Emission Mossbauer Spectroscopy of ^<237>Np Probe in Uranium Compounds.

本研究项目是基于铀化合物中的母核通过~&lt；238&gt；U(γ，n)反应引入母核作为探针的新思想，通过发射~(237)&gt；Np穆斯堡尔谱研究具有强关联电子的铀化合物的物理性质。另一个目的是建立发射谱~(237)&nP穆斯堡尔谱学，使之成为一般的、强有力的鳗系化合物和合金材料研究的工具。因此，这项工作的更具体的目的是开发和构建一台具有足够发射能力的穆斯堡尔谱。研究结果总结如下：1.研究成果。建立了一台用于发射~(237)&gt；nP穆斯堡尔谱的液氦低温恒温器。在低温恒温器中，一个标准的^&lt；237&gt；NPO_2吸收体被保持在78K的恒温。一个样品穆斯堡尔源放在一个温度控制在1.5K和室温之间的长杆上，可以用*100 mm/s的精确速度波形驱动。在上述几何结构中，使用绝对速度校准器测量光源精确驱动的条件，在系统中放置激光干涉仪，以便定期观察精确速度。从精确驱动和速度定标的角度，通过测量常用的穆斯堡尔效应和干涉条纹的时间谱，反复确认整个系统满足发射穆斯堡尔谱的能力要求。因此，本研究项目完成了具有足够发射能力的整个穆斯堡尔谱测量系统。

This research project was started in order to investigate the physical properties of uranium compounds with strong-correlated electrons by emission ^<237>Np Mossbauer spectroscopy on the basis of new idea that parent ^<237>U nuclei as probes are introduced in U compounds through ^<238>U(gamma, n) reaction. It is also a purpose to establish the emission ^<237>Np Mossbauer spectroscopy to be general and powerful tool for material researches of actinide compounds and alloys. Therefore, the more specific purpose of this work is to develop and construct a spectrometer with sufficient ability for the emission ^<237>Np Mossbauer spectroscopy. The results are summarized as follows.1. A liquid-helium cryostat for the emission ^<237>Np Mossbauer spectroscopy was constructed. In the cryostat, a standard ^<237>NpO_2 absorber is maintained at a constant temperature of 78 K.A sample Mossbauer source put on a long stem whose temperature is controlled between 1.5 K and room temperature can be driven by a precise velocity wave form of *100 mm/sec.2. In the geometry mentioned above, the condition for precise drive of source is surveyed using a absolute velocity calibrator using a laser interferometer which is put in the system in order to observe regularly the precise velocity.3. From the view point of precise drive and velocity calibration, it was confirmed repeatedly that the whole system satisfies the ability demanded for the emission ^<237>Np Mossbauer spectroscopy through measurements of the popular ^<57>Fe Mossbauer effects and the time spectra of interference fringes. Consequently, the whole spectrometer system with sufficient ability for the emission ^<237>Np Mossbauer spectroscopy was completed by the present research project.