Ranking TEM cameras by their response to electron shot noise.
Ranking TEM cameras by their response to electron shot noise.
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DOI：
10.1016/j.ultramic.2013.01.003
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发表时间：
2013-10
期刊：
影响因子：
2.2
通讯作者：
Glaeser, Robert M.
中科院分区：
文献类型：
--
作者：
Grob, Patricia;Bean, Derek;Typke, Dieter;Li, Xueming;Nogales, Eva;Glaeser, Robert M.
我们演示了两种方法，其中只由随机分布的电子(散粒噪声)组成的图像的傅立叶变换可以用来比较不同电子相机的相对性能。其原理是确定给定图像的傅里叶变换与理想相机产生的图像的傅里叶变换是否接近，即单电子事件被建模为位于电子入射到相机上的相同像素的Kronecker增量函数的图像。在实验上，单电子响应的平均宽度是通过将单个洛伦兹函数与傅里叶变换的方位平均幅度进行拟合来表征的。洛伦兹函数下降到值0.5的空间频率的倒数提供了相应的线扩展函数下降到值1/e的像素数的估计。此外，由相机(对于单电子事件)的响应幅度的随机变化引起的过量噪声的特征是适当归一化的功率谱超过或不超过图像中的电子总数的量。这些简单的测量提供了一种简单的方法来评估不同相机的相对性能。为了说明这一点，我们提供了三种不同类型的闪烁体耦合相机和硅像素(直接探测)相机的数据。
We demonstrate two ways in which the Fourier transforms of images that consist solely of randomly distributed electrons (shot noise) can be used to compare the relative performance of different electronic cameras. The principle is to determine how closely the Fourier transform of a given image does, or does not, approach that of an image produced by an ideal camera, i.e. one for which single-electron events are modeled as Kronecker delta functions located at the same pixels where the electrons were incident on the camera. Experimentally, the average width of the single-electron response is characterized by fitting a single Lorentzian function to the azimuthally averaged amplitude of the Fourier transform. The reciprocal of the spatial frequency at which the Lorentzian function falls to a value of 0.5 provides an estimate of the number of pixels at which the corresponding line-spread function falls to a value of 1/e. In addition, the excess noise due to stochastic variations in the magnitude of the response of the camera (for single-electron events) is characterized by the amount to which the appropriately normalized power spectrum does, or does not, exceed the total number of electrons in the image. These simple measurements provide an easy way to evaluate the relative performance of different cameras. To illustrate this point we present data for three different types of scintillator-coupled camera plus a silicon-pixel (direct detection) camera.
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影响因子：
2.2
作者：
McMullan, G.;Chen, S.;Henderson, R.;Faruqi, A. R.
通讯作者：
Faruqi, A. R.
影响因子：
--
作者：
FANO, U
通讯作者：
FANO, U
DOI：
10.1016/j.nima.2009.07.017
发表时间：
2009-09-11
影响因子：
1.4
作者：
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通讯作者：
Giubilato, Piero
影响因子：
2.2
作者：
DOWNING, KH;GRANO, DA
通讯作者：
GRANO, DA
影响因子：
2.2
作者：
Meyer, RR;Kirkland, A
通讯作者：
Kirkland, A