MOSCOW - Dr Yuli Khariton, the Cambridge-educated nuclear physicist widely regarded as the father of the Soviet atom bomb, died yesterday at the age of 92, Russian news agencies said. Khariton, one of Russia's most honoured and decorated scientists, often said the greatest moment of his life came on August 29th, 1949, when the first Soviet atom bomb was tested near Semipalatinsk in Kazakhstan. Four years later, in October 1953, the Soviet Union tested its first hydrogen bomb.