Glöggler L T, Gusakova N, Rienäcker B, Camper A, Caravita R, Huck S, Volponi M, Wolz T, Penasa L, Krumins V, Gustafsson F P, Comparat D, Auzins M, Bergmann B, Burian P, Brusa R S, Castelli F, Cerchiari G, Ciuryło R, Consolati G, Doser M, Graczykowski Ł, Grosbart M, Guatieri F, Haider S, Janik M A, Kasprowicz G, Khatri G, Kłosowski Ł, Kornakov G, Lappo L, Linek A, Malamant J, Mariazzi S, Petracek V, Piwiński M, Pospíšil S, Povolo L, Prelz F, Rangwala S A, Rauschendorfer T, Rawat B S, Rodin V, Røhne O M, Sandaker H, Smolyanskiy P, Sowiński T, Tefelski D, Vafeiadis T, Welsch C P, Zawada M, Zielinski J, Zurlo N
Physics Department, CERN, 1211 Geneva 23, Switzerland.
Department of Physics, NTNU, Norwegian University of Science and Technology, Trondheim, Norway.
Phys Rev Lett. 2024 Feb 23;132(8):083402. doi: 10.1103/PhysRevLett.132.083402.
We report on laser cooling of a large fraction of positronium (Ps) in free flight by strongly saturating the 1^{3}S-2^{3}P transition with a broadband, long-pulsed 243 nm alexandrite laser. The ground state Ps cloud is produced in a magnetic and electric field-free environment. We observe two different laser-induced effects. The first effect is an increase in the number of atoms in the ground state after the time Ps has spent in the long-lived 2^{3}P states. The second effect is one-dimensional Doppler cooling of Ps, reducing the cloud's temperature from 380(20) to 170(20) K. We demonstrate a 58(9)% increase in the fraction of Ps atoms with v_{1D}<3.7×10^{4} ms^{-1}.
我们报告了通过用宽带长脉冲243纳米变石激光器强烈饱和1³S - 2³P跃迁，在自由飞行中对大部分正电子素（Ps）进行激光冷却的情况。基态Ps云在无磁场和电场的环境中产生。我们观察到两种不同的激光诱导效应。第一种效应是Ps在长寿命的2³P态中停留一段时间后，基态原子数量增加。第二种效应是对Ps进行一维多普勒冷却，将云团温度从380(20) K降低到170(20) K。我们证明，一维速度v₁D < 3.7×10⁴ m s⁻¹的Ps原子比例增加了58(9)%。
