Transmission imager

A transmission imager, comprising:

• a radiation source for radiating radioactive rays from a target;
• a radiation detector;
• and
• a specimen table provided between the target and the radiation detector for having a specimen to be examined placed thereon,
• wherein the radiation source generates X-rays, the X-rays being generated by the target upon receiving cathode rays emitted from a cathode, wherein a range of the X-rays generated is greater than an effective radiation width;
• wherein the radiation detector is a combination of two, first and second, radiation detectors for detecting transmitted X-rays, the first radiation detector arranged with a detecting surface at a center of the first radiation detector extending substantially at a right angle to a first reference axis which extends from said center to the target, and the second radiation detector arranged with a detecting surface at a center of the second radiation detector extending substantially at a right angle to a second reference axis which extends from said center to the target, the first radiation detector arranged to be moved to and from the target by the action of a driving mechanism and thus positioned further from the target than the second radiation detector, and
• wherein the radiation source is specifically arranged in relation to the two, first and second, radiation detectors so that its target comes at an angle to face a cathode which is disposed closer to the second radiation detector.