Improving predictions from nova models through nuclear physics measurements Anuj Parikh Universitat Politècnica de Catalunya Institut d'Estudis Espacials de Catalunya Barcelona, Spain MS or more evolved companion star nuclear reactions set in

Improving predictions from nova models through nuclear physics measurements Anuj Parikh Universitat Politècnica de Catalunya Institut d'Estudis Espacials de Catalunya Barcelona, Spain MS or more evolved companion star nuclear reactions set in Nova modeling: see plenary talk by J. José 9:30-10, Wednesday!

OBSERVATIONS NOVA CYGNI 1992 history ≈ 30 000 AU ≈ 0.002" ESA / IUE spectra change with time, international ultraviolet explorer, UV = 100 to 4000 A Nova Cygni 1992 (d ~ 10 000 ly) ESA / IUE HST (1994)

MODELS → for nucleosynthesis − 1D hydrodynamic → reaction networks: ≈ 100 species, H − Ca 13C, 15N, 17O 7Li, 26Al (??) solar José and Hernanz (2007) José, Casanova, Moreno, García-Berro, AP, and Iliadis (2010) Most of the thermonuclear reaction rates involved are constrained by experiments NACRE 1999, Iliadis+ 2001, Iliadis+ 2010

NUCLEAR PHYSICS José and Hernanz (2007) José et al. (2010) José and Iliadis (2011) Most of the thermonuclear reaction rates involved are constrained by experiments

NUCLEAR PHYSICS: recent studies with the Munich Q3D magnetic spectrograph 30P(p,γ)31S → 31P(3He,t)31S → 32S(d,t)31S 33S(p,γ)34Cl → 34S(3He,t)34Cl → 33S(3He,d)34Cl 26Al(p,γ)27Si →28Si(3He,α)27Si 18F(p,α)15O →19F(3He,t)19Ne → 20Ne(d,t)19Ne discuss some measurements recently made of these two José, Casanova, Moreno, García-Berro, AP, and Iliadis (2010)

Experiments with magnetic spectrographs can provide nuclear physics information useful for INDIRECT calculations of thermonuclear reaction rates → Ex, Jπ, C2S, Γx/Γtot... Such experiments are useful when σ are too low for direct studies when suitable beams/targets are not available for direct studies when level densities are not "too high" to identify key resonances and guide future direct studies to help estimate rates "in the meantime" for model calculations to keep nuclear physicists occupied 30P: 2.5 min halflife the idea is rather than do the direct study where, eg you populate some state at some energy in some nucleus, you use some other reaction which proceeds through the direct mechanism and populates multiple states in the desired nucleus at the same time. the advantage is that in this other reaction you work above the Couloumb barrier, so cross-sections are much higher. the disadvantage is that while you study the same final nucleus, you son't study the same reaction. this is why this is an indirect method. MLL Q3D IPNO Split-Pole (Yale Split-Pole)

Experiments with magnetic spectrographs can provide nuclear physics information useful for INDIRECT calculations of thermonuclear reaction rates → Ex, Jπ, C2S, Γx/Γtot... MLL Q3D dΩnom ~ 14 msr ΔE/E ~ 2 x 10-4 Δρ ~ 6 cm I3He ~ 500 nA VTmax ~ 14 MV IPNO Enge Split-Pole dΩnom ~ 1.7 msr ΔE/E ~ 5 x 10-4 Δρ ~ 21 cm I3He ~ 50 nA VTmax ~ 14 MV beamtime is hard to get, 3x greater p bite, CIAE is 13 MV +MAGNEX (INFN/LNS-Catania), Q3D (CIAE-Beijing), Grand Raiden (RCNP-Osaka)...

Q3D MAGNETIC SPECTROGRAPH Maier-Leibnitz-Laboratorium (Garching, Germany)

Q3D MAGNETIC SPECTROGRAPH Maier-Leibnitz-Laboratorium (Garching, Germany)

31P(3He,t)31S Q3D MAGNETIC SPECTROGRAPH Maier-Leibnitz-Laboratorium (Garching, Germany) 31P(3He,t)31S 3H 3H 3H 3H in this reaction, 27Si will be populated in discrete excited sttaes, which will correposnd kinematically to discrete momenta values for the 4He ions 31P, 31S 3He

30P(p,γ)31S : STATUS DIRECT : No high quality, high I beams of 30P available (>106 pps of 30P) INDIRECT: some Ex, Jπ ; no Γx (for Tnova) IMPACT: varying a theoretical rate by a factor of 10 1D hydro nova model José et al. 2001 30P+p Q = 6133 keV 31S 30P (1+, t1/2 = 2.5 min)

