The New CLOCIT Irradiation Facility for 40Ar/39Ar Geochronology: Characterisation, Comparison with CLICIT and Implications for High‐Precision Geochronology
The New CLOCIT Irradiation Facility for 40Ar/39Ar Geochronology: Characterisation, Comparison with CLICIT and Implications for High‐Precision Geochronology
复制标题
用于 40Ar/39Ar 地质年代学的新型 CLOCIT 辐照装置：表征、与 CLICIT 的比较以及对高精度地质年代学的启示
DOI：
10.1111/ggr.12217
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发表时间：
2018
影响因子：
3.8
通讯作者：
R. Schickler
中科院分区：
文献类型：
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作者：
D. Rutte;T. Becker;A. Deino;S. Reese;P. Renne;R. Schickler
镉内衬外堆芯辐照管（CLOCIT）是俄勒冈州州立大学TRIGA®反应堆中用于40 Ar/39 Ar地质年代学的新辐照设施。我们报告通量（即，时间积分通量）参数，并将其与现有的镉内衬内芯辐照管（CLICIT）进行比较。CLOCIT提供的平均中子通量当量为1.45-1.53 × 10−4 J h−1，约为CLICIT的55%。径向通量梯度在0.2-4.2% cm−1的量级。J值的平面拟合导致J值的不确定性范围内的残差，但系统偏差解决了中子通量场的非平面分量，这也在CLICIT中观察到。轴向中子注量梯度为0.6-1% cm−1，而CLICIT为0.7-1.6% cm−1。干扰反应的产率比为（40 Ar/39 Ar）K =（4 ± 6）× 10−4，（38Ar/39Ar）K =（1.208 ± 0.002）× 10−2，（36 Ar/37 Ar）Ca =（2.649 ± 0.014）× 10−4，（38 Ar/37 Ar）Ca =（3.33 ± 0.12）× 10−5，（39 Ar/37 Ar）Ca =（9.1 ± 0.28）× 10−4，与CLICIT值相近。
The Cadmium‐Lined Outer‐Core Irradiation Tube (CLOCIT) is a new irradiation facility for 40Ar/39Ar geochronology at the Oregon State University TRIGA® reactor. We report fluence (i.e., time‐integrated flux) parameters from the first four CLOCIT irradiations and compare them with the existing Cadmium‐Lined Inner‐Core Irradiation Tube (CLICIT). CLOCIT provides an average neutron flux equivalent of 1.45–1.53 × 10−4 J h−1; about 55% of CLICIT. Radial fluence gradients were on the order of 0.2–4.2% cm−1. A planar fit of J‐values results in residuals in the range of uncertainty in the J‐value, but systematic deviations resolve a non‐planar component of the neutron flux field, which has also been observed in CLICIT. Axial neutron fluence gradients were 0.6–1% cm−1, compared with 0.7–1.6% cm−1 for the CLICIT. Production rate ratios of interfering reactions were (40Ar/39Ar)K = (4 ± 6) × 10−4 and (38Ar/39Ar)K = (1.208 ± 0.002) × 10−2, (36Ar/37Ar)Ca = (2.649 ± 0.014) × 10−4, (38Ar/37Ar)Ca = (3.33 ± 0.12) × 10−5 and (39Ar/37Ar)Ca = (9.1 ± 0.28) × 10−4, similar to the CLICIT values.