[论文解读] Investigation of Deuterium Loaded Materials Subject to X-Ray Exposure

Theresa Benyo, Bruce M. Steinetz+10 more|arXiv (Cornell University)|Apr 3, 2017

Nuclear Physics and Applications参考文献 1被引用 4

一句话总结

本研究调查了在氘化材料中由X射线诱导的核嬗变，重点关注钛氘化物（TiD₂）和氘化聚乙烯（DPE）。尽管未检测到高于背景水平的伽马辐射，但多个样品在辐照数月后仍表现出持续的β辐射和短寿命α辐射，通过闪烁检测确认了具有氚样β发射的特征，表明在X射线照射下，氘化体系中可能存在中子催化反应或新型核过程。

ABSTRACT

Results are presented from an exploratory study involving x-ray irradiation of select deuterated materials. Titanium deuteride (TiD2) plus deuterated polyethylene ([-CD2-]n; DPE), DPE alone, and for control, hydrogen-based polyethylene ([-CH2-]n; HPE) samples and nondeuterated titanium samples were exposed to x-ray irradiation. These samples were exposed to various energy levels from 65 to 280 kV with prescribed electron flux from 500 to 9000 micro-A impinging on a tungsten braking target, with total exposure times ranging from 55 to 280 min. Gamma activity was measured using a high-purity germanium (HPGe) detector, and for all samples no gamma activity above background was detected. Alpha and beta activities were measured using a gas proportional counter, and for select samples beta activity was measured with a liquid scintillator spectrometer. The majority of the deuterated materials subjected to the microfocus x-ray irradiation exhibited postexposure beta activity above background and several showed short-lived alpha activity. The HPE and nondeuterated titanium control samples exposed to the x-ray irradiation showed no postexposure alpha or beta activities above background. Several of the samples (SL10A, SL16, SL17A) showed beta activity above background with a greater than 4-sigma confidence level, months after exposure. Portions of SL10A, SL16, and SL17A samples were also scanned using a beta scintillator and found to have beta activity in the tritium energy band, continuing without noticeable decay for over 12 months. Beta scintillation investigation of as-received materials (before x-ray exposure) showed no beta activity in the tritium energy band, indicating the beta emitters were not in the starting materials.

研究动机与目标

• 调查X射线辐照氘化材料是否能诱导可检测的核嬗变或辐射发射。
• 确定如TiD₂和DPE等氘化材料在X射线照射后是否会产生可测量的α、β或γ辐射。
• 评估辐照后辐射的持久性，包括照射数月后的持续情况。
• 通过在辐照前测试原始材料，区分固有放射性与X射线诱导的辐射。
• 探讨氘化体系中持续β活性的潜在机制，可能涉及中子催化反应或低能核反应（LENR）。

提出的方法

• 使用电子束能量为65至280 keV、电流为500至9000 μA的微焦点X射线源，对氘化材料（TiD₂、DPE）及对照组（HPE、非氘化Ti）进行辐照。
• 辐照时间范围为55至280分钟，X射线通过电子撞击钨靶产生。
• 使用高纯锗（HPGe）探测器测量伽马活性，以检测即时或延迟的伽马辐射发射。
• 利用气体正比计数器和液体闪烁谱仪对部分样品的α和β活性进行定量分析。
• 通过β闪烁检测器进一步分析β发射，识别与氚衰变一致的能量谱。
• 在辐照前对原始样品进行测试，以排除材料中预先存在的放射性。

实验结果

研究问题

• RQ1 X射线辐照如TiD₂和DPE等氘化材料是否会产生高于背景的可测量α或β活性？
• RQ2 所观测到的辐射是否具有持久性，特别是照射数月后仍持续存在？
• RQ3 β发射是否表现出与氚衰变（β⁻，E_max ≈ 18.4 keV）一致的能量谱？
• RQ4 在X射线照射下，氘化体系中是否存在中子催化或低能核反应的证据？
• RQ5 对照组样品（HPE和非氘化Ti）是否表现出类似的辐照后辐射，表明为背景或仪器干扰？

主要发现

• 使用高纯锗探测器未在任何辐照样品中检测到高于背景的伽马活性，包括TiD₂和DPE。
• 多个样品（SL10A、SL16、SL17A）在X射线辐照数月后仍表现出高于背景的β活性，显著性超过4-sigma。
• β闪烁测量确认了在氚能量范围（E_max ≈ 18.4 keV）内的发射，且在辐照后12个月以上未见明显衰减。
• 原始样品在氚能量范围内未显示β活性，表明发射体在X射线辐照前并不存在。
• 少数样品检测到短寿命α活性，提示可能存在中子催化反应或瞬态核过程。
• 对照组样品（HPE和非氘化Ti）在辐照后未表现出高于背景的α或β活性，证实该效应特异性地存在于氘化材料中。