Laboratory experiments relevant to mesospheric clouds, Saturn’s rings & astrophysical jets
2016.05.31 17:07
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.
댓글 0
번호 | 일시 | 장소 | 연사 | 제목 |
---|---|---|---|---|
208 | August. 16th (Fri), 14:00 | E6 Room(#1323) | Jinxing Zhang |
Multiferroic and Magnetoelectric Effects by Tailoring Interfacial Chemistry and Physics in Correlated Oxides
![]() |
207 | May. 17(Mon) 17:00 | Zoom webinar | Jing Shi (UC Riverside, USA) |
Spin current generation and detection in uniaxial antiferromagnets
![]() |
206 | May. 8th (Wed), 16:00 | E6 Room(#1323) | Jieun Lee |
Imaging valley dependent electron transport in 2D semiconductors
![]() |
205 | May. 8th (Wed), 16:00 | E6 Room(#1323) | Jieun Lee |
Imaging valley dependent electron transport in 2D semiconductors
![]() |
204 | June 27 (Thu), 2:00 PM | #2502, E6-2 | Hyun-Yong Lee |
Gapless Kitaev Spin Liquid to Loop and String Gases
![]() |
203 | 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 |
202 | Dec. 11 (Fri.), 04:00 PM | online | Hyobin Yoo(Sogang Univ.) | Atomic and electronic reconstruction at van der Waals interface in twisted 2D materials |
201 | August. 1st (Thu), 14:00 | E6 Room(#1323) | Hyeok Yoon |
Low-density Superconductivity in SrTiO3 Probed by Planar Tunneling Spectroscopy
![]() |
200 | August 27 (Tue.), 4:00PM | Rm. 1323, E6 | Hiroshi Eisaki |
Critical current properties of Fe-based superconductors
![]() |
199 | January 17 (Fri), 4:00 PM | #1323, E6-2 | Hiroki Ikegami |
Symmetry Breaking and Topology in Superfluid 3He
![]() |
198 | September 26 (Thu.), 16:00 PM | #1323, E6-2 | Han Seb Moon |
Entanglement Swapping with Autonomous Polarization-Entangled Photon-Pairs from Warm Atomic Ensemble
![]() |
197 | December 27(Fri.), 15:00 | E6-2,#5318 | Han Gyeol Suh |
The superconducting order parameter puzzle of Sr2RuO4
![]() |
196 | Dec 27 (Fri), 3:00 PM | #5318, E6-2 | Han Gyeol Suh |
The superconducting order parameter puzzle of Sr2RuO4
![]() |
195 | May. 12(Thu), 4pm | E6-2. #1323 & Zoom | Dr.Philip Chang (University of California San Diego, Department of Physics) | New frontiers of electroweak physics at the LHC |
194 | May. 19(Thu), 4pm | E6-2. #1323 & Zoom | Dr.Jay Hyun Jo (Yale University, Department of Physics) | Chasing Long Standing Neutrino Anomalies with MicroBooNE |
193 | May. 18(Wed), 4pm | E6-2. #1323 & Zoom | Dr.Heeyeon Kim (Rutgers University, Department of Physics and Astronomy) | Geometry, Algebra, and Quantum Field Theory |
192 | Nov. 18th (Fri) 10:30 a.m. | #5318(5th fl.) | Dr. 최 순 원, Havard University | Non-equilibrium many-body spin dynamics in diamond |
191 | Oct. 27th(Thu) 4PM | #1323(E6-2) | Dr. 이 강 희, KAIST, Mechnical Engineering | Terahertz Metal Optics |
190 | June 28 (Fri.), 13:30 PM | #1323, E6-2 | Dr. Yusuke Kozuka |
Magnetic domains and domain wall conduction in pyrochlore iridate thin films and heterostructures
![]() |
189 | Apr. 08 (Fri.), 13:30 PM | E6-2. 1st fl. #1501 | Dr. Yunkyu Bang, Chonnam National Univ. | Theoretical Overview of Iron-based superconductors and its future |