Making the ‘PS’ ready for operation
Friday 10 July 1959 was a red-letter day for the Proton Synchrotron (PS) Division. It was on that day, at 3.10 p.m., that the electric locomotive used to bring the magnets to the ring slowly pulled its final load into the tunnel. Now the 100 magnets – each weighing 38 tonnes – that make up the electromagnet are in place, a major construction phase of the PS can be regarded as completed.
In the south experimental hall, the test bed used to measure the magnetic properties of the 100 magnets has been removed from its concrete support, while the railway used to carry the magnets to the accelerator has been dismantled. Some said that the PS had “burnt its boats”, however, that is not the case as there is a permanent track running inside the accelerator ring from the tunnel to the northern experimental hall. Nevertheless, the dismantling of these elements symbolizes the confi- dence within the PS Division after submitting each of the sub-assemblies to meticulous tests.
Could this be seen as marking the completion of the installation of the magnets? Not really, especially as far as the geodesics team in charge of the final positioning of the electromagnets was concerned. On average, two hours are needed to position each of the 100 magnets with a radial tolerance of one-tenth of a millimetre on a ring with a 200 m diameter. This provides an insight into the scale of the geodesics team’s task. The fact is that once the magnets have briefly been powered up, new tests and adjustments will be necessary. Subsequently, the team will have to take advantage of two annual shutdowns to redo the measurements.
Regulars in the “ring” will not have failed to notice the presence of a sign stating “Tunnel blocked at the 46th magnet”. What was the reason for this warning, punctuated by the incessant flashing of two red lamps? It is important to note that before the magnets are powered up for the first time on 27 July, there will be a final check of the connections and surfaces to ascertain that no tools or other foreign bodies that may be influenced by the magnetic field remain on the magnets or in the gaps. The ring has been blocked off to ensure that these checks can be carried out properly.
• This extract is translated from the article in French, see Courrier CERN August 1959 p4.
Stanford University stirs excitement
Stanford University in California is one of the leading players in the linear accelerator field. It operates a sizeable collection of these machines, some of which are used for medical purposes. Its 75 m long machine produces 700 MeV electrons and its energy is to be increased to 1050 MeV.
At the end of May this year, Stanford again made the headlines with a linear accelerator. Taking the floor at a scientific symposium in Manhattan, President Eisenhower stated that he would be recommending the US Congress to fund “a new linear electron accelerator…a machine measuring over three kilometres long, making it by far the largest ever built”.
If Stanford acquires such a machine, it will be one of the world’s most spectacular atom smashers. Two parallel tunnels, each nearly three kilometres long, would have to be excavated in the rock of a hill near Palo Alto. This natural protection would, of course, act as a barrier against any dangerous radiation likely to be produced. The tunnel with the smaller diameter would house the accelerator itself, while the larger tunnel would be used for services needed to maintain the machine.
The new Stanford accelerator would first produce 15 BeV (GeV) electrons, but there is talk of a possible subsequent energy increase to 40 BeV. It is estimated that machine construction will take six years and cost 100 million dollars. At the time of going to press, the only remaining hurdle to the project’s approval is the decision to be taken following the debate by Congress in July.
•Translated from Courrier CERN August 1959 p7.
While CERN began in 1954, the first edition of the CERN Courier did not appear until August 1959, with the subtitle “Monthly published for the CERN staff”. The early editions were certainly more like an amalgamation of the current Courier and the weekly Bulletin (see http://bulletin.cern.ch/). Only with volume 2, in January 1962, did the Courier come to resemble closely its current form. But it is interesting to see that even the first edition carried news of other laboratories – and that the major story about the PS (only part of which appears here) is reflected in this month’s article on the LHC. Over the coming months we plan to bring you more of these glimpses into the past.