A new path to measure antimatter free fall
A new path to measure antimatter free fall
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测量反物质自由落体的新途径
DOI：
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发表时间：
2007
期刊：
影响因子：
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通讯作者：
N. Kuroda
中科院分区：
文献类型：
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作者：
P. Pérez;L. Liszkay;B. Mansoulie;A. Mohri;Y. Yamazaki;N. Kuroda
我们提出了一个测量中性反氢原子自由落体加速度的实验。这条路径的独创性在于首先产生H +离子。根据Walz和Hänsch [1]，该离子可以冷却到μK温度（即m/s速度）。然后，多余的正电子可以被激光分离，以恢复中性H原子。可以设置该过程以使垂直方向上的动量传递最小化。在冷却H离子时达到的温度给出了主要的系统误差。该离子通过电荷交换过程p + Ps → H + e，然后是H + Ps → H + + e产生。第一个过程的物质对应物已经被测量[2]，与10 cm级截面的计算一致[3]。第二个过程的计算横截面为10 cm [4]。因此，如果10个反质子与密度为10 cm Ps的原子相互作用，则会产生1个H +离子和10个H原子。收集1000个事件应该会提供2%的g测量误差。
We propose an experiment to measure the free fall acceleration of neutral antihydrogen atoms. The originality of this path is to first produce the H + ion. This ion can be cooled down to μK temperatures (i.e. m/s velocities) according to Walz and Hänsch [1]. The excess positron can then be laser detached in order to recover the neutral H atom. This process can be set up to minimize momentum transfer in the vertical direction. The temperature achieved in cooling of the H ion gives the main systematic error. This ion is produced through the charge exchange process p + Ps → H + e, followed by H + Ps → H + + e. The matter counterpart of the first process has been measured [2] in agreement with calculations with cross sections of order 10 cm [3]. The calculated cross section for the second process is 10 cm [4]. Thus if 10 antiprotons interact with a density of 10 cm Ps atoms, 1 H + ion is produced, together with 10 H atoms. Collecting 1000 events should provide a 2% measurement error on g.