论文标题
高性能聚合物的质谱分析，以评估放射性的超低背景材料的稀有事件物理探测器
Mass spectrometric analyses of high performance polymers to assess radiopurity as ultra low background materials for rare event physics detectors
论文作者
论文摘要
据报道，在几种强，未填充的高性能聚合物中，TH-232和U-238的质量浓度是其放射性的度量。为了最大程度地减少探测器材料本身引起的背景信号，需要高度放射线聚合物作为介电材料作为介电材料。据报道，针对聚醚酮（PEEK），聚醚酮酮（PEKK），聚酰胺酰亚胺（PAI，pai，贴上Torlon）和Polybenzimidazole（PBI）（PBI）的仔细采购样品。还讨论了固体聚醚酰亚胺（PEI）的数据，并以商业3D打印丝库存的形式进行了PEI的新数据。发现强大的高性能聚合物PEKK，PBI，PAI和PEI的水平为TH-232和U-238，其水平低于1毫升/千克，包括PEI 3D打印丝。具体而言，对于TH-232和U-238，在Microbq/kg中，我们发现Arkema Kepstan Pekk 6002 Flake的值为149和184。 69和2250用于Solvay Ketaspire Peek Flake； PBI性能产品的346和291低金属100级网格PBI粉末； Drake Plastics Pai Torlon T-4200颗粒的66和105； 401和285用于Drake Plastics Cured Pai Rod； Ensinger Pei Ultem 1000固体的32和41；以及15和85 microbq/kg，用于Thermax PEI ULTEM 1010细丝材料。这些结果均使用新型的干燥方法在由超低背景（ULB）电型铜构成的坩埚中获得。样品用T-229H和U-233作为内部标准在呼吸之前加入，并通过电感耦合等离子体质谱法（ICP-MS）进行确定。相对于这些和其他几种聚合物的机械强度的数值测量，放射性刺激显示为图形显示。
The mass concentrations of Th-232 and U-238 in several strong, unfilled, high performance polymers are reported as measures of their radiopurity. Highly radiopure polymers are required as dielectric materials in the construction of rare event physics detectors, in order to minimize background signals arising from the detector materials themselves. New data are reported for carefully sourced samples of polyetheretherketone (PEEK), polyetherketoneketone (PEKK), a polyamide imide (PAI, branded as Torlon) and polybenzimidazole (PBI). Data for solid polyetherimide (PEI) are also discussed and new data for PEI in the form of a commercial 3D printing filament stock are reported. Strong high performance polymers PEKK, PBI, PAI and PEI were found with levels for Th-232 and U-238 that are below one milliBq/kg, including the PEI 3D printing filament. Specifically, for Th-232 and U-238 respectively, in microBq/kg, we found values of 149 and 184 for Arkema Kepstan PEKK 6002 flake; 69 and 2250 for Solvay Ketaspire PEEK flake; 346 and 291 for PBI Performance Products low metals grade 100 mesh PBI powder; 66 and 105 for Drake Plastics PAI Torlon T-4200 pellets; 401 and 285 for Drake Plastics cured PAI rod; 32 and 41 for Ensinger PEI Ultem 1000 solid; and 15 and 85 microBq/kg, for ThermaX PEI Ultem 1010 filament material. These results were all obtained using a novel dry ashing method in crucibles constructed of ultra low background (ULB) electroformed copper. Samples were spiked with T-229h and U-233 as internal standards prior to ashing and determinations were made by inductively coupled plasma mass spectrometry (ICP-MS). Radiopurity is displayed graphically relative to numerical measures of mechanical strength for these and several other polymers.
