X-ray computer tomograph and method for examining a test piece using an x-ray computer tomograph

An x-ray computer tomograph, comprising:

• an x-ray source configured to generate a fan beam of x-ray radiation;
• a detector array, wherein each of the x-ray source and the detector array is situated on opposite sides of a gantry so that the x-ray radiation passes completely through a test region;
• a row of detector elements situated in a plane of the fan beam and adjoined in at least one direction perpendicular to the fan beam by several additional rows of detector elements;
• wherein during a measurement, no secondary collimator is positioned between the test region and the detector array,
• wherein a width of each of the detector elements is less than or equal to 0.5*β*ZP, where β is twice the angle of spread of the x radiation and ZP is the distance of the measurement point from the detector array, and
• wherein a height (h) of each of the detector elements corresponds to the equation:
• h≦0.2*arc sin(q*λ)*ZP,
• where q is a pulse transmission, λ is a wavelength of the x-ray radiation, and a pulse transmission spectrum lies between 0.2 and 2 nm−1.