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Recent results and prospective of LUNA experiment. Gianluca Imbriani. LNGS. LUNA 50 kV. LUNA 400 kV. Underground laboratory. 3MeV < E g < 8MeV 0.0002 Counts/s. 3MeV < E g < 8MeV 0.5 Counts/s. 14 N(p, g ) 15 O: The experimental problem. E [keV]. E x [keV]. J p. 3/2 +. 2187. 9484.
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Recent results and prospective of LUNA experiment Gianluca Imbriani
LNGS LUNA 50 kV LUNA 400 kV Underground laboratory 3MeV < Eg< 8MeV 0.0002 Counts/s 3MeV < Eg< 8MeV 0.5 Counts/s
14N(p,g)15O: The experimental problem E [keV] Ex [keV] Jp 3/2+ 2187 9484 1444 1/2+ 8741 987 3/2+ 8284 259 1/2+ 7556 7297 7/2+ 7276 6859 5/2+ -507 14N + p 6791 3/2+ 6172 3/2- 5241 5/2+ 1/2+ 5181 0 1/2- 15O
14N(p,g)15O:The adopted set-up SPECIFICATIONS • Umax= 50 – 400 kV • I 500 mA for proton • DEmax= 0.07 keV • Energy spread : 72eV • Total uncertainty is • 300 eV between • Ep=100 400keV Solid target + HPGe detector Gas target + BGO detector
An example of spectrum ECM (keV) Ex (keV) 7540 14N + p 6791 Q = 7297 6172 5180 0 15O Ebeam = 250 keV
ECM (keV) Ex (keV) 7540 14N + p 6791 Q = 7297 6172 5180 0 15O The lowest energy spectrum EP=140 keV accumulated charge 210 C
Ground state results Data from 390 keV to 135 keV
Other transitions 6.79 transition 6.17 transition
Total S-factor LUNA results Solid + Gas target experiment Astrophysical energy information reached directly by LUNA experiment
S(0) and reaction rate • G. Imbriani, et al., European Physical Journal A 25(2005)455-466. • Formicola, et al., Physics Letter B, 591(2004)61-68. • A. Lemut, et al., Physics Letter B, 2006, in press • D. Bemmer, et al. Nuclear Physics A, 2006, in press New Fit/NACRE
14N(p,g)15O Age of Globular Clusters
(p,g) (p,a) 13C 14N 17O 18F (p,g) 1×109 y (p,g) 2×1012y 10 m e+n e+n 64 s e+n 108 m 13N 15O 17F CN NO CNO 2 m 6×109 y e+n (p,g) (p,g) (p,a) (p,g) 15N 16O 18O (p,a) 1×108 y pp-chain The Age of Globular Clusters CNO cycle pp chain CNO CYCLE the onset of the CNO LUNA 2004 12C CN Qeff = 26.02 MeV NO Qeff = 25.73 MeV Turn Off luminosity
Standard CF88 S 14,1 /5 S 14,1 x5 The role of 14N(p,g)15O Influence of 14N(p,g)15O on the determination of Turn off Luminosity S 14,1/5 Influence of 14N(p,g)15O on the evolution of Turn off Luminosity S 14,1 x5 Standard CF88
Isochrones for Globular Clusters after LUNA The age of the oldest Globular Clusters should be increased by about 0.7-1 Gyr V - I The lower limit to the Age of the Universe, using the Gratton et al, 2003 result, becomes 14 ± 1 Gyr. Imbriani et al., Astronomy & Astrophysics, 420, 2004
14N(p,g)15O Solar neutrino
Solar neutrino flux Before LUNA After LUNA
(p, 25Mg 26Al (p, 24Mg 6 s 7 s e+ e+ 26Mg 27Si 25Al 4 s (p, (p, e+ Q = 6306 keV 27Al 25Mg+p (p, -26 25Mg(p,g)26Al:the physical case ECM (keV) Ex (keV) J 190 6496 Novae explosive Burning (T9>0.1) 5+(4+) 130 6436 4- 108 0+ 6414 93 AGB or W-R Stars (T9~0.05) 6399 2- 6364 3+ 58 4- 37 6343 (p, No direct strength resonance data (level structure derived from the singe particle transfer reaction: 25Mg(3He,d)26Al) 6280 3+ • Motivation: • Nucleosynthesis of the elements 24<A<27 • Astronomical interest of 1809 keV 26Mg line Level scheme of 26Al 228 0+ 26Alm Ex (keV) 0 5+ 2+ 1809 26Al0 0 0+ 26Mg
Ex[keV] Ecm [keV] EL79 CH83 CH86 EN87 CH89 RO90 IL96 6344 37.5 5.710-16 1.910-18 2.110-20 (3.1±0.8)10-20 2.4 10-20 2.4 10-20 6364 58.0 (1.6±0.6)10-13 1.2 * 10-12 2.6 * 10-13 (2.6±0.3)10-13 (2.82+1.41-0.94)10-13 6399 92.6 4 10-8 1.0 10-11 4.3 * 10-10 8.5 * 10-11 (2.2±0.5)10-10 (1.16+0.16-0.39)10-10 6415 108.5 4 10-8 1.9 10-10 2.0 10-12 (6.3±5.0)10-12 (2.1+2.1-0.7)10-11 6436 130.4 4 10-8 1.7 * 10-7 1.3 10-9 5.0 10-9 1.4 10-10 Ex[keV] Ecm [keV] NE74 EL79 AN80 KE80 CH83 EN86 IL90/PO98 6496 189.9 (6.7±3.3)10-7 (6.46±3.23)10-7 (7.1±1.0)10-7 6550 244.3 (6.7±3.3)10-6 (1.64±0.82)10-6 (4.9±0.6)10-6 6598 292.3 (3.3± 1.2)10-5 (2.40±0.84)10-5 (4.9±0.6)10-5 6610 304.4 (2.9±0.9)10-2 (2.4±0.6)10-2 ( 3.1±0.3)10-2 (2.7±1.1)10-2 (2.00±0.96)10-2 (3.4±0.4)10-2 (2.9±0.4)10-2 6681 374.5 (4.4±1.3)10-2 ( 5.9±0.7)10-2 (5.6±1.7)10-2 (5.73±1.91)10-2 (7.1±0.6)10-2 6724 418.2 (9,4±0.6)10-2 25Mg(p,g)26Al:State of the art Table of the from NACRE in yellow the strength known with inderect experiments
Resonances to study in the LUNA experiment • 304 keV = (2.9 ± 0.4) 10-2 eV reaction per day with 400A = 1.1·107; • 190 keV = (7.1 ± 0.9) 10-7 eV reaction per day with 400A = 2.1·105; • 130 keV ≤ 1.4 10-10 eV reaction per day with 400A = 54; • 90 keV = (1.16+0.16-0.39) 10-10 eV reaction per day with 400A = 58.
Measurement strategy • We plan to measure 317 and 197 keV resonces using an HPGe detector in close geometry; • And 136 and 96 keV low counting resonances using a BGO detector.
Direct measurement of the absolute cross section of 1H(7Be,g)8B, using NABONA recoil mass separator We quoted a cross section ofs(990 keV) = 0.40 0.12 m b . Scaling the previous analysis the corresponding astrophysial factor is: S(0) = 15.3 4.5 eVb. Nucl.Phys.A688(2001) Eur.Phys.J.A,7(2000).
Nuclear Astrophysics ambitious task is to explain the origin and relative abundance of the elements in the Universe NUCLEAR INPUTS INASTROPHYSICAL THEORIES AND MODELS ARE VERY FAR FROM BEING (WELL) KNOWN !!!