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Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,*,CC2 Input Coupler,Introduction,Installation,&Processing,Tim Koeth,November 16,th,2005,Input Coupler,Delivers power that develops gradient,Allows D-Qing of cavities to match beam loading.,Wave guide TE,01,to coaxial TEM mode,Typical Input Coupler,Input Coupler,Input Coupler Installation,Cavity is assembled in Class 10 CR with 80K window and cold bellows.,Cavity is shipped and installed with this portion installed.Note protective cover with RF test port.,Input Coupler Installation,After the cavity was installed in the cryo vessel,we installed the rest of the input coupler.,Input Coupler Installation,After the vacuum portion was sealed up,a 150C bake performed to remove water.,Ramp 6,o,C/hr,Dwell 24 hrs at 150,o,C,P 1e-5mbar,Input Coupler Installation,Be certain to protect warm ceramic window during bake.Never place heat tape directly on ceramic!,Input Coupler Installation,After bake out,finish Wave Guide Hat installation.,Input Coupler Processing,PMT looking for sparking in vacuum portion,TC thermometer,IR thermometer for ceramic,DC Bias,Wave Guide from Klystron,Coupling Adjust,Dry N,2,(optional),Not shown:3 e-pickups,Signals monitored during processing:,Photo Diode for,Sparking in atm,portion,PRESENT DESY S/H WARE THRESHOLDS:,ValueFS Conv.ValueSoftware ThresholdHardware Threshold,e-5mA,10V0.5 1 V5 6 V,PMT1 LUX,10 V1 3 V5 6 V,P.D.-0.2 V,Temp Cerm.70C90C,In-Cplr Vac12E-7 mbar1E-5mbar,The spark interlock is,NOT,reset!One must inspect the copper waveguide and warm ceramic window after such an event.,Input Coupler Processing,Input Coupler Processing,PROCESS CONTROL LOGIC:,SOFTWARE LOGIC:After each RF pulse,if e-,PMT,light,vacuum,temperature etc signals are higher than the threshold value the power is decreased by one step,if not then the power is increased by one step.,HARDWARE LOGIC:In addition to the software limits used during processing,there are hardware interlocks with greater trip thresholds.The RF is shut off with the“fast switch when the Hardware Threshold is exceeded.,In the event of a Hardware trip:,1.Turn RF off,2.Wait three minutes,3.The conditioning program tries to reset the interlock,4.If reset is successful,RF power setting is set to the minimum(starting)value,and program does fast power increase(10 steps in 10 seconds)to about 90 to 95%of RF power at the event.,Input Coupler Processing,WARM PROCESSING(allows pump to remove contaminants),DESYs Warm Processing Recipe:,Pulse length Pwr Rise/fall RateMax Power Dwell time,20S1kW/min in 30 sec incrm.1 MW1 hour,50 S 1kW/min in 30 sec incrm.1 MW1 hour,100 S1kW/min in 30 sec incrm.1 MW1 hour,200 S1kW/min in 30 sec incrm.1 MW1 hour,400 S1kW/min in 30 sec incrm.1 MW1 hour,800 S1kW/min in 30 sec incrm.500 kW1 hour,1300 S1kW/min in 30 sec incrm.500 kW1 hour,“At the end of the procedure we also do the power sweep for some 2.5 hrs.,D.Kostine,Input Coupler Processing,e-coupler vacuum,e-pickup in cavity vacuum,An example:Multipactoring in“cold portion during processing of AC68 at DESY,Input Coupler Processing,Vacuum,RF Power,Temp,Temp,An example:Power sweep processing during cooldown of AC68 at DESY,Input Coupler Processing,DESYs Cold&On Resonance Recipe:,Pulse length Pwr Rise/fall RateMax Power Dwell Max Pwr,20Srectangular1kW/min(30Ssec)1 MW1 hour,50 S rectangular1kW/min(30Ssec).1 MW1 hour,100 S rectangular1kW/min(30Ssec).1 MW1 hour,200 S rectangular1kW/min(30Ssec).1 MW1 hour,400 S rectangular1kW/min(30Ssec).1 MW1 hour,500+100 S Flat-top1kW/min(30Ssec).1 MW1 hour,500+200 S Flat-top1kW/min(30Ssec).1 MW1 hour,500+400 S Flat-top1kW/min(30Ssec).1 MW1 hour,500+600 S Flat-top1kW/min(30Ssec).500kW1 hour,500+800 S Flat-top1kW/min(30Ssec).500kW1 hour,One must calculate the Eacc for each pulse and set the maximum power accordingly(in our case maximum.Eacc is about 25MV/m at 500 S rise-time and 3e6 coupler Qloaded).,“We do also the high power cavity processing,but it is not possible in Your case one needs 1MW at 100,200,300 us pulses for that purpose and the HPP on the cavity is done for 100,200,300,400,.,1300us pulses up to cavity quench each time.-D.Kostine,“Cold Input Coupler Processing(On Cavity Resonance),Input Coupler Processing,It is important to monitor the gradient as not to quench the cavity or exceed rad-safety x-ray limits.,Goals for Nov/Dec 05,Warm and Cold processing of the input coupler on CC2 at Meson.,Processing done manually!,We have begun developing the needed systems automation of input coupler processing:AD,TD,&CD,
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