Design of terahertz-wave Doppler interferometric velocimetry for detonation physics

Zhao-Hui Zhai,Kun Meng,Qiao Liu,De-Tian Wang,Liang-Hui Du,Sen-Cheng Zhong,Jiang Li,Chang-Lin Sun,Yu-Si Liu,Xu Zhang,Liu-Wei Guo,Shou-Xian Liu,Li-Guo Zhu

doi:10.1063/1.5142415

Abstract

The diagnosis of the initiation and growth of detonation in high explosives (HEs) is important in detonation physics. We designed and experimentally demonstrated a non-invasive high-precision free-space terahertz-wave Doppler interferometric velocimetry (TDV) design for diagnosing the transient detonation processes in HEs. The system can non-intrusively record the propagation of the shock/detonation wavefront inside HEs continuously and measure key detonation parameters (position/displacement, detonation velocity, etc.). A detailed quasi-optical design for TDV is discussed. The terahertz penetration ability and the refractive index of representative HEs are presented in the frequency range of 0.2–1.4 THz. Additionally, a typical shock-to-detonation transition of an insensitive high explosive was studied using a prototype 0.212 THz TDV system, which demonstrated the high precision of displacement measurements made using I/Q demodulation. Furthermore, the performance of the TDV technique is discussed. TDV may enable non-invasive and high-precision diagnostics for detonation and shockwave physics.

Highlights

Scitation.org/journal/apl advantage of these reflections, in this work, we designed and experimentally demonstrated non-invasive high-precision free-space quasioptical terahertz-wave Doppler interferometric velocimetry (TDV) for diagnosing transient detonation processes
A typical shock-to-detonation transition of an insensitive high explosive was studied using a prototype 0.212 THz TDV system, which demonstrated the high precision of displacement measurements made using inphase and quadrature (I/Q) demodulation
A demonstration test shot was performed using a prototype TDV system built at 0.212 THz to extract the vital parameters of a typical SDT inside an insensitive high explosive (IHE) from the transient interference TDV signal

Summary

Introduction

We designed and experimentally demonstrated a non-invasive high-precision free-space terahertz-wave Doppler interferometric velocimetry (TDV) design for diagnosing the transient detonation processes in HEs. The system can non-intrusively record the propagation of the shock/detonation wavefront inside HEs continuously and measure key detonation parameters (position/displacement, detonation velocity, etc.). Scitation.org/journal/apl advantage of these reflections, in this work, we designed and experimentally demonstrated non-invasive high-precision free-space quasioptical terahertz-wave Doppler interferometric velocimetry (TDV) for diagnosing transient detonation processes.

Results

Conclusion