Scholar iON
Academic Synthesis
The papers collectively explore advancements in technology and methodologies within physics and applied mathematics, focusing on the development of sophisticated tools and simulations for understanding complex physical processes. Nakazawa et al. (2019) discuss the design and development of a prototype analog front-end compatible with Time Projection Chambers (TPCs) for applications in dark matter detection and neutrino studies, highlighting the challenges of operating under varying conditions and the innovative use of CMOS technology to meet the stringent electronic requirements. Meanwhile, Erban et al. (2007) provide a practical guide to stochastic simulations of reaction-diffusion processes, elucidating foundational and advanced methods for simulating chemical reactions and molecular diffusion. Both works underscore the significance of technological and methodological advancements in enhancing the precision and scope of experimental and computational research in physical sciences, though they operate in distinct yet complementary domains.
We report on the recent development of a versatile analog front-end compatible with a negative-ion $μ$-TPC for a directional dark matter search as well as a dual-phase, next-generation $\mathcal{O}$(10~kt) liquid argon TPC to study neutrino oscillations, nucleon decay, and astrophysical neutrinos. Although the operating conditions for negative-ion and liquid argon TPCs are quite different (room temperature \textit{vs.} $\sim$88~K operation, respectively), the readout electronics requirements are similar. Both require a wide-dynamic range up to 1600 fC, and less than 2000--5000 e$^-$ noise for a typical signal of 80 fC with a detector capacitance of $C_{\rm det} \approx 300$~pF. In order to fulfill such challenging requirements, a prototype ASIC was newly designed using 180-nm CMOS technology. Here, we report on the performance of this ASIC, including measurements of shaping time, dynamic range, and equivalent noise charge (ENC). We also demonstrate the first operation of this ASIC on a low-pressure negative-ion $μ$-TPC.
A practical introduction to stochastic modelling of reaction-diffusion processes is presented. No prior knowledge of stochastic simulations is assumed. The methods are explained using illustrative examples. The article starts with the classical Gillespie algorithm for the stochastic modelling of chemical reactions. Then stochastic algorithms for modelling molecular diffusion are given. Finally, basic stochastic reaction-diffusion methods are presented. The connections between stochastic simulations and deterministic models are explained and basic mathematical tools (e.g. chemical master equation) are presented. The article concludes with an overview of more advanced methods and problems.