Californium-252 (252Cf) is considered essential by the National Institute of Standards and Technology for the calibration of neutron instrumentation and dosimetry. Californium-252 has a relatively short half-life of 2.645 y; consequently, it must be replaced frequently to produce an adequate neutron flux for calibration. The user community is currently looking for a replacement for 252Cf. The patented technology described herein has a high probability of being that replacement. A preferred method to replace 252Cf would use an affordable and easily maintained neutron source that generates neutrons in an energy spectrum as close to that of 252Cf as possible. Deuterium-tritium (D-T) neutron generators are both affordable and easily maintained, which makes them highly attractive for replacing 252Cf. The patented technology discussed in this paper simulates the 252Cf fission spectrum through a D-T neutron generator by using spectral subtraction. The primary spectrum is built using principally (n,xn) and (n,n') reactions in a variety of materials. In conjunction with the primary spectrum, an engineered background spectrum is generated using a second set of materials. This engineered background spectrum corrects for differences between the primary and desired spectra. This subtraction technique generates a spectrum very similar to 252Cf while maintaining a reasonable flux. Further, by choosing different scattering materials, any fission spectrum can be matched, including the thermal and epithermal components. This flexibility expands the potential use of this technology beyond simulating 252Cf to any desired neutron spectrum below 14 MeV.

中文翻译：

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通过谱减法技术开发 DT 中子发生器的裂变中子谱。

美国国家标准与技术研究院认为锎252 (252Cf) 对于中子仪器和剂量测定的校准至关重要。Californium-252 的半衰期相对较短，为 2.645 y；因此，必须经常更换它才能产生足够的中子通量进行校准。用户社区目前正在寻找 252Cf 的替代品。本文描述的专利技术很有可能成为替代品。替代 252Cf 的首选方法是使用经济实惠且易于维护的中子源，该中子源产生的中子能谱尽可能接近 252Cf 的能谱。氘氚 (DT) 中子发生器价格实惠且易于维护，这使得它们对于替代 252Cf 极具吸引力。本文讨论的专利技术通过谱减法通过DT中子发生器模拟252Cf裂变谱。主要光谱是使用各种材料中的 (n,xn) 和 (n,n') 反应构建的。结合主光谱，使用第二组材料生成工程背景光谱。该工程背景光谱可校正主要光谱和所需光谱之间的差异。这种减法技术可生成与 252Cf 非常相似的光谱，同时保持合理的通量。此外，通过选择不同的散射材料，可以匹配任何裂变光谱，包括热和超热成分。这种灵活性将该技术的潜在用途扩展到模拟 252Cf 以外的任何低于 14 MeV 的中子谱。