0000000000704425
AUTHOR
S. Piccinini
Experience with the ALEPH silicon vertex detector
Abstract The ALEPH experiment [1] at LEP is equipped with a vertex detector [2] using two layers of double-sided silicon strip detectors. These detectors allow a real two-dimensional measurement of charged particle tracks. The present (1991) detector has the inner layer at a radius of 6.5 cm and the outer layer at 11.5 cm. The theta angle coverage is ±33° for the inner layer and ±50° for the outer layer. The inner layer is made out of 9 faces with four silicon detectors each, the outer layer has 15 such faces. We use silicon detectors of 5 × 5 cm 2 and 300 μm thickness. The readout pitch is 100 μm at both sides and using capacitive charge division a resolution in the order of 10 μm can be a…
LIPOCORISTOMA DELL’ANGOLO PONTO-CEREBELLARE: UN NUOVO NOME PER UNA VECCHIA CONOSCENZA
SCOPO DEL LAVORO: I lipochoristomi sono rari tumori benigni (0.1% di tutti i processi espansivi dell’angolo ponto-cerebellare) che in passato si riteneva derivassero dalle cellule della primitiva meninge e pertanto venivano definiti come lipomi dell’angolo ponto-cerebellare (o del condotto uditivo interno). Oggigiorno sono più propriamente definiti come "coristomi lipomatosi" (o lipocoristomi) poiché si è dimostrato che originano dal tessuto mesenchimale proprio del nervo vestibolo-cocleare. Scopo del presente lavoro è quello di presentare dei casi di lipocoristoma alla luce dei dati oggi riportati nella più recente letteratura. MATERIALI E METODI: Saranno presentati casi di pazienti con ri…
Operational experience with a large detector system using silicon strip detectors with double sided readout
Abstract A large system of silicon strip detectors with double sided readout has been successfully commissioned over the course of the last year at the e + e − collider LEP. The readout of this 73 728 channel system is performed with custom designed VLSI charge sensitive amplifier chips (CAMEX64A). An overall point resolution of 12 μm on both sides has been acheived for the complete system. The most important difficulties during the run were beam losses into the detector, and a chemical agent deposited onto the electronics; however, the damage from these sources was understood and brought under control. This and other results of the 1991 data-taking run are described with special emphasis o…