Dual entrance window ion chamber for measuring X-ray exposure

摘要

A dual entrance window ion chamber is provided for purposes of measuring x-ray exposure. The ion chamber includes a housing having a cavity formed therein and which defines an ion chamber. The housing has oppositely disposed first and second openings therein located on opposite sides of the chamber. First and second x-ray entrance windows respectively cover the first and second openings for permitting entrance of x-rays into the chamber. A collector is located in the chamber intermediate the first and second windows for collection of electrons for use in measuring x-ray exposure. The first and second windows are constructed differently from each other such that the first window is optimized so that the ion chamber provides a relatively flat energy response to x-rays over a first x-ray energy range. The second window is optimized so that the ion chamber provides a relatively flat energy response over a second x-ray energy range. The second energy range is of a greater energy level than that of the first energy range.