13 Nations Operate Huge Atom Smasher

Press, Volume XCIX, Issue 29178, 12 April 1960, Page 8

13 Nations Operate Huge Atom Smasher

[By

PIERRE DE LATIL]

It is the biggest undertaking in international scientific collaboration ever attempted and it is a magnificent success. First, let’s agree on the meaning of words. Of course, there have been many examples of useful co-operation, of which the most extensive was the Geophysical Year, and another- example, now under way, is the study of the Antarctic. But the word cooperation does not imply in any way working in common —unless it is around a conference table in order to plan a collective programme, share tasks and, later, take stock of results. But at CERN —the European Centre for Nuclear Research —in Geneva, more than 700 scientists and technicians from 13 nations are really working side by side, closely mingled in teams where nationalities give way before abilities.

This collaboration between physicists is not a mere academic exercise to prove the virtues of teamwork; it has a precise and basically utilitarian purpose. When it was realized after the war that modern research was going to require apparatus on a bigger and bigger scale, the old nations of Europe saw that they were in dimger of being hopelessly outstripped by the two giants of East and West, unless they could devote sufficiently powerful means to scientific experimentation. By pooling their resources, however, they would be able to face any competition. The principle of creating international institutes of scientific research had been established by the United Nations as long ago as 1946, but led to no concrete results. Then, in 1950, the UNESCO General Conference decided to set up a European laboratory devoted to atomic research and under the direction of Professor Pierre Auger, the project was carried through. The year 1952 saw the official birth of the European Organisation for Nuclear Research, whose first decision was to create a large research institute in Geneva. Right from the start, CERN decided to be a spearhead of scientific research. In the special field of high-energy particles—which requires the most expensive apparatus of all—the organisation set out to beat all world records by constructing a 25,000 million electron-volt accelerator. At the time, the United States held the record in this field with a 300 million electron-volt machine soon to be replaced by a 6000 million electron-volt accellerator. But this ambitious programme would require long years of research and preparation. To enable the physicists at CERN to start work as soon as possible, it was decided to build a large synchro-cyclotron—as big as the world’s biggest—which could be constructed in a relatively short time. In fact, the “SC,” as it is called, has been operating since 1957 and has already performed valuable work. And now, well ahead of schedule, the proton synchrotron, the world's most powerful atom-smasher, has just entered the nuclear research race. The Circus Ring * The principle behind these devices is the launching of elec-trically-charged particles on a circular track where they are forced to travel increasingly quickly. The track holding them on their path is an intense magnetic field which obliges them to keep a constantly-curved course. It can be compared to a circus ring in which the horses are the particles. The whipcracks which step up the rotating of the particles before they reach certain points, and then repel them. The analogy of horses in a circus ring is a rather good one. You might also compare the phenomenon to those games in which the player uses a racket to make a tennis ball attached to a string rotate round a pole. The often-used comparison of a sling is not really correct because, with a sling, the accelerating impulses come from the movement of the wrist—that is, from the centre of the ring and not from the perimeter. The first particle accelerators, developed only a quarter of a century ago, were barely a few inches in diameter. The 10,000 million electron-volt machine which the Russians built a few years back at Dubna near Moscow. is 183 feet in daimeter. In other words, scientists had progressed from an apparatus which could be set up on a laboratory table to giants requiring huge

roof was on and the exterior finish almost completed. The board will renew its request to the Education Department for a grant of £6O for the installation of permanent wiring for hall stage lighting. Although the department recommended that such lighting be hired as required, the board considers that permanent reticulation would be safe and more satisfactory and will say that much of the cost is being saved through economies on. the standard hall plan. A sub-committee of the board will consider whether evidence should be presented to the Commission on Education.

buildings. But the scale has changed once more with the accelerator at Geneva: —no building could hope to contain it. Its diameter is 656 feet and its circumference is 2060 feet. To house it, a semi-subterranean tunnel had to be built; it is like an underground railway train “chasing its tail." A tiny train seems to be stationary in this tunnel, its carriages being the 100 blocks of electro-magnet (each weighing 38 tons) which have been set up round the circle, separated from time to time by one of the 16 “acceleration units" which do the job of electrical whipcracking. Through all this machinery runs an elliptical tube whose diameter could almost be spanned by your hand. It is here that the protons are launched in a near-perfect vacuum. And since we’ve already tried so many analogies, let’s compare the accelerator to a prehistoric monster whose vertebrae are the 160 blocks of electromagnets with a vital spinal cord running through them: the tube in which the protons race is gripped between the jaws of the electro-magnets like the spinal cord by the vertebrae. The “package” of protons launched on this track races around it at a speed defying our human imagination: in less than a second, it makes 480,000 revolutions, —that is more than 174,000 miles or nearly three-quarters of the' distance between the earth and moon. It nearly equals the speed of light, the famous ceiling of 186,000 miles a second. As the protons’ speed increases, the accelerating whipcracks step' up their pace; and the magnetic field holding the protons on their course increases its strength to overcome the centrifugal force which becomes stronger and stronger with the growing speed. AH this implies fantastic precision: at top speed, only an eightmillionth of a second elapses between two accelerating impulses. And to regulate these impulses. precision down to a hun-dred-millionth of a second is required. Geometrically speaking, construction of the tube has to be absolutely perfect since the slightest distortion of the circle could cause a loss of protons: these would vanish directly they touched the sides of the tube. As was pointed out at the recent inauguration of the proton synchroton “the job requires the precision- of a chronometer on the scale of a battleship.” Exploring “Anti-Matter" It is hard to explain what is at stake here within the scope of this article but, at any rate, it is something quite new in science, Physicists want to create very high energy particles, capable of disintegrating atomic nuclei. It is during such disintegration and in other phenomena observed under conditions of very high energy that “strange” particles appear along with others which are even more revolutionary because they represent the mysterious “anti-matter.” This is matter built electrically in reverse and which vanishes, producing energy as soon as it comes into contact with the ordinary matter of which our universe is made up. Such is the new realm of physics which the European physicists of CEfiN are setting out to explore. (UNESCO).