Speaker
Mr
Nogwanya Thembalethu
(UWC)
Description
Electron-mediated nuclear plasma interactions (NPIs), such as Nuclear Excita-
tion by Electron Capture (NEEC) or Transition (NEET), may have significant
impact on nuclear cross sections in High Energy Density Plasmas (HEDPs).
These HEDP environments are found in the cosmos where nucleosynthesis takes
place. Attempts have failed so far in measuring the NEEC process [1], while
NEET has recently been observed experimentally [2]. NEEC, NPIs have not
been observed due to the narrowness of nuclear transitions (Γ ≤ 1eV ). The
NPIs may occur on highly excited nuclear states in the quasi-continuum which
is populated in nuclear reactions prior to their decay by spontaneous γ-ray emis-
sion. Direct observation of NPIs are hindered by the lack of a clear signature
of the effect in HEDP environments. Hence, a new signature [3] for NPIs on
highly excited nuclei will be tested by investigating isomeric to ground state
feeding from the quasi-continuum region. An experiment was performed using
the reactions 197 Au( 13 C, 12 C) 198 Au and 197 Au( 13 C, 12 C2n) 196 Au at Lawrence
Berkeley National Laboratory in inverse kinematics with a 197 Au beam of 8.5
MeV/u energy. The activated foils were counted at the low-background count-
ing facility of Lawrence Livermore National Laboratory. I will discuss several
measurements with different target configurations to investigate the feasibility
of NPI studies.
References
[1] P. Morel et al., Nucl. Phys. A 746, 608c (2004)
[2] S. Kishimoto et al., Phys. Lett. 85 , 1831 (2000)
[3] D. L. Bleuel et al., Plasma and Fusion Research 11, 3401075 (2016)
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
Msc
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
Dr Mathis Wiedeking wiedeking@tlabs.ac.za at iThemba LABS
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Primary author
Mr
Nogwanya Thembalethu
(UWC)
Co-authors
Dr
Bleue Darren
(Lawrence Livermore National Laboratory)
Dr
Wiedeking Mathis
(iThemba)
