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

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

Transmutation studies on JINR Dubna Phasotron

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

Transmutation studies on JINR Dubna Phasotron

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

Transmutation studies on JINR Dubna Phasotron

Transmutation studies on JINR Dubna Phasotron

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

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 http://t2.lanl.gov/data/data.html Transmutation studies on JINR Dubna Phasotron

Transmutation studies on JINR Dubna Phasotron

Transmutation studies on JINR Dubna Phasotron

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

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

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

Transmutation studies on JINR Dubna Phasotron

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