Ching-Yen Wu’s involvement in nuclear physics began with his thesis work, which focused on the experimental study of the shape transition in the Os-Pt region using the sub-barrier Coulomb excitation method. During the course of this work, he learned nuclear structure physics as well as the techniques for gamma-ray and charged-particle detection and the construction of parallel-plate avalanche counters (PPACs) for segmented 4π gamma-ray arrays.

Wu’s latest accomplishment was the development of the Compact Heavy Ion Counter (CHICO2), a two-dimensional pixelated PPAC, as an auxiliary charged-particle detector array for the Gamma-Ray Energy Tracking In-beam Nuclear Array (GRETINA), one of the most advanced gamma-ray energy tracking arrays. This integration was successfully implemented in a recent science campaign at Argonne National Laboratory to study various aspects of nuclear collectivity. As a result of the campaign’s success, the US Department of Energy Office of Science approved a project to upgrade CHICO2 to CHICOX to be accommodated by GRETA, a 4π version of GRETINA, a unique integration that will be one of the most sensitive spectrometers to study the nuclear gamma-ray spectroscopy.

Wu’s detector experience also enables the development of specialized PPACs for fission-fragment detection, which provides the tagging capability and opportunity to study the fission observables relevant to programmatic projects, such as the prompt neutron and gamma emission in fission.

Wu’s research interests include the evolution of shell structure and collectivity in nuclei, neuron-induced reactions, and fission.

Ph.D., Physics, University of Rochester, 1983

B.S., Physics, National Central University, Taiwan, 1976

(122 total in referred journals; 41 since 2010)

1. M.Q. Buckner, C.Y. Wu, et al., Comprehensive ^242mAm neutron-induced reaction cross sections and resonance parameters, Physical Review C 95, 061602 (R) (2017).
2. B. Bucher, S. Zhu, C.Y. Wu, et al., Direct evidence for octupole deformation in ¹⁴⁶Ba and the origin of large E1 moment variations in reflection-asymmetric nuclei, Physical Review Letters 118, 152504 (2017).
3. B. Bucher, S. Zhu, C.Y. Wu, et al., Direct evidence of octupole deformation in neutron-rich ¹⁴⁴Ba, Physical Review Letters 116, 112503 (2016).
4. C.Y. Wu, et al., CHICO2, a two-dimensional pixelated parallel-plate avalanche counter, Nuclear Instruments and Methods in Physics Research A 814, 6 (2016).
5. A. Chyzh, C.Y. Wu, et al., Total prompt gamma-ray emission in fission of ²³⁵U, ^239,241Pu, and ²⁵²Cf, Physical Review C 90, 014602 (2014).
6. E. Kwan, C.Y. Wu, et al., Precision measurement of the electromagnetic dipole strength in ¹¹Be, Physics Letters B 732, 210 (2014).
7. L.P. Gaffney et al., Studies of pear-shaped nuclei using accelerated radioactive beams, Nature 497, 199 (2013).
8. A.M. Hurst, C.Y. Wu, et al., Narrowing of the neutron sd-pf shell gap in ²⁹Na, Physics Letters B 674, 168 (2009).
9. A. B. Hayes, D. Cline, C. Y. Wu, et al., Breakdown of K selection ¹⁷⁸Hf, Physical Review Letters 96, 042505 (2006).
10. C.Y. Wu, H. Hua, and D. Cline, The role of the intrinsic E2 matrix element between the first two 0⁺ states in their configuration mixing in ¹⁰⁰Zr, Physics Letters B 541, 59 (2002).

• Excellence in Publication, LLNL, 2013
• Award of Excellence in Defense Programs, LLNL, 2009