Antihydrogen formation dynamics in a multipolar neutral anti-atom trap

A proposal for laser cooling antihydrogen atoms

We present a scheme for laser cooling applicable for an extremely dilute sample of magnetically trapped antihydrogen atoms($\bar{H}$). Exploiting and controlling the dynamical coupling between the $\bar{H}$'s motional degrees of freedom in a magnetic trap, three-dimensional cooling can be achieved from Doppler cooling on one dimension using the $1s_{1/2}-2p_{3/2}$ transition. The lack of three-dimensional access to the trapped $\bar{H}$ and the nearly separable nature of the trapping potential leads to difficulties in cooling. Using realistic models for the spatial variation of the magnetic fi…

Detecting Antihydrogen: The Challenges and the Applications

ATHENA's first detection of cold antihydrogen atoms relied on their annihilation signatures in a sophisticated particle detector. We will review the features of the ATHENA detector and its applications in trap physics. The detector for a new experiment ALPHA will have considerable challenges due to increased material thickness in the trap apparatus as well as field non-uniformity. Our studies indicate that annihilation vertex imaging should be still possible despite these challenges. An alternative method for trapped antihydrogen, via electron impact ionization, will be also discussed.

通过慢速等离子体合并优化反氢原子产生

Optimizing Antihydrogen Production via Slow Plasma Merging

本文研究在嵌套 Penning-Malmberg 阱中通过慢速合并反质子与正电子等离子体优化反氢产生，发现低温正电子和小半径注入可最大化产额，最终实现每次运行 2.3×10⁶ 个反氢原子，比此前最佳结果提高 20 倍。

Confinement of antihydrogen for 1000 seconds

Atoms made of a particle and an antiparticle are unstable, usually surviving less than a microsecond. Antihydrogen, made entirely of antiparticles, is believed to be stable, and it is this longevity that holds the promise of precision studies of matter-antimatter symmetry. We have recently demonstrated trapping of antihydrogen atoms by releasing them after a confinement time of 172 ms. A critical question for future studies is: how long can anti-atoms be trapped? Here we report the observation of anti-atom confinement for 1000 s, extending our earlier results by nearly four orders of magnitude…

在Penning-Malmberg陷阱中积累反质子及其为改进的反氢束生产做准备

Record accumulation of antiprotons in a Penning-Malmberg Trap and their preparation for improved production of antihydrogen beams

GBAR实验通过电荷交换反应产生反氢用于重力研究，采用脉冲漂移管减速反质子束，随后在陷阱中压缩反质子云，实现反质子积累和反氢束生产效率提升

反氢束的测量性质

Measured Properties of an Antihydrogen Beam

本研究测量ASACUSA尖点阱下游的反氢束，发现其强度提升100倍，通过选择性电离里德伯原子测定速度与结合能，结合模拟推测约16%的原子处于基态。

Three Dimensional Annihilation Imaging of Antiprotons in a Penning Trap

We demonstrate three-dimensional annihilation imaging of antiprotons trapped in a Penning trap. Exploiting unusual feature of antiparticles, we investigate a previously unexplored regime in particle transport; the proximity of the trap wall. Particle loss on the wall, the final step of radial transport, is observed to be highly non-uniform, both radially and azimuthally. These observations have considerable implications for the production and detection of antihydrogen atoms.