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2025 ANS Winter Conference & Expo
November 9–12, 2025
Washington, DC|Washington Hilton
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Nano to begin drilling next week in Illinois
It’s been a good month for Nano Nuclear in the state of Illinois. On October 7, the Office of Governor J.B. Pritzker announced that the company would be awarded $6.8 million from the Reimagining Energy and Vehicles in Illinois Act to help fund the development of its new regional research and development facility in the Chicago suburb of Oak Brook.
Juan U. Koppel
Nuclear Science and Engineering | Volume 12 | Number 4 | April 1962 | Pages 532-541
Technical Paper | doi.org/10.13182/NSE62-A26102
Articles are hosted by Taylor and Francis Online.
The time dependent thermalization following a burst of fast neutrons is analyzed in the space independent case. The spectrum is decomposed in an asymptotic and a transient part, and the latter is expanded in a series of Laguerre polynomials. The argument of the polynomials is proportional to the time after the burst and the coefficients of the expansion are linear combinations of the transient time moments.