The invention relates to a gas target window and the use thereof. The aim of the invention is provide a gas target window with a means of reliably reducing the heat load produced during radiation. Said gas target window should also be constructed in such a way that the energy of the incident particle beam is reduced only slightly. To this end, the inventive gas target window is provided with at least one cooling channel through which a coolant flows. It can be used in an irradiation device for separating a beam hole from a target chamber. In said beam hole, sub-atomic particles are directed through the gas target window at a gas which is enclosed in the target chamber.
