07/11/98 Update

PEP-II Update July 11, 1998

PEP-II Commissioning Update July 11, 1998:

PEP-II has been in an installation period from February to July 1998.

The last aluminum pumping chamber for the Low Energy Ring (LER) was produced and installed in May. The last copper vacuum chamber for the LER interaction region was finished in mid-June.

The interaction region support tube containing the (final) permanent magnet dipoles and quadrupoles and high power vacuum chambers was finished in June by Andy Ringwall, Martin Nordby, Mike Sullivan, and Stan Ecklund and the IR group. The support tube was installed in the tunnel on June 18.

The last LER magnet raft was installed July 4 by the installation crews coordinated by Tom Taylor, Bill Wagner, and Al Mixon. The last LER vacuum chamber was installed July 9 at 12 noon under the direction of Leo Giannini, Dan Wright, Dave Bostic, Lowell Klaisner, Jim Davis, Kathy Ratcliffe, and the vacuum crews. Both ring vacuum systems were made leak free by 10 pm July 10.

Through out this period the RF systems for both rings have been tested by Jim Judkins, Heinz Schwarz, Paul Corredoura, Dick Cassel, and the RF group. The magnets and power supplies have all been tested by Mike Zisman, Paul Bellomo, Dave Macnair, Val Nesterov, and the power conversion group.

After locking the tunnel late on July 10, the Operations group with the help of the injection group (Dave Schultz, Rich Iverson, and Jim Turner) delivered positron and electron beams for injection to both rings.

Shortly after midnight the rings were ready for beams. [The LER commissioning is under the direction of Michael Zisman and Tom Himel, the HER by Uli Wienands, and the interaction region by Mike Sullivan and Stan Ecklund.]

By 5:05 am July 11 the electron beam had reached the interaction region. By 5:22 am the positron beam had also reached the interaction region after going around half the LER for the first time. Only one corrector was needed to get the positron beam this far. Both beams were intentionally stopped just upstream of the new (complete) interaction region so that careful steering studies can be done.

The near term plans are to store a beam in the LER for the first time, reestablish the HER beams with the new interaction region, and attempt first collisions. This beam run ends August 1 for reasons of site power transformer work.

Thanks to everyone for your very hard work during this last installation push. It's been an exciting time.

Best regards, John Seeman

Suggestions to: John Seeman

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