An IBM 1800 time-sharing system is used in our X-ray laboratory to control a four-circle diffractometer for structure research, several powder diffractometers, a pole-figure goniometer and a microdensitometer along with other instruments outside the diffraction area. A survey of the computer system is given and the hardware necessary to automate the diffractometers is discussed. The computer supervision ranges from simple data-logging with a minimum of control to complete control of all actions depending on the diffractometer and the requirements of the experiment. Also described is the use of the computer to process the data and to perform background jobs.
AbstractA commercial micro-densitometer is run by an IBM 1800 computer under time sharing. It is used for measuring the transmission of mass spectrometer plates and x-ray powder diffraction films. The x-ray data are processed on the 1800 computer in three steps: First a linear background approximation is performed by least-squares methods, then the data corrected for background are searched for peaks and the position of the peaks is determined. After an optional manual peak selection facilitated by CRT display of the data and results, d-spacings are calculated and printed out together with approximate intensities. The programs are also used for processing data obtained By automated x-ray diffractometers.
The capabilities of a disc-based microcomputer system are explored by adapting a sophisticated modeling program for emitting and absorbing plasma discharges to it. Results are favorable, with performance equal to or exceeding that obtained from a large, time-sharing computer system.