ASTROPHYSICAL FACTOR OF 3 He(4 He, γ)7 Be USING ACTIVATION METHOD 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, 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
OUTLINE MOTIVATION 1. MOTIVATION FOR 3 He(4 He, γ)7 Be EXPERIMENT 2. EXPERIMENTAL MEASUREMENT OF s(E) FOR 3 He(4 He, γ)7 Be CMAM 3. CMAM FACILITY SET UP 4. SET-UP CONSIDERATIONS & ESTIMATIONS 5. EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS & ESTIMATIONS 6. OBSERVABLES MEASUREMENTS 7. RESULTS 8. ONGOING AND FUTURE WORK MEASUREMENT OF s(E) OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
MOTIVATION OUTLINE MOTIVATION S 34(0)= 0. 56 ± 0. 02 (exp) ± 0. 02 (model) ke. V·b compared with the previous value (0. 53 ± 0. 05) ke. V·b (The analysis is based on all activation data plus ERNA recoil data) MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK Solar fusion cross sections II: ar. Xiv: 1004. 2318 v 3 M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
EXPERIMENTAL MEASUREMENT OF s(E) FOR 4 He(3 He, g)7 Be 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 ke. V, 429 ke. V 0 3. Detection of gamma radiation of 478 kev from excitation of 7 Li after decay of 7 Be: OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS T 1/2=53. 350 (50) days. 4 He OBSERVABLES RESULTS ONGOING AND FUTURE WORK Proton e+ Neutron 7 Be Li 3 He M. Carmona-Gallardo Direct detection of 7 Be or prompt g radiation detection Activation Method Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011 de-
EXPERIMENTAL MEASUREMENT OF s(E) FOR 4 He(3 He, g)7 Be II §GAS TARGET OF 4 He AND BEAM OF 3 He+ PARTICLE §BEAM ENERGIES: 2. 3, 3. 2, 4, 4. 8 5. 3 Me. V OUTLINE MOTIVATION §THE GAS CHAMBER MUST BE ELECTRICALLY INSULATED FROM THE LINE, SEPARATED BY A OIL MEASUREMENT OF s(E) §FOIL MUST KEEP THE PRESSURE DIFFERENCES BETWEEN LINE AND CHAMBER CMAM SET UP CONSIDERATIONS & ESTIMATIONS § AS THIN SCATTERING-FOIL AS POSSIBLE WHILE STILL RESISTANT TO HEAT FROM THE BEAM NI FOIL 1 mm THICK § GAS SYSTEM TO GUARANTEE CONSTANT PRESSURE IN THE REACTION CHAMBER §EXPRESION : OBSERVABLES RESULTS ONGOING AND FUTURE WORK §OBSERVABLES: Nº ion 7 Be, nº of incident 3 He+ ion, nº ions 4 He in the target §EXPERIMENT IN NOVEMBER 2009 M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
CMAM • Centro de Microanálisis de Materiales de Madrid (CMAM), at Universidad Autónoma de Madrid OUTLINE • Seven experimental lines. One line for Experimental Nuclear Physics operated by Grupo de Fisica Nuclear Experimental del IEMCSIC MOTIVATION MEASUREMENT OF s(E) CMAM • High voltage system Cockcroft-Walton SET UP • Tandem electrostatic accelerator of 5 MV CONSIDERATIONS & ESTIMATIONS OBSERVABLES • Two ion sources: Sputtering source Duoplasmatron source (used during the experiment) RESULTS ONGOING AND FUTURE WORK NUCLEAR PHYSICS LINE M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
EXPERIMENTAL SET-UP Silicon detector OUTLINE Np (MONITORING) Scattered beam MOTIVATION Collimator MEASUREMENT OF s(E) Pressure gauge CMAM SET UP Np (CHARGE INTEGRATION) -180 V suppressor CONSIDERATIONS & ESTIMATIONS OBSERVABLES 4 He Gas 3 He beam RESULTS Ni foil ONGOING AND FUTURE WORK Nt=9. 966 · 10 18· l·P/(T+T 0) M. Carmona-Gallardo Cu catcher Insulator Astrophysical Factor of 3 He(4 He, γ)7 Be recoils MADRID April 2011
EXPERIMENTAL SET UP II OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS &ESTIMATIONS q Catcher electrically connected to the chamber OUTLINE MOTIVATION MEASUREMENT OF s(E) q Suppressor at -100 V to avoid escape of e - and loss of current integrations q. SRIM and LISE++ used for previous calculations-. CMAM q ≈1µA (6. 2 · 10 12 3 He/s) ≈3µbar ≈50 torr & 300 K SET UP q 3 He(4 He, γ)7 Be Eγ =429 Ke. V CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS -100 V C. R. ≈ 295 7 Be/s 7 Be in catcher q · θ ≈ 45º ·Ebeam ≈ 4 Me. V / 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 ≈4155 3 He at 45º Particles mesaured at Si detector same than RS ONGOING AND FUTURE WORK q Ebeam= 4 Me. V 26. 04 cm Ni foil - Si Energy Loss in Ni foil M. Carmona-Gallardo E(3 He at Si) ≈ 2. 694 Me. V Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
