From settles@mppmu.mpg.de Wed Aug 8 15:45:54 2007 Date: Wed, 8 Aug 2007 10:08:18 +0200 (CEST) From: Ronald Dean Settles To: lctpc@desy.de Subject: [lctpc] Phonemeeting WP#36 today 08.08.2007 Dear lctpc friends, In the announcement yesterday, I wrote the wrong meeting number for the LP1 phonemeeting (sorry about that). Here is a list of things to decide, and we will see how far we get today... Cheers, Ron P.S. I will be out of touch for the next couple of hours while traveling to Hamburg. WP#36 08/08/2007 -------------------------------------------- Wednesday 8 August 2007 West Coast East Coast W.Europe Japan 07.00 10.00 16.00 23.00 To join, dial +494089981390, after a few seconds into an answer in German, type the code number 52872# (LCTPC#). Issues for the agenda ----------------------- 1. Cosmic trigger: status reports from whomever of the reponsible persons is ready: Basic design: Klaus Scintillator slabs plus light fibres plus MPPC: Takeshi Electronics and power supply: Paul and/or CDC Assembly and Lab test: Sacly/Paul Support and installation at PCMAG: Klaus Schedule: ready beginning 2008. 2. LP1 fieldcage/endplate a. Dan wrote yesterday: I have updated some drawings on the web page: http://w4.lns.cornell.edu/~dpp/linear_collider/LargePrototype.html to 1) update the 3GEM+G backframe specification 2) publish the bounding box drawing and 3) emphisize points about the relative geometry. Dan Reminder: the status from the last meetings: ---magnet inner bore 850mm ID --SiLC detectors (see phonemeeting #27) 35mm on radius --clearance inside of SiLC 780mm --extra clearance (see phonemeeting #27) 5mm on radius --OD of field cage 770mm --field cage wall 25mm --ID of field cage 720mm --module insertion clearance to field cage 3mm on radius --"stay clear" diameter 714mm --40 bolts, 6mm x 1mm, with bolts in the vertical and horizontal positions and 4 pin positions in the field cage. --Weight of the endplate: 16kg (could be reduced if needed) b. Some design parameters on which we must agree are: 0) endcap-weight tolerance, 1) bolt circle radius for the 40 M6 bolts (this is 376mm in the drawing shown on the web page), 2) whether the o-ring groove placed in the field cage flange of in the endplate, 3) o-ring size and radial location (this is a 4mm grove, with IR=365mm, in the drawing on the web page), 4) location of the first field shaping band (this 35mm, to the edge of the first band, in the drawing on the web page), 5) location of the field shaping band that defines the end of the drift field (this determines the step in the endplate), 6) endcap-flatness specs, including "skirt" (drift-field termination surfaces-probably made of copper sheet-for areas where there is no panel), c. Other matters: 7) gas seal overpressure: 2mbar, 8) gas seal test should be made in a G-10 field cage flange, 9) stress-relief tests done: analysis in progress, 10) cable supports: brackets to be included, 11) gas inlet/outlet: TBD, 12) temperature stability/cooling: tolerance TBD. Related to points 6) and 7), Dan calculated the bowing due to overpressure using the simple analytical formula from an engineering handbook (finite elements are not needed). The result is about 50micrometer deflection at the center for 6mbar overpressure (therefore 3 times less for 2mbar overpressure). (Note added by RS: this should be included in Peter Schade's electrostatic simulations, to see if this is good enough.) 3. AOB News: Status of LDC/GLD