A multichannel photoionization chamber for absorption analysis

TLDR: In this paper, a multichannel photoionization chamber is described, which includes a plurality of ion collection plates which permit measurement of ion current ratios to determine whether the absorption cross section is independent of both pressure and path length; i.e., Beer's law is obeyed.

Abstract: A multichannel photoionization chamber is disclosed for measuring absorption, photoionization yield and photoionization coefficients of gases. The chamber includes a plurality of ion collection plates which permit measurement of ion current ratios to determine whether the absorption cross section is independent of both pressure and path length; i.e., Beer's law is obeyed. Also disclosed are a plurality of pressure gauges for measuring chamber pressure at locations adjacent each of the collector plates. The pressure values corresponding to ion current maxima for each collector plate are used to determine the absorption cross section of the filling gas. Identical values of cross section calculated in this way are another indication that Beer's law is obeyed.