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Constraining nova observables: Direct measurement of 33 S(p, ) 34 Cl in inverse kinematics

Constraining nova observables: Direct measurement of 33 S(p, ) 34 Cl in inverse kinematics. Jennifer Fallis, DRAGON. Motivation. Nucleosynthesis calculations of ONe novae predict an overproduction of 33 S by a factor of 150 compared to solar.

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Constraining nova observables: Direct measurement of 33 S(p, ) 34 Cl in inverse kinematics

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  1. Constraining nova observables: Direct measurement of 33S(p,)34Cl in inverse kinematics Jennifer Fallis, DRAGON CAWONAPS - Dec 10th, 2010

  2. Motivation • Nucleosynthesis calculations of ONe novae predict an overproduction of 33S by a factor of 150compared to solar. • This could vary by factors of 0.01 to 3 due to the current experimental uncertainty in the rate of 33S destruction via 33S(p,)34Cl. CAWONAPS - Dec 10th, 2010

  3. Motivation CAWONAPS - Dec 10th, 2010

  4. Classification of presolar grains • Large over-abundances of several specific isotopes can be used to identify presolar grains, and their astrophysical origins. • 12C/13C, 14N/15N, 30Si/28Si • The measured isotopic ratios can constrain models of stellar nucleosynthesis. • The mere existence of grains from novae can provide information about nova ejecta. • To get C-rich grains from O-rich ejecta limits condensation conditions CAWONAPS - Dec 10th, 2010

  5. Classification of presolar grains • AGB stars and SN nucleosynthesis cannot explain these grain signatures. • Seeing an over- abundance of 33S would be an indicator for ONe novae. CAWONAPS - Dec 10th, 2010

  6. Classification of presolar grains AGB stars J-type C stars SN AGB stars AGB stars Novae Novae? • AGB stars and SN nucleosynthesis cannot explain these grain signatures. • Seeing an over- abundance of 33S would be an indicator for ONe novae. CAWONAPS - Dec 10th, 2010

  7. Classification of presolar grains • Sulfides are expected to be incorporated into SiC grains. (K. Lodders and B. Fegley Jr., Meteroritics 30 (1995) 1959) • Sulfide measurements are complicated by the H2SO4 used to separate SiC grains. • … but a recent paper measured the 34S/32S ratio in a SiC grain of SNII origin. ( P. Hoppe et al., ApJ 719 (2010) 1370 ) 33S? CAWONAPS - Dec 10th, 2010

  8. Possible -telescope target? • 33S(p,)34Cl is the only means of production of 34mCl in classical novae. • Characteristic -rays resulting from its subsequent -decay (t1/2 = 32 m) might be a future target for  -ray telescopes. • Requires nova ejecta to become transparent to ’s in a short enough time period, or for there to be large enough amounts of 34mCl that it hasn’t all decayed in the intervening time. Eg = 1.2, 2.1, 3.3 MeV Photo: ESA CAWONAPS - Dec 10th, 2010

  9. 34Cl level structure above 33S+p • Currently, experimental measurements of  only exist down to Er = 434 keV. • The energy region corresponding to nova temperatures (0.2-0.4 GK) goes as low as Er = 220 keV. • As of 2008, there were two possible states within the Gamow window and 3 just below it, which had not been measured directly. • Deduced from (p,) -decay schemes (Waaders, Dassie) • From various indirect studies F. B. Waaders et al., Nucl. Phys. A411 (1983) 81 D. Dassie et al., Nucl Phys. A276 (1977) 260 & 279 R. M. Del Vacchio et al., Nucl. Phys A265 (1976) 220 H. Nann et al., Phys Rev C. 15 (1977) 1959 C. J. van der Poel et al., Nucl Phys A373 (1982) 81 P. Baumann et al., Phys Rev. C 18 (1978) 247 CAWONAPS - Dec 10th, 2010

  10. 34Cl level structure above 33S+p 1.00E+00 29 1.00E-01 137 Er = 398 434 172 1.00E-02 398 244 244 1.00E-03 Er = 244 398 492 663 620 434 1.00E-04 492 1.00E-05 NA<v> (cm3/s/mol) 530 530 1.00E-06 754 620 642 710 1.00E-07 642 663 1.00E-08 710 798 754 1.00E-09 172 137 798 1.00E-10 0.25 0.3 0.35 0.4 0.45 T (GK) José et al., Astrophys. J. 560 (2001) 897 CAWONAPS - Dec 10th, 2010

