From dbowring at lbl.gov Fri Jun 22 18:10:04 2012 From: dbowring at lbl.gov (Daniel Bowring) Date: Fri, 22 Jun 2012 15:10:04 -0700 Subject: [MAP] Be Wall Cavity: on- or off-axis? Message-ID: All, Is it necessary that the beryllium wall cavity be coaxial with the magnetic field in the Lab G solenoid? Debate on this issue has slowed the design effort. We would like to finish the design very soon, but one last attempt at consensus seems warranted. Our next design meeting with SLAC will probably happen on Tuesday, June 26. If you have strong feelings about this issue, please share those feelings with me before then. (And please accept my apologies for the somewhat late notice.) Please see our recent IPAC paper for background information: http://199.190.250.75/prepress/THPPC033.PDF In that design, the cavity center is 2 cm lower than the magnet axis. Very briefly: - Some people feel the cavity axis should be aligned with the axis of the solenoid. Since we know so little about the physics of breakdown in strong magnetic fields, it is felt that azimuthal symmetry would simplify our analysis of future data. The only way to achieve azimuthal symmetry is to design a cavity that is coaxial with the solenoidal fields. - On the other hand, there's not much room in the solenoid. Centering the cavity is surprisingly difficult once you account for nonzero waveguide thicknesses, bolted flanges, vacuum conductance, etc. Given our time and budgetary constraints, a prolonged R&D effort in this direction may be unwarranted. Especially because there is not currently any convincing *physics* argument in favor of such an effort. These arguments are expanded in my most recent MTA-RF meeting presentation: https://indico.fnal.gov/conferenceDisplay.py?confId=5697 Furthermore, Yagmur has provided a link to the solenoid's field map. Scroll down to the bottom of this page: http://mice.iit.edu/mta/magnet/magnet.html If you have input, please send it to me by Tuesday, June 26. (Please do not "reply-all" to this email.) Thanks very much, Daniel From bross at fnal.gov Fri Jun 22 18:14:43 2012 From: bross at fnal.gov (Alan D Bross) Date: Fri, 22 Jun 2012 22:14:43 +0000 Subject: [MAP] Be Wall Cavity: on- or off-axis? In-Reply-To: References: Message-ID: <161C422AB24ADC468109844457B06BAFCBB5BD@MAIL01.fnal.gov> Daniel, The field is relatively uniform in the center of the magnet, so that should be taken into consideration. If there is worry about the field along the entire length of the coupler, that would be a different matter. BTW, can you send me the original (hi-res) of the upper right picture on pg. 3? Thanks, Alan Alan Bross (630) 840-4880 (office) (639) 667-3061 (cell) bross at fnal.gov -----Original Message----- From: map-l-bounces at lists.bnl.gov [mailto:map-l-bounces at lists.bnl.gov] On Behalf Of Daniel Bowring Sent: Friday, June 22, 2012 5:10 PM To: MAP-l at lists.bnl.gov Subject: [MAP] Be Wall Cavity: on- or off-axis? All, Is it necessary that the beryllium wall cavity be coaxial with the magnetic field in the Lab G solenoid? Debate on this issue has slowed the design effort. We would like to finish the design very soon, but one last attempt at consensus seems warranted. Our next design meeting with SLAC will probably happen on Tuesday, June 26. If you have strong feelings about this issue, please share those feelings with me before then. (And please accept my apologies for the somewhat late notice.) Please see our recent IPAC paper for background information: http://199.190.250.75/prepress/THPPC033.PDF In that design, the cavity center is 2 cm lower than the magnet axis. Very briefly: - Some people feel the cavity axis should be aligned with the axis of the solenoid. Since we know so little about the physics of breakdown in strong magnetic fields, it is felt that azimuthal symmetry would simplify our analysis of future data. The only way to achieve azimuthal symmetry is to design a cavity that is coaxial with the solenoidal fields. - On the other hand, there's not much room in the solenoid. Centering the cavity is surprisingly difficult once you account for nonzero waveguide thicknesses, bolted flanges, vacuum conductance, etc. Given our time and budgetary constraints, a prolonged R&D effort in this direction may be unwarranted. Especially because there is not currently any convincing *physics* argument in favor of such an effort. These arguments are expanded in my most recent MTA-RF meeting presentation: https://indico.fnal.gov/conferenceDisplay.py?confId=5697 Furthermore, Yagmur has provided a link to the solenoid's field map. Scroll down to the bottom of this page: http://mice.iit.edu/mta/magnet/magnet.html If you have input, please send it to me by Tuesday, June 26. (Please do not "reply-all" to this email.) Thanks very much, Daniel _______________________________________________ MAP-l mailing list MAP-l at lists.bnl.gov https://lists.bnl.gov/mailman/listinfo/map-l From mszisman at lbl.gov Fri Jun 22 22:41:30 2012 From: mszisman at lbl.gov (Michael S. Zisman) Date: Fri, 22 Jun 2012 19:41:30 -0700 Subject: [MAP] Be Wall Cavity: on- or off-axis? In-Reply-To: References: Message-ID: <86751A7A-B299-42E9-9798-2BB0ECDA3151@lbl.gov> I don't think a 2 cm displacement in a solenoid matters much. I would proceed. --Mike Michael S. Zisman Mail Stop 71R0211 Lawrence Berkeley National Lab One Cyclotron Road Berkeley, CA 94720 On Jun 22, 2012, at 3:10 PM, Daniel Bowring wrote: > -------- > WARNING: At least one of the links in the message below goes to an IP address (e.g. > 10.1.1.1), which could be malicious. To learn how to protect yourself, please go here: > http://www.lbl.gov/cyber/services/suspicious-links.html > -------- > > All, > > Is it necessary that the beryllium wall cavity be coaxial with the > magnetic field in the Lab G solenoid? > > Debate on this issue has slowed the design effort. We would like to > finish the design very soon, but one last attempt at consensus seems > warranted. Our next design meeting with SLAC will probably happen on > Tuesday, June 26. If you have strong feelings about this issue, > please share those feelings with me before then. (And please accept > my apologies for the somewhat late notice.) > > Please see our recent IPAC paper for background information: > http://199.190.250.75/prepress/THPPC033.PDF > In that design, the cavity center is 2 cm lower than the magnet axis. > > Very briefly: > > - Some people feel the cavity axis should be aligned with the axis of > the solenoid. Since we know so little about the physics of breakdown > in strong magnetic fields, it is felt that azimuthal symmetry would > simplify our analysis of future data. The only way to achieve > azimuthal symmetry is to design a cavity that is coaxial with the > solenoidal fields. > > - On the other hand, there's not much room in the solenoid. Centering > the cavity is surprisingly difficult once you account for nonzero > waveguide thicknesses, bolted flanges, vacuum conductance, etc. Given > our time and budgetary constraints, a prolonged R&D effort in this > direction may be unwarranted. Especially because there is not > currently any convincing *physics* argument in favor of such an > effort. > > These arguments are expanded in my most recent MTA-RF meeting presentation: > https://indico.fnal.gov/conferenceDisplay.py?confId=5697 > > Furthermore, Yagmur has provided a link to the solenoid's field map. > Scroll down to the bottom of this page: > http://mice.iit.edu/mta/magnet/magnet.html > > If you have input, please send it to me by Tuesday, June 26. (Please > do not "reply-all" to this email.) > > Thanks very much, > Daniel > _______________________________________________ > MAP-l mailing list > MAP-l at lists.bnl.gov > https://lists.bnl.gov/mailman/listinfo/map-l > From mapalmer at fnal.gov Wed Jun 27 15:35:52 2012 From: mapalmer at fnal.gov (Mark A Palmer) Date: Wed, 27 Jun 2012 19:35:52 +0000 Subject: [MAP] Upcoming MuPAC Review Message-ID: Dear All, As you are aware, the MAP Program Advisory Committee will be conducting its review on July 11-13. The committee this year is chaired by Tor Raubenheimer the present membership consists of: Muon Accelerator Program Advisory Committee (MuPAC) * Sergey Belomestnykh (BNL) * Tom McManamy (ORNL) * Katsunobu Oide (KEK) * Ritchie Patterson (Cornell) * Tor Raubenheimer (SLAC) - Chair * Thomas Roser (BNL) * Susan Smith (Daresbury) * Mike Syphers (FNAL) * Tom Taylor (CERN) * Frank Zimmermann (CERN) A web-site has been prepared for the review at: Indico Page This page is password protected (muons12). If you are planning to attend the review (as one of the designated speakers, or just to be present), please register on the site so that we know how many will likely be there. We will be providing a WebEx connection for the meeting (details to follow) to allow those who are off-site to follow the meeting. In addition, we have scheduled practice talks in preparation for the review which will take place next Thursday and Friday (July 5-6). We will circulate a timetable and separate Indico link for the practices over the course of the next few days. Best Regards, Mark Mark A. Palmer, Director, U.S. Muon Accelerator Program Fermilab, P.O. Box 500, MS221, Batavia, IL 60510-0500 Email: mapalmer at fnal.gov Voice: (630)640-0138 -------------- next part -------------- An HTML attachment was scrubbed... URL: https://lists.bnl.gov/mailman/private/map-l/attachments/20120627/9ff87b0a/attachment.html From fernow at bnl.gov Wed Jun 27 17:22:45 2012 From: fernow at bnl.gov (Fernow, Richard C) Date: Wed, 27 Jun 2012 21:22:45 +0000 Subject: [MAP] Don't call it a Fernow-Neuffer plot Message-ID: <4BE4E4CD8E1357488502DE2E91AE02FD0D0FCDEA@EX10-MB2.BNL.GOV> A number of people have been calling plots of transverse versus longitudinal emittance for muon collider cooling a "Fernow-Neuffer" plot. I assume this came about because a plot of this type appeared in a paper about cooling for a Higgs Factory that David and I wrote in 2001. I feel greatly honored to join the ranks of people like Fowler and Nordheim in having a plot named after them, but alas it turns out I really don't deserve this honor. I have recently come across a plot of this type (attached) that was presented at the MuTAC Review in 1999. I am fairly certain that this plot was created by Bob Palmer, although I have been unable to find transparencies from that review that would confirm this. Thus, unless someone can find an earlier example, call it a "Palmer" plot if you feel it's necessary to attach someone's name to it, or just call it an emittance scenario plot. -------------- next part -------------- A non-text attachment was scrubbed... Name: emittance plot.pdf Type: application/pdf Size: 72685 bytes Desc: emittance plot.pdf Url : https://lists.bnl.gov/mailman/private/map-l/attachments/20120627/79b2d193/attachment-0001.pdf