Hugoniot points of liquid D 2 were measured at shock pressures of 107, 54, and 28 GPa using converging explosively driven systems ͑CSs͒. The two data sets measured with a laser ͑L͒ and pulsed currents ͑PCs͒ differ substantially. Our results are in excellent agreement with the PC data and the error bars of the CS-PC data are less than half those of the L data. The limiting compression obtained from the best fit to the CS-PC data is 4.30± 0.10 at 100 GPa. The CS-PC data are in good agreement with path integral Monte Carlo and density functional theory calculations, which is expected to be the case at even higher shock temperatures and pressures, as well.The single-shock compression curve ͑Hugoniot͒ of deuterium up to 100 GPa ͑1 Mbar͒ pressures has been controversial because limiting shock compression close to sixfold of initial liquid density has been reported using a high-intensity laser ͑L͒ ͑Ref. 1͒ and limiting compression close to fourfold has been reported using large pulsed currents ͑PCs͒. 2-4 That is, as pressure achieved with a single shock increases, so too does temperature, which limits compression at sufficiently high pressures. Examination of the systematics of singleshock compression of diatomic liquids suggests that the PC data are correct. 5 Deuterium in all the shock experiments is in thermal equilibrium because there are more than 10 4 collisions between atoms and/or molecules within the respective time resolutions. Deuterons in these experiments are classical. 6 Thus, there is no a priori reason why fluid deuterium would be expected to behave differently than other low-Z diatomics, as reported in Ref. 1. In order to determine the correct Hugoniot of D 2 , we began experiments on solid 7,8 and liquid samples in 1999. In this paper we report Hugoniot points at 109, 54, and 28 GPa for liquid D 2 samples.Strong shock waves were generated with hemispherical convergence driven by explosives ͑CS͒, the same method we used previously to measure points at 121 and 61 GPa for solid samples. 7,8 Our points at 109 and 121 GPa achieve limiting compression. Our points at 109 and 121 GPa and at 54 and 61 GPa used liquid and solid D 2 samples, respectively, to demonstrate self-consistency and reproducibility. Our point at 28 GPa demonstrates agreement with data measured at lower pressures with a two-stage gas gun ͑GG͒. 9 To minimize uncertainties, our CS method 10,11 requires that a given experiment be repeated several times and the results averaged. We have performed thirteen cryogenic, explosively driven experiments to obtain the three data points for liquid samples reported here. Our method produces data at 100 GPa pressures in the simple materials Al and Cu which are in excellent agreement with data obtained with a two-stage gun and planar explosives. 12,13 Thus, while our method produces relatively few data points, our results are in excellent agreement with data obtained by other techniques of demonstrated accuracy at shock pressures which can be obtained with all three methods.High shock pressures were gener...

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