The development of the intense positron beam at Washington State University

Abstract A High Voltage Engineering K-4000 Van de Graaff ion accelerator has been acquired by Washington State University. This accelerator will be used to create a positron source through the 12 C(d, n) 13 N reaction. The accelerator is capable of accelerating protons or deuterons up to 4 MeV with a maximum beam current between 200 and 300 μA. During normal operation, a 3 MeV deuteron beam will impinge on a diamond or graphite target producing ∼3.3 Ci of 13 N from which a ∼1×10 7 s −1 monoenergetic positron beam will be created. In addition to creating positrons, the source will also emit a large number on neutrons (∼1.2×10 11 s −1 ), producing a serious radiation hazard. The development of this 13 N based positron beam is discussed including the expected positron yield and radiation shielding requirements.