Significant advances in readout elements of microchannel plate based sensors have led to the development of detectors with less than 10 μm spatial resolution. We have shown that cross strip (XS) anodes have spatial resolution as small as 5 μm FWHM when a simple and fast center of gravity centroiding technique is used. In this paper we investigate the variation of XS anode spatial resolution for several types of centroiding algorithms (N-finger center of gravity, Gaussian, Lorentzian, parabolic and hyperbolic cosine centroiding) and determine the optimum algorithm in terms of spatial resolution and image linearity. We found that for existing 32x32 mm² cross strip anodes and associated electronics, the best resolution and linearity is achieved with center of gravity centroiding with properly chosen thresholds on the data set. The images of USAF resolution test target obtained with MCP's with 6 μm pores on 7.5 μm centers resolve 71.8 line pairs per mm (Group 6 element 2, with line width of only ~7 μm). Thus the ~7 μm spatial resolution of the detector with cross strip anode is indeed limited now by the size of the MCP pores, while the resolution of XS readout is on the order of only few micrometers FWHM.

Date Published: 8 December 2003
PDF: 12 pages
Proc. SPIE 5164, UV/EUV and Visible Space Instrumentation for Astronomy II, (8 December 2003); doi: 10.1117/12.508409

Published in SPIE Proceedings Vol. 5164:
UV/EUV and Visible Space Instrumentation for Astronomy II
Oswald H. W. Siegmund, Editor(s)