Simulating an Exploding Fission-Bomb Core With a Desktop Computer

Cameron Reed
Monday, March 28, 2016 - 2:30pm to 4:00pm

This colloquium will describe a program developed for a desktop computer which carries out a time-dependent simulation of the core of an exploding nuclear weapon. The logic of the program is understandable to any student familiar with kinematics and vectors; the necessary nuclear concepts will be introduced as needed. The simulation models a core comprising a mixture of two isotopes: A fissile one (such as uranium-235) and an inert one (such as uranium-238) that captures neutrons and removes them from circulation. The user sets the enrichment percentage and...

Ultrafast dynamics of ferroelectrics and transition metal dichalcogenides

Haidan Wen
Thursday, March 24, 2016 - 3:30pm to 4:30pm

The quest of new states of matter in the time domain and the need for ultrafast control of material properties have been fueled by the recent advance of large-scale ultrafast x-ray facilities. These new experimental capabilities enable direct probe of structural dynamics with unprecedented spatial and temporal resolution, shedding light on the fundamental material processes and guiding the design of ultrafast devices. In the first example, I will show that the ultrafast optical and terahertz excitations offer new pathways of controlling lattice structure of...