Measurement device and measurement method for in-situ time-resolved X-ray absorption spectrum

Abstract

The invention provides a measurement device and a measurement method for an in-situ time-resolved X-ray absorption spectrum. The measurement device mainly comprises an X-ray source, a first slit, a sound-light X-ray filter, a radio frequency emitter, a second slit, a front ionization chamber, a front ionization chamber signal amplifier, a sample to be detected, a rear ionization chamber, a rear ionization chamber signal amplifier, a data acquisition unit and a computer and the like. An X-ray source, the sound-light X-ray filter and the radio frequency emitter are used for generating a single-color X light beam; the front ionization chamber is used for measuring the strength before the X light beam penetrates through the sample; the rear ionization chamber is used for measuring the strength after the X light beam penetrates through the sample; the front ionization chamber signal amplifier, the rear ionization chamber signal amplifier, the data acquisition unit and the computer are used for acquiring data and processing the data. According to the measurement device and the measurement method, any mechanical part does not move in a measurement process, so that time-resolved measurement of the X-ray absorption spectrum can be realized; furthermore, the measurement precision on the X-ray absorption spectrum is relatively high.

Description

technical field [0001] The invention relates to the field of X-ray absorption spectrum measurement, in particular to an in-situ time-resolved X-ray absorption spectrum measurement device and measurement method. Background technique [0002] X-ray absorption spectroscopy can provide information on the microscopic local structure (including electronic results and geometric structure) of matter, and is one of the most powerful tools for delineating local structures[1,2]. Time-resolved X-ray absorption spectroscopy measurement technology It can obtain intrinsic dynamic information of local atomic and electronic structures in some important reaction processes in nature, and has been widely used in materials science, life science, environmental science, catalysis science and other fields [3-7]. [0003] The structure of the time-resolved X-ray absorption spectrometer [8, 9] commonly used in the world is as follows: figure 1 As shown, it mainly includes an X-ray source 1 , a doubl...

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Problems solved by technology

[0008] The main disadvantages of the current time-resolved X-ray absorption spectrum measurement device and measurement method are: (1) During the measurement process, the mechanical structure inside the twin-crystal monochromator is always in a continuous motion process. Due to the mechanical motion involved, Therefore, the measurement speed of X-ray absorption spectrum is relatively slow. For example, it takes about 4 seconds to obtain a complete EXAFS spectrum. The X-ray absorption spectrum needs to be able to complete the rapid measurement in the sub-second or even millisecond level, and the testing devices and methods commonly used at present are obviously incompetent; (2) due to the measurement process, the double crystal monochromatic The detector has been in a continuous motion state, and the ionization chamber has been maintaining continuous data acquisition. These two actions are parallel, so in the process of data processing (when calculating the corresponding photon energy of each absorption coefficient value in the absorption spectrum sequence), often There will be a non-negligible data matching error, which will cause the measurement error of the absorption spectrum

However, the main disadvantages of this time-resolved measurement method are: (1) Compared with the measurement method using an ionization chamber, since this method uses a linear array CCD to achieve signal acquisition, the measurement accuracy of the X-ray absorption spectrum is not high; (2) ) The energy resolution of the measurement system is low; (3) The measurement band of the X-ray absorption spectrum cannot be adjusted flexibly

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