Of all the young scientists attracted to work with Rutherford, only Kapitza and a radio scientist carved out their own research fields. Kapitza was the most colourful and the one with international intrigue.

After one year of working with Rutherford, during which he confirmed that the alpha particle had no energy left at the end of its range in air, Kapitza convinced Rutherford to fund the development of methods of producing pulsed, but very high, magnetic fields. As these might be of use to Rutherford's work, who had been the first to use magnetic fields to deviate alpha particles, Rutherford raised considerable sums in support of Kapitza, culminating in having the Mond Laboratory built. By then Kapitza had expanded into low temperature physics. So when Kapitza returned to Russia for his usual summer visit in 1934 it was a shock to all to learn that Russia was not allowing his return to Cambridge. Kapitza was thus forced to advance science and technology in his homeland. Rutherford's fruitless, behind-the-scenes then public negotiations were finally abandoned and his last support of Kapitza was to allow Russia to purchase much of Kapitza's equipment at the Cavendish. In 1978 Kapitza was awarded a Nobel Prize in Physics for "his basic inventions and discoveries in the area of low-temperature physics." His helium liquifier was commercialised by Collins and the Arthur D Little companies and facilitated low temperature research world-wide.

Larry Badash has drawn on Rutherford's correspondence and papers, and Kapitza's correspondence to his wife. She was still in Cambridge during the first year of his new life in Russia so extracted parts of those letters for Rutherford.