IR Heating Issues Stan Ecklund 4 August 2004 PEP-II Run 4 Post Mortem IR Heating Issues2 Overview of IR Heating Issues Vertex Bellows Cooling added in 2002 is still effective MD data with cooling off and new Thermocouples MD data with Varying LER bunch Length Q1/Q2 Bellows SiC-AlN absorbers intended to absorb HOM power from Q2 crotch chamber Raft and Magnet Motion from Vacuum Chamber Heating See Talk by Andrei Seryi 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues3 IR Vacuum Chambers Vertex Bellows Q1/Q2 Bellows 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues4 Vertex Bellows Cooling Added in 2002 is still working Increased Currents From 1500 on 1000 To 2450 on 1500 Shorter Bunch Length 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues5 Forward Vertex Bellows Before Cooling T_VTX2 Thermocouple ( dT = 105 F = 58 C) Beryllium Vertex Chamber B1 Chamber Hottest Point according to model (300 C) 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues6 Forward VTX BLWS Cooling 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues7 Thermocouple Locations T_V0B270 On Ta foil, z=blws-70mm -y x=0,z=113 mm T_V1B270 Al Clam, end near IP, -y, theta=270 z=157 T_V2B270 Al clam, corner theta=270, z=17.5 T_VTX2 TC1: Forward alum clamshell (+y) T_V3B000 Inboard end of blws theta=0 T_V3B135 Inboard end of blws theta=135 T_V3B180 Inboard end of blws theta=180 T_V3B225 Inboard end of blws theta=225 T_V3B270 Inboard end of blws theta=270 T_V3B_O Inboard H2O out, -x +y T_V4B_O1 Collar H2O out -x T_V4B_O2 Collar H2O out +x T_V5B000 SS end of B1 Chamber theta =0 T_V5B180 SS end of B1 Chamber theta =180 T_V3B_AI Air in Bellows, top T_V6B_AI Air btwn B1 chamber & magnet,+y,z=295mm,slice3/slice4 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues8 VTX Bellows Cooling Installation 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues9 Hottest T_VTX2 without Cooling Step out of or 12% Better fit, rms=0.7 deg F Time constant 221 sec Linear term dT = 14 F at 1400 ma HOM term = dT = 44 F at 1400 ma Good Fit Data in Blue Fit in Red 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues10 Sample Data 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues11 Backward and Forward Vertex BLWS Temperatures 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues12 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues13 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues14 Thermo Model (May 2001) for 100 Watts Power input behind fingers. Does not match data in detail. 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues15 LER Bunch Length MD 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues16 Bunch Length MD Fit T(t) = T 0 + L * I LER + LHOM * (I LER 2 / N b ) *(V/3.8 MV) Exponential time response of temperature Good fit with above form with linear RF gap voltage driving HOM For hottest TC T_VTX2 L = degF/ma LHOM = degF/ma2 With out cooling LHOM = ( 2.77 times larger) Projects to for LER HOM heating (add about 34% - 24% for HER): Jul 2004 LER 2500 ma, V=3.8 MV, HOM dT= 44 F Jul 2005 LER 3300 ma, V=5.4 MV, HOM dT= 110 F Jul 2006 LER 3900 ma, V=7.7 MV, HOM dT= 219 F Jul 2007 LER 4500 ma, V=7.7 MV, HOM dT= 291 F 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues17 Q1/Q2 Bellows on B side (Forward) Out water temperature Moved from chilled water system Sept 2003 Parallel flow 18 Feb P = 10 KW 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues18 Measured and Projected Power 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues19 LEB+HEB HOM Power ~ i b 2 z -2 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues20 Be Vertex Pipe and Bellows 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues21 Q1/Q2 Bellows 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues22 Q1/Q2 Bellows Thermo Model at 10 KW (N. Kurita) 4 August 2004PEP-II Run 4 Post Mortem IR Heating Issues23 Conclusions Vertex Bellows likely ok for Run 5 Q1/Q2 Bellows is pushing limit. Power to double in Run 5 Water temperature rise now dT = 39 F -> 78 F Tile max temperature now 142 C -> 247 C