Xemis TPC Readout for Extraction of Charge and Time

Run reference : A35C18_2 - IC ams 0.35µm CMOS 4 ML C35B4C3 (datasheet)


A new liquid xenon Compton camera, called XEMIS2, is developed to image small animals using 3 gamma imaging. This new prototype is a monolithic liquid xenon cylindrical camera, which totally surrounds the small animal thanks to its 24 cm axial field of view. The 20480 pads of the ionisation chamber are read thanks to a dedicated ASIC called Idef-X. This 32-channel very-front-end electronics delivers an amplified and filtered signal. This signal delivered by the front-end electronics is readout by a specific 32-channel circuit, called XTRACT, in order to deliver the timing and charge of the relevant events. Each channel of XTRACT is auto-triggered, with a memorization the address of the channel triggered but also the memorization of the peak value of the input voltage signal and its time of arrival. The transmission of these informations (amplitude, time and channel numbers) is performed during a reading sequence thanks to an Asynchronous Binary Tree Multiplexer (ATBM). The power consumption of the complet 32-channel circuit is limited to 50mW.