CHARGE SHARING AND RESOLUTION STUDIES OF DOUBLE-SIDED SILICON MICROSTRIPE DETECTORS WITH BORON SPRAY IMPLANTS

Measurements of the signal to noise, charge sharing, cluster distribut ion properties, charge correlation and spatial resolution as a functio n of angle of incidence have been conducted in a high energy pion beam at Fermilab for a variety of DC-coupled double-sided silicon microstr ipe detectors (Micron, Inc.) utilizing a special boron-spray technique for ohmic side isolation. Readout was accomplished with the Berkeley SVX-D IC/SRS/SDA sequencer system. Stripe pitch configurations include d 50 mu m and 25 mu m with every stripe read out (''501'', ''25*1''), and also with every other stripe read out (''50 2'', ''25*2''). One of the detectors under study was 15 mu m thick, rather than the usual 300 mu m. Of interest are the establishment, for 300 mu m thick detect ors, of sub-2.5 mu m resolution perpendicular to the beam on an ohmic side with 38 mm long stripes for both 251 and 25*2 configurations, an d diode side (58 mm stripes) resolutions ranging from below 3 mu m at near normal incidence to about 11 mu m at 60 degrees. At large angle t he 252 configuration generally gave comparable or better resolution t han 251. The thin detector gave a resolution ranging from about 5.5 m u m at 21 degrees to about 7 mu m at 45 degrees for 251 and 6.4 to 9. 0 mu m for 252, which, for each of the three common angles of data, w as better than the resolution yielded by the 300 mu m detector to whic h it was compared. Signals and charge sharing results are compared to detailed Monte Carlo calculations based on an energy loss distribution due to Bichsel.