Measurements of the targeting accuracy of the Gray Laboratory charged-particle microbeam

The charged-particle microbeam provides a unique opportunity to precisely c ontrol both the dose to individual cells and the localization of dose withi n the cell. In the Gray laboratory, both the performance of the detection s ystem and the targeting system has been assessed for 3.5 MeV He-3(2+) ions. Using an 18 mum transmission scintillator and a photomultiplier tube as th e particle detection system, detection efficiency is higher than 99%. When a 5 mum collimator is used, the overall targeting accuracy (which includes the error associated with target finding and alignment) is < 2.8 mum for 98 .7% of hits. (C) 2001 Elsevier Science B.V. All rights reserved.