High bandwidth power supplies for optical pumping of francium atoms for atomic parity violation studies

用于钫原子光泵浦的高带宽电源，用于原子宇称违反研究

• 批准号: SAPEQ-2021-00005
• 负责人: Gwinner, Gerald
• 金额: $ 4.98万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Research Tools and Instruments
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=742993
• 关键词: bandwidth; power; supplies; optical; pumping

The fundamental forces of nature are one of the fascinating subjects that can be studied at the ISAC radioactive beam facility at TRIUMF, Canada's national laboratory for nuclear and particle physics. In particular, the weak force, causing the beta-decay of nuclei, is unique in exhibiting the phenomenon of parity-violation: the mirror images of physical processes mediated by the weak force are not observed in nature. ISAC offers the possibility to study atomic parity-violation in francium (Fr), an element combining a very heavy nucleus (Z=87) with the simple, essentially hydrogenlike, valence structure of an alkali. Fr nuclei are the least stable among the first 103 elements in the periodic table, the longest-lived isotope decays in only 23 minutes. To make optimum use of the minute sample, the Fr atoms are slowed down with laser light and captured into a `magneto-optical' laser trap, suspended in free space at temperatures millions of times colder than room temperature. We have established a francium trapping facility at ISAC; in collaboration with researchers from the United States and Mexico, we are now using this francium source to carry out a series of precision experiments using laser and microwave spectroscopy. Working our way towards atomic parity violation measurements, we are exciting an exceedingly faint electronic transition, 7s to 8s, and measure its property. For these measurements, the atoms have to be optically pumped with laser light into a quantum state that has the atom's magnetic moment aligned with an externally applied magnetic field. Optical pumping is not compatible with the laser trapping setup, and we have to rapidly, on the order of a millisecond, switch back and forth between magnetic field configurations suitable for laser trapping and optical pumping. For this purpose we require 3 high-current power supplies that can be switched on and off at the hundred microsecond scale to control a three-dimensional coil configuration. With this equipment in place, we can push towards an atomic parity violation experiment in francium.

自然界的基本力是一个迷人的课题，可以在加拿大国家核和粒子物理实验室TRIUMF的ISAC放射性束设施进行研究。特别是，导致原子核β衰变的弱力在显示宇称破坏现象方面是独一无二的：由弱力介导的物理过程的镜像在自然界中是观察不到的。ISAC提供了研究<$（Fr）中原子宇称破坏的可能性，<$是一种将非常重的核（Z=87）与简单的、基本上类似氢的碱金属价结构结合在一起的元素。在元素周期表的前103种元素中，Fr核是最不稳定的，寿命最长的同位素衰变仅需23分钟。为了最大限度地利用微小的样品，Fr原子被激光减速，并被捕获到一个“磁光”激光阱中，悬浮在比室温低数百万倍的自由空间中。我们在ISAC建立了一个<$捕获设施;与美国和墨西哥的研究人员合作，我们现在正在利用这个<$源，利用激光和微波光谱学进行一系列精确的实验。我们正在努力实现原子宇称违反测量，我们正在激发一个非常微弱的电子跃迁，7s到8 s，并测量其属性。对于这些测量，原子必须用激光光泵浦到一个量子态，该量子态具有与外部施加的磁场对齐的原子磁矩。光泵浦与激光捕获装置不兼容，我们必须在毫秒量级上快速地在适合激光捕获和光泵浦的磁场配置之间来回切换。为此，我们需要3个高电流电源，可以在百微秒尺度上打开和关闭，以控制三维线圈配置。有了这个设备，我们就可以在<$中进行原子宇称破坏实验了。