1. Mariano Carmona Gallardo Grupo de Física Nuclear Experimental Instituto de Estructura de la Materia CSIC-Madrid O. Tengblad 1, B.S. Nara Singh 2, M. Hass 3, M. Alcorta 1, M.J.G. Borge 1, J.A. Briz 1, M.Cubero 1, C. Cruz 1, R. Dominguez-Reyes 1, B. Fulton 2, H. Fynbo 5, N. Gordillo 6, G. Haquin 4, Y. Nir-El 4, V. Kumar 3, A. Maira 6, A. Muñoz 6, A. Perea 1,Z. Yungreis 4 1 Intituto de Estructura de la Materia-CSIC, Madrid, Spain 2 University of York, York, UK 3 Weizmann Institute of Science, Rehovot, Israel 4 Soreq Research Center, Yavne, Israel 5 Aarhus University, Aarhus, Denmark 6 Centro de Microanálisis de Materiales-UAM, Madrid, Spain WORKSHOP ON REACTIONS OF ASTROPHYSICAL INTEREST (EUROGENESIS ) April 2011 A STROPHYSICAL F ACTOR OF 3 He( 4 He,γ) 7 Be U SING A CTIVATION M ETHOD

2. OUTLINE M. Carmona-Gallardo MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be 1. MOTIVATION FOR 3 He( 4 He,γ) 7 Be EXPERIMENT 2.EXPERIMENTAL MEASUREMENT OF  (E) FOR 3 He( 4 He,γ) 7 Be 3.CMAM FACILITY 4.SET-UP 5. EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS & ESTIMATIONS 6.OBSERVABLES MEASUREMENTS 7.RESULTS 8.ONGOING AND FUTURE WORK OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

3. MOTIVATION M. Carmona-Gallardo MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK S 34 (0)= 0.56 ± 0.02 (exp) ± 0.02 (model) keV·b compared with the previous value (0.53 ± 0.05) keV·b (The analysis is based on all activation data plus ERNA recoil data) Solar fusion cross sections II: arXiv:1004.2318v3

4. 1.Direct detection of 7 Be recoils produced during the reaction. (European Recoil Separator for Nuclear Astrophysics) 2. Detection of direct gamma reaction produced during the reaction: DC  429 keV, 429 keV  0 3.Detection of gamma radiation of 478 kev from de- excitation of 7 Li after decay of 7 Be: T 1/2 =53.350 (50) days. EXPERIMENTAL MEASUREMENT OF  (E) FOR 4 He( 3 He,  ) 7 Be e+e+ 7 Be 7 Li Proton Neutron 4 He 3 He MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7BeM. Carmona-Gallardo Activation Method Direct detection of 7Be or prompt  radiation detection OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

5.  GAS TARGET OF 4 He AND BEAM OF 3 He + PARTICLE  BEAM ENERGIES: 2.3, 3.2, 4, 4.4, 4.8 5.3 MeV  THE GAS CHAMBER MUST BE ELECTRICALLY INSULATED FROM THE LINE, SEPARATED BY A OIL  FOIL MUST KEEP THE PRESSURE DIFFERENCES BETWEEN LINE AND CHAMBER  AS THIN SCATTERING-FOIL AS POSSIBLE WHILE STILL RESISTANT TO HEAT FROM THE BEAM  NI FOIL 1  m THICK  GAS SYSTEM TO GUARANTEE CONSTANT PRESSURE IN THE REACTION CHAMBER  EXPRESION : M. Carmona-Gallardo EXPERIMENTAL MEASUREMENT OF s(E) FOR 4 He( 3 He,  ) 7 Be II  OBSERVABLES: Nº ion 7 Be, nº of incident 3 He + ion, nº ions 4 He in the target  EXPERIMENT IN NOVEMBER 2009 MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

6. M. Carmona-Gallardo CMAM Centro de Microanálisis de Materiales de Madrid (CMAM), at Universidad Autónoma de Madrid Seven experimental lines. One line for Experimental Nuclear Physics operated by Grupo de Fisica Nuclear Experimental del IEM- CSIC High voltage system Cockcroft-Walton Tandem electrostatic accelerator of 5MV Two ion sources: Sputtering source Duoplasmatron source (used during the experiment) NUCLEAR PHYSICS LINE MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

7. EXPERIMENTAL SET-UP Silicon detector Collimator Pressure gauge 4 He Gas Cu catcherNi foil -180 V suppressor 3 He beam Scattered beam Insulator N p (CHARGE INTEGRATION) N p (MONITORING) N t =9.966 ·10 18 · l·P/(T+T 0 ) 7 Be recoils MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7BeM. Carmona-Gallardo OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

8. EXPERIMENTAL SET UP II M. Carmona-Gallardo MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

9. M. Carmona-GallardoAstrophysical Factor of 3He(4He,γ)7Be MADRID April 2011  Catcher electrically connected to the chamber  Suppressor at -100V to avoid escape of e - and loss of current integrations  SRIM and LISE++ used for previous calculations-.  ≈1µA (6.2 · 10 12 3 He/s) ≈3µbar ≈50torr & 300 K  3 He( 4 He,γ) 7 Be E γ =429 KeV  · θ ≈ 45º ·E beam ≈ 4 MeV / I ≈ 1µA ·t Ni ≈ 1 µm / d = 8.9 g/cm 3 ·Energy-loss in the Ni foil taken into account. Assuming the R.S at the middle of the foil  E beam = 4 MeV 26.04 cm Ni foil - Si Energy Loss in Ni foil 7Be in catcher Particles mesaured at Si detector same than RS -100V C.R.≈ 295 7Be/s ≈4155 3He at 45º E(3He at Si) ≈ 2.694 MeV EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS &ESTIMATIONS OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

