A performance and an imaging result of silicon strip detector

Since capacitively coupled readout has an advantage of shielding the readout electronics from sensor leakage current, we fabricated an AC-coupled single-sided silicon strip sensor on 5-in. 380 μm-thick wafer and its active area is 3.2 × 3.2 cm². It has 64 implanted and readout strips with a strip pitch of 500 μm. Two silicon strip sensors were mounted perpendicularly one another to get two-dimensional position information with a 5 mm space gap. Two low noise analog ASICs, VA1 chips, were used for signal readout of the strip sensor. The single-sided silicon strip detector (SSSD) consists of the two AC-coupled single-sided strip sensors and readout electronics. The SSSD was housed in an Al light-tight box. A CsI(Tl) scintillation crystal and a 2-in. photomultiplier tube were used to trigger signal events. The data acquisition systems were based on a 64 MHz FADC and control softwares for the PC-Linux platform. Experiments were performed at room temperature and silicon sensors were fully depleted. The SNRs were measured to be 29.1 ± 2.2 and 26.4 ± 0.3, respectively, for a 45 MeV proton beam and a ⁹⁰Sr radioactive source. Imaging tests were performed using a Pb phantom with a ⁹⁰Sr radioactive source and a 45 MeV proton beam, respectively. From the two-dimensional hit distribution, the phantom images were obtained and the position resolution was estimated to be about 240 μm.