基于蒙特卡罗的量子仿真实验

Simulation Experiment Based on Monte Carlo Quantum Method

结合量子力学计算与蒙特卡罗随机方法,发展了一种仿真实验方法。该方法通过对实验仪器不确定度的引入,对Schulz等在2003年开展的100 MeV/u C^(6+)与氦原子的碰撞电离实验(Nature, 2003, 422(6927):48.)进行了仿真模拟。结果表明,反应显微成像谱仪位置分辨、靶温度以及引出电场电压的细微的波动都能够对最终实验结果产生显著的影响。通过对这些参数的扫描发现,当靶温达到16 K,或者引出场电压波动达到0.05 V时,均能重复出当时的实验结果,为领域内长期存在的“C^(6+)谜题”提供了一种可能性较高的解释。该仿真方法的成功应用,为快速确定实验参数对量子少体动力学实验的影响提供了一种实用解决方案。

Simulation programmes which combine the quantum model and Monte Carlo method by Schulz et al. are developed to reconstruct the experimental spectra of the single ionization in collisions between 100 MeV/u C^(6+)and He(Nature,2003, 422(6927): 48.). By introducing the uncertainty of the experimental set-ups the discrepancy between the theory and the experimental data can be studied. The simulation results show that the position resolution of the detector, target temperature and the small fluctuation of the extraction DC voltage applied to the spectrometer can have a significant influence on the final experimental results. The experimental fully differential cross sections can be reproduced when the target temperature reaches 16K, or the voltage fluctuation reaches 0.05 V, which provides an alternative perspective for the long-term C^(6+)puzzle. The simulation also provides a practical method for fast discrimination of influences from different set-up aspects in real few-body quantum dynamics experiments.