Microprocessor based data acquisition system for Moessbauer spectrometer

A data acquisition system, for Moessbauer spectrometer and other probability distribution spectrum is described. This utilizes the advantages of incorporating a microcomputer for providing a flexible analytical capability and speed of hard wired MCS unit updating channel contents in DMA. Holbourn, Player and Woodhams have recently described a microprocessor controlled Moessbauer spectrometer where microprocessor performs the task of updating channel contents, requiring about 60 micro seconds in interrupt mode. This imposes restrictions on increasing the channel number and on increasing the velocity scan frequency in order to cover higher velocity ranges. The system described in this article performs data acquisition in faster direct memory access. It is a two module system, (1) MCS module (2) Microcomputer module, arranged around a common address, data and control buses. The microcomputer module has an access to the system data during flyback periods and can be programmed for the task of monitor on progess of experiment and as a manipulator of various control operations needed during experiment. The system firmware includes: (1) MONITOR (2) BLOCK-TRANSFER (3) DATA-SMOOTHING (4) DECIMAL-CONVERTER (5) MATH. The scope of this firmware is briefly described. (author)