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ESOURCE: Feng Zhou reporting.
The electron source has 3 items on list 1 of the punch list, and 1 item on list 2. Of these, 3 have been addressed by the deckmasters -- all the ones related to cryo modules and cryogenic system segmentation. The new lattices have been sent to the System Integration people and will be put into production shortly. The remaining item is to adjust the optics and geometry of the injection line after the RTML has designed its vertical dogleg for the positron system (since that dogleg will require additional tunnel length, which means that the e- source components will no longer be matched to the tunnel geometry); that cannot be accomplished until the RTML item has been done.
PSOURCE: Feng Zhou reporting.
The positron list has a larger number of items, but the items on this list related to cryomodules and cryo segmentation have also been done and the revised lattices handed over to SysInt. At the moment there is no deckmaster for positron source, and Feng is working full time for electron source this year. The area leader and the Project Manager for Area Systems have been informed of the problem and are working on it.
DR: Ina Reichel reporting.
A new set of lattices for the inj / ext lines has been produced -- the new version is "MAD-ready" in that the kickers are treated as bends and the quads with off-axis transport are treated as gradient bends. These lattices have been transmitted to SysInt.
RTML: David Sagan reporting.
The new RTML deckmasters are getting their tools for lattice design interfaced to the RTML design lattices. They may need more information from CFS to accomplish their design work.
ML: Alex Valishev reporting.
The positron linac "beta bump" issue has been investigated. It's caused by the two short cryo strings in the positron linac -- the bump is due to beta matching across the resulting aperiodicity. We need to ask Tom Peterson if cryogenics really wants two short cryo strings in the positron linac (they are needed in the electron linac because of the undulator). As far as the angle between the ML and the BDS is concerned, there has been some thinking about the issue, which is summarized in a presentation. The angle is 340 urad, which can be corrected with either a vertical arc or with an increase in the curvature of the 150-250 GeV portion of the linac. The arc would have to be at least 20 meters of bend magnet based on SR power considerations, and there are additonal optics and SR emittance growth issues to consider. Increasing the curvature of the ELIN2/PLIN2 area would not require any lengthening of the linac (the "kinks" in this section would grow by about 50%), but would result in the downstream end of ELIN2 / PLIN2 being about 1 meter "deeper" underground than the upstream end, which could have implications for cryogenic systems (if the entire ELIN/PLIN was 1 system, all the cryofluids would flow to the lowest part of the system, which in this case is the downstream end). At the moment the last kink in the ELIN2 / PLIN2 lattices is the aforementioned 340 urad, and the last few correctors in the linac are on strongly to put in this angle and simultaneously cancel dispersion. The angle may be too big to manage this way because of corrector strength and SR. Needs to be looked at.
BDS: Mark Woodley reporting.
There are discussions of possible optics changes which would occur as part of the engineering design phase. None of these changes would occur on the time scale of Winter 2008, so they would not conflict with the current effort to get the lattices together for the EDR startup.
System Integration: PT reporting.
Since Mark will be working on ATF / ATF2 for the remainder of 2007, PT has taken on his role in support of lattice integration for that period. PT has the e- and e+ lattices and is working to integrate them into the current set of files, and is also working on improvements to the punch list site, which will be released today or tomorrow (hopefully!).
PT made a presentation on the tentative and not-yet-approved plans to migrate the ILC lattice format from XSIF to Accelerator Markup Language (AML) over the course of the ED phase. Although the plans are not approved, the concept in general has the approval of the GDE EC and the PM for area systems. The tentative plan calls for preparatory work during the winter and spring of 2008, and this initial effort should be invisible to the deckmasters as they assemble the lattices for the ED phase (in XSIF).
There will be no meeting next week due to conflicts with the LET and WakeFest meetings at SLAC. The final deckmasters' meeting for 2007 will be Thursday, December 20.