Zhao-Hui Zhai, Chang-Lin Sun, Qiao Liu,, Liu-Wei Guo, Yu-Si Liu, Xu Zhang, De-Tian Wang, Kun Meng, Jiang Li, Liang-Hui Du, Shou-Xian Liu, Sen-Cheng Zhong, Li-Guo Zhu,
 |
| (a) Schematic diagram of the TDV system (dashed box) and the detonation testing field. See the supplementary material for the details. (b) THz transmission efficiency vs distance between L3 and L4, assuming the THz beam waist of the TDV output is 15 mm and L4 has a diameter of 50 mm (solid lines) or 30 mm (dashed lines). (c) Simulated THz beam diameter and field depth inside the target for various numerical apertures (NAs) of L4 (assuming n = 1.7). The red circles in (b) and (c) are the parameters of the prototype PDV system. |
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.
The National Science Foundation of China (Grant Nos. 61427814, 11704358, and 11604316) and the Foundation of CAEP (Grant No. CX20200001).
The authors own related patents (Nos. CN105807082B, CN105509817B, and CN108398691A).
The authors would like to thank Z. Q. Liu, J. H. Meng, J. H. Tian, P. Gao, and L. H. He for their help with the detonation experiments.
No comments:
Post a Comment