Complex sentence: The fact that the hohlraum material was U enriched in U was deduced based on the final fission reaction fragments detected in the radiochemical analysis, conclusively shown by the U found by the Japanese in the shot debris.
Split into simpler sentences: The fact that the hohlraum material was U enriched in U is based on the presence of the final fission reaction fragments detected in the radiochemical analysis. It was conclusively shown by the U found by the Japanese in the shot debris.