Author/Authors :
Kleinfelder، نويسنده , , S. and Li، نويسنده , , Howard S. and Bieser، نويسنده , , F. and Gareus، نويسنده , , R. and Greiner، نويسنده , , L. and King، نويسنده , , Roger J. R. Levesque، نويسنده , , J. and Matis، نويسنده , , H.S. and Oldenburg، نويسنده , , M. and Ritter، نويسنده , , H.G. and Retiere، نويسنده , , F. and Rose، نويسنده , , A. and Schweda، نويسنده , , K. and Shabetai، نويسنده , , A. and Sichtermann، نويسنده , , E. and Thomas، نويسنده , , J.H. and Wieman، نويسنده , , H.H. and Bichsel، نويسنده , , H.، نويسنده ,
Abstract :
A vertex detector that can measure particles with charm or bottom quarks would dramatically expand the physics capability of the STAR detector at RHIC. To accomplish this, we are proposing to build the Heavy Flavor Tracker (HFT) using 2×2 cm Active Pixels Sensors (APS). Ten of these APS chips will be arranged on a ladder (0.28% of a radiation length) at radii of 1.5 and at 5.0 cm. We have examined several properties of APS chips, so that we can characterize the performance of this detector. Using 1.5 GeV/c electrons, we have measured the charge collected and compared it to the expected charge. To achieve high efficiency, we have considered two different cluster finding algorithms and found that the choice of algorithm is dependent on noise level. We have demonstrated that a Scanning Electron Microscope can probe properties of an APS chip. In particular, we studied several position resolution algorithms. Finally, we studied the properties of pixel pitches from 5 to 30 μm.
Keywords :
Active pixel sensors , RHIC , Vertex detector , CMOS: STAR , Tracking and positive sensitive detectors
