• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文会议>Conference on X-Ray and Gamma-Ray Detectors and Applications IV, Jul 7-9, 2002, Seattle, Washington, USA >Improvement of the position resolution of the CCDs: Mesh experiment for small pixel CCDs and back-illuminated CCDs
【24h】

Improvement of the position resolution of the CCDs: Mesh experiment for small pixel CCDs and back-illuminated CCDs

机译：改善CCD的位置分辨率：小像素CCD和背照式CCD的网格实验

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We have employed the mesh experiment for the front-illuminated (FI) CCD having small pixel size of 8μm and for the back-illuminated (BI) CCD having pixel size of 24μm. BI CCDs possess the same structure as the FI CCDs. Since X-ray photons enter from the back surface of the CCD, the primary charge cloud is formed far from the electrodes. The primary charge cloud expands through diffusion process until they reach the potential well which is just below the electrodes. Therefore, the diffusion time for the charge cloud produced by X-rays is longer than those in the FI CCD, resulting the larger charge cloud shape to be expected. The mesh experiment enables us to specify the X-ray point of interaction with a subpixel resolution. We then have measured a charge cloud shape produced in the FI CCD as well as the BI CCD. We found that there are two components of the charge cloud shape having different size: a narrow component and a broad component for both CCDs. The size of narrow component obtained with the FI CCD is 0.6 ― 1.4μm in unit of a standard deviation which is consistent with the previous experiments with FI CCD whole pixel size is 24μm. For the BI CCD, the size of the narrow component is 2.8 ― 5.7 μm and strongly depends on the attenuation length in Si of incident X-rays. The shorter the attenuation length of X-rays is, the larger the charge cloud becomes. This result is qualitatively consistent with a diffusion model inside the CCD. On the other hand, the size of the broad component is roughly constant of (approx=) 13μm and does not depend on X-ray energies. Judging from the design value of the CCD and the fraction of each component, we conclude that the narrow component is originated in the depletion region whereas the broad component is in the field-free region. Taking into account the charge cloud shape obtained, we calculated the X-ray point of interaction for all X-ray events. We estimated the uncertainty of the position resolution to compare it with the location of the mesh hole. We then obtained the position resolution of 1 μm for both CCDs which is similar value of the previous results whereas the fraction of split pixel event becomes roughly three times and an order of magnitude larger than previous results. We can thus develop the X-ray spectroscopic detector having a micron order position resolution with a high throughput.
机译：我们已经将网格实验用于像素大小为8μm的前照式（FI）CCD和像素大小为24μm的后照式（BI）CCD。 BI CCD具有与FI CCD相同的结构。由于X射线光子从CCD的背面进入，因此形成的初级电荷云离电极很远。初级电荷云通过扩散过程进行扩展，直到它们到达电极下方的势阱为止。因此，由X射线产生的电荷云的扩散时间比FI CCD中的扩散时间长，从而可以期待更大的电荷云形状。网格实验使我们能够指定具有亚像素分辨率的X射线相互作用点。然后，我们测量了FI CCD和BI CCD中产生的电荷云形状。我们发现电荷云形状的两个分量具有不同的大小：两个CCD的窄分量和宽分量。 FI CCD获得的窄分量的大小为0.6到1.4μm（以标准偏差为单位），这与先前的FI CCD整个像素大小为24μm的实验一致。对于BI CCD，窄分量的大小为2.8〜5.7μm，并且在很大程度上取决于入射X射线的Si衰减长度。 X射线的衰减长度越短，电荷云变得越大。该结果在质量上与CCD内部的扩散模型一致。另一方面，宽分量的大小大致恒定为（大约=）13μm，并且不依赖于X射线能量。从CCD的设计值和每个分量的分数来看，我们得出的结论是，窄分量起源于耗尽区，而宽分量起源于无场区。考虑到获得的电荷云的形状，我们计算了所有X射线事件的X射线相互作用点。我们估计了位置分辨率的不确定性，以将其与网格孔的位置进行比较。然后，我们获得了两个CCD的1μm位置分辨率，这与以前的结果相似，而分裂像素事件的比例大约是以前的结果的三倍，并且数量级大。因此，我们可以开发出具有高通量的微米级位置分辨率的X射线光谱探测器。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号