The CLEO-II Silicon Vertex Detector

SVX Diagram

The CLEO-II Silicon VerteX Detector (SVX) is depicted above in an end view (top) and side view (lower). The electron and positron beams of CESR will run in and out of the screen at the center of the end view; the SVX will be the innermost element of the CLEO-II detector.

Double-sided silicon strip detectors, manufactured by Hamamatsu, form the active elements of the device, and the locations are indicated by the thick black lines in the end view. The detectors are supported by U-channels of carbon fiber composite. Hybrid circuits built on a substrate of Beryllium Oxide, that incorporate CAMEX and JAMEX integrated circuits, are used to read out the detectors. These are not shown in the diagram above, but are shown in subsequent photos. The entire structure is supported by a carbon fiber composite tube.

The sensitive strips on the detector sides that face away from the center run in and out of the screen, and are used to measure particle trajectories in the plane of the screen (r-phi). The strips that face inward run in the plane of the screen, and measure trajectories in and out of the plane of the screen (r-z). For this side, an extra layer of metallization on the silicon is used to route the signals to the electronics at the ends of the detector.

There are a total of 64 silicon detectors in the assembly, and 96 silicon wafers. Pairs of silicon wafers are ganged together lengthwise in the third layer. The sensitive strips that measure in the r-phi plane are separated by 112 microns, those that measure in the r-z plane are separated by 105 microns. A total of 26208 channels are read out.

A module of the vertex detector, consisting of one octant of the Layer 1 and 2 detectors (4 total) mounted on the carbon fiber beam is shown in the first two subsequent pages:

CESR Overview CLEO Overview Home
Harry Nelson,