System and method for collimating x-rays in an x-ray tube

A method for providing a predefined x-ray field, the method comprising:

• emitting, by a cathode unit, electrons toward an anode unit;
• generating x-rays when the emitted electrons impinge on a target surface of the anode unit;
• and
• collimating, by a primary set of blades, the generated x-rays within a vacuum chamber for providing the predefined x-ray field at a detector, wherein the primary set of blades is disposed in the vacuum chamber at a first distance from the anode unit.

A collimating apparatus comprising:

• a primary set of blades disposed within a vacuum chamber of an x-ray tube, and configured to provide a predefined x-ray field at a detector;
• a secondary set of blades disposed at a first distance from the primary set of blades, and configured to modify the predefined x-ray field;
• and
• a driving unit coupled to the primary set of blades and the secondary set of blades and configured to coordinate position of the primary set of blades and the secondary set of blades.