[Triumf-seminars] TRIUMF ISAC Seminar today at 15:30

[TRIUMF Seminars]

Date/Time: Mon 2017-11-27 at 15:30

Location:  Auditorium          

Speaker:   Thanassis Psaltis (McMaster University)

Title:     Breakout reactions from the pp-chain and the nu-p process: Measurement of the 7Be(alpha,gamma)11C reaction rate in inverse kinematics

Abstract: The origin of about 35 neutron-deficient stable isotopes with mass numbers A >74, known as the p-nuclei, has been a long-standing puzzle in Nuclear Astrophysics. The neutrino-p process is a candidate for the production of the light p-nuclei, but it presents high sensitivity to both supernova dynamics and nuclear physics [1,2]. It has been recently shown that the breakout from pp-chains through the 7Be(alpha,gamma)11C reaction, which occurs prior to nu-p process, can significantly influence the production of p-nuclei in the 90<A<110 region [2]. Nevertheless, this reaction has not been studied well yet in the relevant temperature range--- T_9 =1.5-3. To that end, the first study of important resonances of 7Be(alpha,gamma)11C reaction with unknown strengths using DRAGON [3] was recently held at TRIUMF. The reaction was studied in inverse kinematics using a radioactive 7Be (t1/2 =53.24 d) beam provided by ISAC-I and two resonances above the alpha-threshold --- Eth = 7543.62 keV --- were measured. 

The experimental details, some preliminary results, and GEANT3 simulations of the transmission of the recoils and the efficiency of the BGO array of DRAGON will be discussed.

References
[1] C. Frohlich et al., Phys. Rev. Lett. 96, 142502 (2006).
[2] S. Wanajo, H.-T. Janka and S. Kubono, Astrophys. J. 729, 46 (2011).
[3] D.A. Hutcheon et al., Nucl. Instr. Meth. Phys. Res. A 498, 190 (2003).




informal talks on research progress

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