\documentstyle[12pt]{article} %\addtolength{\topmargin}{-.5in} %\addtolength{\textheight}{.5in} %\addtolength{\oddsidemargin}{-.75in} %\addtolength{\evensidemargin}{-.75in} %\addtolength{\textwidth}{.5in} \textwidth=6 true in \textheight=8.5 true in \topmargin= 0.0 true in \begin{document} \begin{center} {\bf DETECTOR POSITION NUMBERING SCHEME} \vspace{1.0cm} \\ \end{center} The array has 72 detector positions (with No 6 for the beam in and number 72 for the beam out). The numbering for the six germanium detectors in each main pentagon face starts with the upermost detector in the corner of the pentagon and goes clockwise around the face and ends with the detector in the middle. The numbering for the type 1 BGO detectors is clockwise alphabetical `a' to `j' with `a' and `j' nearest a corner of a main pentagon. The type 2 BGO detectors around the central Ge detector are numbered `a' to `e' with `a' and `e' nearest the lowest numbered Ge detector. \vspace{1.0cm} \\ J.Simpson. \end{document}