Speaker
Description
The Alpha Magnetic Spectrometer (AMS-02) is a particle detector that operates on the International Space Station (ISS), aiming to search for antimatter and dark matter by performing precision measurements of cosmic ray composition and flux. In order to increase physics sensitivity, a new layer(L0) of silicon strip tracker was planned to be installed on top of AMS-02 to improve cosmic ray acceptance and heavy ions resolution. This tracking layer consists of two planes of silicon strip detectors, each composed of 36 units called "ladders". Each ladder is composed of a readout PCB board and 8, 10, or 12 silicon strip sensors. During the construction and quality control phases of the ladders, we observed that electrostatic charges on the passivation layer of silicon strip sensors can significantly increase the electronic noise level of the affected readout channels.
Firstly, we introduce the design of the silicon strip detector sensor and the ladder. Then, how we mimic the procedure to generate electrostatic charge on the surface of the sensor is presented. Detailed measurements of the readout electronics noise level and charge collection efficiency were carried out for normal and contaminated channels. The TCAD simulation of the silicon strip sensor and the SPICE simulation for readout circuits were used to help understand the mechanism of the impact of the static charge on the detector performance. And finally, the setups for eliminating the effect on the strip sensor will be shown.