  11. 34Cl level structure above 33S+p Recent work by A. Parikh et al. using 34S(3He,t)34Cl PRC 80, 015802 (2009) In 2009: • 8 states (6 new!) without any measured  within the relevant energy region. CAWONAPS - Dec 10th, 2010

  12. CAWONAPS - Dec 10th, 2010

  13. 33S beam development SUPERNANOGAN • Stable beams of 33S from Supernanogan: • 1x1010 pps of 33S6+, no contamination seen CAWONAPS - Dec 10th, 2010

  14. CAWONAPS - Dec 10th, 2010

  15. Determining  nrecoils = Y = 2 (Mbeam +mtgt) () . nbeamBGO CSD sep DSSSD2mtgt . stopping cross-section / target atom CAWONAPS - Dec 10th, 2010

  16. 33S(p,)34Cl run Coincidence Singles • Re-measured the important 33S+p resonances at Er = 434 and 492.5 keV.   Er = 492 CAWONAPS - Dec 10th, 2010

  17. 33S(p,)34Cl run • Re-measured the important 33S+p resonances at Er = 434 and 492.5 keV.   Er = 492 CAWONAPS - Dec 10th, 2010

  18. 33S(p,)34Cl run • Re-measured the important 33S+p resonances at Er = 434 and 492.5 keV.   • Er = 492.5 keV • 3240 counts seen in ~ 3hrs •  (preliminary) : 0.07(1) eV •  (Endt90) : 0.088(25) eV • Er = 434 keV • 2912 counts seen in ~ 3 hrs •  (preliminary) : 0.06(1) eV •  (Endt90) : 0.050(13) eV So far so good . . . P. M. Endt, Nucl. Phys. A521 (1990) 1 CAWONAPS - Dec 10th, 2010

  19. 33S(p,)34Cl run 400 244 ~10 hrs ~18 hrs ~38 hrs 214 183 ~21 hrs • Er = 400, 342, 281, 244 and 183 keV • To be astrophysically relevant needed on the order of • 330, 50, 8, 3 and 0.5 counts/hr respectively • No coincidence events above background seen CAWONAPS - Dec 10th, 2010

  20. 33S(p,)34Cl run • Er = 310 keV: 10 events in 17 hrs • Er = 293 keV: 31 events in 13.5 hrs 310 293 CAWONAPS - Dec 10th, 2010

  21. Resonance Strength () CAWONAPS - Dec 10th, 2010

  22. Energy Measurement & Determining Er • ISAC beam energy is measured at DRAGON charge slits • without gas : to determine Ebeam • with gas : to measure stopping power CAWONAPS - Dec 10th, 2010

  23. Energy Measurement & Determining Er • ISAC beam energy is measured at DRAGON charge slits • without gas : to determine Ebeam • with gas : to measure stopping power • Location of narrow resonances in gas target can be determined using BGO array • knowing the target profile, location in target and stopping power, we can determine Er CAWONAPS - Dec 10th, 2010

  24. BGO z-position 431 Er=492 keV 293 310 CAWONAPS - Dec 10th, 2010

  25. Conclusions • With little contribution to the rate from the previously unmeasured states, the lower limit shown above, based on existing measurement, is likely to remain the current experimental rate of the 33S(p,)34Cl reaction. Image from A. Parikh et al., PRC 80, 015802 (2009) Preliminary! CAWONAPS - Dec 10th, 2010

  26. Collaborators • A. Parikh (Technische Universität München) • C. Ruiz, D. A. Hutcheon, L. Buchmann, U. Hager, D. Ottewell, S. Sjue (TRIUMF) • B. Davids, S. Reeve (TRIUMF/Simon Fraser University) • J. M. D’Auria (Simon Fraser University) • S. Bishop, C. Herlitzius (Technische Universität München) • C. Wrede (U Washington) • C. M. Deibel (JINA/ Argonne), J. A. Clark (Argonne) • A. A. Chen (Excellence Cluster Universe, McMaster), • K. Setoodehnia (McMaster) • U. Greife (CSM), A. M. Laird (York), P. D. Parker (Yale), C. Vockenhuber (ETH Zurich) , J. José (UPC, IEEC Barcelona) • B. Guo, G. Lian, Y. Wang, Z. Li, E. Li, W. Liu (China Institute of Atomic Energy) CAWONAPS - Dec 10th, 2010

  27. CAWONAPS - Dec 10th, 2010

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