IAMS lecture on April 20, 3:30pm, CT. Chang Memorial Hall, Prof. Klaus Muller-Dethlefs
截止日期：2011-04-12
IAMS Lecture Announcement
中研院原分所演講公告
Title: A Novel Ultra-cold Rydberg Plasma: from Wigner Crystallisation to a Degenerate Bose Gas?
Speaker: Prof. Klaus Muller-Dethlefs (The Photon Science Institute, Univ. of Manchester, UK)
Time: 3:30PM, April 20 (Wednesday)
Place: C.T. Chang Memorial Hall (4F), IAMS (本所4樓張昭鼎紀念講堂)
Contact: Dr. Wen-Bih Tzeng 曾文碧博士
Abstract:
We produce an ultra-cold, very long lifetime Rydberg plasma by two-photon resonant excitation into the ionization threshold region, via the A-state (NA=0), in the expansion region of a supersonic jet close to the nozzle. Collisions in the jet expansion cool the ions in the plasma to ca. 0.2K thus avoiding disorder heating as in MOT Rydberg plasma experiments.
This plasma has a very long lifetime and after ca 310ms, when the plasma hits a 4mm diam. aperture, a dramatic increase in density is observed experimentally just behind this aperture. These observations can be explained by a compression of the plasma, which exhibits the properties of a sponge like material, i.e. a plasma crystal.
A possible explanation is the formation of a Wigner crystal. A possible route towards the formation of a degenerate Bose gas of the 14N16O+ cations, that is a molecular Bose-Einstein Condensate will be discussed.
中研院原分所演講公告
Title: A Novel Ultra-cold Rydberg Plasma: from Wigner Crystallisation to a Degenerate Bose Gas?
Speaker: Prof. Klaus Muller-Dethlefs (The Photon Science Institute, Univ. of Manchester, UK)
Time: 3:30PM, April 20 (Wednesday)
Place: C.T. Chang Memorial Hall (4F), IAMS (本所4樓張昭鼎紀念講堂)
Contact: Dr. Wen-Bih Tzeng 曾文碧博士
Abstract:
We produce an ultra-cold, very long lifetime Rydberg plasma by two-photon resonant excitation into the ionization threshold region, via the A-state (NA=0), in the expansion region of a supersonic jet close to the nozzle. Collisions in the jet expansion cool the ions in the plasma to ca. 0.2K thus avoiding disorder heating as in MOT Rydberg plasma experiments.
This plasma has a very long lifetime and after ca 310ms, when the plasma hits a 4mm diam. aperture, a dramatic increase in density is observed experimentally just behind this aperture. These observations can be explained by a compression of the plasma, which exhibits the properties of a sponge like material, i.e. a plasma crystal.
A possible explanation is the formation of a Wigner crystal. A possible route towards the formation of a degenerate Bose gas of the 14N16O+ cations, that is a molecular Bose-Einstein Condensate will be discussed.