Patent Number: 059178744
Section: claims

1. A target for irradiation of a sample by a particle beam to produce a radioisotope comprising: a body having a depression in a front side for holding said sample, and cooling fins on a backside opposite said depression;  a foil sealingly joined to said body front side to cover said depression;  a perforate grid fixedly joined to said body atop said foil for supporting said foil, and for transmitting said particle beam therethrough; and  means for circulating a coolant over said fins to cool said body during said particle beam irradiation of said sample in said depression.  a housing joined to said body around said cone to define a plenum therebetween; and  an inlet and outlet disposed in said housing in flow communication with said plenum for circulating said coolant therethrough to remove heat from said body.  said depression is shallow in depth for allowing said particle beam to irradiate substantially all said sample therein to produce said radioisotope; and  said grid is thin with a thickness of about said depression depth for conducting heat from said foil to said body. 2. A target according to claim 1 wherein said body further includes a cone extending from said backside behind said depression, and said fins are disposed on said cone. 3. A target according to claim 2 wherein said cooling means comprise: 4. A target according to claim 3 wherein said cone includes an apex and an opposite base, and said fins are circumferentially spaced apart around said cone and extend axially between said apex and base. 5. A target according to claim 4 wherein said fins are axially straight. 6. A target according to claim 4 wherein said housing inlet is coaxially aligned with said cone apex, and said outlet is spaced radially outwardly therefrom. 7. A target according to claim 3 wherein said grid comprises a disk having a perforate center core for supporting said foil, and a surrounding rim fixedly joined to said body front side for conducting heat thereto. 8. A target according to claim 7 wherein: 9. A target according to claim 7 further comprising a retaining ring fixedly joined to said body to clamp said grid rim thereagainst, and having a central aperture surrounding said grid core. 10. A target according to claim 3 wherein said foil is aluminum and about six microns thin.