Institute of Cancer Research Repository https://publications.icr.ac.uk Please direct all emails to: publications@icr.ac.uk This is an author produced version of an article that appears in: The internet address for this paper is: NUCLEAR INSTRUMENTS AND METHODS IN PHYSICS RESEARCH SECTION A https://publications.icr.ac.uk/9758/ Published text: H M Zin, A C Konstantinidis, E J Harris, J P F Osmond, A Olivo, S E Bohndiek, A T Clark, R Turchetta, N Guerrini, J Crooks, N M Allinson, R Speller, P M Evans (2010) Characterisation of regional variations in a stitched CMOS active pixel sensor, Nuclear Instruments and Methods in Physics Research Section A, Vol. 620(2-3), 540-548