Knocking out the Proton Synchrotron beam
On 12 May 1963, at thirty-five minutes past four in the afternoon, history was made again at the CERN Proton Synchrotron (PS). The first accelerating machine in the world to produce 25 GeV protons then became the source of the world's first beam of 25 GeV protons to travel freely in air. The story of events in the accelerator's main control room on that day is told here by Berend Kuiper, one of those chiefly responsible.
The mood of the ejection team in the PS main control room on Sunday morning, 12 May, was one of moderate confidence, since several operations of the ejection magnets together with the proton beam had already been rehearsed before and results had proved reasonably close to the predictions.
After patching up the high-voltage feeds, which had recently led to some trouble, the kicker magnet had been reinstalled in its vacuum box in straight-section 97 the previous Friday night. On Saturday morning the box had been reopened for a final check and the electrical connections verified by pulsing the magnet in air for an hour. The lid had just been replaced on the tank when suddenly the mechanics of the Nuclear Physics Apparatus (NPA) division, Albert Bertuol, Yves Favereau, Anton King and Pierre Pugin produced a baby pine tree with a beautiful yellow lace, which they solemnly mounted on top of the hydraulic accumulator by means of that indispensable tool of the physicist, "Scotch tape". Saturday afternoon had been spent on rehearsing some of the gymnastics of the magnet movement and the beam displacement, so as to study the correct positioning of one to the other. Also, the two magnets were for the first time electrically pulsed in the presence of a proton beam. The leakage field of the bending magnet proved not to disturb the unkicked beam appreciably, and the kicker magnet produced the expected deflection of the protons. All these preliminary results were the basis for the good hopes on Sunday morning when, between 8 and 9 a.m., Hugh Hereward with his Machine Proton Synchrotron operating team were setting up the 3 second 25 GeV synchrotron cycle and the NPA ejection men warmed up their equipment...
[During the day the small crowd in the control room, consisting of the ejection team, the machine operators and engineers, and some "passers-by" followed the progress via a television camera arranged to view fluorescent screens at various key points in the beam line. There were problems with the delay between the kicker magnet and the bending magnet, which Hendrick Dijkhuizen and Javier Goñi tried hard to fix, and to make things worse the PS itself began to behave badly. (Ed.)]
...Meanwhile the clock had reached 4 p.m. and time was quickly running out, as the machine shifts allocated to ejection studies were due to end an hour later. To make a final attempt before closing time, Dijkhuizen and Goñi locked the kicker and the bending magnet over entirely separate timing units onto the PS cycle. This permitted their proper phasing without mutual interference. The magnets were now pulsed again, but the PS still didn't function any better than before. Each time the PS accelerated a few pulses the mob dashed to the TV screen, but over and over again the PS fell out before anything could be seen. Then, finally, at 4.35 p.m., the "beam on" signal stayed alight rather longer than usual and the TV reproduced the picture of the beam being kicked into the bending magnet window. As Horst Wachsmuth again switched the receiver to camera two, a piercing light flash near the cross mark on the fluorescent screen proved that the world's first 25 GeV proton beam had been successfully ejected - very close to the theoretical trajectory.
•Taken from CERN Courier May 1963 p63.
NASA to copy CERN's synchrocyclotron
The Langley Research Center of NASA, the US National Aeronautics and Space Administration, is to be equipped with a synchrocyclotron that will be used especially for the simulation of all the different kinds of ionizing radiation that will be encountered in space flights. This cyclotron will be an almost exact copy of the accelerator at CERN.
The synchrocyclotron will form the nucleus of the Space Radiation Effects Laboratory, which will probably be operated for NASA jointly by the College of William and Mary, the University of Virginia and the Virginia Polytechnic Institute.
•Taken from CERN Courier May 1963 p70.
Editor's note
One of the most remarkable photographs used on the cover of the CERN Courier was the image shown here (above), from the May 1963 issue. On 12 May, for the first time ever, a 25 GeV proton beam was extracted from the PS to travel in air. The following day G Bertin and F Juillard from the Public Information Office set up their camera to record the glow as the beam passed through scintillators along its path. Berend Kuiper's article in the same issue described the scenes leading up to this historic event.