wrapped around the secondary and the spark plug's plutonium rod. The ratio of deuterium (and tritium) atoms burned by 14 MeV neutrons spawned by the burning was expected to vary from 5:1 to 3:1, a standardization derived from Mike, while for these estimations, the ratio of 3:1 was predominantly used in ISRINEX. The neutronicity of the fusion reactions harnessed by the fusion tamper would dramatically increase the yield of the device. SHRIMPs indirect drive Attached to the cylindrical ballistic case was a natural-uranium liner, the radiation case, that was about 2.5 cm thick. Its internal surface was lined with a copper liner that was about 240 μm thick, and made from 0.08-μm thick copper foil, to increase the overall albedo of the hohlraum. Copper possesses excellent reflecting properties, and its low cost, compared to other reflecting materials like gold, made it useful for mass-produced hydrogen weapons. Hohlraum albedo is a very important design parameter for any inertial-confinement configuration. A relatively high albedo permits higher interstage coupling due to the more favorable azimuthal and latitudinal angles of reflected radiation. The limiting value of the albedo for high-Z materials is reached when the thickness is 5–10 g/cm, or 0.5–1.0 free paths. Thus, a hohlraum made of uranium much thicker than a free path of uranium would be needlessly heavy and costly. At the same time, the angular anisotropy increases as the atomic number of the scatterer material is reduced. Therefore, hohlraum liners require the use of copper (or, as in other devices, gold or aluminium), as the absorption probability increases with the value of Z of the scatterer. There are two sources of X-rays in the hohlraum: the primary's irradiance, which is dominant at the beginning and during the pulse rise; and the wall, which is important during the required radiation temperature's (T) plateau. The primary emits radiation in a manner similar to a flash bulb, and the secondary needs constant T to properly implode. This constant wall temperature is dictated by the ablation pressure requirements to drive compression, which lie on average at about 0.4 keV (out of a range of 0.2 to 2 keV), corresponding to several million kelvins. Wall temperature depended on the temperature of the primary's core which peaked at about 5.4 keV during boosted-fission. The final wall-temperature, which corresponds to energy of the wall-reradiated X-rays to the secondary's pusher, also drops due to losses from the hohlraum