Crystalline ion beams
Crystalline ion beams
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DOI：
10.1038/35089045
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发表时间：
2001-08
期刊：
影响因子：
64.8
通讯作者：
T. Schätz;U. Schramm;D. Habs
中科院分区：
文献类型：
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作者：
T. Schätz;U. Schramm;D. Habs
通过在高能储存环中冻结粒子之间的运动，应该可以产生离子线，提供标准加速器物理学领域之外的研究机会。通常由于束内碰撞而产生的加热应该完全消失，从而产生前所未有的辉煌状态。尽管束流冷却技术不断改进，如电子冷却和激光冷却，但在高能储存环中束流结晶的最终目标尚未达到。电子冷却的高电荷态离子稀束呈现出类液体的有序性，具有独特的应用。使用激光冷却的实验表明，减少了光束内加热，尽管结果不明确。在这里，我们展示了在射频四极储存环PALLAS循环的激光冷却Mg+光束的结晶，在2,800 m s-1的速度，这对应于1 eV的光束能量。横向束尺寸的突然收缩和低的纵向速度分布清楚地表明了相变。连续的环形结晶梁表现出卓越的稳定性，在不冷却的情况下可以持续旋转3,000多次。
By freezing out the motion between particles in a high-energy storage ring, it should be possible,,,to create threads of ions, offering research opportunities beyond the realm of standard accelerator physics. The usual heating due to intra-beam collisions should completely vanish, giving rise to a state of unprecedented brilliance. Despite a continuous improvement of beam cooling techniques, such as electron cooling and laser cooling, the ultimate goal of beam crystallization has not yet been reached in high-energy storage rings. Electron-cooled dilute beams of highly charged ions show liquid-like order,with unique applications. An experiment using laser cooling,suggested a reduction of intra-beam heating, although the results were ambiguous. Here we demonstrate the crystallization of laser-cooled Mg+beams circulating in the radiofrequency quadrupole storage ring PALLAS,at a velocity of 2,800 m s-1, which corresponds to a beam energy of 1 eV. A sudden collapse of the transverse beam size and the low longitudinal velocity spread clearly indicate the phase transition. The continuous ring-shaped crystalline beam shows exceptional stability, surviving for more than 3,000 revolutions without cooling.