Abstract: A target system includes a beam path for receiving a particle beam and a target chamber for housing a sample material. A target foil is operable for holding the sample material in the target chamber. A pressure cell is formed along a portion of the beam path between the target foil and a pressure foil. When irradiating the sample material with the particle beam, the pressure inside the target chamber and the pressure cell is increased and maintained at substantially the same pressure. A method includes inserting a sample material into a target chamber of a target system. The target system includes a pressure cell formed along a portion of a beam path between a pressure foil and a target foil, adjacent the target chamber. The pressure cell and the target chamber are pressurized and maintained at substantially the same pressure. The sample material is irradiated to produce a radioisotope.

Abstract: A method and apparatus for detecting beta particles in the presence of high gamma background using secondary electron emission (SEE) as the primary beta particle detector. Diamond-like thin films having coefficients for SEE as high as 50 are preferably used in a small hand-held probe whereby radiolabeled malignancies as small as 3 mm in diameter can be detected. An electron multiplier amplifies the secondary electron signal for generation of an audible signal or a display indicative of the level of beta radiation passing through the air-vacuum interface of the hand-held probe.

Abstract: A slow positron source having a cylindrical geometry which permits increased conversion efficiency from high energy into low energy positrons. A thin walled inner cylinder is filled with a positron emitting liquid radioisotope and is separated from an outer cylinder by an annular cavity. The outer cylinder surrounds the inner cylinder and is coated with a high atomic number material thick enough to stop all the positrons while providing a high fraction of backscattered positrons. A thin layer of moderator is also deposited on the inner surface of the outer cylinder. A positively biased pusher disk is placed at one end of the cylinders, while a negatively biased extraction grid is placed at the other end of the cylinders for extracting the low energy moderated positrons from the cavity so as to form a substantially monoenergetic positron beam. The positron beam is directed to impinge upon an annihilation screen at selected points using standard CRT focusing and deflection arrangements.