Patent ID: 8422633

Claim:
An X-ray beam device for X-ray analytical applications, comprising: an X-ray source designed such as to emit a divergent beam of X-rays; and an optical assembly designed such as to focus said beam onto a focal spot, wherein said optical assembly comprises a first reflecting optical element, a monochromator device and a second reflecting optical element sequentially arranged between said source and said focal spot, wherein said first optical element is designed such as to collimate said beam in two dimensions towards said monochromator device, and wherein said second optical element is designed such as to focus the beam coming from said monochromator device in two dimensions onto said focal spot; wherein the X-ray source has a source size S of 100 microns or less; and wherein the said first optical element has a focal length F 1 given by Δθ M ≦S/F 1 ≦5*Δθ M in order to produce a focal spot size which is only slightly asymmetric, wherein F 1 is also the distance between said X-ray source and said first optical element, and wherein Δθ M is the angular acceptance of said monochromator device.