An apparatus for radioisotope production comprising: a housing; a disk holder positioned inside the housing and configured to hold one or more targets (16, 40, 60) in the housing for radioisotope production; at least one curved window coupled to the housing and positioned adjacent to the target holder, the at least one curved window having a convex curved surface oriented facing into the housing toward the target holder, the at least one curved window operable to transmit radiation from outside the housing into the target holder for irradiation of one or more targets (16, 40, 60) held by the target holder within the housing to produce a radioisotope from the one or more targets (16, 40, 60); wherein the target holder comprises a coolant inflow portion operable to receive a coolant flowing through the housing during radioisotope production so that the coolant removes heat from one or more targets (16, 40, 60) held by the target holder and so that the coolant removes heat the at least one curved window; and wherein the target holder comprises a coolant outflow portion operable to outlet coolant from the target holder after the coolant passes over and removes heat from the one or more targets (16, 40, 60) and the at least one curved window, characterised in that the at least one curved window comprises two curved windows coupled to the housing and positioned on opposite sides of the target holder, the two curved windows each having a convex curved surface oriented facing toward the target holder from opposite sides of the target holder, the two curved windows operable to transmit radiation from two different directions into the target holder for irradiation of the one or more targets (16, 40, 60) from two different directions at the same time. a housing; a disk holder positioned inside the housing and configured to hold one or more targets (16, 40, 60) in the housing for radioisotope production; at least one curved window coupled to the housing and positioned adjacent to the target holder, the at least one curved window having a convex curved surface oriented facing into the housing toward the target holder, the at least one curved window operable to transmit radiation from outside the housing into the target holder for irradiation of one or more targets (16, 40, 60) held by the target holder within the housing to produce a radioisotope from the one or more targets (16, 40, 60); wherein the target holder comprises a coolant inflow portion operable to receive a coolant flowing through the housing during radioisotope production so that the coolant removes heat from one or more targets (16, 40, 60) held by the target holder and so that the coolant removes heat the at least one curved window; and wherein the target holder comprises a coolant outflow portion operable to outlet coolant from the target holder after the coolant passes over and removes heat from the one or more targets (16, 40, 60) and the at least one curved window, characterised in that the at least one curved window comprises two curved windows coupled to the housing and positioned on opposite sides of the target holder, the two curved windows each having a convex curved surface oriented facing toward the target holder from opposite sides of the target holder, the two curved windows operable to transmit radiation from two different directions into the target holder for irradiation of the one or more targets (16, 40, 60) from two different directions at the same time.