Stato dell'esperimento LUNA marzo 2015 Laboratory Underground Nuclear Astrophysics Alessandra Guglielmetti Università degli Studi di Milano e INFN, Milano, ITALY Risultati recenti: 17O(p,a)14N (coordinatrice Alba Formicola), 18O(p,a)15N (coordinatrice Marialuisa Aliotta), 22Ne(p,g)23Na fase HPGe (coordinatore Daniel Bemmerer) Misure in corso: 22Ne(p,g)23Na fase BGO (coordinatore Antonio Caciolli), 23Na(p,g)24Mg (coordinatore Gianluca Imbriani), 18O(p,g)19F (coordinatore Andreas Best), 2H(p,g)3He (coordinatore Davide Trezzi) Collaborazione attuale e contatti in via di definizione Stato del progetto LUNA MV

The 17O(p,a)14N reaction: astrophysical motivation Influence 17O abundance in several stellar sites In AGB stars ( T=0.03-0.1 GK ) CNO cycle takes place in core of star only Measured 17O/16O abundance in pre-solar grain give information on AGB surface composition: higher 17O quantity with respect to predictions Information on mixing processes if cross section is well known

The 17O(p,a)14N reaction: nuclear physics aspects Q-value = 1.2 MeVexpected alpha energy 1 MeV Two narrow resonances at 70 and 193 keV (lab)

The 17O(p,a)14N reaction: state of the art 193 keV Resonance: Authors Resonance strength Approach Chafa (2005-07) (1.6±0.2) x10-3 eV Activation Moazen (2007) (1.70±0.15) x10-3 eV Direct (inverse kinematics) Newton (2007-10) (1.66±0.17) x10-3 eV Direct Our goal! 70 keV Resonance: Berheide (1992) < 8x10-10 eV Direct (upper limit) Blackmon (1995) 5.5 +1.8-1.5 x10-9 eV Direct Sergi (2010) 3.66+0.76 -0.64 x10-9 eV Indirect (Trojan horse)

The 17O(p,a)14N reaction: experimental setup Silicon detector proton beam from LUNA 400 kV enriched 17O targets 8 silicon detectors foils of Al Mylar to stop backscattered protons low alpha particle energy (200-250 keV) Solid target position

The 17O(p,a)14N reaction: 193 keV res 1-2 alphas/s/detector at ~250 keV clear peak visible in spite of low energy and rate In agreement with literature!

The 17O(p,a)14N reaction: 70 keV res Evidence of a counting excess in the region of interest!

The 17O(p,a)14N reaction: 70 keV res PRELIMINARY -expected energy -expected width -significance >5 sigma

The 17O(p,a)14N reaction: 70 keV res PRELIMINARY Very preliminary analysis favours a larger strength value compared with literature If confirmed, it would have an astrophysical impact Analysis is still ongoing…

The 18O(p,a)15N reaction: astrophysical motivation Synthesis of 15N, 18O, 19F in novae and AGB stars In AGB stars ( T=0.03-0.1 GK ) CNO cycle takes place in core of star only Measured 18O/16O abundance in pre-solar grain give information on AGB surface composition: lower 18O quantity with respect to predictions Information on mixing processes if cross section is well known

The 18O(p,a)15N reaction: nuclear physics aspects Qvalue = 4 MeV expected alpha energy 3.1-3.3 MeV

The 18O(p,a)15N reaction- state of the art and objectives Re-scan excitation function: Any new resonance? 95 keV resonance: strength? Resonance energy [(96.6 ± 2.2) keV (La Cognata 2008)] Measure below 70 keV beam energy: Closer to Gamow peak. Low counting rate

The 18O(p,a)15N reaction: excitation function Data taking completed. Data analysis on going 152 keV resonance 334 keV resonance 216 keV resonance In agreement with previous data Might improve precision on resonance energy and strength

The 18O(p,a)15N reaction:96 keV resonance and below: Precision about 10% (30% literature). Resonance energy determined with 0.5 keV precision (3 keV literature) Data below 70 keV not fully analysed yet. Necessary R-matrix fit

The 18O(p,a)15N reaction:low energies Plot shows 50% statistic for only one detector out of four Very clear peaks at Ep = 70 and 65 keV Peak at Ep = 60 keV visible. Lowest direct data point in literature. Expected ~20% statistical uncertainty at 60 keV from full analysis PRELIMINARY 18O(p,α) alpha peak

The 22Ne(p,g)23Na reaction: astrophysical motivation NeNa cycle of H burning. Active in astrophysical novae Impact on the abundances of: 22Ne (factor 100) 23Na (factor 7) 24Mg (factor 70)

The 22Ne(p,g)23Na reaction The resonances within the “green” box have been investigated The “red” resonances have been directly observed for the first time For the resonances at 71, 105 and 215 keV in “black” an upper limit has been found

