Development and Applications of Time-Resolved M ssbauer Spectroscopy

时间分辨穆斯堡尔谱被认为是非常有用的非常规穆斯堡尔实验，如延迟符合和快速通道扫描实验。本课题利用单板微处理器和个人计算机开发了一种低成本、多功能的穆斯堡尔光谱仪，使我们能够进行多参数、快速的速度通道扫描实验。我们的系统在程序控制下运行，允许我们通过替换程序来选择两种不同的模式。正常模式：在这种模式下得到通常的穆斯堡尔谱。该系统作为多标度仪运行，具有同时记录多个独立光谱的能力。事件处理模式：该模式适用于记录具有快速速度通道扫描的频谱，并且易于完成多参数测量。当某一事件（射线探测）发生时，将瞬间速度的数据以及需要的时间、温度、场等其他实验参数的数据存储在微处理器中，然后用个人计算机根据实验目的进行处理。例如，在延迟符合穆斯堡尔实验中，需要将时间尺度划分为几个区间，记录时间分辨穆斯堡尔光谱。我们的系统也用于测量配体在低温下光解离血红蛋白（如肌红蛋白-一氧化碳化合物）后的穆斯堡尔光谱变化。

a time-resolved Mossbauer spectroscopy is considered to be very useful for unconventional Mossbauer experiments such as delayed coincidence and fast velocity-channel sweep experiments. In this project we developed a low cost and versatile Mossbauer spectrometer using a one-board microprocessor and a personal computer, which enables us to make multi-parameter and fast velocity-channel sweep experiments.Our system is operated under a program control and allows us to choose two different modes by substituting the program.Normal mode: Usual Mossbauer spectra are obtained in this mode. The system operates as multiscalers and features a capability for simultaneous recording of multiple independent spectra.Event processing mode: This mode is useful for recording a spectrum with fast velocity-channel sweep, and a multi-parameter measurement is also easily accomplished. When an event ( -ray detection) occurs, the data of the momentary velocity and the other experimental parameters such as time, temperature and fields, if required, are stored in the microprocessor, and then processed in accordance with the purpose of the experiment using the personal computer. For example, in a delayed-coincidence Mossbauer experiment it is necessary to divide the time scale into several intervals and record time-resolved Mossbauer spectra. Our system is also used to measure the Mossbauer spectral change after photo-dissociation of the ligand in hemoproteins such as myoglobin-CO compound, at low temperatures.