1. 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

2. 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!

3. 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 ~ ly)
ESA / IUE
HST (1994)

4. 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

5. 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

6. 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)

7. 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)

8. 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)...

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

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

11. 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

12. 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)

13. 30P(p,γ)31S via 31P(3He,t)31S 31S E3He = 20 MeV, 1.5° Yale Split-Pole
ΔE = 25 keV
5 50 nA
Wrede + (2007, 2009)
E3He = 25 MeV, 10°
MLL Q3D nA
ΔE = 10 keV
AP+ (2011)
counts
30P+p
Q = 6133 keV
31S
30P (1+, t1/2 = 2.5 min)

14. 30P(p,γ)31S via 31P(3He,t)31S 1/2+ 31S E3He = 20 MeV 1.5°
Yale Split-Pole
ΔE = 25 keV
5 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 nA
ΔE = 10 keV
AP+ (2011)
counts
30P+p
Q = 6133 keV
31S
30P (1+, t1/2 = 2.5 min)

15. 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

16. 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

17. 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

18. 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:

19. 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 /cm 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 , 2010, 2011)
2-3 kpc detectability
PROHIBITIVE. look for help from indirect methods...

20. 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

21. 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, Ing )

22. 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
≈ AU ≈ 0.002"
nucleosynthesis: H – Ca
Most of the thermonuclear reaction rates involved are constrained by experiments
Nova Cygni 1992 (d ~ ly)
HST (1994)