Speaker
Description
The Alpha Magnetic Spectrometer(AMS-02) is a particle detector that operates on the International Space Station(ISS), which aims to search for antimatter, and dark matter while performing precision measurements of cosmic rays composition and flux. To enhance the detection acceptance by a factor of three, a new large-area silicon tracker layer (Layer-0) will be installed on top of AMS-02 in 2026. Layer-0 is composed of two back-to-back detector layers, each with an active area about $3.5\,\mathrm{m}^2$. To achieve such a large active area with limited power consumption, we designed very long silicon detector ladders. Each ladder has 8, 10, or 12 silicon strip detector sensors (SSDs) connected in serial, producing an effective strip length from 64 cm to 96 cm. To evaluate the performance of these ladders, multiple beam tests were conducted at CERN’s Super Proton Synchrotron (SPS) and Proton Synchrotron (PS) facilities.
In this talk, we present a detailed characterization of ladder performance, including: (i) comparisons across ladders of different lengths; (ii) position-dependence of SSDs along a single ladder; and (iii) the dependence of performance on the incidence angle. Performance is quantified in terms of detection efficiency, charge-collection efficiency, and spatial resolution for minimum-ionizing particles (MIPs).
