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September 8–11, 2025
Atlanta, GA|Atlanta Marriott Marquis
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The Frisch-Peierls memorandum: A seminal document of nuclear history
The Manhattan Project is usually considered to have been initiated with Albert Einstein’s letter to President Franklin Roosevelt in October 1939. However, a lesser-known document that was just as impactful on wartime nuclear history was the so-called Frisch-Peierls memorandum. Prepared by two refugee physicists at the University of Birmingham in Britain in early 1940, this manuscript was the first technical description of nuclear weapons and their military, strategic, and ethical implications to reach high-level government officials on either side of the Atlantic. The memorandum triggered the initiation of the British wartime nuclear program, which later merged with the Manhattan Engineer District.
V. Ya. Goloborod'ko, V. V. Lutsenko, S. N. Reznik, V. A. Yavorskij
Fusion Science and Technology | Volume 27 | Number 3 | May 1995 | Pages 292-297
Technical Paper | Plasma Engineering | doi.org/10.13182/FST95-A30391
Articles are hosted by Taylor and Francis Online.
Three-dimensional Fokker-Planck simulation of collisional losses of mega-electron-volt fusion products in axisymmetric tokamaks with plasma currents I < 2 MA is carried out. The calculations take into account both loss due to radial diffusion and loss caused by pitch-angle scattering in the first-orbit loss region in velocity space. Collisional losses of deuterium-deuterium (D-D) fusion products in the energy range 0.5 ≤ ε/ε0 ≤ 1 (where ε0 is the birth energy) are found to be increased with plasma current and comparable to a first-orbit loss at I > 1.5 MA. The loss mechanism considered may be responsible for the observed experimentally delayed losses of D-D fusion products in the Tokamak Fusion Test Reactor (TFTR). The dependencies of collisional losses on plasma current, effective charge number of the plasma (Zeff), and aspect ratio are investigated. The distributions of escaped ions over pitch angles, energies, and poloidal angles are evaluated. The fraction of collisionally lost fast fusion products is shown to scale like (ν⊥/νs)0.6 or (here ν⊥ and νs are characteristic collision rates of pitch-angle scattering and slowing down, respectively). The approach used may be considered as an alternative to the approach based on Monte Carlo modeling of scattering and can serve as a validity check of the latter.