Analysis device with variably illuminated strip detector
An X-ray or neutron-optical analysis device comprising means for directing radiation from a source ( 1 ) onto a sample ( 2 ), and a detector ( 7 ) with n substantially identical detector elements (D i ) which are disposed parallel, next to each other in a first direction x and which extend in strips in a second direction y, wherein i= 1 , . . . n, for one-dimensional spatially-resolved detection of radiation reflected, scattered or diffracted by the sample ( 2 ) onto the detector ( 7 ), and with a detection electronics for processing the detector signals of the n detector elements (D i ), wherein the detection electronics can reliably process a maximum radiation intensity per detector element (D i ) without overloading, is characterized in that an optical element is disposed in front of the detector ( 7 ) which covers or weakens radiation incident on the surfaces of the respective n detector elements (D i ) in correspondence with a predetermined, non-constant transmission function f(x) and/or the optical element comprises a collimator ( 6 ) which can be displaced along the strip direction y. The inventive analysis device permits artificial enlargement of the dynamic range of the detector ( 7 ).
1. An X-ray or neutron optical analysis device for measuring a sample, the device comprising:
a radiation source;
a radiation detector, said detector having a plurality of substantially identical, separate detector elements disposed parallel to and adjacent to each other in a first x-direction and extending as strips in a second y-direction, orthogonal to said x-direction, to provide one-dimensional spatially resolved detection in said x-direction of radiation reflected, scattered or diffracted by the sample;
a detection electronics for processing detector signals from each of said plurality of detector elements, said detection electronics having a maximum radiation intensity per detector element which is reliably processed without overloading; and
an optical element disposed upstream of said detector to reduce radiation intensity incident on surfaces of said detector elements, said optical element comprising a filter structured to produce a transmission function f(x) which changes in said x-direction and/or a collimator which is structured for displacement relative to said radiation detector along said y-direction.
2. The analysis device of claim 1 , wherein the radiation emitted from the sample onto said detector has an intensity distribution l(x) which varies over at least one order of magnitude.
3. The analysis device of claim 2 , wherein said intensity distribution varies over several orders of magnitude or is a diffractogram of the sample.
4. The analysis device of claim 1 , wherein said transmission function f(x) increases monotonically in said x-direction to a maximum value f max .
5. The analysis device of claim 4 , wherein f max =1.
6. The analysis device of claim 2 , wherein said transmission function f(x) is selected to substantially follow an inverse of an envelope of an expected intensity distribution.
7. The analysis device of claim 6 , wherein said expected intensity distribution is a diffractogram.
8. The analysis device of claim 1 , further comprising a filter which integrally weakens an overall intensity of the radiation incident on said detector by a factor k.
9. The analysis device of claim 1 , wherein said optical element is partially transparent and partially impermeable to the radiation.
10. The analysis device of claim 1 , wherein said optical element comprises a wedge filter in said x-direction.
11. The analysis device of claim 1 , wherein said optical element has a gap in said x-direction which is structured for displacement in said y direction.
12. The analysis device of claim 11 , wherein said gap has a width which is small compared to a separation between neigboring detector elements or which is smaller than half said separation.
13. The analysis device of claim 1 , wherein said optical element comprises two blades which are structured for separate displacement thereof.
14. The analysis device of claim 1 , wherein said optical element has transparent regions of varying number and/or size distributed over a detector surface in a region of at least some of said n detector elements.
15. The analysis device of claim 1 , wherein said optical element comprises a plurality of individual elements which are mutually replaced and/or combined with each other.
16. The analysis device of claim 1 , wherein said detector and said detection electronics register and count an incidence of individual radiation quanta on said detector elements.
17. The analysis device of claim 1 , wherein an angle between radiation incident on the simple and radiation emerging from the sample is between 165° and 180°.
18. The analysis device of claim 1 , wherein said detector is structured for rotation about an axis perpendicular to a detector surface.
19. The analysis device of claim 1 , wherein the analysis device comprises means for constructing a point detector (0-D detector) by adding radiation intensities of individual said detector elements detected by said detection electronics.