| abstract |
The invention relates to a gas cell ( 1 ) adapted for carbon dioxide and including a cavity ( 10 ) which is adapted for a chosen gas volume, a light s source ( 11 ) and a light-bundle receiving unit ( 12 ). The light source ( 11 ) is placed in a focal point (F) associated with a partially elliptical mirror surface ( 13 ) forming a reflector for the light source ( 11 ) and a first defining surface of the cavity ( 10 ). Two other cavity-defining surfaces are comprised of gas-conducting surfaces ( 14 a , 14 b ) orientated from the end-parts ( 13 a ′, 13 b ′) of the mirror surfaces ( 13 a , 13 b ). The light-bundle receiving unit ( 12 ) is placed in a second focal point (F′) associated with the partially elliptical mirror surfaces ( 13 a , 13 b ). |