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장소 #1323(E6-2 1st fl.) 
일시 Jun 1 (Wed) 4 PM 
연사 Kil-Byoung Chai, Caltech 

Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets

 

Jun 1 (Wed) 4 PM, #1323(E6-2 1st fl.)
Kil-Byoung Chai, Caltech

 

An rf discharge with liquid nitrogen cooled electrodes and injected water vapor has been used to study nucleation, growth, and dynamics of water-ice grains spontaneously formed in a plasma environment. Examples of water-ice dusty plasmas include polar mesospheric clouds, Saturn’s diffusive rings, and protoplanetary disks. We found that fast grain growth to nonspherical shape with up to 5:1 elongation occurs when the water molecule mean free path exceeds the ice grain screening length. Ice grains grow largest in light gas plasmas, up to 500 µm long in hydrogen plasma. Elongated ice grains align along the plasma ambipolar electric field. Microscope images reveal that the ice grains have fractal nature with 1.7 typical fractal dimension. After the growth process ends, poloidal vortex motion of ice grains is observed and is shown to result from the non-conservative ion drag force.

The Caltech jet experiment produces low beta, high Lundquist number, high density (~1022 m-3) MHD-driven plasma jets and so is similar to astrophysical jets and solar corona loops. We have recently studied various phenomena associated with magnetic reconnection induced by a kink-driven Rayleigh-Taylor instability using comprehensive diagnostics. The results of this study include the following: A spatially localized EUV burst is imaged at the presumed position of fast magnetic reconnection in a plasma jet; the existence of this localized EUV burst indicates strong localized electron heating. Circularly polarized high frequency whistler waves are simultaneously observed indicating that Hall dynamics likely governs the reconnection. Spectroscopic measurement shows simultaneous fast ion heating. We propose that the electron heating is consistent with Ohmic dissipation while the ion heating is consistent with ion trajectories becoming stochastic.

 

번호 일시 장소 연사 제목
공지 2019/09/18 - 12/5  Seminar Room #1323  Prof. David Schuster and etc.  Fall 2019: Physics Seminar Serises
공지 2019/09/02 - 12/09  Seminar Room 1501  이호성 박사 (한국표준과학연구원) and etc.  Fall 2019: Physics Colloquium
170 May 30 (Thu.), 16:00 PM  #1323, E6-2  Prof. Chang-Hee Cho  Tuning the excitonic properties of semiconductors with light-matter interactions file
169 July 9 (Mon.), 14:00 PM  #1323, E6-2  Prof. Cesar A. Hidalgo, MediaLab, MIT  The principles of collective learning file
168 Aug. 4, 2016 (Thu.), 2:30 pm  KAIST Natural Science Building (E6-5), EDU 3.0 Room(1st fl.)  Prof. Argyris Nicolaidis  Relational Logic (with applications to Quantum Mechanics, String Theory, Cosmology, Neutrino Oscillations, Statistical Mechanics)
167 2019. 8. 22 4PM & 8. 23 3PM  #1323, E6-2  Prof. Andrew N Cleland  Physics and Applications in Nanoelectronics and Nonomechanics file
166 8/19 (Mon), 10:00~11:30, 8/22 (Thur), 10:00~11:30  Rm. 1322, E6-2  Nicolas Treps  Tutorials on Multimode Quantum Optics in the Continuous Variable Regime file
165 Oct. 17th (Mon) 11:00 AM  #1323,(E6-2, 1st fl.)  Nguyen Quang Liem, Institute of Materials Science, VAST, Viettnam  IMS and examples of the studies on optoelectronic materials
164 January 23, 2019  Rm. C303, Creation Hall (3F), Munji Campus  Mikko Mottonen  Ultrasensitive Microwave Bolometer: Opportunity for Axion Detectors file
163 July 26, 2018 at 14:00  Room 5318, KAIST Natural Sciences Lecture Hall(E6).  Manki Kim (Department of Physics, Cornell University)  Inflation in String Theory and Backreaction file
162 Jul 3rd, 2019 (Wed)  E6-2, 2501  Kyung Soo Choi  Many-body quantum electrodynamis (QED) with atoms and photons: A new platform for quantum optics" file
» Jun 1 (Wed) 4 PM  #1323(E6-2 1st fl.)  Kil-Byoung Chai, Caltech  Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets
160 2012/02/13-05/14  E6, 1501  Kenji Ohmori (Photo-Molecular Science, IMS)  Physics Colloquium : 2012 Spring
159 August. 6th (TUE), 14:00  E6 Room(#1323)  Kanghyun Chu  Visualization of in-plane piezoresponse vector fields file
158 July 21 - August 2  E6-2,# 5318  Junmou Chen/Thomas Flacke/Kaoru Hagiwara/Junichi Kanzaki/Chris Kelso/Jeong Han Kim/Kyoungchul Kong/Gabriel Lee/Hye-Sung Lee/Ian Lewis  Challenges and Opportunities in Theoretical Particle Physics 2019 file
157 Sep10(Tue), 15:00  #2502, E6-2  Jun Ho Son  (2+1) D Duality Web from 3D Euclidean Lattice file
156 August. 16th (Fri), 14:00  E6 Room(#1323)  Jinxing Zhang  Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides file
155 May. 8th (Wed), 16:00  E6 Room(#1323)  Jieun Lee  Imaging valley dependent electron transport in 2D semiconductors file
154 May. 8th (Wed), 16:00  E6 Room(#1323)  Jieun Lee  Imaging valley dependent electron transport in 2D semiconductors file
153 June 27 (Thu), 2:00 PM  #2502, E6-2  Hyun-Yong Lee  Gapless Kitaev Spin Liquid to Loop and String Gases file
152 Jun. 16 (Thu) 4PM  #1323(E6-2, 1st fl.)  Hyochul Kim, Samsung Advanced Institute of Technology  Quantum information processing using quantum dots and photonic crystal cavities
151 August. 1st (Thu), 14:00  E6 Room(#1323)  Hyeok Yoon  Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy file