GBAR. Gravitational behavior of antihydrogen at rest
GBAR. Gravitational behavior of antihydrogen at rest
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GBAR。
DOI：
10.1007/s10751-011-0379-4
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发表时间：
2012
影响因子：
--
通讯作者：
P. Debu
中科院分区：
文献类型：
--
作者：
P. Debu
GBAR项目旨在通过测量超冷反氢原子的自由落体来进行反物质等效原理的首次测试。目标是在第一阶段测量重力加速度超过百分之一，从长远来看，使用反氢的重力量子态可以达到更高的精度。通过Be{sup +}离子对H-bar{sup +}离子的交感冷却，产生了{approximate}20 {mu}K原子。H-棒{sup +}离子是通过两步过程产生的，包括来自欧洲核子研究中心AD（或ELENA升级）的10个{sup 7}慢反质子的爆发与密集的正电子素云的相互作用。为了产生足够的正电子素，有必要实现一个强的慢正电子源，每秒几十个。这是用小型电子直线加速器完成的。在Penning-Malmberg阱中，每一个周期都会积累几个{sup 10}正电子，然后将它们喷射到正电子-正电子素转换器中。实验的总体方案进行了说明，并在萨克雷的原型正电子源的安装状态。给出了正电子的积累方案，并给出了正电子偶素的形成结果。给出了实验各个步骤的估计性能和效率。
The GBAR project aims to perform the first test of the Equivalence Principle with antimatter by measuring the free fall of ultra-cold antihydrogen atoms. The objective is to measure the gravitational acceleration to better than a percent in a first stage, with a long term perspective to reach a much higher precision using gravitational quantum states of antihydrogen. The production of {approx}20 {mu}K atoms proceeds via sympathetic cooling of H-bar{sup +} ions by Be{sup +} ions. H-bar{sup +} ions are produced via a two-step process, involving the interaction of bursts of 10{sup 7} slow antiprotons from the AD (or ELENA upgrade) at CERN with a dense positronium cloud. In order to produce enough positronium, it is necessary to realize an intense source of slow positrons, a few 10{sup 8} per second. This is done with a small electron linear accelerator. A few 10{sup 10} positrons are accumulated every cycle in a Penning-Malmberg trap before they are ejected onto a positron-to-positronium converter. The overall scheme of the experiment is described and the status of the installation of the prototype positron source at Saclay is shown. The accumulation scheme of positrons is given, and positronium formation results are presented. The estimated performance and efficiency of the various steps of the experiment are given.