[en] The production of ¹⁸F electrophilic reagents via the ¹⁸O(p,n)¹⁸F reaction has been investigated in small-volume target bodies made of aluminum, copper, gold-plated copper and nickel, having straight or conical bore shapes. Three irradiation protocols--single-step, two-step and modified two-step--were used for the recovery of the ¹⁸F activity. The single-step irradiation protocol was tested in all the target bodies. Based on the single-step performance, aluminum targets were utilized extensively in the investigation of the two-step and modified two-step irradiation protocols. With an 11-MeV cyclotron and using the two-step irradiation protocol, >1Ci [¹⁸F]F₂ was recovered reproducibly from an aluminum target body. Probable radical mechanisms for the formation of OF₂ and FONO₂ (fluorine nitrate) in the single-step and modified two-step targets are proposed based on the amount of ozone generated and the nitrogen impurity present in the target gases, respectively