[en] An improved aluminium target system for production of elemental fluorine via the ¹⁸O(p,n)¹⁸F reaction using a two-step irradiation protocol is described. In the first step highly enriched gaseous oxygen-18 is irradiated with protons to form fluorine-18 which gets deposited on the inner target surface. In the second step, after cryogenic recovery of oxygen-18 target gas, a mixture of elemental 'cold' fluorine and krypton is introduced and a short proton irradiation is done, whereby an isotopic exchange between the gaseous fluorine and the deposited radiofluorine occurs. The second step leads to the recovery of the radiofluorine as [¹⁸F]fluorine. Optimisation studies were performed regarding the yield and specific radioactivity of [¹⁸F]fluorine. Furthermore, some irradiation parameters relevant to the recovery step were investigated. It was found that a 15 to 20 min irradiation with a beam current of 20 μA is sufficient for the isotopic exchange between the fluorine-carrier and the ¹⁸F-radioactivity deposited on the inner wall of the target. The distribution of the ¹⁸F-radioactivity deposited on the inner target surface is inhomogeneous, probably due to convection effects. Extensive radioanalytical techniques were applied to characterise the reactivity of [¹⁸F]fluorine and to identify undesired nonreactive ¹⁸F-compounds, mainly [¹⁸F]tetrafluoromethane and [¹⁸F]nitrogentrifluoride. The [¹⁸F]fluorine produced in the system used has the distinction of having a negligible contamination from those inert ¹⁸F-compounds. This is a combined effect of the use of highest purity gases and a welded target construction, which avoids any contact of the gases with organic material during irradiations. The target has proved to be very reliable for production of [¹⁸F]fluorine in high yields of up to 34 GBq and specific activities of 350-600 GBq/mmol, both at 30 min after end of activation bombardment