Quick Shot
Calorimetry Measurements of Liquid Deuterium Supercooling in a Direct-Drive Target
March 16, 2015
Roger Gram, a Research Engineer at LLE, is shown adjusting the position of a temperature sensor that is attached to a NIF-size cryogenic target. The inset shows the target assembly in more detail: the 3-mm-diam target, while supported and filled through a stainless-steel tube, is thermally attached to a copper foil that contains a heater and temperature sensor. The size and mass of the components are kept to a minimum, allowing the heat that is released when liquid deuterium freezes to be measured. This experimental platform is being used to evaluate methods to seed the growth of a deuterium crystal from the condensed liquid while preventing the liquid from supercooling. The goal is to optimize the process used to form a single-crystal defect-free ice layer inside a target.