Study On A Calibration Method In Soft X-Ray/EUV Band

This article studies on a novel method about detector calibration and monochromator calibration by using silicon pin photodiode. The detector and the monochromator of one spectrum measurement system had been calibrated using the method, and the spectrum distribution of one laser-produced plasmas (LPP) source with jet gas target was measured. The use of a specific combination of the silicon photodiode and multiplayer reflect films is the notable character in monochromator calibration. The reflectivity of films was measured with Virtual D AQ (Data Acquisition) system. The Virtual DAQ was built based on LabVIEW (Laboratory Virtual Instrument Engineering Workbench) and DAQ block produced by NI (National Instrument Inc.). Finally, the calibration error was made certain in 11-17% through data analysis. The work was held out by the fund of Nature Science, 863 fund and innovation fund of Chinese academy of sciences. In this work, we firstly got the relative spectrum distribution of LPP source with jet gas target in domestic LPP source study. It is a cornerstone of the exact measurement in times to come.The first chapter is introduction, which mainly introduce the detector used in extreme ultraviolet (EUV) and soft X-ray band. Its main purpose is to know different kinds of detecting method. Generally, EUV and soft X-ray photodetector included five types: ionization gas, semiconductor, electron multiplier and film. In lab the most often used is electron multiplier and semiconductor type. The electron multiplier detector is appropriate to do ordinary detect works for its high sensitive and semiconductor photodiode (such as Silicon diode) is appropriate to act as transfer standard detect for its high stability.The second chapter is the basic theory of calibration, which mainly expounds the absolute standard, function deduction, calibration and performance of Si photodiode and so on. Typical absolute standards include two types: absolute standard detector and absolute standard light source. In EUV and soft X-ray band, the most often used detector is ion chamber with rare gas, from whose collective electrode we can directly calculate intensity of photon flux. Often used standard light source is synchrotron radiation source and wall stabilized argon arc source. Synchrotron radiation source's excellent characteristic made it as ideal EUV and soft X-ray standard source, the spectrum can be calculated from the storage ring parameters. After the Si photodiode was calibrated by synchrotron radiation, we can get the quantum efficiency of 5 to 50 nm bandwidth which made a transfer standard to spectrum measurement system. The deducted calibration function is appropriate to calibrate Si photo diode and monochronomator, and made a basis for the following calculation in experiment. In third chapter, the article introduced every part of whole spectrum measurement system, such as LPP source, monochromator, detecting system, data acquisition system and vacuum system. The data acquisition system was improved: the data can be acquired and processed automatically by Virtual Data Acquisition Istrument. In fourth chapter, the quantum efficiency of the electron multiplier was displayed, and the design of monochromator calibration setup was provided. In fact, the setup had been built up. Lastly, the calibration error and measurement data had been analysed.