报告题目：Enhancing the lifetime of ultracold plasma: steady-state conditions and confinement techniques
报告人：Professor Sergey Saakyan
报告人单位：Joint Institute for High Temperatures of the Russian Academy of Sciences, Moscow, Russian
主持人：董光炯 教授
时间：2024年6月26日（周三）下午4:00
报告地点：光学大楼A508会议室
报告摘要：
Ultracold plasmas (UCP) represent a unique and versatile platform for investigating fundamental plasma physics phenomena. These system, characterized by their low temperature, offer insights into collective behaviors and many body interactions that are challenging to observe in traditional high temperature plasmas. Of particular interest is the study of strongly coupled plasmas, where the coupling between particles is so strong that collective effects dominate the individual particle dynamics. Recent advancements in UCP research have focused on high density UCPs characterized by relatively short lifetimes, typically not exceeding 100 ���s. The experiments involving laser cooling of ions [1] and magnetic confinement [2] have shown promise in extending UCP lifetimes and enhancing coupling strength, these ef forts have encountered limitations in achieving significantly prolonged lifetimes.
Here, we present a novel methodology for the controlled generation of steady state ultra cold plasma [3]. Our approach leverages continuous two step optical excitation of calcium atoms from magneto optical trap, leading to the formation of a strongly coupled ultracold plasma.
Experimental investigation of plasma parameters is performed by laser induced fluorescence of calcium ions, enabling comprehensive analysis of the system dynamics. Our method ology enables the creation of ultracold plasma with a peak ion density of 2.7 ⋅ 106 cm−3 and a minimum electron temperature near 2 K. Furthermore, by integrating our steady state approach with stringent magnetic confinement techniques, we anticipate achieving extremely strong coupling within these systems, opening avenues for exploring novel plasma physics phenomena and potential applications in various fields. Here, we also discuss alternative strategies for enhancing the lifetime of ultracold plasma.
References
[1] Langin T.K.; Gorman G.M.; Killian T.C.: “Laser cooling of ions in a neutral plasma” Science 363, 6422 61 64 (2019).
[2] Gorman G.M.; Warrens M.; Bradshaw S.J.; Killian T.C.: “Magnetic confinement of an ultracold neutral plasma” Phys. Rev. Lett. 126, 085002 1 5 (2021).
[3] Zelener B.B.; Vilshanskaya E.V.; Morozov N.V.;, Saakyan S.A.;, Bobrov A.A.;, Sautenkov V.A.;, Zelener B.V.: “Steady State Ultracold Plasma Created by Continuous Photoionization of Laser Cooled Atoms” Phys. Rev. Lett. 132, 115301 1 5 (2024).
报告人简介：
Professor Sergey Saakyan received his Ph.D. in Physics from the Joint Institute for High Temperatures of the Russian Academy of Sciences in 2016, focusing on “Partially Ionized Ultracold Rydberg Atoms of Li-7.” He is currently an Assistant Professor in the Faculty of Physics at the National Research University Higher School of Economics in Moscow. His main research interests include laser spectroscopy, laser cooling and trapping, Rydberg atoms, and ultracold plasma.