Radiation-Detection Materials for Next-Generation X-Ray Imaging (Oct 2026)

Title: LBNL Scintillation Engineering Lab: Radiation-Detection Materials for Next-Generation X-Ray Imaging

Speaker: Weronika W. Wolszczak

Date: Monday October 19th, 2026 – 11am

Location: Building 15 room 253 (zoom link)

Host: Antoine Islegen-Wojdyla (Advanced Light Source/Berkeley Lab)

Description: Scintillators convert ionizing radiation into visible or ultraviolet light and remain central to radiation detection, imaging, and spectroscopy. Their performance emerges from a multiscale energy-conversion process: the initial creation of energetic carriers is followed by carrier thermalization, transport, trapping, defect formation, and radiative recombination. Despite the long history of scintillator development, these early processes remain poorly understood in many material classes and continue to limit light yield, timing performance, proportionality, radiation tolerance, and energy resolution.

This seminar will introduce scintillator research activities and developing capabilities at LBNL, with an emphasis on connecting materials discovery, synthesis, characterization, and fundamental studies of scintillation mechanisms. I will briefly review the historical evolution of scintillator materials and discuss how new scintillators have traditionally been discovered. I will then outline a vision for a more mechanism-guided approach, in which materials design is informed by direct measurements of the transient states that govern radiation-to-light conversion.

I will present examples from our work on new plastic scintillators and on methods for probing scintillation processes across a broad range of time scales. A central focus will be an ultrafast gamma-pump/optical-probe experiment performed recently at the BELLA Center. The experiment combines laser-plasma-accelerator-driven inverse-Compton gamma-ray pulses with a femtosecond white-light-continuum probe to observe radiation-induced transient absorption dynamics with approximately 40 fs pump–probe synchronization. This experiment is intended to assess the earliest stages of carrier localization, defect formation, and self-trapping before later recombination and trapping processes obscure the initial dynamics.

I will discuss the results of the BELLA campaign, the challenges of coupling an LPA-driven gamma source to pump–probe spectroscopy, and the materials questions this approach can address. Finally, I will outline possible opportunities to connect these materials and characterization capabilities with detector and imaging needs at ALS and invite discussion on the performance requirements and material challenges most relevant to the ALS community.