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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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Energy Secretary to speak at the 2025 ANS Winter Conference & Expo
In less than two weeks, the American Nuclear Society’s second annual conference of the year, the 2025 ANS Winter Conference & Expo, will come to Washington, D.C.
Today, ANS is announcing that Energy Secretary Chris Wright will be joining the list of nuclear leaders slated to speak at the conference.
Click here to register for the meeting, which will take place November 9–12 in Washington, D.C., at the Washington Hilton. Be sure to do so before November 7 to take advantage of priority pricing.
Masaoki Komata
Nuclear Science and Engineering | Volume 47 | Number 4 | April 1972 | Pages 489-493
Technical Note | doi.org/10.13182/NSE72-A22442
Articles are hosted by Taylor and Francis Online.
The perturbation formula of Usachev-Gandini for a ratio of reaction rates is newly explained by (a) a formal functional treatment of perturbation theory and (b) the variational principle. At the outset a time-dependent problem is considered, and a perturbation formula of a reaction number ratio is obtained. In a static problem this formula directly turns to a formula of a reaction rate ratio which reduces to the Usachev-Gandini formula when an adiabatic approximation is introduced. It is shown that there is no need to solve iterative equations of successive neutron generations.
