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"Recent experimental progress in positronium-laser physics"

Date:

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Time:

Thursday, 07. Nov. 2019

Video-Recording for any system with MP4-support

- Video.mp4 (ca.374 Mb)

15:15 – 16:25

David Cassidy

(University College London)

The field of experimental positronium physics has advanced significantly in recent years,

in many cases by employing new techniques for trapping and manipulating positrons

using Surko-type buffer gas traps [1]. These devices capture and store positrons,

allowing for the production of high quality DC beams, or high intensity pulsed beams.

The latter approach can be used to create an instantaneous cloud of Ps atoms that can

be probed with standard ns pulsed lasers. This allows for the optical production of

excited Ps states, ranging from 2P levels, which decay back to the ground state in 3.2 ns,

to metastable 2S states, that cannot decay radiatively, but will self-annihilate

(in 1.1 microseconds), to long-lived Rydberg states, that do not annihilate at all and,

for easily produced states, may have radiative lifetimes of hundreds of microseconds [2].

The ability to generate Ps atoms in excited states facilitates numerous experimental

programs [3], including precision optical and microwave spectroscopy and the application

of Stark deceleration methods to guide, decelerate and focus Rydberg Ps beams.

In this talk I will discuss recent examples of such experiments and what may be possible

in the near future.