A polycrystalline diamond micro-detector for X-ray absorption fine-structure measurements.

Lixiong Qian,Bingjie Wang,Yunpeng Liu,Zhongjun Chen,Lei Yao,Zhonghua Wu,Guang Mo,Xueqing Xing

doi:10.1107/s1600577521013011

Abstract

The microminiaturization of detectors used to record the intensity of X-ray beams is very favorable for combined X-ray experimental techniques. In this paper, chemical-vapor-deposited (CVD) polycrystalline diamond film was used to fabricate a micro-detector owing to its well controlled size, good thermostability, and appropriate conductivity. The preparation process and the main components of the CVD diamond micro-detector are described. The external dimensions of the packaged CVD diamond micro-detector are 15 mm × 7.8 mm × 5.8 mm. To demonstrate the performance of the detector, K-edge X-ray absorption fine-structure (XAFS) spectra of Cr, Fe, Cu, and Se foils were collected using the CVD diamond micro-detector and routine ion chamber. These XAFS measurements were performed at beamline 1W2B of Beijing Synchrotron Radiation Facility, covering an energy range from 5.5 to 13.5 keV. By comparison, it can be seen that the CVD diamond micro-detector shows a more excellent performance than the routine ion-chamber in recording these XAFS spectra. The successful application of the CVD diamond micro-detector in XAFS measurements shows its feasibility in recording X-ray intensity.

Highlights

The X-ray absorption fine-structure (XAFS) (Palmer et al, 1996; Teo & Joy, 1981; Ankudinov et al, 1998; Dalba & Fornasini, 1997; Rehr & Albers, 2000) technique can be used to probe atomic coordination structures, including electronic structure, chemical valence, local atomic structure, and chemical bond information
The XAFS spectra of standard Cr, Fe, Cu, and Se foils were collected by the CVD diamond micro-detector, and were compared with those collected by a routine ionization chamber (IC)
It can be found that the fitting parameters are all in excellent agreement with the crystallographic data for both Cu and Se foils. These results demonstrate again that the CVD diamond micro-detector is as suitable for XAFS measurements as the routine IC

Summary

Introduction

The X-ray absorption fine-structure (XAFS) (Palmer et al, 1996; Teo & Joy, 1981; Ankudinov et al, 1998; Dalba & Fornasini, 1997; Rehr & Albers, 2000) technique can be used to probe atomic coordination structures, including electronic structure, chemical valence, local atomic structure, and chemical bond information. To avoid the connection of the two quasi-combining techniques have been developed In these aluminium electrodes, photoresist was applied to the four combining techniques, ICs with a huge volume were used edges of the CVD diamond piece before evaporating the to collect the transmission XAFS signals. The intense diffraction spots produced by single- were connected to the aluminium electrodes on both sides of crystal diamond irradiate to other detectors used to the CVD diamond piece via gold wires, and were used to apply record other experimental signals. To verify the feasibility of making CVD diamond laminae into a detector, the XAFS spectra of four elemental foils (Cr, Fe, Cu, and Se) have been collected in the energy range from 5.5 to 13.5 keV Both incident and transmission X-ray intensities will be simultaneously recorded by the polycrystalline diamond detectors. The current or voltage signal from the CVD diamond micro-detector can be directly recorded as the analog quantity of the corresponding X-ray intensity

Experimental setup

Results and discussions

Conclusion