1. 11 33 S(n,  ) Cross Section: Implications for Neutron Capture Therapy and Astrophysics Javier Praena 1, José Manuel Quesada 1, Manuel Lozano 1, Pierfrancesco Mastinu 2, Carlos Guerero 4, Eric Berthoumieux 4, and Ignacio Porras 3 1) Universidad de Sevilla, Spain 2) Laboratori Nazionali di Legnaro, INFN, Italy 3) Universidad de Granada, Spain 4) CERN, Switzerland Javier Praena, CNA-Universidad de Sevilla, España

2. 22 Plan of the talk 1.Motivations. 2.Sample coatings. nat S, 33 S. 3.Rutherford BackScattering analysis at CNA (PIXE). 4.Micromegas. 5.Some signals before PS Inyector broke down. 6.2012 compaing: parasitic mode. Javier Praena, CNA-Universidad de Sevilla, España

3. 33 Motivations Javier Praena, CNA-Universidad de Sevilla, España Micromegas for (n,  ) reactions at n_TOF, (n,p). Medical Physics 33 S as cooperative target for BNCT. Astrophysics: Origin of 36 S: although the role of 33 S seems to be solved due to the 34 S as bottle-neck. Schatz et al Accurate experimental data for testing Hauser-Feshback statistical model used in p-process. Kappeler

4. 4 Bibliographic research. Person in charged: Wil Vollenberg of Vacum Surface Coatings at CERN. Sublimation of sulfur in vacuum. nat S and 33 S samples Javier Praena, CNA-Universidad de Sevilla, España

5. 5 nat S and 33 S samples Evaporation on Kapton and Mylar BAD ADHERENCE Javier Praena, CNA-Universidad de Sevilla, España

6. 6 Previous evaporation of Cu on Kapton (Cr and Ti) taken proffit of the experience with 10 B. Even the quantity of nat S was high the adherence was poor. And after four days it could be noticed aging effects Simple Method for Making Sulfur Targets D. D. Watson ; Rev. Sci. Instrum. 37, 1605 (1966); Ag 2 S formation by sulfur evaporation at 200 ºC and condensation on bulk Ag heated at 150 ºC. nat S and 33 S samples Javier Praena, CNA-Universidad de Sevilla, España

7. 7 FINAL METHOD: external heating of the chamber. Also Kapton (60  C) I=70 A through crysol con S. In case of 33 S it was evaporated 15 mg (75  m/cm 2, thick) and 5 mg (25  m/cm2, thin) TIME: 1 h vacuum pump, 2 h heating of Kapton and chamber, 5 min 70 A for S 1 h keeping on the temperature after coating. Heating tape Heated Kapton sample With thin Cu film With thin CuS Heating tape nat S and 33 S samples Javier Praena, CNA-Universidad de Sevilla, España

8. 8 RBS analysis at CNA Protones de 1782 keV Backscattered protons It is possible to calculate the number of atoms per cm 2. We had problems with the Alphatross source of the Tandem, next we will performance with alpha beam. Sample holder Javier Praena, CNA-Universidad de Sevilla, España

9. 9 Proton shoot on zone without Cu. We fixed the at/cm 2 of Cr and Ti. RBS analysis at CNA Proton shoot on zone with Cu. We fixed the at/cm 2 of Cu. Proton shoot on zone without Cu. We fixed the at/cm 2 of CuS.

10. 10 Mesh-Cu- 10 B-Mesh; 6.1 mm+ 1mm 6 mm+ 1mm (B) Mesh-CuS-CuS-Mesh, 2·25  g/cm 2 5mm + 1mm Mesh-CuS-CuS-Mesh, 2·70  g/cm 2 5mm + 1mm 2 thick 33 S samples back-to-back. 2 thin 33 S samples back-to-back. 1 10 B 4 C and 1 blank sample. Samples in Micromegas Javier Praena, CNA-Universidad de Sevilla, España

11. 11 Micromegas in experimental hall Micromegas as parasitic of PPACs Javier Praena, CNA-Universidad de Sevilla, España

12. 12 Signals during three days We observed signals at: 13.5 keV, 22 keV, 56 keV, 80 keV, 200 keV, 200 eV??? Javier Praena, CNA-Universidad de Sevilla, España

13. 13 Bad news and the future The inyector of the PS was broken tha data 16/11/12 and the CERN compaing 2011 was finished. We expected 6 days more. During the three days we were also testing different voltages. We should perform the experiment next year 2012 (middle, please). We suppose we should be again parasitic of PPAC. We would like to perform the experiment with the big Micromegas: 6 samples of 33 S. 2 samples of 10 B 4 C back-to-back (to study the effect). 2 blank samples back-to-back. Javier Praena, CNA-Universidad de Sevilla, España

14. 14 THANK YOU FOR YOUR ATTENTION Javier Praena, CNA-Universidad de Sevilla, España

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17. 17 63 Cu(n,  ) -> Q=1715 keV (69%) 63 Cu(n,p) -> Q=715 keV 50 Cr(n,  ) -> Q=319 keV (2%) 33 S(n,p) -> Q=533 keV 17 O(n,  ) -> Q=1817 keV (0.03%) 47 Ti(n,p) -> Q=182 keV (7%) 47 Ti(n,  ) -> Q=2189 keV 63 Cu(n,  ) -> Q=1715 keV Elastic scattering from H

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