The micro-groove detector

We introduce the Micro-Groove Detector (MGD), a new type of two-dimensional position-sensitive gas proportional counter produced using advanced Printed Circuit Board (PCB) technology. The MGD is based on a thin kapton foil, clad with gold-plated copper on both sides. An array of micro-strips at a typical Ditch of 200 mu m is defined on the top metal layer. Using as a protection mask the metal left after the patterning, charge amplifying micro-grooves are etched into the kapton layer. These end on a second micro-strip pattern defined on the bottom metal plane. The two arrays of micro-strips can have an arbitrary relative orientation and so can be used for read-out to obtain 2-D positional information. First results from our systematic assessment of this device are reported: gas gain > 15 000, rate capability above 10(6) mm(-2) s(-1), energy resolution 22% at 5.4 keV, no significant charging or aging effects up to 5 mC/cm and full primary charge collection efficiency even at high drift fields, (C) 1999 Published by Elsevier Science B.V. All rights reserved.