<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=US-ASCII" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 8.00.6001.18928"></HEAD> <BODY style="FONT-FAMILY: Arial; COLOR: #000000; FONT-SIZE: 10pt" id=role_body bottomMargin=7 leftMargin=7 rightMargin=7 topMargin=7><FONT id=role_document color=#000000 size=2 face=Arial> <DIV>Hi All,</DIV> <DIV>    I believe the discussion of charge separation is a diversion from what the muon cooling team should be addressing.  I still maintain that if the issue is feasibility, then charge separation is irrelevant.  Suppose, for example, that a $1B cooling channel or part of one had to be duplicated for a muon collider because we couldn't figure out how to separate charges.  An extra $1B for a $10B project is still only a 10% effect, which is in the noise compared to the other uncertainties in a MC design.</DIV> <DIV> </DIV> <DIV>    There are more pressing issues and straightforward ways to address them by experiment and calculation.</DIV> <DIV>    We have to come to grips with the comparisons of techniques, not only for the assumptions in the simulations but the implied hardware capabilities.     </DIV> <DIV>    The proponents of cooling channels should be asked to prepare their end-to-end simulation input files so that an unbiased but knowledgeable accelerator scientist could duplicate the calculations. </DIV> <DIV>    Understanding the maximum charge that an RF bucket can hold for a given frequency and phase angle will have very large implications for any design that has an end to end cooling/acceleration/collision plan.  </DIV> <DIV>    Likewise, the maximum RF gradient, breakdown sensitivity, and sensitivity to external magnetic fields for vacuum and pressurized cavities are important inputs to any comparisons.  Identifying critical experiments will be helpful to get priority to do them and a very important role the muon cooling team could play.</DIV> <DIV>    Engineering questions related to superconducting magnets and energy absorbers can limit the performance of the cooling channels.  Understanding and pushing the state of the art and developing prototypes should also be encouraged by the muon cooling team.</DIV> <DIV>    Rol</DIV> <DIV><FONT lang=0 size=2 face=Arial FAMILY="SANSSERIF" PTSIZE="10">Dr. Rolland Johnson<BR>President, Muons, Inc.<BR>(757) 870-6943 (cell)<BR>(757) 930-1463 (home office) <DIV> </DIV> <DIV> <DIV>In a message dated 6/30/2010 4:02:19 P.M. Eastern Daylight Time, tjrob@fnal.gov writes:</DIV> <BLOCKQUOTE style="BORDER-LEFT: blue 2px solid; PADDING-LEFT: 5px; MARGIN-LEFT: 5px"><FONT style="BACKGROUND-COLOR: transparent" color=#000000 size=2 face=Arial>As discussed last week, we will have a meeting to discuss charge separation in <BR>the context of muon cooling. This is part of the ongoing series of meetings and <BR>discussions on comparing and assessing cooling techniques.<BR><BR>    Date:   July 7, 2010<BR>    Time:   14:00 CDT<BR>    Room:   Rec Room (WH4NW)<BR>    Bridge: 510-665-5437, ID 0002<BR>    URL:    http://indico.fnal.gov/conferenceDisplay.py?confId=3456<BR><BR>Bob Palmer, Rick Fernow, and Dave Neuffer will talk about their ideas and <BR>results. If you also have something to present on this topic, send email to Tom <BR>Roberts (tjrob@fnal.gov).<BR>_______________________________________________<BR>MAP-l mailing list<BR>MAP-l@lists.bnl.gov<BR>https://lists.bnl.gov/mailman/listinfo/map-l<BR></FONT></BLOCKQUOTE></DIV></FONT></DIV></FONT></BODY></HTML>