After writing his March 7 memorandum, Kurchatov gave his rough notes to Pervukhin’s assistant, A.I. Vasin, to be destroyed.7 In the coming years he had to obtain special permission to show any of the intelligence reports from abroad to his fellow scientists. At the same time he had to make use of the information he had acquired, without letting his colleagues know where it had come from. This he did by proposing promising lines of research, and by suggesting ideas in meetings and seminars.
