发明名称 |
THERMALLY MODULATED FIELD EMISSION CATHODE AND BEAM CURRENT MEASUREMENT TECHNIQUE |
摘要 |
An x-ray source includes a carbon nanotube FE (field emission) cathode that is heated with laser light propagated down a fiber optic cable. The resulting two-terminal x-ray tube allows for independent control of tube voltage and tube current. Control of the tube voltage is typically achieved using a control electrode, whereas the field emission tube current is controlled by thermal modulation. A technique is provided for accurately measuring beam current in the x-ray source. The method includes activating the cathode and adjusting the laser intensity, until a desired dose of output x-ray radiation is attained, then measuring the total x-ray tube current. The cathode is then turned off, so that the electron beam is turned off. The total x-ray tube current is measured again. The cathode is turned on again, immediately thereafter. The difference between the two values of the total x-ray tube current gives the correct x-ray tube beam current. |
申请公布号 |
WO2004066335(A3) |
申请公布日期 |
2008.08.14 |
申请号 |
WO2004US00974 |
申请日期 |
2004.01.15 |
申请人 |
CARL-ZEISS-STIFTUNG, D/B/A CARL ZEISS, OBERKOCHEN, GERMANY;DINSMORE, MARK |
发明人 |
DINSMORE, MARK |
分类号 |
H05G1/34;A61N5/10;H01J35/32;H05G1/46 |
主分类号 |
H05G1/34 |
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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