MRI: Acquisition of a TPX3Cam for High-Rate Coincidence Velocity Map Imaging

Augustana University Association, Sioux Falls SD

Investigators

Abstract

General audience abstract: This Major Research Instrumentation award funds the acquisition of a hybrid silicon pixel detector and integrated electronics, known as a TPX3Cam, for use by a collaboration of five institutions: Augustana University, the University of Mary Washington, the University of Virginia, Michigan State University, and Kansas State University. Researchers in the collaboration share a common interest in using the TPX3Cam to enable sophisticated experiments that probe the interactions of molecules with intense, ultrashort laser pulses. Observing and controlling atoms and molecules at their native timescales has long been a grand challenge in atomic, molecular, and chemical physics. Moreover, as hybrid silicon pixel detectors emerge into wider use, the development of protocols and methods for processing the information from the detector can accelerate the spread of this tool into other areas of science, medicine, and engineering. Notably, the collective use of the TPX3Cam will foster collaborations between Augustana University and the University of Mary Washington, schools that primarily serve undergraduate student populations, and the three large research universities in the collaboration. These efforts will expose undergraduate students to forefront experimental facilities and research efforts and thereby continue to motivate the pursuit of STEM-related education and eventually help produce a highly-skilled workforce. Technical audience abstract: The TPX3Cam will be used to make correlated measurements of multiple particles and thus the reconstruction of molecular dynamics. When coupled with ultrafast laser sources, the experiments will probe the ionization and structural evolution of polyatomic molecules, which are examples of complex quantum systems. Since hybrid pixel detectors operate in a fundamentally different manner than other charged particle detectors, the TPX3Cam instrument will extend these illuminating measurements to situations not easily accessed with standard delay-line anode technology. Examples to be conducted with this new instrumentation include strong field ionization and coherent control of molecules. Strong field ionization (SFI) of molecules results in complex dynamics involving coupled electronic and nuclear motion, often entails correlated electron dynamics, and is used as a probe for molecular structure and dynamics. SFI also enables attosecond science by creating the electron wave packet that subsequently is driven to recollide with its parent atom or molecule, resulting in an attosecond burst of light. Thus, there are numerous basic and application-driven reasons for SFI studies. Strong-field processes in polyatomic molecules are at the forefront of the decades-long pursuit of coherently controlled chemical reactions. Strong-field coherent control methods using shaped ultrafast laser pulses are a general approach to influencing chemical dynamics since they can exploit dynamic Stark shifts and multiphoton processes to alter energy flow. These strong-field control methods can be improved by targeting very specific control outcomes that exploit the unique detection capabilities of the TPX3Cam. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.