Towards the study of Ne(p, Na at LUNA in Gran Sasso · Towards the study of 22Ne(p, )23Na at LUNA...
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Towards the study of 22 Ne(p, ) 23 Na at LUNA in Gran Sasso Rosanna Depalo* for the LUNA Collaboration *Università degli studi di Padova and INFN Padova International School of Subnuclear Physics – Erice, 24/6 - 3/7/2013 References: [1] N. Prantzos et al. A & A 470, 179–190 (2007) [2] C. Iliadis et al. ApJSS 142, 105-137 (2002) [3] P. Podsiadlowski et al. arXiv:astro-ph/0608324 (2006) [4] S.E. Hale et al. Phys. Rev. C 65, 015801 (2001) [5] J.R. Powers et al. Phys. Rev. C 4, 2030-2046 (1971) [6] C. Iliadis et al. Nucl. Phys. A 841, 1-322 (2010) [7] C. Broggini et al. Annu. Rev. Nucl. Part. Sci. 60, 53-73 (2010) The 22 Ne(p,γ) 23 Na is a key reaction of the NeNa cycle of hydrogen burning. Its cross section influences the abundance of the elements between 20 Ne and 27 Al in: Shell H burning in Red Giant Branch and Asymptotic Giant Branch stars [1] Explosive H burning in Classical Novae [2] 22 Ne+p may influence the 23 Na production in type Ia supernovae (“standard candles” in cosmology). Then 23 Na(e - , e ) 23 Ne decreases the electron abundance, affecting the 56 Ni yield and the peak luminosity [3]. The reaction rate uncertainty in the astrophysically relevant energy region reaches a factor of ~2000 because of 13 resonances of unknown strength: The Laboratory for Underground Nuclear Astrophysics is located at Laboratori Nazionali del Gran Sasso (Italy) [7]. 400kV electrostatic accelerator (50 < E protons < 400 keV ; I max = 500 μA) Windowless gas target. Natural neon (9.25% 22 Ne), or 99.9% Enriched 22 Ne. 2 HPGe γ-ray detectors (high energy resolution, efficiency ~ 1%) in close geometry + lead and copper shield 440keV g.s. 2076 440keV The 22 Ne(p,γ ) 23 Na resonance at E lab =186keV has been observed with 42 ± 17 events in 12h. The 22 Ne(p,γ ) 23 Na resonance at E lab =186keV has been observed with 42 ± 17 events in 12h. Study of temperature and pressure profile in the target chamber Beam heating study (ongoing ) Study of 22 Ne(p,γ) 23 Na resonances with 2 HPGe detectors (planned for 2013 ) ASTROPHYSICAL MOTIVATION ASTROPHYSICAL MOTIVATION EXPERIMENTAL SETUP EXPERIMENTAL SETUP MEASUREMENT STRATEGY MEASUREMENT STRATEGY Test run with the pre-existing 2 H(α,γ) 6 Li experiment setup (study of beam induced background, hints on resonant reaction rate) LUNA RANGE Fig. 2: Level scheme of 23 Na with resonance energies of the 22 Ne+p reaction in the center of mass system. The levels at 8862, 8894 and 9000 keV have been reported as tentative by J.R. Powers et al. (1971) [5] but not observed by S.E. Hale et al. (2001) [4]. Fig. 1: The NeNa cycle Fig. 4: Peaks in the γ-ray spectrum corresponding to the decay of the first and second excited states in 23 Na. LUNA 400kV GAS TARGET SOLID TARGET Fig. 3: Pictures of the LUNA setup (left), and of the accelerator ion source (right)
Transcript of Towards the study of Ne(p, Na at LUNA in Gran Sasso · Towards the study of 22Ne(p, )23Na at LUNA...
Towards the study of 22Ne(p,)23Na at LUNA in Gran SassoRosanna Depalo* for the LUNA Collaboration
*Università degli studi di Padova and INFN Padova
International School of Subnuclear Physics – Erice, 24/6 - 3/7/2013
References:[1] N. Prantzos et al. A & A 470, 179–190 (2007) [2] C. Iliadis et al. ApJSS 142, 105-137 (2002)[3] P. Podsiadlowski et al. arXiv:astro-ph/0608324 (2006) [4] S.E. Hale et al. Phys. Rev. C 65, 015801 (2001)[5] J.R. Powers et al. Phys. Rev. C 4, 2030-2046 (1971) [6] C. Iliadis et al. Nucl. Phys. A 841, 1-322 (2010)[7] C. Broggini et al. Annu. Rev. Nucl. Part. Sci. 60, 53-73 (2010)
The 22Ne(p,γ)23Na is a key reaction of the NeNa cycle of hydrogen burning.Its cross section influences the abundance of the elements between 20Ne and 27Al in:
Shell H burning in Red Giant Branch and Asymptotic Giant Branch stars [1]
Explosive H burning in Classical Novae [2]
22Ne+p may influence the 23Na production in type Ia supernovae (“standard candles” in cosmology). Then 23Na(e-,
e)23Ne decreases the electron abundance, affecting
the 56Ni yield and the peak luminosity [3].
The reaction rate uncertainty in the astrophysically relevant energy region reaches a factor of ~2000 because of 13 resonances of unknown strength:
The Laboratory for Underground Nuclear Astrophysics is located at Laboratori Nazionalidel Gran Sasso (Italy) [7].
400kV electrostatic accelerator (50 < E
protons < 400 keV ; Imax = 500 μA)
Windowless gas target. Natural neon (9.25% 22Ne), or 99.9% Enriched 22Ne.
2 HPGe γ-ray detectors (high energy resolution, efficiency ~ 1%) in close geometry + lead and copper shield
440keV g.s.
2076 440keVThe 22Ne(p,γ)23Na resonance at Elab=186keV has been observed
with 42 ± 17 events in 12h.
The 22Ne(p,γ)23Na resonance at Elab=186keV has been observed
with 42 ± 17 events in 12h.
Study of temperature and pressure profile in the target chamber
Beam heating study (ongoing)
Study of 22Ne(p,γ)23Na resonances with 2 HPGe detectors (planned for 2013)
ASTROPHYSICAL MOTIVATIONASTROPHYSICAL MOTIVATION
EXPERIMENTAL SETUPEXPERIMENTAL SETUP
MEASUREMENT STRATEGYMEASUREMENT STRATEGY
Test run with the pre-existing 2H(α,γ)6Li experiment setup (study of beam induced background, hints on resonant reaction rate)
LU
NA
RA
NG
E
Fig. 2: Level scheme of 23Na with resonance energies of the 22Ne+p reaction in the center of mass system. The levels at 8862, 8894 and 9000 keV have been reported as tentative by J.R. Powers et al. (1971) [5] but not observed by S.E. Hale et al. (2001) [4].
Fig. 1: The NeNa cycle
Fig. 4: Peaks in the γ-ray spectrum corresponding to the decay of the first and second excited states in 23Na.
LUNA 400kV
GAS TARGETSOLID TARGETFig. 3: Pictures of the LUNA setup (left), and of the accelerator ion source (right)
