arXiv subjects

Yong-jie Zhang

Publications and source records attributed to Yong-jie Zhang.

2 recordsLinked to original sources

arXiv2026

Performance Analysis of Digital Flux-locked Loop Circuit with Different SQUID $V$-$ϕ$ Transfer Curves for TES Readout System

A superconducting quantum interference device (SQUID), functioning as a nonlinear response device, typically requires the incorporation of a flux-locked loop (FLL) circuit to facilitate linear amplification of the current signal transmitted through a superconducting transition-edge sensor (TES) across a large dynamic range.This work presents a reasonable model of the SQUID-FLL readout system, based on a digital proportional-integral-differential (PID) flux negative feedback algorithm.This work investigates the effect of $V$-$ϕ$ shape on the performance of digital FLL circuits.Such as the impact factors of bandwidth, design limits of slew rate of the system and the influence of the shapes of SQUID $V$-$ϕ$ curve.Furthermore, the dynamic response of the system to X-ray pulse signals with rise time ranging from $4.4{\sim}281$ $\mathrm{μs}$ and amplitudes ranging from $6{\sim}8$ $\mathrm{ϕ_0}$ was simulated.All the simulation results were found to be consistent with the existing mature theories, thereby validating the accuracy of the model.The results also provide a reliable modelling reference for the design of digital PID flux negative feedback and multiplexing SQUID readout electronic systems.

astro-ph.IM↗

arXiv2023

Forecasts of CMB lensing reconstruction of AliCPT-1 from the foreground cleaned polarization data

Cosmic microwave background radiation (CMB) observations are unavoidably contaminated by emission from various extra-galactic foregrounds, which must be removed to obtain reliable measurements of the cosmological signal. In this paper, we demonstrate CMB lensing reconstruction in AliCPT-1 after foreground removal, combine the two bands of AliCPT-1 (90 and 150~GHz) with Planck HFI bands (100, 143, 217 and 353~GHz) and with the WMAP-K band (23~GHz). In order to balance contamination by instrumental noise and foreground residual bias, we adopt the Needlet Internal Linear Combination (NILC) method to clean the E-map and the constrained Internal Linear Combination (cILC) method to clean the B-map. The latter utilizes additional constraints on average frequency scaling of the dust and synchrotron to remove foregrounds at the expense of somewhat noisier maps. Assuming 4 modules observing 1 season from simulation data, the resulting effective residual noise in E- and B-map are roughly $15~μ{\rm K}\cdot{\rm arcmin}$ and $25~μ{\rm K}\cdot{\rm arcmin}$, respectively. As a result, the CMB lensing reconstruction signal-to-noise ratio (SNR) from polarization data is about SNR$\,\approx\,$4.5. This lensing reconstruction capability is comparable to that of other stage-III small aperture millimeter CMB telescopes.

astro-ph.CO↗