1. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20061 Second IP EUROTRANS Internal Training Course on Nuclear Data for Transmutation: status, needs and methods. Investigation of the production of gas and volatile elements in lead- bismuth ADS spallation targets. Yoro TALL, SUBATECH Nantes, France

2. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20062 Contents  MEGAPIE project  Motivations of ISOLDE experiment  ISOLDE facility & Overview of the experiment  Different techniques of measurement  Results  Conclusions and future works

3. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20063 MEGAPIE project MEGAPIE an initiative from European institutions (among them PSI, FZK, CEA, CNRS, ENEA) and Japanese institution (JAERI). MEGAPIE (1.74 mA, 575 MeV) is an important step to the validation of PbBi ADS target. Its main objectives is to design, build, operate a spallation PbBi target under protons beam irradiation. The target is now installed in the SINQ facility and one year irradiation is expected.

4. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20064 Motivations of ISOLDE Experiments  During MEGAPIE irradiation, gas and volatile elements are produced, both stable and radioactive. Calculated values of stable gases indicated a production of about 1 l/month (mainly stable H and 4 He). The radioactive gas will be handled by a specially designed cover gas system. It is important to experimentally verify these predictions.  There is the need to know the production rate of specific radioisotopes for the disposal of the target.  Such an experiment offers a chance to benchmark widely used codes such as FLUKA and MCNPX.

5. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20065 ISOLDE Facility (CERN, SUISSE) Collection foils and Faraday cup Tape station PSB (Protons Synchrotron Booster) LBE target

6. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20066 Overview of the experiment LBE Energy protons beam : 1.0 GeV and 1.4 GeV. Pulsed protons beam. Repetition rate : 14.4 s Intensity of beam : 10 13 protons/pulse. Lists of isotopes measured 6,8 He 19,23,24 Ne 41,43,44 Ar 75,...,90 Kr 112,..,137 Xe 200,...,211 At 186,...,205 Hg Experimental parameters

7. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20067 Lead-Bismuth target  Cylinder L = 20 cm, r = 1 cm  Mass Pb-Bi : 547 g  Temperature target : 600 °C and 400 °C  Schematic view of the volatile elements release Protons beam diffusion effusion Overview of the experiment

8. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20068 acceleratortarget protons spallation Volatile elements Plasma source ionisation ions Mass separator detector Online measurement Off line measurement Overview of the experiment

9. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 20069 Different techniques of measurements Off line  -spectroscopy (collection station, GLM) : medium-long lived-isotopes

10. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200610 Different techniques of measurements HPGe (gamma) scintillator (beta) Beam line Online  -spectroscopy (tape station) : short and medium long-lived isotopes

11. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200611 Astatine Yields as function of temperature of 123 Xe and 204,209,210 At. Temperature dependence Po is not released from the target but observed ONLY from At decay Xenon

12. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200612 Temperature dependence Mercury For Hg the release at 600 ºC seems to be complete, not as for Xe.

13. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200613 Release measurements of Neuhaussen Iodine Polonium Polonium starts to be released at about 1000 K A small part of iodine released at 800 K

14. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200614 Good agreement between data obtained with the three techniques Mercury production rates 2004 data Results Mass number

15. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200615 Good agreement between results and simulations. Mass number Production rates (Atoms/  C) Results Mercury production rates data 2005

16. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200616 Good agreement between results and simulations. Production rates (Atoms/mC) Results Mass number Xenon production rates

17. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200617 In the A~125 mass region, the two models are close at 1 GeV, while at 1.4 GeV Bertini/Dresner is higher than INCL4/ABLA Mass number Results Comparison data and calculations at 1.4 GeV Xenon production rates (2004) Yields(Atoms/proton) Mass number

18. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200618 Good agreement between simulations. Confirmation of the small release of iodine Production rates (Atoms/  C) Results Iodine production rates Mass number

19. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200619 Production rates Atoms/  C Fair agreement with simulations and data (calculations factor 2-3 higher) Not measured in 2004 Possible imperfection on models or not complete release of noble gases Results Krypton production rates Mass number

20. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200620 Good agreement between data (off line and on line measurements) and simulations. No Po release observed, ONLY from decay of At. Temperature dependence observed for all isotopes. Possible not complete release for noble gases at 600 °C. Agreement with release experiments of Neuhausen. Only about less than 15 % of iodine released (compared to calculations). Validation of Monte Carlo codes used for the neutronic design Very important results obtained in the frame of the realization of the XT-ADS. conclusions

21. Yoro TALL Santiago de Compostela (Spain) June 7 – 10, 200621 Future works Finalisation of data analysis for tape station (release shape) Post irradiation analysis of the target (mass and gamma spectroscopy) Evaluation for the XT-ADS the production rates of residues (activity, radiotoxicity, emissions of volatile elements…) by calculations with MCNPX coupled with the different options (BERTINI, INCL4, ISABEL, CEM2K)