Production of Radioactive Molecules in Radiofrequency Quadrupole Gas-Cells

射频四极气体电池中放射性分子的生产

• 批准号: SAPIN-2022-00026
• 负责人: Charles, Christopher
• 金额: $ 2.4万
• 依托单位: University of Western Ontario
• 依托单位国家: 加拿大
• 项目类别: Subatomic Physics Envelope - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=751126
• 关键词: Production; Radioactive; Molecules; Radiofrequency; Quadrupole

Radioactive molecules (RM) are exotic molecular species containing rare radioisotopes. Next-generation subatomic physics experiments wish to use RM in new searches for physics beyond the Standard Model, i.e., fundamental symmetries, implications for dark matter, and fundamental quantum chemistry. Facilities like TRIUMF can synthesize limited sets of exotic RM in their hot-cavity target ion sources. However, these molecules form in cavity targets and extraction systems by a highly inefficient and complex cascade of reaction kinematics following fission, spallation and fragmentation. These poorly understood molecular processes occur after the primary proton beam impinges on solid targets containing different elements in the form of metal foils or composite ceramics. Upcoming subatomic studies require efficient creation of the required rare molecule at high purity and yield. However, extreme non-equilibrium conditions in hot-cavity on-line targets (e.g., high temperatures, poor vacuum, high radiation fields, isobaric interferences, unfavorable chemical conditions and reaction energies) present a major challenge to targeted RM creation for experiments. This research will study how to create RM by ion-gas reaction chemistry with rare isotopes inside radiofrequency quadrupole (RFQ) gas-cells. Two new RFQ systems will be developed at TRIUMF: (1) an ion reaction cell (IRC), and (2) the ARIEL RFQ cooler-buncher (ARQB). Incoming positive rare isotope beams are brought into the RFQ gas-cell, where electric fields confine the ions. Chemical reactions occur between the radioactive ions and pure gaseous or vapor reactants under controlled conditions. Product molecules are finally delivered from the RFQ exit to the subatomic physics experiments. RFQ's like the IRC and ARQB are versatile, efficient, and controlled, rather than inside hot target environments abundant with reactants from all elements and isotopes produced by spallation, fragmentation and fission. The rich array of possible gas-reaction chemistries remains unexploited for subatomic physics, although RFQ reaction-cells are established in other fields. Currently, no other laboratory has a dedicated on-line rare molecule beam facility. This research has the potential to (1) establish a long-term RM facility at TRIUMF, (2) significantly expand the portfolio of beams at TRIUMF for subatomic physics in Canada, (3) strengthen the science opportunities for upcoming low-energy precision subatomic experiments with molecules, (4) offer many interdisciplinary opportunities for students, (5) develop new scientific collaborations with external partners, and (6) support Canadian high-tech industry for new leading-edge instruments.

放射性分子(Rm)是含有稀有放射性同位素的外来分子物种。下一代亚原子物理实验希望使用RM来探索超越标准模型的物理，即基本对称性、暗物质的含义和基础量子化学。像TRIUMF这样的设备可以在它们的热腔目标离子源中合成有限的奇异RM。然而，这些分子在空腔靶和提取系统中通过裂变、层裂和破碎后的高度低效和复杂的反应运动学级联形成。这些鲜为人知的分子过程发生在初级质子束撞击含有金属箔或复合陶瓷形式的不同元素的固体目标之后。即将到来的亚原子研究需要以高纯度和高产量有效地创造所需的稀有分子。然而，热腔在线靶中的极端非平衡条件(如高温、低真空、高辐射场、等压干扰、不利的化学条件和反应能量)给实验靶区的创建带来了重大挑战。这项研究将研究如何在射频四极(RFQ)气室内利用稀有同位素通过离子-气体反应化学反应生成Rm。TRIUMF将开发两个新的RFQ系统：(1)离子反应池(IRC)和(2)Ariel RFQ冷却器-聚束器(ARQB)。入射的正稀有同位素束被带入RFQ气室，在那里电场限制离子。放射性离子与纯气态或气态反应物在受控条件下发生化学反应。产品分子最终从RFQ出口输送到亚原子物理实验。像IRC和ARQB这样的RFQ是通用、高效和可控的，而不是在炎热的目标环境中，这些环境中充满了由层裂、碎裂和裂变产生的所有元素和同位素的反应物。尽管RFQ反应池在其他领域已经建立，但丰富的可能的气体反应化学反应仍然没有被亚原子物理利用。目前，还没有其他实验室拥有专门的在线稀有分子束设备。这项研究有可能(1)在TRIUMF建立一个长期的RM设施，(2)显著扩大TRIUMF用于加拿大亚原子物理的束流组合，(3)加强即将进行的低能精密亚原子分子实验的科学机会，(4)为学生提供许多跨学科的机会，(5)与外部合作伙伴发展新的科学合作，以及(6)支持加拿大高科技产业的新的尖端仪器。