On image reconstruction with the two-dimensional interpolating resistive readout structure of the Virtual-Pixel detector

Abstract

The two-dimensional interpolating readout concept of the Virtual-Pixel detector (ViP detector) goes along with an enormous reduction of electronic channels compared to pure pixel devices. However, the special concept of the readout structure demands for adequate position reconstruction methods. Theoretical considerations reflecting the choice and the combination of linear algorithms with emphasis on correct position reconstruction and spatial resolution are presented. A subsequent two-dimensional coordinate transformation further improves the image response of the system. Measured images show how far the theoretical predictions of the simulations can be verified and to what extent they can be used to improve the position reconstruction.PACS: 29.40.Gx, 02.60.Cb

Reconstruction algorithm study of 2D interpolating resistive readout structure

“…The node indications and the coordinate systems of the particular algorithms are also given in Fig1. The specified algorithms are listed below: [7] 4-Anode Algorithm: The origin of the coordinate system is located at anode 3. (2)…”

“…𝑄 𝜏6𝑦 = 𝑄 0 + 𝑄 1 + 𝑄 3 + 𝑄 4 + 𝑄 6 + 𝑄 7 (7) 3-Anode Algorithm: The origin is the same as 6-Anode Algorithm.…”

Development of a two-dimensional virtual-pixel X-ray imaging detector for time-resolved structure research

“…The depletion at the cell border shows the non-linear charge division behaviour. By using a more complex linear 4/6/3-node algorithm (Wagner et al, 2003) these kind of distortions do not occur anymore (Fig. 7 b)).…”

“…In this section we briefly describe the working principle and the setup of the detector. Detailed information about the detector can be found elsewhere (Besch et al, 1997;Sarvestani et al, 1998a;Wagner et al, 2003;Orthen et al, 2003a). A review of a previous, similar detector with smaller sensitive detection area and a less sophisticated position reconstruction, with a different gas gain structure and with slower electronics and readout has also been published earlier (Sarvestani et al, 1999a).…”

“…using only the collected charges Qi at the four readout nodes of one cell (4-node algorithm), the event position can be calculated within the cell. For a proper reconstruction using combinations of several linear algorithms (463-node algorithm) always 9 nodes should be read out (Wagner et al, 2003).…”