Last week we had our first experimental run with the crystal I talked about a couple of months back. The crystal we used was installed in the SPS, the “Super Proton Synchrotron”, which with 6 km circumference was the largest machine at CERN before the LHC (then LEP) was built. It’s claim to fame is finding the “W and Z Bosons”, unstable particles that mediate the so-called weak interaction. Finding these particles provided the underpinning of the “Standard Model,” our present theory of particle interactions, and netted CERN a Nobel Prize. In accelerator physics and engineering, it demonstrated for the first time that it is possible to build high-energy proton-antiproton colliders with sufficient rate of particle collisions to do real physics with (not everybody thought this was going to work). Nowadays, besides providing beams for the LHC it has its own experimental program, our crystal experiment being one of them. In the experiment we managed to bring the crystal close enough to the beam that clearly the deflected particles were observed, and our equipment worked well. I had one detector from SLAC (we used it in PEP-II) installed for a test, and it performed well also. Our next goal will be to show that the crystal can have a useful application in removing beam particles that will get lost anyway in a controlled fashion, thus reducing beam loss around the ring. Beam loss distributed around the ring is bad because it creates radioactivity and makes maintenance difficult.
A section of the CERN SPS with some of our equipment in the foreground. The blue and red devices further back are accelerator magnets. Note the gentle curvature of the ring in the distance. The beam comes through the round pipe visible in the foreground.
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