1. 13 Dec. 2004 MAC Review – Future IR Heating Issues 1 Future IR Heating Issues 13 December 2004 Stan Ecklund

2. 13 Dec. 2004 MAC Review – Future IR Heating Issues 2 IR Heating Issues - Overview Since Last Review (April) –MD data with Vertex Bellows cooling off and –Data on bunch length dependence of HOM power. –New improved chiller system for cooling water. Status –HOM Heating Vertex Bellows 2002 Cooling is working well – Power now 500 W Q1/Q2 Bellows –Larger HOM absorbers in 2002. –Will need to improve HOM/Power capability - now 11 KW –Synchrotron Radiation LEB B1 Fan Hits LEB Leg of Q2 Crotch and Q4 chamber –May be cause of magnet motion (~20 microns). –New Q4 chamber, bellows and Q5 chamber HEB – B1 fan aimed at High Power Dump must miss Q5R chamber flange. New Q5R chamber.

3. 13 Dec. 2004 MAC Review – Future IR Heating Issues 3 Near IR

4. 13 Dec. 2004 MAC Review – Future IR Heating Issues 4

5. 13 Dec. 2004 MAC Review – Future IR Heating Issues 5 IR Vacuum Chambers

6. 13 Dec. 2004 MAC Review – Future IR Heating Issues 6 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)

7. 13 Dec. 2004 MAC Review – Future IR Heating Issues 7 Forward VTX BLWS Cooling

8. 13 Dec. 2004 MAC Review – Future IR Heating Issues 8 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

9. 13 Dec. 2004 MAC Review – Future IR Heating Issues 9 VTX Bellows Cooling Installation

10. 13 Dec. 2004 MAC Review – Future IR Heating Issues 10 Vertex Bellows Cooling Added in 2002 is still working Increased Currents: From 1500 on 1000 to 2450 on 1500 Shorter Bunch Length dT=reduced by factor of 2.7 Time constant 100 sec vs. 220 before OK with today’s increased currents and till 2006 plan. Next design needs cooled absorber

11. 13 Dec. 2004 MAC Review – Future IR Heating Issues 11 Vertex Bellows Absorber Design

12. 13 Dec. 2004 MAC Review – Future IR Heating Issues 12 Erratic Behavior Similar to Before

13. 13 Dec. 2004 MAC Review – Future IR Heating Issues 13 Cooling off T_VTX2 Forward Vertex bellows Step Change at 1400 ma –Step -0.004 out of 0.034 or 12% –From bellows motion? Data in Blue Fit in Red Time constant 221 sec Linear term 0.00985 –dT = 14 F at 1400 ma HOM term = 0.0341 –dT = 44 F at 1400 ma

14. 13 Dec. 2004 MAC Review – Future IR Heating Issues 14 Cooling off Summary

15. 13 Dec. 2004 MAC Review – Future IR Heating Issues 15 Backward and Forward Vertex BLWS Temperatures

16. 13 Dec. 2004 MAC Review – Future IR Heating Issues 16

17. 13 Dec. 2004 MAC Review – Future IR Heating Issues 17

18. 13 Dec. 2004 MAC Review – Future IR Heating Issues 18 Thermo Model (May 2001) for 100 Watts Power input behind fingers. Does not match data in detail.

19. 13 Dec. 2004 MAC Review – Future IR Heating Issues 19 LER Bunch Length MD Vary V rf = [2.9, 3.2, 3.8, 4.5, 4.8 MV], I LER =[500, 1000, 1400] Fit T(t) = T 0 + L * I LER + LHOM * (I LER 2 / N b ) *(V rf /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 = 0.0024 degF/ma LHOM = 0.0123 degF/ma2 With out cooling LHOM = 0.0341 ( 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

20. 13 Dec. 2004 MAC Review – Future IR Heating Issues 20 V rf I LER

21. 13 Dec. 2004 MAC Review – Future IR Heating Issues 21 Bellows Power July 2004 Taken from max – min of Thermocouples HSTB data during a typical day TC on water out tubes Turbine flow meter measures water flow Mass flow meter measures air flow VTX 416 Watts Q1/Q2: 11 KW

22. 13 Dec. 2004 MAC Review – Future IR Heating Issues 22 Measured and Projected Power

23. 13 Dec. 2004 MAC Review – Future IR Heating Issues 23 LEB+HEB HOM Power ~  i b 2  z -2

24. 13 Dec. 2004 MAC Review – Future IR Heating Issues 24 Be Vertex Pipe and Bellows

25. 13 Dec. 2004 MAC Review – Future IR Heating Issues 25 Synchrotron Radiation – Backward LER B1& Q1Fans LER Leg of Q2 Crotch chamber and Q4 chamber dT=84 F / 2250 ma. Suspect this is cause of observed magnet motion. Working on ways to improve cooling on LER Q2 and Q4 chambers with additional cooling. LEB side,+x,y=0, small Cu finger, z=-2.8 m LER Q4 vac, +x, z=-3.64 next to flange

26. 13 Dec. 2004 MAC Review – Future IR Heating Issues 26 LEB Fans

27. 13 Dec. 2004 MAC Review – Future IR Heating Issues 27 HEB Fans – new Q5 chamber

28. 13 Dec. 2004 MAC Review – Future IR Heating Issues 28 New Chiller Water System Improved Reliability –Heat exchange to IR2 Chiller with 4 units –Mixing valve and pump –New Allen-Bradley controllers Better Temperature Control –Heaters in hall for 10 individual water circuits can respond to changes in beam heating quickly. –Sensors on IR vacuum chambers can control heaters. Full Flow strainer Larger Capacity –From 20 to 50 KW Project completed this summer –Some Programming work remains to be done.

29. 13 Dec. 2004 MAC Review – Future IR Heating Issues 29 Future IR Heating Issues - Summary HOM Heating –Planned increase in bunch current and decrease in bunch lengths drive up HOM heating dramatically. –Increase in heating may be less if bunch length increases with bunch current. –Vertex Bellows: 2002 cooling works up to 1.8 A HER on 3.3 A LER Add absorber to new design in next long downtime with ST removal. –Q1/Q2 Bellows Now taking out 11 KW Expect power to increase to 22 KW Working on design to handle higher power. Synchrotron Fan Heating –Backward LEB Q2 Leg and Q4 chamber needs solution for cooling/motion –Plan to take more Data to better characterize heating dependence on bunch length, bunch current, number of bunches,… –Improve VTX Beryllium diagnostic. New Vacuum chambers –Spare forward Q2 chamber –Radial Ion pump –Q1/Q2 Bellows with improved power capacity –VTX Bellows with absorber –Q4, Q5 chambers …