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Breakdowns at 352 MHz. Rolf Wegner. Results: no substantial results no measurements of BDR Aim: exchange of ideas work together * 352 MHz cavity + test stand * no automated conditioning system * no measurement system for BDR. Outline. Motivation SPL / Linac4 CCDTL prototype
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Breakdowns at 352 MHz Rolf Wegner Rolf Wegner Breakdowns at 352 MHz
Results: • no substantial results • no measurements of BDR Aim: • exchange of ideas • work together* 352 MHz cavity + test stand * no automated conditioning system* no measurement system for BDR Rolf Wegner Breakdowns at 352 MHz
Outline • Motivation • SPL / Linac4 • CCDTL prototype • PIMS prototype • Discussion Rolf Wegner Breakdowns at 352 MHz
Motivation • high power test of CCDTL, • f0= 352 MHz, standing wave cavitytp= 0.5 ms (176’000 cycles, ~ 10*QL)frep= 1..50 Hzcondition 1 week, operation 1 week, BDR < 10-5 • tp= 1.0 ms ==> many breakdowns, 1 day conditioning • tp= 2.0 ms ==> many breakdowns • CLIC workshop: E ~ tp-1/6(BDR=const.) Rolf Wegner Breakdowns at 352 MHz
SPL / Linac4 Rolf Wegner Breakdowns at 352 MHz
SPL / Linac4 Rolf Wegner Breakdowns at 352 MHz
SPL / Linac4 Rolf Wegner Breakdowns at 352 MHz
CCDTL prototype Rolf Wegner Breakdowns at 352 MHz
CCDTL prototype Rolf Wegner Breakdowns at 352 MHz
CCDTL prototype f0 = 352.2 MHz Pd = 170 kW (1 tank) Wstored = 2.7 J (1 tank) Q0,m = 38000 r/Q = 364 Ω ZT2 = 42 MΩ/m E0 = 3.8 MV/m Emax = 30 MV/m (1.7 Kilp.) Hmax = 17 kA/m Scmax = 22 kW/mm2 Max(|H|)17 kA/m Max(Sc)22 kW/mm2 Max(|E|) 30 MV/m Rolf Wegner Breakdowns at 352 MHz
Kilpatrick f = 1.643 Ek2 * exp(-8.5/Ek) [f in MHz, Ek in MV/m] Rolf Wegner Breakdowns at 352 MHz
CCDTL prototype Rolf Wegner Breakdowns at 352 MHz
CCDTL prototype Rolf Wegner Breakdowns at 352 MHz
PIMS prototype Rolf Wegner Breakdowns at 352 MHz
PIMS prototype f0 = 352.2 MHz Pd = 110 kW (1 cell) Wstored = 1.6J (1 cell) Q0,m = 23000 r/Q = 143 Ω ZT2 = 33 MΩ/m E0 = 4.0 MV/m Emax = 33 MV/m (1.8 Kilp.) Hmax = 11 kA/m Scmax = 18 kW/mm2 Max(|H|)11 kA/m Max(Sc)18 kW/mm2 Max(|E|) 33 MV/m Rolf Wegner Breakdowns at 352 MHz
PIMS prototype Rolf Wegner Breakdowns at 352 MHz
PIMS prototype Rolf Wegner Breakdowns at 352 MHz
discussion Sc ~ 20 kW/mm2, tp = 1 ms scaling tp0 = 100 ns Rolf Wegner Breakdowns at 352 MHz
discussion Sc ~ 20 kW/mm2, tp = 2 ms scaling tp0 = 100 ns Rolf Wegner Breakdowns at 352 MHz