A new concept for a hybrid structure gaseous detector module with ion backflow suppression for the time projection chamber in a future circular collider is presented. It is a hybrid structure cascaded Gas Electron Multiplier (GEM) with a Micromegas detector. Both Micromegas and GEM have the capability to naturally reduce most of the ions produced in the amplification region. The GEM also acts as the preamplifer device and increases gas gain together with the Micromegas. Feasibility tests of the hybrid detector are performed using an 55Fe X-ray source. The energy resolution is better than 27% for 5.9 keV X-rays. It is demonstrated that a backflow ratio better than 0.2% can be reached in the hybrid readout structure at a gain of 5000.
@article{arxiv.1609.08010,
title = {A hybrid structure gaseous detector for ion backflow suppression*},
author = {YuLian Zhang and HuiRong Qi and BiTao Hu and Hai-Yun Wang and Qun Ou-Yang and Yuan-Bo Chan and Jian Zhang and Zhi-Wen Wen},
journal= {arXiv preprint arXiv:1609.08010},
year = {2017}
}