Evolutionary Algorithm Optimization of Zeeman Deceleration: Is It Worthwhile for Longer Decelerators?
Evolutionary Algorithm Optimization of Zeeman Deceleration: Is It Worthwhile for Longer Decelerators?
复制标题
塞曼减速的进化算法优化：更长的减速器值得吗？
DOI：
--
复制
发表时间：
2019
影响因子：
2.9
通讯作者：
B. R. Heazlewood
中科院分区：
文献类型：
--
作者：
J. Toscano;Lok Yiu Wu;M. Hejduk;B. R. Heazlewood
在塞曼减速中，入射光束中只有一小部分低场粒子具有初始速度和位置，使它们处于设备的相空间接受范围内。为了最大限度地提高粒子的数量，成功地减速到选定的最终速度，我们寻求优化相空间接受的减速器。三维粒子轨迹模拟研究使用协方差矩阵自适应进化策略（CMA-ES）优化方法的减速器长于12个阶段和减速物种比H原子的潜在好处。在所有考虑的情况下，进化算法优化的序列在目标速度范围内产生更多的粒子。这在已知标准序列表现不佳的情况下尤其明显;模拟表明，在24级减速器中将H原子从500 ms-1的初始速度减速到200 ms-1的最终速度的标准序列的CMA-ES优化产生了成功减速粒子数量的可观的5921%（或60倍）增加。粒子的损失，发生与标准脉冲序列，例如，所产生的纵向和横向运动的耦合，克服了在CMA-ES优化过程中的所有粒子通过减速器的通道是明确考虑和聚焦效果占在优化过程中。
In Zeeman deceleration, only a small subset of low-field-seeking particles in the incoming beam possess initial velocities and positions that place them within the phase-space acceptance of the device. In order to maximize the number of particles that are successfully decelerated to a selected final velocity, we seek to optimize the phase-space acceptance of the decelerator. Three-dimensional particle trajectory simulations are employed to investigate the potential benefits of using a covariance matrix adaptation evolutionary strategy (CMA-ES) optimization method for decelerators longer than 12 stages and for decelerating species other than H atoms. In all scenarios considered, the evolutionary algorithm-optimized sequences yield vastly more particles within the target velocity range. This is particularly evident in scenarios where standard sequences are known to perform poorly; simulations show that CMA-ES optimization of a standard sequence decelerating H atoms from an initial velocity of 500 ms–1 down to a final velocity of 200 ms–1 in a 24-stage decelerator produces a considerable 5921% (or 60-fold) increase in the number of successfully decelerated particles. Particle losses that occur with standard pulse sequences—for example, arising from the coupling of longitudinal and transverse motion—are overcome in the CMA-ES optimization process as the passage of all particles through the decelerator is explicitly considered and focusing effects are accounted for in the optimization process.
DOI：
10.1063/1.4866906
发表时间：
2014
期刊：
The Journal of chemical physics
影响因子：
--
作者：
Dulitz K
通讯作者：
Dulitz K