Access Type

Open Access Dissertation

Date of Award

January 2017

Degree Type


Degree Name




First Advisor

Wen Li


Electron‐electron interaction is an important and interesting research theme both in chemistry and physics. Experimental study of electron correlation is hindered by the long dead time (the time within which no more than two electrons can be detected) of electron detection system. We developed a new three‐dimensional (3D) particle coincidence imaging system to remove this restriction. The detection system employs a new strategy: It uses a fast‐frame camera to record positional information on 2D MCPs/phosphor detector (so the particle velocities in two dimensions can be measured); It utilizes a high‐speed digitizer to pick up the signal from MCP lead, off‐line analysis is performed on the waveform recorded by the digitizer to get time information (so the velocity in third dimension is measured) with best resolution and accuracy. This particle coincidence imaging system has three major breakthroughs: It achieved 0.64 ns dead time for electron detection; It’s also possible to have true zero dead with less than 1 ns TOF uncertainty; The best TOF resolution reaches 32 ps.

This detection system is then implemented in photoion‐photoelectron coincidence detection apparatus to study electron correlation (the main goal) and dynamics in dissociative double ionization.

We also developed a new method to probe orbital alignment of atoms in photodissociation by strong field ionization.

Included in

Chemistry Commons