Study of the resonance states in 27P by using Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Study of the resonance states in 27P by using elastic scattering of 26Si + p 2011. 6. Young Kwan Kwon Department of physics, Chung-Ang University, Republic of Korea

1.809 g-ray image, made by COMpton TELescope Overview • • • Analysis and results • • • • Experiment • • • • • • • Experiment • • • Astrophysical implication • • • Summary 1.809 g-ray image, made by COMpton TELescope Estimation of the abundance of 26Al under different stellar sites, i.e., Novae, Supernovae, etc. : Important for building a model of stellar evolution, or identifying the main origin of the g-sources 26mAl and 26gAl have different paths. Then, they should be dealt with as different species??

Under higher temperature of T > 0.4 GK, they can communicate Overview • • • Analysis and results • • • • Experiment • • • • • • • Experiment • • • Astrophysical implication • • • Summary Under higher temperature of T > 0.4 GK, they can communicate through internal transitions. (Ward80, Coc00, and Runk01) Therefore the abundance of 26mAl become s important and we should know the reaction rate of 26Si (p, g)27P, which competes with 26Si(b+n)26mAl. More contributable, the resonance reaction rate needs the information of the resonances within Gamow window, such as E i (resonance energy), J (spin).

To get the resonance parameters of resonance states in 27P, Overview • • • Analysis and results • • • • Experiment • • • • • • • Experiment • • • Astrophysical implication • • • Summary To get the resonance parameters of resonance states in 27P, • Probe : Elastic scattering with a radioactive ion beam 26Si, because of its large scattering cross section • Physical quantity to be measured : Excitation function of the elastic scattering of 26Si + p using thick target scan technique • Tool for analysis : R-matrix based code SAMMY M6-beta • Physical quantities to be extracted : Resonance parameters, such as energy, spin-parity, and proton decay width for each observed resonance • Astrophysical Information to be presented : Reaction rate for resonant capture as a function of temperature

Dr. Jung Young Moon’s PhD work Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary 1st experiment Date : June 9 2003 ~ June 15 2003 RI beams at F2 : 25Al (11.1 kcps, 5.1 % purity), 26Si (2.32kcps, 1.1 %) for full 24Mg beam of 600enA Dr. Jung Young Moon’s PhD work 2nd experiment Date : Jan 9 2011 ~ Jan 15 2011 RI beams at F3 : 25Al (33 kcps, 61.8 % purity), 26Si (12kcps, 23.2 %) for full 24Mg beam of 1600enA Miss Hyo Soon Jung’s PhD work

Experimental setup in 2003 D1 D2 Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Experimental setup in 2003 CRIB (CNS Radioactive Ion Beam separator) @ RIKEN, Japan 24Mg beam (7.439 MeV/u, ~ 600 emA) + 3He gas (1atm) 3He (24Mg, n)26Si D2 D1 PPAC Target holder DE-E array @ 0 deg. DE-E array @ 17 deg. PPAC

E cm (26Si) = 3.606 MeV on target Beam Intensity = 2 .32 kcps Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Depending on different Br, the fragments are separated by two dipole magnets. E cm (26Si) = 3.606 MeV on target Beam Intensity = 2 .32 kcps By using position sensitive detectors, proton spectra can be converted to those in C.M. frame.

Experimental setup in 2003 26Si14+ - Energy ~ 3.710MeV/u Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Experimental setup in 2003 26Si14+ - Energy ~ 3.710MeV/u - Purity ~ 23 % - Intensity ~ 1.2X104 pps

26Si RIB 3.710MeV/u recoiled protons H2 gas target (30cm, 330torr) Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary 26Si RIB 3.710MeV/u recoiled protons H2 gas target (30cm, 330torr) DSSDs at 0o and 15o for DE-E telescope PPACs

Excitation function from experimental data Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Excitation function from experimental data The excitation function of 26Si + p can be analyzed by R-matrix theory and Shell model calculation to extract the resonance parameters.