The 22Ne(p,g)23Na reaction: ERlab=259.7 keV 1919 Branching The 22Ne(p,g)23Na reaction: ERlab=259.7 keV γ-transition Eγ [keV] Branching [%] R→440 8602 47.4 ± 0.8 R→2076 6963 19.4 ± 0.6 R→2704 6335 11.4 ± 0.5 R→3848 5193 13.9 ± 0.6 R→3914 5127 1.5 ± 0.3 R→5927 3115 3.9 ± 0.2 R→6042 3000 2.6 ± 0.2 R→6354.5 2686.5 1.5 ± 0.2 R→6820 2221 2.2 ± 0.2 New gamma decay modes discovered. Branching ratios determined

The 22Ne(p,g)23Na reaction: results ERlab [keV] ωγ [eV] LUNA direct experiment [Gӧrres82] indirect experiment [Hale02] 71 ≤ 3.4 10-9 ≤ 3.2 10-6 ≤ 1.9 10-10 105 ≤ 7.0 10-9 ≤ 0.6 10-6 ≤ 1.4 10-7 156.2 [1.48 ± 0.09 (stat) ± 0.04 (syst)] 10-7 ≤ 1.0 10-6 ≤ 9.2 10-9 189.5 [1.87 ± 0.03 (stat) ± 0.05 (syst)] 10-6 ≤ 2.6 10-6 215 ≤ 2.4 10-8 ≤ 1.4 10-6 259.7 [6.89 ± 0.08 (stat) ± 0.14 (syst)] 10-6 ≤ 1.3 10-7 3 resonances observed for the first time The new upper limits on 71, 105 and 215 keV resonances are 2 orders of magnitude (or more) lower compared to the previous direct measurement

On going (from last week): the 22Ne(p,g)23Na reaction BGO phase Aim: measure or improve upper limits for 71 and 105 keV resonances. Check the 156 keV resonance to compare with HPGe phase Measure DC component at 200, 280 and 360 keV

The 22Ne(p,g)23Na reaction BGO phase Pressure and temperature profiles in the gas target measured with and without gas… one ingredient!

On going: the 23Na(p,g)24Mg reaction NeNa Cycle 20Ne 23Na (p,g) (p,a) 22Na 22Ne e+n 3 yr 21Ne 21Na 22 s 19F (p, 24Mg 27Al (p, 27Si e+ 4 s 26Al 26Mg 6 s 25Mg 25Al 7 s MgAl Cycle 23Na(p,g)24Mg is the bridge between NeNa cycle and MgAl cycle. Important for AGB stars

The 23Na(p,g)24Mg reaction: nuclear physics aspects and state of the art AGB stars T= 70 MK E=138 keV resonance (Ep=144 keV) wg Cesaratto ≤ 5.2 neV (2 neV ?)

23Na(p,g)24Mg reaction: measurement plan BGO measurement of: Ep= 250, 308 keV (calibration) DC component Ep=144 keV (according to Cesaratto “strength limit” about 80 events/day with I=100 mA) High efficiency. Gamma-ray summing moves signal away from natural background Total time about 6 months HPGe measurement if feasible Targets: evaporated Na2WO3 (Notre Dame, Atomki) metallic Na pressed between two backings (Napoli) Need to check stability under beam

23Na(p,g)24Mg reaction: lead shielding Few massive pieces: For BGO about 10 cm For HPGe about 20 cm (both at 0° and 55°) Movable on rails. Easy access to target Gamma shielding effective

On going (in parallel) 18O(p,g)19F reaction Oxygen depletion in low-mass AGB star atmospheres (T=40 MK) and in 15% of all pre-solar grains possibly explained through enhanced 18O(p,g)19F at low temperatures? 95 keV negligible Bruckner 2012 95 keV dominant Fortune 2013 (95±3) keV: energy uncertainty has large effect on rate uncertainty

18O(p,g)19F reaction: measurement plan BGO measurement of: E= 95 keV resonance DC component HPGe measurement of: E=95 keV branching ratios (if feasible) High energy DC component Same experimental setup of 23Na(p,g)24Mg. Enriched 18O targets produced by anodization (Ta2O5) in LNGS

The 2H(p,γ)3He reaction Total amount of deuterium produced in the early Universe depends on the cosmological parameters and on the nuclear cross sections of the reactions involved (main source of uncertainty 2H(p,γ)3He). BBN predictions (PLANCK+SFII) 2H/H = (2.65 ± 0.07) x 10-5 ASTRONOMICAL observations 2H/H = (2.53 ± 0.04) x 10-5 Poor data in the BBN energy range (40-400 keV). Try to reduce uncertainty from 9 to 3% 10% disagreement between nuclear theory (ab-initio calculations) and experimental data. New calculations in 20% disagreement

The 2H(p,γ)3He test (October 2014) Test of the reaction using a setup similar to the one used for the 22Ne(p,g)23Na. Gas target filled with 2H (0.3 mbar), no recirculation 136% HPGe detector at 90°with respect to the beam

