The resolution estimation of wedge and strip anodes

Abstract

A new resolution estimation method for wedge and strip anode based on the single photon imaging configuration is provided. The limiting resolution estimation equation is deduced theoretically according to the threshold principle. The relation between the charge cloud and the covered electrodes is discussed, and the equivalent diameter number is calculated. The resolution equation for the position deviation amplitude or FWHM is provided if noise exists. The relation between the position deviation amplitude and the total charge deviation amplitudes is discussed. The constancy of the position deviation amplitudes versus positions is provided. The results calculated from these equations are discussed. According to the equations, it is indicated that the spatial resolution is affected by the detection system configuration and noise. These conclusions may be useful for the designing and performance improvement of future photon imagers.

Modeling the encoding structure and spatial resolution of photon counting imagers with Vernier anode readout

“…Position [1][2][3][4] and arrival time [5][6][7][8] recordings of single photons can be achieved by photon counting detection, which realizes ultra-weak radiation imaging with high spatial and time resolutions. Thus, photon counting imagers have been widely used in many important fields such as space detection, astronomy, biomedicine, nuclear physics, quantum key distribution (QKD), photon counting microscopy, etc.…”

“…A photon counting imaging system based on a Vernier anode usually consists of the detector, the readout circuit, and the data acquisition and decoding subsystem [1][2][3][4] . The detector consists of an input window, photocathode, MCP, Vernier anode, vacuum packaging shell, etc.…”

“…The readout noise may consist of thermal and shot noise of the readout electronics, nonlinearity, and inconsistency of the amplifiers for nine signal channels. The acquisition noise mainly comes from the quantized error of the A/D converters (ADCs) [2] .…”

“…For limiting resolution estimation, the spatial resolution of the detector will be determined by the quantized noise due to the limited bit width of the ADCs and the encoding structure of the anode [2] . The Vernier anode generally contains many pitches, which can be divided into three triplets, as shown in Fig.…”

“…The relationship between the charge microvariation and the area microvariation of the electrode covered by the charge cloud can be simplified as ΔS ¼ k • ΔQ. The parameter k is defined as [2] k ¼…”