Clock synchronization design and evaluation for trigger-less data acquisition system

For modern particle physics experiments,trigger-less data acquisition(DAQ) system has been put into practice because of the need of reaction multiplicity and trigger flexibility.In such new DAQ systems,global synchronized clock plays an important role because it affects the granularity of time slice and precision of reference clock.In this paper,a novel synchronized clock distribution method is proposed.With the help of modulation technique,master clock module distributes system clock to each slave module.To synchronize slave clocks,the propagation delay is adjusted and the clock phase is aligned by an FPGA chip automatically.Furthermore,an ADCbased method is proposed to evaluate the performance of multi-module clock synchronization simultaneously.The experiments of a prototype system show that slave clocks can be synchronized less than 100 ps over 150 m range.The proposed method is simple and flexible,and it can be used in trigger-less DAQ system and other applications of clock distribution preciously.

Studies of an event-building algorithm of the readout system for the twin TPCs in HFRS

The High-energy Fragment Separator(HFRS),which is currently under construction,is a leading international radioactive beam device.Multiple sets of position-sensitive twin time projection chamber(TPC)detectors are distributed on HFRS for particle identification and beam monitoring.The twin TPCs'readout electronics system operates in a trigger-less mode due to its high counting rate,leading to a challenge of handling large amounts of data.To address this problem,we introduced an event-building algorithm.This algorithm employs a hierarchical processing strategy to compress data during transmission and aggregation.In addition,it reconstructs twin TPCs'events online and stores only the reconstructed particle information,which significantly reduces the burden on data transmission and storage resources.Simulation studies demonstrated that the algorithm accurately matches twin TPCs'events and reduces more than 98%of the data volume at a counting rate of 500 kHz/channel.

Advances in nuclear detection and readout techniques

“A Craftsman Must Sharpen His Tools to Do His Job,”said Confucius.Nuclear detection and readout techniques are the foundation of particle physics,nuclear physics,and particle astrophysics to reveal the nature of the universe.Also,they are being increasingly used in other disciplines like nuclear power generation,life sciences,environmental sciences,medical sciences,etc.The article reviews the short history,recent development,and trend of nuclear detection and readout techniques,covering Semiconductor Detector,Gaseous Detector,Scintillation Detector,Cherenkov Detector,Transition Radiation Detector,and Readout Techniques.By explaining the principle and using examples,we hope to help the interested reader underst and this research field and bring exciting information to the community.