The 2H(p,γ)3He test (October 2014) Runs at literature (Ma et al.) energies + 380 keV (maximum LUNA energy) + 340 keV (19F(p,ag)16O reaction resonance). Low level beam induced background (Carbon and Fluorine contamination) No deuterium implantation Good agreement between data and simulations → Differential cross section at low energies Data analysis in progress

The 2H(p,γ)3He reaction Test program accomplished except for the HPGe efficiency measurement (estimated with Montecarlo simulations) Measurement campaign planned for the end of 2015-beginning of 2016: -BGO phase → Using the 22Ne BGO setup (low-medium energy range) -HPGe phase → Using a new setup (under R&D) (high-medium energy range) Solid targets under investigation.

The LUNA collaboration (1) A. Best, A. Boeltzig*, A. Formicola, S. Gazzana, I. Kochanek, M. Junker, L. Leonzi | INFN LNGS /*GSSI, Italy D. Bemmerer, M. Takacs, T. Szucs | HZDR Dresden, Germany C. Broggini, A. Caciolli, R. Depalo, R. Menegazzo, D. Piatti | Università di Padova and INFN Padova, Italy C. Gustavino | INFN Roma1, Italy Z. Elekes, Zs. Fülöp, Gy. Gyurky| MTA-ATOMKI Debrecen, Hungary O. Straniero | INAF Osservatorio Astronomico di Collurania, Teramo, Italy F. Cavanna, P. Corvisiero, F. Ferraro, P. Prati, S. Zavatarelli | Università di Genova and INFN Genova, Italy A. Guglielmetti, D. Trezzi | Università di Milano and INFN Milano, Italy A. Di Leva, G. Imbriani, | Università di Napoli and INFN Napoli, Italy G. Gervino | Università di Torino and INFN Torino, Italy M. Aliotta, C. Bruno, T. Davinson | University of Edinburgh, United Kingdom G.F. Ciani, G. D’Erasmo, E.M. Fiore, V. Mossa, F. Pantaleo, V. Paticchio, R. Perrino, L. Schiavulli, A. Valentini| Università di Bari and INFN Bari, Italy

The LUNA collaboration (2) 23Na(p,g)24Mg reaction: J. De Boer, M. Wiescher | Notre Dame University, USA (High energy measurements and R matrix calculations) L. Gialanella, R. Buompane, L. Gasques | Seconda Università di Napoli and INFN Caserta, Italy (ERNA/CIRCE collaboration) (Measurement of the 23Na(p,a)20Ne competing reaction at CIRCE collaboration with LUNA members). 2H(p,g)3He reaction: L. Marcucci, A. Kievsky and M. Viviani | Università di Pisa and INFN Pisa, Italy (ab initio calculations)

The LUNA collaboration (3) LUNA MV- Under definition Z. Janas, C. Mazzocchi et al., Warsaw University, Poland K. Czerski et al., Szczecin University, Poland

LUNA MV project LUNA MV accelerator will be installed in the south part of Hall C of LNGS laboratory (OPERA location) Provisionary dimensions of the hall: 27x11x5 m3 Opera decommissioning started in Jan 2015 To be finished by October 2016. (S. Gazzana link to LUNA MV)

LUNA MV project Accelerator: Intense H+, 4He+, 12C+ e 12C++ beams in the energy range: 350 keV-3.5 MeV. One beam line with all necessary elements (magnets, ..). Total budget about 3.9 Meuro: from LUNA MV Premium projects (total 5.3 Meuro) Tendering procedure («procedura ristretta»): full documentation submitted to INFN central administration at end of february 2015 (for the INFN Executive Board and Directorate meetings of March 2015) Tender assignment: 50% tecnical performances (beam intensity, beam quality, maintenance, additional components, …) , 50% price RUP: G. Imbriani, Università di Napoli DEC & designer: M. Junker, LNGS

LUNA MV project: INFN executive board March 18th, 2015

LUNA MV-timeline Accelerator tender: Contract signed by 12/2015. Accelerator built and tested by the producing company by 11/2017. Accelerator installed at LNGS and tested by 07/2018. Then first experiments Building & shielding: final solution to be defined by June 2015. GEANT4 simulations with different materials are under development in order to find out the best compromise among performance as neutron shield, price, easiness of decommissioning, thickness (maximize internal space, … Plants: to be defined by December 2015 From January 2016 start of tendering for building & shielding and plants

LUNA MV- organigram PI Guglielmetti Prati GLIMOS Gazzana RAE Coord of authorization request Prati GLIMOS Gazzana RAE Gas target beam line Solid target beam line Imbriani Gamma detectors & DAQ Menegazzo Neutron detectors & DAQ Paticchio Neutron simulation Trezzi Plants Civil engineering Building & Infrastructure Accelerator Junker/ Imbriani Scientific equipments Formicola Accelerator advisory committee RUP support office Technical coordinator