Search

The “fission electron-collection” neutron detector (FECND) is a fission-based neutron detector which has simple structure and could be used as a passive detector. In this work, a FECND prototype is fabricated and studied with thermal neutrons from a reactor. Due to the low sensitivity of FECND, the fission coat with an diameter of 93 mm and a235U mass thickness of 1 mg/cm2 was electroplated on the coated electrode of the prototype to obtain a robust signal. The experimental results indicate that the sensitivity of the prototype to thermal neutrons is 2.8 × 10−18C·cm2 and 1.3 × 10−18C·cm2 without a high voltage when the electrodes gap is 30 mm and 15 mm respectively. The sensitivities for various applied voltages are also provided for the two gaps. The data show that the both sensitivities were increased to about 1.0 × 10−17C·cm2 after a high voltage of one hundred volts was applied, and a higher voltage up to 4 kV would not increase the sensitivity distinctly. The impacts of different electrode gaps and various applied voltages are discussed.

For the solution of disputes arising out of the contracts of international sale of goods, in my point of view, to determine the competent court or courts is the first and probably the most important question to solve. The reasons are obvious. First of all, the choice of the competent court has great influence on the distribution of the litigation costs borne by the parties. In addition, to a great extent, it decides which country’s procedural law, even material law, will be applied hereto and therefore determines the outcome of the actions, even the recognition and enforcement of the judgment. Fist of all, the civil procedural rules that dominate the actions are up to the competent court. Second, the court will use its own nation’s laws of conflicts to decide the applicable material laws concerning the disputed contracts.

The fission electron-collection neutron detector (FECND) is a current-type neutron detector. Based on the analysis of the generation process of the gamma signals of the FECND, a mechanism utilizing symmetrical structure is proposed and discussed to suppress the gamma signals. According to this mechanism, the electrons generated from the gamma rays can be well compensated for by the adjustment of the electrodes' thickness and distance. In this study, based on the Monte–Carlo simulation of the gamma signals of the FECND, the varying patterns are obtained between the gamma signals and the detector parameter settings. As indicated by the simulation results, the gamma electrons can be compensated for completely by simply adjusting the coated electrode substrate thickness and distance. Moreover, with a proposed optimal parameter setting, the gamma sensitivity can be as low as 3.39×10−23 Ccm2, while the signal-to-noise ratio can be higher than 200:1. The compensation results of the γ-rays in the FECND will be slightly affected by the manufacturing error or the assembly error.