  Quantum Well Infrared Photodetector (QWIP) usually suffer from a too moderate
quantum efficiency and too large dark current which is often announced as
crippling for low flux applications. Despite this reputation we demonstrate the
ability of QWIP for the low infrared photon flux detection. We present the
characterization of a state of the art 14.5\mu m QWIP from Alcatel-Thales 3-5
Lab. We developed a predictive model of the performance of an infrared
instrument for a given application. The considered scene is a Cryogenic Wind
Tunnel (ETW), where a specific Si:Ga camera is currently used. Using this
simulation tool we demonstrate the QWIP ability to image a low temperature
scene in this scenario. QWIP detector is able to operate at 30K with a NETD as
low as 130mK. In comparison to the current detector, the temperature of use is
three times higher and the use of a QWIP based camera would allow a huge
simplification of the optical part.
