasotron
Neutron field
Al, Au, Bi foils
Reactions : 27Al + n
Spatial and energetic (from thermal (resonance) to ~50 MeV) distribution of neutrons
Maximum : 8-10 cm
Range of proton shower : 30cm
Reaction products
Threshold* (MeV)
28Al+g
27Mg+p
1,89632
24Na+a
3,24996
26Al+2n
13,54607
...
* Thresholds from
Transmutation studies on JINR Dubna Phasotron

11. Transmutation studies on JINR Dubna Phasotron

12. Transmutation studies on JINR Dubna Phasotron

13. Transmutation studies on JINR Dubna Phasotron
Iodine samples
4 samples (2×127I,2×129I) : 9th and 21st cm along the target
From reactions (n,g) and (n,xn) we get iodine isotopes (all the way to 118I) which then decay (e, b+, IT) towards the line of stability (blue elements)
During the experiment ~1/1011 part of the iodine nuclei transmuted
Stable
t=hours,days
t=years
Transmutation studies on JINR Dubna Phasotron
t=minutes

14. Ratios of produced iodine isotopes
130I produced mostly in 129I samples (n,g) – it decays b- to 130Xe
With the exceptions of 130I and 128I, ratios of produced elements are higher in 127I samples (blue)
Transmutation studies on JINR Dubna Phasotron

15. Transmutation studies on JINR Dubna Phasotron
MCNPX program code
One of simulation codes for which such benchmark tests are done
Used as a tool at planning of experiments
Implemented all the time, experiments are simulated under different versions
Simulated spectrum, calculated yields of produced elements -> simulate the yields
Results suit well experiments (DCM)
Transmutation studies on JINR Dubna Phasotron

16. Transmutation studies on JINR Dubna Phasotron

17. Transmutation studies on JINR Dubna Phasotron
Conclusion
The experiment on Phasotron will serve as a good benchmark test :
Proton beam – intensive, but well focused
Neutrons – experimental data agree with expectations from previous experiments and with simulation
Iodine – detected short lived isotopes
The data was presented at two international conferences : 7th Session of AER working group for spent fuel transmutation (the Czech Republic), 17th Baldin seminar (Russia) Thank you.
Transmutation studies on JINR Dubna Phasotron