X-ray monitoring optical elements
An X-ray article and method for analyzing hard X-rays which have interacted with a test system. The X-ray article is operative to diffract or otherwise process X-rays from an input X-ray beam which have interacted with the test system and at the same time provide an electrical circuit adapted to collect photoelectrons emitted from an X-ray optical element of the X-ray article to analyze features of the test system.
1. An X-ray article for processing a hard X-ray beam to measure features of the X-ray beam after interaction with a test system comprising,
an X-ray optical element comprising a single crystal x-ray diffracting crystal operative to receive a hard X-ray beam at an exposure surface of the X-ray optical element and process the hard X-ray beam which has interacted with the test system for analysis thereof;
the exposure surface configured to emit electrons;
a surface electrode electrically connected with the exposure surface and an electron supply configured to provide electrons to replace the emitted electrons, creating a current, the surface electrode positioned adjacent to the exposure surface so as not to receive the hard X-ray beam;
an amp meter positioned in electrical contact between the surface electrode and the electron supply for measuring the current; and
the X-ray optical element further including intrinsic optical states which can be excited by the hard X-ray beam, thereby producing emission of photoelectrons and enhancement of surface;
wherein the X-ray article includes a substrate and a second electrode electrically coupled to the substrate and to the surface electrode;
wherein the measured current is proportional to X-ray flux of the hard X-ray beam incident on the exposure surface.
2. The X-ray article as defined in claim 1 wherein the X-ray optical element is selected from the group of single crystals for X-ray optics including diamond, Si, Ge, Be, Al 2 O 3 , SiC and SiO 2 .
3. The X-ray article as defined in claim 1 wherein the hard x-ray beam and x-ray optical element exhibit Bragg diffraction.
4. The X-ray article as defined in claim 1 wherein the X-ray optical element is selected from the group of an X-ray refractive lens, diffractive lens, an X-ray reflective mirror, capillary optics, a collimating slit and a transmitting optical element, thereby enabling the X-ray optical element to analyze the X-ray beam which has interacted with the test system.
5. The X-ray article as defined in claim 1 wherein the X-ray article includes a substrate and another electrode coupled to the substrate.
6. The X-ray article as defined in claim 1 further including a third electrode having a positive potential and the-third electrode is disposed above the X-ray optical element to capture electrons escaping from the exposure surface, thereby accelerating the photoelectrons escaping from the X-ray optical element and preventing return of the photoelectrons to the X-ray optical element.
7. The X-ray article as defined in claim 1 further including a voltage source to lower electrical potential of a surface of the X-ray optical element and to enhance the electric current in the circuit due to a change in surface conductivity induced by the X-ray beam.
8. The X-ray article as defined in claim 6 wherein the additional electrode comprises a charged grid.
9. The X-ray article as defined in claim 1 further including an electrical circuit comprised of a first electrode and a second electrode and an ammeter coupled to ground.
10. A method of analyzing features of a test system, comprising:
applying a hard X-ray beam to the test system;
disposing X-ray article having a substrate and an X-ray optical element comprising a single crystal x-ray diffracting crystal operative to receive a hard X-ray beam at an exposure surface of the X-ray optical element and process the X-ray beam which has interacted with the test system for analysis thereof, the X-ray optical element including intrinsic optical states which can be excited by the hard X-ray beam, thereby producing emission of photoelectrons and enhancement of surface
coupling a second electrode to the substrate and the surface electrode;
emitting photoelectrons from the exposure surface of the X-ray optical element;
capturing photoelectrons with an electrode above the surface;
replacing emitted photoelectrons from an electron supply through a surface electrode, which is positioned adjacent to the exposure surface so as not to receive the hard X-ray beam, on the X-ray optical element causing a surface current; and
measuring surface current, with an amp meter positioned in electrical contact between the surface electrode and the electron supply, induced by the X-ray beam striking the X-ray optical element and also collecting X-rays which have interacted with the test system and processed by the X-ray optical element, thereby accumulating information from both the induced current and the processed X-rays for analysis of features of the test system;
wherein the measured current is proportional to X-ray flux of the hard X-ray beam incident on the exposure surface.
11. The method as defined in claim 10 further including the step of applying a bias voltage to the X-ray optical element, thereby accelerating the photoelectrons escaping from the X-ray optical element.
12. The method as defined in claim 11 wherein the bias voltage arises from an electrode being disposed adjacent the X-ray optical element.
13. The method as defined in claim 12 wherein the bias voltage electrode comprises a charged grid.