The equation of state, shock-induced molecule dissociation, and transparency loss for multi-compressed dense gaseous H2 + D2 mixtures

Abstract

The experimental equation of state and temperature data of the dense gaseous H2 + D2 mixtures under multi-shock compression were presented in a pressure range of 2–36 GPa and a temperature range of 2300–5300 K. The strong shock wave was produced using the flyer plate impact by accelerated up to 5.1–6.2 km/s with a two-stage light-gas gun and introduced into the plenum gas sample, which was pre-compressed from environmental pressure to 30–40 MPa. Time-resolved spectral radiation histories were acquired with two sets of multi-wavelength channel pyrometers, which were used to determine the shock velocity and shock temperature in the sample. Shock pressure and particle velocity were obtained by the impedance matching method. The experimental data prove the validity of self-consistent fluid variational theory (SFVT) model in the partial dissociation region. The time-resolved spectral radiation histories along with the SFVT calculation show that the shocked gas samples lose their transparency in visible light wavelength ranges of 400–800 nm at about 12.99 GPa and 4413 K or higher.

Measurements of the principal Hugoniots of dense gaseous deuterium−helium mixtures: Combined multi-channel optical pyrometry, velocity interferometry, and streak optical pyrometry measurements

“…Before each shot, the MCOPs and SOP were carefully calibrated using a standard tungsten light source for shock temperature measurements. This calibration is similar to that described in the work of Gu et al 26 and Ni et al 27 The twelve pins connected to the DPS via fibers were distributed symmetrically in four rings of diameters 5.4, 8.0, 10.0, and 12.4 mm, and used to launch the probe laser beams from DPS operating at a wavelength of 1550 nm and to collect the light returning to the DPS. The probe laser beams from DPS-I were directed onto the baseplate/sample interface or shock wave front through the 1.25 mm diameter apertures to measure its velocity; the probe laser beams from DPS-II were directly reflected by the Al reflecting film to measure the velocity of sample/LiF interface.…”

Multishock Compression Properties of Warm Dense Argon

“…Several theoretical simulations including QMD 15 , PIMC 15 16 , and the chemical pictures 13 17 , have been performed, but none of them could give a creditable prediction of the WDM states for different materials. For dense gaseous mixtures of H 2 +He 18 , and H 2 +D 2 19 , limited third-shock compression data were obtained by the spectral radiance histories of the specimen on the premise of good shock transparency of the anvil interface. Though the shock reverberation technique has been applied to the EOSs study 20 21 22 , the determination of multiply compressed states were done with the help of hydrodynamic simulations.…”

Diagnostics and Production of Warm Dense Matter with Multishock Reverberation Compression Technique

“…Recent technical advances, experimental capabilities and facilities make it possible to create and confine of warm dense states of matter in the laboratory [2] and advanced diagnostics required for the characterization and interrogation of such states [3]. These experimental capabilities include radiation-synchrotron sources [4], energetic materials [5][6][7][8], high power lasers [9][10][11][12][13][14][15][16], particle beams [17,18], Z-pinch devices [19][20][21][22][23], and mechanical impact techniques such as utilized in gas-gun launchers [24][25][26][27][28]. WDM is an important state of the evolution and presence of matters in inertial confinement fusion (ICF) and heavy-ion fusion [29].…”