10.  Previous and post calibration of Silicon detector with triple alpha and 148 Gd sources  Some Parameters: Bias (detector de Si): -100 V Leakage current: 0.48 µA Leak Rate 0.10 torr/h (Very good) Line pressure ≈ 1.1 · 10 -6 torr Typical currents 180 - 200 nA  Six catchers with different parameters  MAESTRO: Number of particles which suffer elastic scattering  Beam Intensity Energy of Particles  Beam energy  C foil used to measure the detector angle precisely. ( Z(C) < Z(Ni))  Ni foil thickness measured with an external set up in a vacuum chamber and a Si detector M. Carmona-GallardoAstrophysical Factor of 3He(4He,γ)7Be MADRID April 2011 EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS &ESTIMATIONS OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

11. OBSERVABLES MEASUREMENTS M. Carmona-Gallardo A) E CM  We assume the reactions take placed at the center of gas target [1][2]  Beam energies with ±20 keV error  Energy loss in the Ni foil and gas target simulated with TRIM  Straggling in Ni foil and Gas target simulated with TRIM negligible [1] B. S. Nara Singh et al. PRL 93, 262503 (2004) [2]A.R. Junghans et al. PRL 88, 0411101 (2 002) OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be

12. OBSERVABLES MEASUREMENTS M. Carmona-Gallardo B) 4 He: (N t : number of gas target ions per cm 2 ) Assuming ideal gas due to the low pressures we can consider: MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK P: gas pressure (Torr) T 0 : room temperature (k) l: target length (cm) T c temperature correction due to the beam heating measured experimentally using the 1.518 MeV resonance in the 10 B( ,p) 13 C. 17K for 500nA @ 2 MeV. [1] E beam (MeV)P on (Torr)T (K) DISTANCE (catcher-foil) 2.354.68±0.21300.263313.95±0.01 3.263.77±0.27309.226113.95±0.01 450.64±0.02313.767211.63±0.01 4.450.66±0.01316.513011.48±0.01 4.850.83±0.07318.435211.58±0.01 5.356.68±0.29319.039613.95±0.01 [1] B. S. Nara Singh et al. PRL 93, 262503 (2004)

13. OBSERVABLES MEASUREMENTS M. Carmona-Gallardo C) 3 He: Charge Integration & Elastic Scattering in the Ni foil MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK E beam (MeV) INTENSITY (pulses) N P (charge integration) (at) Rutherford spectra integration N P ( 3 He with R.s 2.3 4.54E+72.834E+16 5.90E+072.79E+16 3.2 8.00E+74.993E+16 4.93E+075.00E+16 4 1.00E+87.321E+16 4.33E+077.17E+16 4.4 8.37E+75.226E+16 2.54E+075.16E+16 4.8 5.16E+73.224E+16 1.29E+073.17E+16 5.3 6.24E+73.893E+16 1.27E+073.85E+16

14. M. Carmona-Gallardo D) 7 Be: E) Complementary measurements  Angle of Silicon Detector  Ni foil thickness OBSERVABLES MEASUREMENTS MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be ~900 cts. After 6 days OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

15. M. Carmona-Gallardo RESULTS  E CM (KeV)  b) S 34 (E) (keV·b) (INTEGRATION) S 34 (E) (keV·b) (RUTHERFORD) 903.6311,8720.398 0.407 1487.452,8960.304 0.303 2010.643,780.295 0.304 2256.035,0750.363 0.370 2499.055,5020.367 0.376 2791.216,4460.402 0.410 MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be GOOD AGREEMENT BETWEEN BOTH TECHNIQUES OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

16. M. Carmona-Gallardo RESULTS  COMPARATION WITH PREVIOUS MEASURMENTS MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

17. M. Carmona-Gallardo ONGOING & FURTURE WORK  Try to reduce statistical errors with new activation method measurements  New strategy as we only have one low HpGe station  Calculate all errors  Use different theoretical model in order to extrapolate up to S 34 (0) MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

18. M. Carmona-Gallardo T HANKS FOR YOUR ATTENTION OUTLINE MOTIVATION MEASUREMENTS OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

19. M. Carmona-Gallardo RESULTS  COMPARATION WITH PREVIOUS MEASURMENTS MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

20.  (E) of 4 He( 3 He,γ) 7 Be reaction is an important parameter in SSM for determining the high energy neutrino flux from β decay del 8 B from 7 Be(p, 8 B). 2.This reaction plays an important role in the abundance of 7 Li during the BBN (Big Bang Nucleosynthesis) in the Standard Cosmological Theory. MOTIVATION M. Carmona-Gallardo MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7Be OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK

21. 3.Actual data for astrophysical factor “S” show big discrepancies: SSM quotes 0.53(5) 1 keV·b for S 34 (0) and SBBN uses 0.54(9) 2 keV · b. 4.Lack of new measurements during more than 20 years until values by B.S. Nara Singh et al. in 2004 1 A. E. Adelberguer et al., Rev. Mod. Phys.70, 1265 (1998) 2 C.Angulo et al., Nucl. Phys. A656, 3, (1999) MOTIVATION  FLLLK NUCLEAR TERM OF CROSS SECTION Lineal Scale Easier extrapolation  (E) probability of reaction. PROBABILITY OF CROSSING COULOMB BARRIER BY TUNNELING EFFECT Geometrical Factor  k 2 ≈1/E MADRID April 2011 Astrophysical Factor of 3He(4He,γ)7BeM. Carmona-Gallardo OUTLINE MOTIVATION MEASUREMENT OF  (E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK