Wenting Lu

Searching for the low-energy resonances in the 12C(12C,n)23Mg reaction cross section relevant for s-process nucleosynthesis

The 12C(12C,n) reaction (Q=-2.6 MeV) is a potential neutron source for the weak s-process occurring in shell-carbon burning of massive stars. The uncertainty in this reaction rate limits our understanding of the production of elements in the range 60 < A < 110. Current stellar models must rely on the smooth extrapolation of a dubious statistical model calculation based on experimental data taken at energies well above the Gamow window which lies below 3.2 MeV. At Notre Dame, this reaction cross section has been measured in finer steps at energies above 3.5 MeV, while successful measurements down to 3.1 MeV have just recently been achieved. In addition, a new extrapolation based on measurements of the mirror system has been developed which predicts a number of low-energy resonances while accounting well for the high-energy resonances. An overview of this work along with the most recent results and astrophysical implications are presented.

Does a 4-? linear chain exist in 16O?

The12C(4He,8Be)8Be reaction has been measured with a beam energy ranging from 12.2 to 20.0 MeV. The ?-particles emitted in the decay of 8Be were detected in an array of four double sided silicon strip detectors. The excitation function for events in which the 8Be centre of mass angle ?cm = 90? provides evidence that the previously observed 6+ resonance at an excitation energy of 19.35 MeV in 16O is a 6+ doublet, with members at ~ 19.30 and 19.37 MeV.

The role of 12C(12C,n) in the astrophysical S-process

The elements between iron and strontium are largely produced by the weak s-process occurring in massive stars during the late stages of convective core He burning and the convective shell carbon burning with the primary source of neutrons coming from the reaction 22Ne(α,n)25Mg. However, shell carbon burning may produce hot enough temperatures to activate 12C(12C,n)23Mg as a significant neutron source. Few studies have been done on this reaction, and the extrapolation from experimental data down to the relevant astrophysical energies is uncertain. Recent studies performed at the Nuclear Science Laboratory of Notre Dame aim to improve the existing reaction data using new experimental techniques as well as provide a more reliable extrapolation to the low energies not accessible by experiment. Preliminary results will be presented and the astrophysical implications will be discussed.

Activity measurement of Fe60 through the decay of Co60m and confirmation of its half-life

The half-life of the neutron-rich nuclide, {\fesixty} has been in dispute in recent years. A measurement in 2009 published a value of

Disentangling unclear nuclear breakup channels of beryllium-9 using the three-axis Dalitz plot

(2.62 \pm 0.04)\times10^{6}

The first direct measurement of ¹²C (¹²C,n) ²³Mg at stellar energies

years, almost twice that of the previously accepted value from 1984 of

First Direct Measurement of C 12 (C 12, n) Mg 23 at Stellar Energies

(1.49 \pm 0.27)\times10^{6}

First Direct Measurement ofC12(C12,n)Mg23at Stellar Energies

years. This longer half-life was confirmed in 2015 by a second measurement, resulting in a value of

First Direct Measurement of C12(C12,n)Mg23 at Stellar Energies

(2.50 \pm 0.12)\times10^{6}

Breakup branches of Borromean beryllium-9

years. All three half-life measurements used the grow-in of the