Readout Electronics for CASCA in XTP Detector

CASCA (Charge Amplifier with Switched Capacitor Array) is a 32-channel readout ASIC in 0.18 \(\upmu m\) CMOS technology for a TPC based X-ray Polarimeter (XTP). It measures two dimensional photoelectron tracks generated by the incident X-ray photons with one dimensional strip readout. The other dimension is calculated by the drift time from the signal waveform. This paper presents a readout electronics system based on the CASCA chip. The system mainly consists of three kinds of modules: the CASCA Frond-end card, the Adapter card and the Main DAQ card. The Frond-end card, mounted with CASCA chips, are designed for receiving detector signals. The Adapter card, edged-mounted with the Frond-end card, is in charge of digitizing the output signals from CASCA chip. The Main card collects digitized data from Adapter cards and then transfers data to server through Gigabit Ethernet protocol. One Main card is able to handle more than 128 electronic channels.