Rigaku Corporation

Tomoyasu Ueda

Kazuhiko Omote

Kiyoshi Ogata

Yoshiyasu Ito

Kenji Wakasaya

Tetsuo Kani

A motion control system comprising a servo motor for moving a rotary stage; a scale provided on the rotary stage or on an object that moves integrally with the rotary stage; a plurality of reading heads for detecting the scale and outputting a signal; a data processing part for calculating an average value of rotation angle data based on each of the output signals from the reading heads and outputting the average value as a signal; and a servo amplifier for controlling the motor based on the signal representing the average value of the rotation angle. The motion control system can cause the rotary stage to rotate to a desired rotation angle to a high degree of accuracy using the reading heads.

Motion control system and X-ray measurement apparatus

The dead time of a pulse type X-ray detector is measured without estimation of a true X-ray intensity. The first and the second conditions are used for varying an intensity of an X-ray entering the X-ray detector. The first condition may be the slit width of a receiving slit, at least three kinds of slit width being selected. The second condition may be with or without an absorption plate. The first observed X-ray intensities are observed, with the absorption plate inserted, for three or more values in slit width. Next, the second observed X-ray intensities are observed similarly but with the absorption plate removed. A predetermined relational expression is made up among the first observed X-ray intensity, the second observed X-ray intensity, a ratio k of the second observed X-ray intensity to the first observed X-ray intensity (depending upon attenuation in X-ray intensity caused by the absorption plate) and the dead time &#x3c4; of the X-ray detector. Based on the relational expression, a fitting operation is carried out with the least squares method so as to determine the dead time &#x3c4; precisely.

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Hamura, Japan

Tomoyasu Ueda