arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1002.0156physics.ins-detphysics.acc-ph
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使用电离室进行高动态成像

Imaging with high Dynamic using an Ionization Chamber

Ralf-Hendrik Menk, Heinz Amenitsch, Fulvia Arfelli, Sigrid Bernstorff, Hans Juergen Besch, Francesco Voltolina

摘要:

在这项工作中,一个电离室与一维空间分辨率和MicroCAT结构的组合。气体增益操作和集成前端电子设备之间的组合产生高达八到九个数量级的动态范围。因此,该设备非常适合医学成像或应用,例如小角度X射线散射,其中对探测器的动态要求非常高。基本上,所描述的检测器是适于扇形束几何形状的电离室,其具有192 cm 2的有效面积和150微米的阳极条间距。在垂直方向上,可以接受高达10 mm的梁。每个读出条连接到一个模拟集成电子通道,在定制的VLSI芯片实现。用作屏蔽网格的MicroCAT结构可实现高达10kHz的帧速率。观察到的高动态范围源于MicroCAT能够在气体中进行主动电子放大。因此,即使使用积分电子器件,也可以针对低光子通量获得单光子分辨率。该装置的特点是,对于每个光子通量,可以以实现最大DQE值的方式调节气体放大。

英文摘要:

In this work a combination of an ionization chamber with one-dimensional spatial resolution and a MicroCAT structure will be presented. The combination between gas gain operations and integrating front-end electronics yields a dynamic range as high as eight to nine orders of magnitude. Therefore this device is well suitable for medical imaging or applications such as small angle x-ray scattering, where the requirements on the dynamic of the detector are exceptional high. Basically the described detector is an ionization chamber adapted to fan beam geometry with an active area of 192 cm and a pitch of the anode strips of 150 micrometer. In the vertical direction beams as high as 10 mm can be accepted. Every read-out strip is connected to an analogue integrating electronics channel realized in a custom made VLSI chip. A MicroCAT structure utilized as a shielding grid enables frame rates as high as 10kHz. The high dynamic range observed stems from the fact that the MicroCAT enables active electron amplification in the gas. Thus a single photon resolution can be obtained for low photon fluxes even with the integrating electronics. The specialty of this device is that for each photon flux the gas amplification can be adjusted in such a fashion that the maximum DQE value is achieved.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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