Anyone inside would only yell and his voice would be back to the operator. Or, if he direct action, he could press as the ten plainly marked buttom wall which would instantly to thing off.

Although no appreciable could ever get outside the walls, there are geiger counting nervously all around, just. Even the small door to the has safety devices which see no one going through gets a squeeze--built-in are seven switches that on touch two door's electric motor.

The cyclotron's control brick building on Oxford Street is a big control panel and with row on row of dials, and a plethora of red, green, and orange lights. From here operator can control everything on inside the big concrete walls. the operator, up against the wall, is a triple tier of counters on stilts which merrily click and boast little varicolored lights their own. Along the passageway to the gray edifice are large boxes with additional controls. Cyclotron consists of three major

vacuum to provide space where articles can whirl around without into any air molecules. When in 1949, the vacuum chamber was of 99.9999 percent of the air it.

A large magnetic field--95 inches--to hold the particles in circular paths. The magnet in Harvard's cycltron has power enough to yank hammers out of people's hands.

3) a radio-frequency oscillator which sends out impulses to pull on the moving particles and thus speed them up. The top speed reached by particles in the University's machine is about half the speed of light--93,000 miles per second. They travel in an ever-widening circle until they hit the target, an inch square tidbit of metal placed at the outside edge of the cylinder. The atoms in the target burst apart when hit, becoming radioactive in the process. After the bombardment is all over, the target is carried off in a metal can to be studied in electrical, chemical, and photographic tests.

Until 1946 there were no cyclotrons where the particles' path was more then 60 inches across. This meant, among other things, that the power of any model was limited to 30,000 volts and the speed of the particles to much less than half the speed of light. The oscillator was the main obstacle to a bigger machine.

This is the explanation. When particles go beyond a certain speed they begin to get heavier. Beyond this point, the faster they go the heavier they get. Although each impulse from the oscillator still accelerates them, the rate of the acceleration falls off, In past years when that happened, the oscillator used to fall out of step. This had physicists stymied until the development of frequency modulation solved their difficulty. Now, when the particles begin to grow heavy as the pick up speed, the timing of the impulses is automatically adjusted.

A Staff of 40

The Nuclear Laboratory has a staff of about 40 people which includes researchers, electronics experts and highly skilled maintenance men. Besides their normal duties, the staff must perform as a construction gang when any new apparatus is being built.

Since the Laboratory was dedicated, no new particles have been found there, nor have there been any other sensations which newspapers could enthuse over. It is the technical journals which have benefitted the most among periodicals. A slew of papers has appeared, based on facts gleaned from the Harvard cyclotron. In a quite way this machine has been of great value in exploring the atom's nucleus and expanding what knowledge scientists have on that subject.