It seems to be getting quite a habit for the proton synchrotron to provide the most important CERN news every month.

On 24 August, a 50 MeV particle beam was obtained at the output end of the last of the three LINAC cavities. Final energy of the LINAC was thus reached. That evening, the accelerated proton current reached half a milliampere. Tests made at night - maximum energy is only produced at night so as to avoid unnecessary radiation hazards for the staff - have since made it possible to increase this figure to nearly 5 milliamperes. This is almost the maximum beam intensity for this part of the machine. The beam then passed through a port in the radiation shielding wall at the end of the linear accelerator room.

Further on, the proton beam entered the inflector, which should be completely installed by the middle of September. The purpose of this device is to bend the beam emerging from the linear accelerators into the 100 m radius orbit of the proton synchrotron ring. The inflector gives the 50 MeV beam the optimum shape and characteristics for use in the big circular accelerator.

After the final adjustments have been made on the inflector, the beam will enter the synchrotron vacuum chamber for a distance of about 15-20 magnet units. This distance corresponds to what is known by scientists as a "betatron wavelength", and will allow careful study of the behaviour of the beam after it has been properly injected into the proton synchrotron. Simultaneously, the beam may be directed into the circular vacuum chamber to make one or more complete revolutions. During this preliminary test, the beam will not be accelerated.

All this is scheduled to happen in September. In October, all the components of the radiofrequency accelerating system will have been assembled. The beam will probably be accelerated for the first time at the end of that month.

The running-in period will follow. This may perhaps end with the announcement of a high-energy beam before the end of 1959. In the opinion of those concerned, this will be the critical period. Although it may be relatively easy to design the components of a machine, test them separately and assemble them, it is the perfect running of the machine as a whole that always gives the most trouble.

Of course, there is a precedent - the energizing of the electromagnet - when a whole system was brought into regular operation without any major snags. A magnetic field corresponding to the maximum energy of the accelerator, 25 GeV, was obtained. Apart from some details needing adjustment, only one addition will be necessary: in the interphase transformer assembly.

Putting things right

On the subject of corrections, readers have been kind enough to assist an absent-minded proof-reader. Thanks to their eagle eye, two misprints have been spotted in the French edition of our first issue. It is certainly rather incongruous to have reduced the CERN site to a tenth of its actual area. The organization will run much better if it is restored to its original size of about 41 hectares.

Also - and the reader will probably have corrected this himself from the context - the final energy of the proton synchrotron should have read 25,000 million electron-volts and not 25 million.

To err is human, as they say.

• From CERN Courier September 1959 p1.

Editor's note

Since it first appeared in 1959, the CERN Courier has featured many articles on the accelerators at CERN.

The image to the right shows Franco Bonaudi, who was a leading figure in the design and construction of the laboratory's main machines from the very beginning. He is seen reading the second edition of the CERN Courier, the leading article of which is reproduced here.