Effect of temperature on LX-17 and PBX 9502 in the cylinder test

LX-17 and PBX 9502 have been measured in the cylinder test (CYLEX) from -55 to 125°C. The change in detonation energy, compared to that at ambient temperature, is observed to decrease slightly with increasing temperature. The data are fit by a theory that 1) adds in the energy difference between the solid explosive enthalpy and the gas products, and 2) multiplies by the ratio of the densities. Although the data are taken from relative volumes of 2.4 to 7.0, extrapolation back to C-J is applied under the assumption that the energy change goes into the energy of compression. This shows that the detonation velocity does not change as long as the C-J volume remains constant as a function of temperature. Since the data shown depend on a correction for the air gap between the explosive and the cylinder, the latest correction, based on three large-gap concentric shots, is discussed.