Electric discharge relevant to pyroelectric spontaneous polarization inducing irreproducibility of pyroelectric x-ray generation
Electric discharge relevant to pyroelectric spontaneous polarization inducing irreproducibility of pyroelectric x-ray generation
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与热释电自发极化相关的放电导致热释电 X 射线产生的不可重复性
DOI：
10.1117/12.2632418
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发表时间：
2022
期刊：
影响因子：
--
通讯作者：
Kodaira Satoshi
中科院分区：
文献类型：
--
作者：
Naito Masayuki;Kusano Hiroki;Nagaoka Hiroshi;Hasebe Nobuyuki;Kodaira Satoshi
利用热释电晶体的自发极化特性，在~1 Pa的低压气体中发射X射线，具有体积小、重量轻、功耗低等优点，有望成为未来的原位X射线源。热释电X射线的产生仍然存在强度和再现性等问题，因为电子产生的机制仍然是一个悬而未决的问题。我们已经实验和数值评估的热释电X射线产生相关的热释电晶体周围的放电与各种尺寸的目标支持和目标有/没有针。观察到晶体顶部与金属靶之间的放电（CT-MT放电）、晶体顶部与晶体底部之间的放电（CT-CB放电）和晶体表面沿着的放电（CS放电）。CT-MT放电由1cm × 5cm靶座或带针靶测量，其引起不规则X射线增加。X射线强度变得可再现，但不是那么大时，CT-MT放电进行测量。CTCB和CS放电对于大靶板是活跃的。这两种放电不规则地发生，导致再现性低。虽然CS放电导致的晶体电位降低不大，但CT-CB放电使X射线发射停止。当不测量CT-CB时，X射线强度变大。晶体周围电场的计算结果支持了实验结果，表明选择合适的靶支撑是热释电X射线产生获得大的、可重复的X射线强度的重要因素之一。
The spontaneous polarization of pyroelectric crystal is utilized to X-ray emission in low pressure gas of ~1 Pa, which has a potential as a future in-situ X-ray source with small size, light weight, and low electric power consumption. The pyroelectric X-ray production still has problems as its intensity and reproducibility because the mechanism of electron production is still an open question. We have experimentally and numerically evaluated pyroelectric X-ray generation relevant to electric discharges around the pyroelectric crystal with various sizes of target support and target with/without a needle. Three kinds of electric discharge, between crystal top and metallic target (CT-MT discharge), between crystal top and crystal bottom (CT-CB discharge), and along with crystal surface (CS discharge), were observed. The CT-MT discharge was measured by the 1 cm × 5 cm target support or target with a needle, which induced irregular X-ray increases. X-ray intensity became reproducible, but not so large when the CT-MT discharges were measured. The CTCB and CS discharges were active for the large target plates. These two discharges occur irregularly, resulting low reproducibility. While reduction of crystal potential by the CS discharge was not large, the CT-CB discharge stopped Xray emission. When the CT-CB was not measured, the X-ray intensity became large. Calculation results of electric fields at around the crystal supported the experimental results, which implied that selection of appropriate target support is one of important factors to obtain large and reproducible X-ray intensity by the pyroelectric X-ray generation.