EXPERIMENTAL MEASUREMENTS: CONSIDERATIONS &ESTIMATIONS q Previous and post calibration of Silicon detector with triple alpha and 148 Gd sources OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES q 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 n. A q Six catchers with different parameters q. MAESTRO: Number of particles which suffer elastic scattering Beam Intensity Energy of Particles Beam energy q. C foil used to measure the detector angle precisely. (Z(C) < Z(Ni)) RESULTS ONGOING AND FUTURE WORK q. Ni foil thickness measured with an external set up in a vacuum chamber and a Si detector M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
OBSERVABLES MEASUREMENTS A) ECM OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM v. We assume the reactions take placed at the center of gas target [1][2] v. Beam energies with ± 20 ke. V error v. Energy loss in the Ni foil and gas target simulated with TRIM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK v. 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 (2002) M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
OBSERVABLES MEASUREMENTS OUTLINE B) 4 He: (Nt : number of gas target ions per cm 2 ) Assuming ideal gas due to the low pressures we can consider: P: gas pressure (Torr) T 0 : room temperature (k) l: target length (cm) MOTIVATION MEASUREMENT OF s(E) CMAM SET UP Tc temperature correction due to the beam heating measured experimentally using the 1. 518 Me. V resonance in the 10 B(a, p)13 C. 17 K for 500 n. A @ 2 Me. V. [1] Ebeam (Me. V) CONSIDERATIONS & ESTIMATIONS Pon (Torr) T (K) DISTANCE (catcher-foil) 2. 3 13. 95± 0. 01 50. 64± 0. 02 313. 7672 11. 63± 0. 01 4. 4 50. 66± 0. 01 316. 5130 11. 48± 0. 01 4. 8 50. 83± 0. 07 318. 4352 11. 58± 0. 01 5. 3 ONGOING AND FUTURE WORK 63. 77± 0. 27 309. 2261 4 RESULTS 13. 95± 0. 01 3. 2 OBSERVABLES 54. 68± 0. 21 300. 2633 56. 68± 0. 29 319. 0396 13. 95± 0. 01 [1] B. S. Nara Singh et al. PRL 93, 262503 (2004) M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
OBSERVABLES MEASUREMENTS C) 3 He: Charge Integration & Elastic Scattering in the Ni foil OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES Ebeam (Me. V) INTENSITY (pulses) NP(charge integration) (at) Rutherford spectra integration RESULTS 2. 3 4. 54 E+7 2. 834 E+16 5. 90 E+07 2. 79 E+16 3. 2 8. 00 E+7 4. 993 E+16 4. 93 E+07 5. 00 E+16 4 1. 00 E+8 7. 321 E+16 4. 33 E+07 7. 17 E+16 4. 4 8. 37 E+7 5. 226 E+16 2. 54 E+07 5. 16 E+16 4. 8 5. 16 E+7 3. 224 E+16 1. 29 E+07 3. 17 E+16 5. 3 6. 24 E+7 3. 893 E+16 1. 27 E+07 3. 85 E+16 ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be NP(3 He with R. s MADRID April 2011
OBSERVABLES MEASUREMENTS D) 7 Be: OUTLINE ~900 cts. After 6 days MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK E) Complementary measurements §Angle of Silicon Detector §Ni foil thickness M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
RESULTS I ECM (Ke. V) MOTIVATION MEASUREMENT OF s(E) CMAM S 34(E) (ke. V·b) (INTEGRATION) S 34(E) (ke. V·b) (RUTHERFORD) 903. 631 OUTLINE s (E) (mb) 1, 872 0. 398 0. 407 1487. 45 2, 896 0. 304 0. 303 2010. 64 3, 78 0. 295 0. 304 2256. 03 5, 075 0. 363 0. 370 2499. 05 5, 502 0. 367 0. 376 2791. 21 6, 446 0. 402 0. 410 GOOD AGREEMENT BETWEEN BOTH TECHNIQUES SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
RESULTSII : COMPARATION WITH PREVIOUS MEASURMENTS OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
ONGOING & FURTURE WORK OUTLINE MOTIVATION MEASUREMENT OF s(E) CMAM §Try to reduce statistical errors with new activation method measurements §New strategy as we only have one low Hp. Ge station §Calculate all errors SET UP CONSIDERATIONS & ESTIMATIONS §Use different theoretical model in order to extrapolate up to S 34(0) OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo Astrophysical Factor of 3 He(4 He, γ)7 Be MADRID April 2011
OUTLINE MOTIVATION MEASUREMENTS OF s(E) CMAM THANKS FOR YOUR ATTENTION SET UP CONSIDERATIONS & ESTIMATIONS OBSERVABLES RESULTS ONGOING AND FUTURE WORK M. Carmona-Gallardo
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