Preliminary result Excitation function of 26Si+p In 2003 In 2011 0o Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary Excitation function of 26Si+p In 2003 0o Preliminary result In 2011

R-matrix analysis for 1st exp’s data Overview • • • Analysis and results • • • • Experiment • • • • • • • Astrophysical implication • • • Summary R-matrix analysis for 1st exp’s data It was hard to determine a good spin-parity combination for the observed peaks, because of large statistical error. So all candidates were taken and used in determining the important resonance parameters.

Comparison with the shell model calculation (OXBASH) Overview • • • Analysis and results • • • • Experiment • • • • • • • Experiment • • • Astrophysical implication • • • Summary Comparison with the shell model calculation (OXBASH) Iliadis et al., NPA 618, 166 (1997) : ~ 0.2 for 1d3/2, 5/2 ~ 0.4 for 2s1/2 Spectroscopic factor Calculation (Oxbash) - Model space : sdpn - Interaction : wpn - Core : 16O(g.s., 0+)

Overview • • • Analysis and results • • • • Experiment • • • Experiment • • • • • • • Astrophysical implication • • • Summary

Preliminary result Results for 2nd experiment Ex (keV) Gp (keV) Overview • • • Analysis and results • • • • Experiment • • • • • • • Experiment • • • Astrophysical implication • • • Summary Results for 2nd experiment Ex (keV) Gp (keV) Jp(l-wave) c2/NDAT (1) 2888 8.3 7/2+ 1.55 2897 1.5 3/2+ 2974 84.5 1/2+ 3310 84.2 3436 106.2 3491 56.3 5/2+ 3548 10.2 (2) 2879 4.4 1.98 2960 85.9 3146 1.2 3338 124.4 3504 68.8 3570 248.6 Preliminary result

** 26Si + p  27P radiative capture reaction rate calculation Overview • • • Analysis and results • • • • Experiment • • • Experiment • • • • • • • Astrophysical implication • • • Summary 26Si + p  27P radiative capture reaction rate calculation 1. Parameters, used in the resonant capture reaction rate calc. ** ** Weisskopf width, calculated and based on the transition information of 27Mg 2. Direct capture reaction rate So = 0.036 from Caggiano et al. (PRC 64 025802, 2001) 3. Total capture reaction rate Resonant capture + Direct capture reaction rate

Not including new levels Overview • • • Analysis and results • • • • Experiment • • • Experiment • • • • • • • Astrophysical implication • • • Summary Not including new levels 1.2 MeV 1.631 MeV Including new levels

X-ray burst model 1.35Msun 1.25Msun 26Si + p  27P 26Si b-decay Overview • • • Analysis and results • • • • Experiment • • • Experiment • • • • • • • Astrophysical implication • • • Summary Competition between 26Si + p  27P and 26Si  26mAl b-decay solid and dashed line : rXH<sv>/AH = 0.693/T1/2 (XH = 0.5, T1/2 = 2.2283 s) X-ray burst model 1.35Msun 1.25Msun 26Si + p  27P 26Si b-decay For T > 2GK and r < 10-2 g cm-3 , the newly found states become more significant.

26Si+p resonant elastic scattering has been measured successfully. Overview • • • Analysis and results • • • • Experiment • • • Experiment • • • • • • • Astrophysical implication • • • Summary 26Si+p resonant elastic scattering has been measured successfully. - The R-matrix analysis is in progress. CRIB is one of the best facilities for studying nuclear astrophysics with low energy RI beams. - There are number of astrophysically important nuclear reactions to be studied. - Future works : alpha transfer reaction -15O(6Li,d)19Ne (alpha,p) reaction – 26Si(a,p)29P KoRIA (Korea Rare Isotope Accelerator) in Korea (2018~ (plan)) - KRS (Korea Recoil Spectrometer) for NAP in KoRIA - Absolutely we need man powers in related fields - Strong collaboration with CRIB is very helpful for success of KoRIA : educating people at CRIB, comments or ideas from CRIB etc

[Collaborators]