arXiv subjects

Wenzhao Wei

Publications and source records attributed to Wenzhao Wei.

4 recordsLinked to original sources

arXiv2026

Liquid argon purification and purity monitoring: apparatus and first results

We report results from a 13-liter purified liquid argon test stand at Wellesley College in Massachusetts, USA. The system includes a single-pass liquid-phase purification column that can achieve sub-part-per-billion impurity levels. The liquid argon purity is measured with a double-gridded purity monitor to assess the electron lifetime. Measurements demonstrate an O2-equivalent impurity concentration of $0.21 \pm 0.05$ ppb (stable over a 20-hour duration), corresponding to an electron lifetime of 1.6 ms at a drift field of 500 V/cm. This test stand supports ongoing detector R\&D on charge and light readout for liquid argon time projection chambers, such as Q-Pix and other cold electronics systems.

physics.ins-det↗

arXiv2024

First operation of a multi-channel Q-Pix prototype: measuring transverse electron diffusion in a gas time projection chamber

We report measurements of the transverse diffusion of electrons in P-10 gas (90% Ar, 10% CH4) in a laboratory-scale time projection chamber (TPC) utilizing a novel pixelated signal capture and digitization technique known as Q-Pix. The Q-Pix method incorporates a precision switched integrating transimpedance amplifier whose output is compared to a threshold voltage. Upon reaching the threshold, a comparator sends a 'reset' signal, initiating a discharge of the integrating capacitor. The time difference between successive resets is inversely proportional to the average current at the pixel in that time interval, and the number of resets is directly proportional to the total collected charge. We developed a 16-channel Q-Pix prototype fabricated from commercial off-the-shelf components and coupled them to 16 concentric annular anode electrodes to measure the spatial extent of the electron swarm that reaches the anode after drifting through the uniform field of the TPC. The swarm is produced at a gold photocathode using pulsed UV light. The measured transverse diffusion agrees with simulations in PyBoltz across a range of operating pressures (200-1500 Torr). These results demonstrate that a Q-Pix readout can successfully reconstruct the ionization topology in a TPC.

hep-ex↗

arXiv2024

Technical Report: Competition Solution For Modelscope-Sora

This report presents the approach adopted in the Modelscope-Sora challenge, which focuses on fine-tuning data for video generation models. The challenge evaluates participants' ability to analyze, clean, and generate high-quality datasets for video-based text-to-video tasks under specific computational constraints. The provided methodology involves data processing techniques such as video description generation, filtering, and acceleration. This report outlines the procedures and tools utilized to enhance the quality of training data, ensuring improved performance in text-to-video generation models.

cs.CV↗

arXiv2023

The Decay Q Value of Neutrinoless Double Beta Decay

An earlier publication "The implication of the atomic effects in neutrinoless double beta (0$νββ$) decay" written by Mei and Wei has motivated us to compare the decay Q value ($Q_{ββ}$) derived from the decay of the parent nucleus to the daughter nucleus with the two ejected beta particles in the final state to the $Q_{ββ}$ directly derived from the decay of the initial neutral atom to the final state of double-ionized daughter ion with the two ejected beta particles in the final state. We show that the results are the same, which is the mass-energy difference ($ΔMc^2$) subtracted by the total difference of the atomic electron binding energy ($ΔE_{b}$) between the ground states of initial and final neutral atoms. We demonstrate that $ΔMc^2$ is the sum of $Q_{ββ}$ and the atomic relaxation energy ($ΔE_{b}$) of the atomic structure after the decay. Depending on the atomic relaxation time, the release of the atomic binding energy may not come together with the energy deposition of the two ejected beta particles.

nucl-ex↗