Hi Warren et al,
A few things to keep in mind regarding the quad layout.
1) The current rf distribution design (see below) exploits the space near the center of the center cryomodule afforded by the quad to all allow a simple waveguide split to fed the cavities in this cryomodule.
2) Having 1 quad per 4 cryomodules means having 4 different installation plans, 4 different waveguide layouts, 4 different quad power/monitoring cable runs, 4 different rack layouts in the service tunnel, 4 different rf unit control system configurations and 4 different temperature-vs-phase responses during operation - having one quad per 3 cryomodules would reduce these to one, and thus greatly simplify the design, installation and operation of the linac - the cost savings are hard to quantify, but 10-20 M$ is not unreasonable given the reduction in complexity (this represents about 10% of the linac installation cost).
3) The quads could be smaller with the 1 in 3 layout, making them somewhat cheaper.
From: Warren Funk [mailto:lwfunk@xxxxxxxx]
Sent: Monday, June 12, 2006 9:15 AM
Cc: ml-ccb@xxxxxxxxxxxx; ml-ext-gde@xxxxxxxxxxxx
Subject: Re: [Ext-GDE-46] ML Change Request - June 12, 2006
I agree to act as reviewer for this change.
I disagree with the classification of this change as Class 0. The proposal calls for an increase of ~170 magnet sets. I estimate that the cost of this will fall somewhere between $15M and $20M, when development costs are included. There is evidently some offset (savings in RF distribution) but unless I'm missing something (it's happend before!) that won't be large.
I request that you consider classifying it as Class 1.
Dear Colleagues, I am announcing that CCB has received a change request for the Main Linac (ML) section of ILC Baseline Config Doc from C.Adolphsen, who is representing the ML AG. This change request mainly relates to layout specifications for the cryostats, beam position monitors, focusing quads and the associated orbit correction dipole magnets. Another part of the change request relates to elimination of a duplicate subsection (cryogenics). The requesters suggest Class 0 as classification for this change request. The CCB chair tentatively agrees to treat this as Class 0, pending consultation within CCB. I am asking W.Funk and C.Pagani to act as CCB reviewers (to be confirmed shortly). Now this request is brought to review by CCB, and is also open to general discussion. Any members of GDE or GDE-related task groups with comments or questions on this request, please, direct them to ml-ccb@xxxxxxxxxxxx and/or ml-ext-gde@xxxxxxxxxxxx by the end of Friday, June 16, PDT. BCD is available at http://www.linearcollider.org/wiki/doku.php?id=bcd:bcd_home BCD change history is available at http://www.linearcollider.org/wiki/doku.php?id=bcd:bcd_history ML-related RDR materials are compiled and posted at http://www.linearcollider.org/wiki/doku.php?id=rdr:rdr_as:main_linac_home Sincerely, - Nobu Toge (KEK, Accelerator Lab) email: toge@xxxxxxxxxxxx voice: +81-29-864-5224 fax: +81-29-864-3182
-- L. Warren Funk Accelerator Division Jefferson Lab 12000 Jefferson Ave. Bldg. 12, Rm. C-221, MS-12A2 Newport News, VA 23606 Phone: 757-269-7690 Fax: 757-269-6099 email: lwfunk@xxxxxxxx