Dear All, (this contains replies to Ashutosh's queries in the main body - but also new considerations). If the ILC goes ahead, it seems to me that a 100 TeV VLHC if it is achievable is clearly a front-runner in science potential and technical feasibility for superseding LHC and complementing the ILC program by exploring much higher mass scales in direct production. Whether the VLHC is at the right scale and would find new things is a different matter. If ILC doesn't go ahead in the next few years, I think there will still be a compelling argument to have a high energy e+e- facility to do the physics outlined in paragraph 3. Perhaps the best way to address the ILC sensitivity about the VLHC discussion would be to make it clearer that the VLHC discussion is in the context of having a plan to really supersede LHC in the hadron collider approach to energy frontier physics in tandem with a lepton collider like ILC which would be really complementary to LHC/VLHC. (I doubt VLHC (or the MC) is targeting H-> c cbar ...) Paragraph 4: Suggest: options -> possibilities. Options reads as if all these things really are realistically on the menu and implies that they can be chosen as potential alternatives to HL-LHC and particularly ILC. I don't think this body, at least in the context of the energy-frontier science discussion paragraphs, is the one to make recommendations related to R&D priorities, especially accelerator R&D priorities. If it does so it should be balanced and also recognize the need for continued funding for LARP, detector R&D for HL-LHC, and accelerator and detector R&D for ILC to get the best physics out of the programs outlined in paragraphs 2 (LHC) and 3 (decision-point lepton collider). However the R&D most needed to get new facilities like both ILC and VLHC is political and financial R&D ! Clearly two things that could extend the energy reach of ILC and VLHC and/or potentially lower the cost would be continued high-gradient superconducting RF R&D and high-field magnet R&D respectively. My understanding from the talks was that high-field magnet R&D is something that is currently being pursued quite actively including as a generic accelerator technology, and should clearly continue and be supported. But my understanding is that the high gradient SC RF program at Fermilab has been eliminated. I think calling out VLHC accelerator R&D in the further future facilities paragraph is unwise and reads like a recommendation. (Suggest accelerator R&D -> accelerator). What would seem to me most needed for VLHC - but Chip is the expert - is a revamped integrated accelerator and physics conceptual design study. My understanding is that there is no technical show-stopper. I think what is needed is a more robust and reviewed physics case (in this post Higgs discovery phase, planned HL-LHC, plain-vanilla SUSY not experimentally detected at LHC8, pre-LHC14, pre-ILC era), plans for achievable energies, and believable cost and schedule estimates. regards Graham On 8/24/2013 8:53 PM, Ashutosh Kotwal wrote: > On Aug 24, 2013, at 6:15 PM, "Graham W. Wilson" <[log in to unmask]> wrote: > >> Dear Chip, Michael and Ashutosh, >> >> This looks reasonably OK within the confines of what has so far been discussed, but I do >> worry that not everybody will read it in the same informed spirit as Ashutosh. I do agree with points a and b. > > hi Graham, > What we can do is lay out the logic in the longer part of the Summary in a little more detail so that people will read it in the informed spirit. > > > >> I would however counsel against the explicit mention of accelerator R&D. The earlier wording about >> "more concerted work on its design and physics capability" seems to me to strike the right tone. > > that would be OK too… but presumably accelerator R&D is referring to high field magnet R&D, which is a US strength we should not let go of… > > >> We should also all realize that current US accelerator R&D is already funding >> LARP, high-field magnets, MAP, but has cut back/zeroed out high-gradient >> super-conducting RF (ILC) and put on life-support other parts of the ILC R&D program. >> Getting the best science out of ILC will need US accelerator development efforts. > > well, are you thinking that we should choose one or the other between SRF and high-field magnets? I think that would be way too restrictive. > > or are you saying we should mention something about ILC accelerator R&D also? > > regards, > Ashutosh > > >> regards >> Graham > -- Graham W. Wilson Associate Professor Dept. of Physics and Astronomy University of Kansas Lawrence, KS 66045 Office Tel. 785-864-5231 Web: http://heplx3.phsx.ku.edu/~graham/ ######################################################################## Use REPLY-ALL to reply to list To unsubscribe from the SNOWMASS-EF list, click the following link: https://listserv.slac.stanford.edu/cgi-bin/wa?SUBED1=SNOWMASS-EF&A=1