-G(c is the velocity of. light). v can be eliminated between Eqs. (1) and (2) to give zl Eco mm, q’ (3) 7° From Eq. (3) we see that all particles of a particular m/q will strike. the plate somewhere along a parabolic locus which is characteristic of that m/qratio. From Eq. (2) we see that the particular point struck by a given particle is a measure of the ratio of charge to kinetic energy of that particle. The apparatus shown in Fig. 3 was designed for use in conjunction with the Livermore Pool-Type Reactor (LPTR) at the Lawrence Radiation Laboratory in Livermore, A 0.001-inch-thick foil of U 239 was mounted on an alumi- num plug and inserted into an evacuated tube in a hole in the reactor shielding. The thermal neutron flux at the inner end of the hole was approximately DX io! neutrons/cm”/ second. The beam of fragments passed along the tube, through a collimating hole furnished with a remotely-controlled shutter, and between the poles of a 12-inch-diameter electromagnet. Also between the poles of the magnet were a pair of parallel plates, one at ground potential, the other insulated and connected to a source of negative high voltage (up to 20 kV). edge The beam entered the field region close to the grounded plate to avoid effects insofar as possible. On emerging from the field region, the beam travelled for about 1 meter and impinged on a piece of 0,001-inch-thick aluminum foil fastened to a rigid backing. kept below 107° torr. Pressure in the e:utire system was | The uranium foil was inserted in the beam tube with the reactor shut down, the tube was evacuated, and the reactor started. When full reactor power was reached (2 MW) the magnet and high voltage were turned on and the . 5001839