Signal modeling and impulse response shaping for semiconductor detectors

The output-signal models and impulse response shaping(IRS)functions of semiconductor detectors are important for establishing high-precision measurement systems.In this paper,an output-signal model for semiconductor detector systems is proposed.According to the proposed model,a multistage cascade deconvolution IRS algorithm was developed using the C-R inverse system,R-C inverse system,and differentiator system.The silicon drift detector signals acquired from the analog-to-digital converter were tested.The experimental results indicated that the shaped pulses obtained using the proposed model had no undershoot,and the average peak base width of the output shaped pulses was reduced by 36%compared with that for a simple model proposed in a previous work[1].Offline processing results indicated that compared with the traditional IRS algorithm,the average peak base width of the output shaped pulses obtained using the proposed algorithm was reduced by 11%,and the total elapsed time required for pulse shaping was reduced by 26%.The proposed algorithm avoids recursive calculation.If the sampling frequency of the digital system reaches 100 MHz,the proposed algorithm can be simplified to integer arithmetic.The proposed IRS algorithm can be applied to high-resolution energy spectrum analysis,highcounting rate energy spectrum correction,and coincidence and anti-coincidence measurements.

Defect-induced magnetism in χ_(3) borophene

Borophene is an emerging and promising twodimensional material for spintronics applications.Nevertheless,the origin and controllability of its magnetism remain poorly understood,thereby hindering the further development of borophene-based devices.In this study,it is demonstrated that χ_(3) borophene with vacancy defects,which contains zigzag edges and dangling bonds,exhibits spin polarization.To understand the origin and characteristics of its magnetism,a magnetic study of vacancy defects in χ_(3) borophene using first-principles calculations was performed.It is determined that the unpaired dangling bond electrons in the σ state contribute to its magnetism,and the zigzagged vacancy structure helps to maintain the localization and stability of unpaired electrons.Ferromagnetic coupling is completed by the s-p orbital interaction and mediated by p-orbital itinerant electrons.The magnetic coupling energy difference oscillates with the distance of magnetic atoms because of the indirect magnetic exchange by itinerant electrons and electronic shielding,in accordance with the Ruderman-Kittel-Kasuya-Yosida(RKKY)model.Furthermore,the causality between the dangling bonds and magnetism is identified by saturating magnetic B atoms using H,C and N atoms.This study provides a reference for the regulation of borophene in magnetic semiconductors.