05/12/97 Update

First Beam

We have had a terrific weekend!

After getting the beam into the ring at 3 h on Saturday morning the beam loss monitors were checked out, timed in and have worked like a charm since. Beam position monitors were next and very early on Sunday we saw our first orbit. This allowed us to diagnose and correct a slight energy mismatch and to fine tune the orbits using the injection magnets, resulting in a very nicely centered orbit without using the ring correctors at all (well, actually, we did use one in Arc 1). Leaving some time for tuning the injection line we came back to the ring Sunday afternoon for more: dispersion measurement and aperture scan. Both of these gave roughly the expected results (no beer bottles in this part of the ring vacuum!).

Judging by our weekend experience the HER ring systems appear to be in very good shape: magnet strengths close to design, alignment excellent, and the hardware has held up remarkably well given that several systems got pressed into operation with little or no burn-in time. The controls work, and already we can fit beam orbits all the way through the injection line into the ring and to IR 2. This fit also indicates that the quadrupole strengths are close to design.

There is little to add to Jonathan's message of Saturday except to express my personal thanks to all of you who have worked so hard - and so successfully - to make this happen. We have a long beam-commissioning road in front of us, but the start of this journey could hardly have been better.

Uli

Suggestions to: John Seeman

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