论文标题
Muonic原子光谱与微克目标材料
Muonic atom spectroscopy with microgram target material
论文作者
论文摘要
Muonic原子光谱 - 在Muonic原子的形成过程中发出的X射线的测量 - 在探测核的形状和大小方面具有悠久的历史。实际上，几乎所有稳定的元素都经过Muonic原子光谱测量值，并且从这些测量值中提取的绝对电荷半径通常提供最高的精度。但是，到目前为止，只能使用至少几百毫克的靶标，因为它需要直接在目标中停止muon束以形成muonic原子。我们已经开发了一种新方法，该方法依靠在100杆氢气电池内进行的重复转移反应，并具有0.25％氘的混合物，这使我们能够大大减少所需的目标材料的量，同时仍然提供足够的效率。转移反应的详细模拟与测量的数据相匹配，这表明对气体混合物内发生的过程有很好的了解。作为原理的证明，我们通过5μg金靶的2p-1s Muonic X射线进行了测量。
Muonic atom spectroscopy -- the measurement of the x rays emitted during the formation process of a muonic atom -- has a long standing history in probing the shape and size of nuclei. In fact, almost all stable elements have been subject to muonic atom spectroscopy measurements and the absolute charge radii extracted from these measurements typically offer the highest accuracy available. However, so far only targets of at least a few hundred milligram could be used as it required to stop a muon beam directly in the target to form the muonic atom. We have developed a new method relying on repeated transfer reactions taking place inside a 100-bar hydrogen gas cell with an admixture of 0.25% deuterium that allows us to drastically reduce the amount of target material needed while still offering an adequate efficiency. Detailed simulations of the transfer reactions match the measured data, suggesting good understanding of the processes taking place inside the gas mixture. As a proof of principle we demonstrate the method with a measurement of the 2p-1s muonic x rays from a 5-μg gold target.
