发明名称 |
X-RAY SPECTROMETER WITH AN ANALYZER CRYSTAL HAVING A PARTLY VARIABLE AND A PARTLY CONSTANT RADIUS OF CURVATURE |
摘要 |
An imaging optical system having a Rowland geometry can be used in a spectrometer for X-ray fluorescence. For the focusing of the X-ray beam emanating from the specimen to be analyzed, use is made of a curved analyzer crystal (28) whose radius of curvature may be variable, as in the case of a crystal surface (29) in the form of a logarithmic spiral (40). If such an analyzer crystal is to be made sufficiently large so as to achieve adequate intensity in the X-ray detector, a part of the crystal would have to be given a radius of curvature which is smaller than permissible so as to avoid fracturing of the crystal. In accordance with the invention, a first part (40) of the reflective surface (29) has a radius of curvature which is dependent on the location on the crystal whereas another part (42) of the reflective surface has a constant radius of curvature (44). A crystal part having a constant radius of curvature exhibits angular deviations, but for as long as these angular deviations are smaller than a given (not very low) limit value, they can be ignored in relation to other, larger deviations of the log spiral part. Such larger deviations occur notably when a multilayer mirror is chosen for the analyzer crystal (28).
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申请公布号 |
WO9828609(A1) |
申请公布日期 |
1998.07.02 |
申请号 |
WO1997IB01526 |
申请日期 |
1997.12.04 |
申请人 |
PHILIPS ELECTRONICS N.V.;PHILIPS NORDEN AB |
发明人 |
VAN EGERAAT, WALTERUS, ALPHONSUS, LAURENTIUS, ANTO |
分类号 |
G01J3/20;G01N23/20;G01N23/205;G01N23/207;G01N23/223;G21K1/06;(IPC1-7):G01N23/207 |
主分类号 |
G01J3/20 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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