A prototype of a 10-element photodiode array coated by 10-element CsI(Tl) scintillator array has been made and used as an X-ray detector. Its active area of photodiode is 0.75mm×1.25mm

apparent size is 10.25mm×1.75mm and the pitch of that is 1.25mm. Test results have been presented in this paper. The noise voltage of photodiode is about 10-4V; the non-uniformity is 0.08; the crosstalk between pixel to pixel has been obversed; moreover

some other performances of our detector have also been given as curves in this paper. Discussions on how to improve signal amplitude

how to decrease noise of detector system

how to amend crosstalk between pixels have been given.