University of Connecticut

Events Calendar

Edward Pollack Distinguished Lecture

Friday, April 15, 2016
4:00pm – 5:00pm

Storrs Campus
Gant Science Complex, Physics, Room PB-38

Professor Thomas Gallagher, Physics Department, University of Virginia

“Ionization and Recombination in Strong Microwave Fields”

Multiphoton ionization of atoms by strong laser fields has been studied for some time, yet surprising new phenomena continue to appear. Bound Rydberg states of He have been observed to accompany multiphoton ionization of He by 1 GV/cm laser fields. Such fields are many orders of magnitude higher than required to ionize the Rydberg states, prompting the questions of why the Rydberg atoms survive and how they are produced in the first place. Insight into these questions is provided by an alternative way of exploring multiphoton ionization, using Rydberg atoms and microwave fields. Recent experiments in microwave ionization show that precisely the same phenomenon seen in the high power laser experiments is observed in microwave ionization, provided the stray fields are well controlled. Specifically, subsequent to a microwave pulse which ionizes 90% of the atoms in an initially excited Rydberg state, 10% are left in highly lying bound states which can be ionized by static field five orders of magnitude smaller than the microwave field. Experiments with high microwave frequencies demonstrate that the production of high lying states is a resonant process which does not always accompany ionization, in agreement with a proposal made some time ago.

Please join us in the Physics Library, Room PB-103 for the Employee Recognition Event. The department will be hosting a special refreshments hour from 3:00-4:00 p.m. in recognition of all Physics employees.


Dawn Rawlinson, 486-4916,

Physics Department (primary)

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