30P(p,γ)31S via 31P(3He,t)31S 31S E3He = 20 MeV, 1.5° Yale Split-Pole ΔE = 25 keV 5 d @ 50 nA Wrede + (2007, 2009) E3He = 25 MeV, 10° MLL Q3D 12 h @ 650 nA ΔE = 10 keV AP+ (2011) counts 30P+p Q = 6133 keV 31S 30P (1+, t1/2 = 2.5 min)

30P(p,γ)31S via 31P(3He,t)31S 1/2+ 31S E3He = 20 MeV 1.5° Yale Split-Pole ΔE = 25 keV 5 d @ 50 nA Wrede et al. 2007 dσ/dΩ (μb/sr) dσ/dΩ (μb/sr) 1/2+ ϴCM (deg) ϴCM (deg) E3He = 25 MeV, 10° MLL Q3D 12 h @ 650 nA ΔE = 10 keV AP+ (2011) counts 30P+p Q = 6133 keV 31S 30P (1+, t1/2 = 2.5 min)

30P(p,γ)31S via 31P(3He,t)31S Contributors to remaining uncertainty: unknown Γp existence of doublet at 6.40 MeV not seen in recent γ-ray study (Doherty+ 2012, fusion-evaporation) AP++ (2011) experimental rate varied within uncertainties 1D hydro nova model need spec factors

30P(p,γ)31S via 32S(d,t)31S 30P(p,γ)31S via 31P(3He,t)31S 25° 54° Ed= 24 MeV MLL Q3D ΔE = 8 keV Irvine, Chen, AP++ (submitted) E3He = 25 MeV, 10° MLL Q3D ΔE = 10 keV AP++ (2011) 25° 54° need spec factors

18F(p,α)15O: STATUS T of interest for novae DIRECT: Beer+ (2011) TRIUMF 5x106 pps 2 counts in 5 days Interference between broad 3/2+ at 665 keV with "3/2+ (?)" states at "8" and "38" keV factor of ≈5 variation in the rate at 0.2 GK affects 18F production in novae by a factor of ≈2 2-3 kpc detectability PROHIBITIVE. look for help from indirect methods... → only tentative Jπ for ER < 665 keV

18F(p,α)15O via 19F(3He,t)19Ne Three states observed around 6.4 MeV Laird, AP++ PRL (2013) 19F(3He,t)19Ne, 25 MeV MLL Q3D, ΔE = 15 keV Three states observed around 6.4 MeV all with different experimental angular distributions Previously, two states (3/2+) states had been assumed R-matrix fit → nova model:

26Al(p,γ)27Si: STATUS ≈100 keV lower measured DIRECT: E of interest for novae Ruiz, AP++ (2006) TRIUMF 3x109 pps 150 cts in 10 days (lowest E measured) 2 lower energy resonances, ≈ weeks to months needed with a (non-existent) 26Al target of 1017 /cm2 + 100 μA proton beam rate uncertainty at relevant T > factor of 10...can affect 26Al produced in novae and Wolf-Rayet stars by a factor of ≈2 (Iliadis++ 2002, 2010, 2011) 2-3 kpc detectability PROHIBITIVE. look for help from indirect methods...

Jπ determined still need Γp 26Al(p,γ)27Si via 28Si(3He,α)27Si studied previously (Schmalbrock+ 1986, Wang+ 1989) , no Jπ assigned E = 25 MeV 15° MLL Q3D AP++ (2011) ΔE ~ 12 keV Jπ determined still need Γp

to obtain proton-transfer C2S → Γp 26Al(p,γ)27Si via 26Al(3He,d)27Si to obtain proton-transfer C2S → Γp PREVIOUS ATTEMPT Create a 26Al target using implantation. Approved (high priority) at TRIUMF-ISAC I26Al ≈ 3 x 1010 pps → 26Al(3He,d)27Si AND → 26Al(3He,t)26Si*(p)25Al for Γp / Γ for 25Al(p,γ)26Si Vogelaar+ (1996) Princeton Q3D 20 MeV, 5° ΔE = 12 keV 26Al TARGET: 1016 atoms/cm2 (evaporation) 6% 26Al comparable to all previous 26Al targets (Buc84, Koe97, Ing02 ... )

Classical nova explosions d = 8.6 ly DA-B = 8 − 30 AU Compact object: white dwarf (CO / ONe) Lmax: ~ 104 – 105 Lsol tlightcurve: ~ days – months Torbital: ~ 1 – 16 h trec: ~ 104 – 105 yr Tpeak: ~ 0.1 – 0.4 GK ρpeak: ~ 103 – 104 g / cm3 envelope: ~ 100 km #Galaxy: ~ 30 / yr Ejecta: ~ 10-4 – 10-5 Msol / nova Sirius A MS star Sirius B white dwarf HST ≈ 30 000 AU ≈ 0.002" nucleosynthesis: H – Ca Most of the thermonuclear reaction rates involved are constrained by experiments Nova Cygni 1992 (d ~ 10 000 ly) HST (1994)