The Design And Research On Key Technology Of Front-end Readout ASIC Chips For Gas Detector

As the largest and most energetic heavy ion research facility in China,Heavy Ion Research Facility in Lanzhou?HIRFL?has made a series of achievements in the field of material,basic physics and medicine.In the future,it is planned to do researches on radionuclides far from stable state of the radionuclides by the radiation ion beam line which is part of the facility.Especially researches on developing new gas detectors to measure the beam trace with high intensity,to diagnose the beam line,and to identify new particles.Time projection chamber?TPC?is a widely used gas detector,which has high precision with 3-D tracking detection ability and can give the momentum and energy loss information of particles.So,it has been widely used in physics experiments in recent years.Compared with traditional multi-wire drift proportion TPC,TPC based on GEM has strong advantages in counting rate,positive ion absorbs and position resolution.In order to cover the angle space of the reactivity products as much as possible,the large-area GEM-TPC detector has become the first choice in physical experiments.Therefore,high speed,high integration and low power consumption are required for the readout electronics system.Higher requirements will inevitably bring great challenges in new technologies and new methods.Many laboratories have developed ASIC chips for detector readout and established corresponding readout systems.The usage of ASIC greatly simplifies the structure of front-end electronics and reduces the power consumption as well as hardware expenditure.Therefore,the design of front-end readout ASIC is the key technologies that needs to be solved urgently.This paper according to the working principle and signal characteristics of gas detector and its readout demands,conducted a multi-channel,low noise,high count rate,large dynamic range of a front-end ASIC research work.And based on the 180nm CMOS technology,many front-read ASIC chip has been developed.Including an eight-channel CSA?Charge Sensitive Amplifier?chip,a four-channel shaper amplifier chip,a four-channel CSA which can absorbing detector's leakage current?200 nA?,and a 16-channel front-end ASIC manufacturing by the foundry.The experimental results show that these chips achieve good integral nonlinearity and energy resolution in 1pC dynamic range.Shaping time can adjust among 50ns,100ns and 1?s.The counting rate achieves 20k/s.We have tested two electronic systems based on the above ASICs and Multi-Channel Analyzer?MCA8000D?,combined with the TPC detector and a radiation source ⁵⁵Fe.The relative energy resolution was better than 23%and 28.2%respectively,approximate 24.8%which is the test result of commercial electronics with Ortec modules.The result shows that the ASICs can meet the demand of energy measurement for gas detectors.And it has laid a solid foundation for the further development of the ASICs which can be used for engineering.