TABLE 718.— DEVICES FOR PRODUCING HIGH-ENERGY PARTICLES * t t 



Impulse generator. 



Transformer rectifier. — Max about 2 Mev. 



Electrostatic generator, belt type. — Originated by R. J. VandeGraaff at M.I.T. 

 Developed for use in nuclear physics at M.I.T. by Van de Graaff and at Carnegie Institu- 

 tion in Washington by M. A. Tuve. About 1-3 Mev. Performance improved at Wisconsin, 

 by enclosing equipment in pressure chamber (with freon added to air), up to 4-5 Mev 

 (under pressure) 100 lb/in. 2 This device can accelerate any kind of charged particle. 

 Under construction (M.I.T., Los Alamos) 12 Mev. 



Cyclotron. — Originated at Berkeley by E. O. Lawrence. For accelerating any heavy 

 charged particles (not electrons). 44 Mev alpha-particles, 22 Mev deuterons, 9.5 Mev 

 protons. 



Betatron. — Originated at Illinois by D. W. Kerst. For accelerating electrons. 300 Mev, 

 Illinois ; 100 Mev, General Electric Co. 



Synchro-cyclotron. — Developed at Berkeley. 390 Mev alpha-particles, 400 Mev pro- 

 tons, 195 Mev deuterons. 



Synchrotron (electron). — Berkeley, 335 Mev electrons; General Electric Co., Cor- 

 nell, Michigan, Perdue, Berkeley, about 300 Mev; Harvard, 125 Mev. 



Linear accelerator. — Berkeley, 32 Mev protons ; Stanford, 5.7 Mev electrons (under 

 construction, 1000 Mev) ; M.I.T., 20-30 Mev electrons. 



Proton synchrotron. — Berkeley, 3-6 Mev (under construction) ; Brookhaven, 3 Mev 

 (under construction). 



Some of the smaller cyclotrons at various laboratories have been converted to F. M. 

 cyclotrons. There are now in use, or under construction in this country, over 100 devices 

 for producing particles of over 1 Mev energy. 



* This list was prepared by R. G. Herb, University of Wisconsin, and W. W. Brobeck, University 



of California. See Brookhaven National Laboratory Publication BNL-L-101, Particle accelerators, 1948. 



t High-speed neutrons cannot, of course, be produced directly by any of these devices. Neutrons are 



produced by bombarding certain materials with one of the high-speed particles produced by these devices. 



If beryllium, boron, or lithium are bombarded by a-particles neutrons are produced thus: 



4 Be» + 2 He'-^eC 12 + o" 1 

 B B" + 2 He'-^N" + „i 

 jH* + hu^Ri + n» 

 t Machines up to about 6 Mev now produced commercially. 



SMITHSONIAN PHYSICAL TABLtS 



