Focused microbeam single event with a scintillating foil trigger and magnetic blanking

The focused proton microbeam of the Laboratori Nazionali di Legnaro, Italy has been upgraded to perform "Single Event (SE) physics". For this, a trigg er, which recognizes the crossing of a single proton, and a beam blanking s ystem have been implemented. The trigger consists of the light signal comin g from a scintillating plastic blade and read by a pair of photomultipliers , while the beam deflection is induced by a magnetic raster system, usually employed in elemental mapping. In spite of its slowness, this last device proves suitable, due to the extremely low particle rate we were able to ach ieve. Early tests are described here, during which regular matrices of etch ed nuclear tracks were produced on polymer CR39 foils. Althought, as far as efficiency and spot size are concerned, performance is still far from bein g satisfactory, we believe this procedure for SE studies to be practicable. (C) 1999 Elsevier Science B.V. All rights reserved.