Test plan of ESS HB elliptical cavity Han
Test plan of ESS HB elliptical cavity Han Li On behalf of FREIA team FREIA Laboratory, Uppsala University 3 rd of Oct. 2017 1
The list of tests in some order of priority 1. 2. 3. 4. 5. 6. 7. Central cavity frequency and spectrum of higher-order modes (HOM) + Loaded Q (basically measurement of the 3 d. B bandwidth) + Q 0 (calorimetric measurement) + Max gradient + Tuning range of the slow step tuner + Stabilization of the cavity field with LLRF using only RF compensation - + Dynamic Lorentz force detuning (change in the cavity frequency during the RF pulse) - + 8. Compensation for the dynamic Lorentz force detuning with the fast piezo tuner 9. Stabilization of the cavity field with LLRF using both RF and piezo tuner compensation 10. Onset and level of field emission + 11. Sensitivity to helium pressure fluctuations + 12. Multipacting + 13. Cryo related test both at 4 K and 2 K + 14. Overall test of electronics. - + 2
Warm test ü ü ü Central cavity frequency and spectrum of HOM Qe Coupler warm conditioning Cool down Cold test Warm up Frequency shift due to cool down ü Coupler cold conditioning Frequency shift vs. T ü Cavity conditioning ü ü Central frequency and HOM Loaded Q and Qe ü Cavity level profile: let the LHe evaporate to low levels ü Effect of CV 105 in heat load ü Cavity's power limit ü Effect of different FPC cooling temperatures in heat load ü Max load on the 2 K pumps ü ü Q 0 Dynamic heat load Max gradient Dynamic Lorentz force detuning ü Stabilization of the cavity field with LLRF using only RF compensation ü Dynamic Lorentz force detuning ü Tuning range of the slow step tuner CRYO VNA SGD signal generator driven SEL Lund system Lund university ü Tuner related testing 3
Warm test detail Process or check item Work Description Team ü Build loop and • Build SEL RF cabling Loop and special device Power Low power SEL: Copper cavity, SEL, FPGA, interlock switch, RF switch and RF station ü instrumentation check • • validation of instruments SEL, FPGA software debuging RF SGD: Signal generater driven system, interlock system, coupler vacuum, RF station, conditioning software VNA: VNA, frequency auto checking software ü S parameter measurement • • ü Qe Get central cavity frequency Simply estimate the coupling factor and Qe RF VNA 4
Warm test detail Process or check item Work Description Team • ü preparing of Interlock system • • ü Coupler warm conditioning • • Validation of software Set related parameters in the software and vacuum interlock thredshold Ramp up forward power to 1. 1 MW during filling time Increase pulse width to 3. 5 ms Get an optimal procedure for RF conditioning CTRL RF Loop and special device SGD: software, RF station, SGD: RF station, FREIA software Power Low power High power 5
Cool down test detail Team Process or check item ü Frequency shift vs. T Work Description • Frequency shift due to cool down VNA, frequency auto checking software CRYO ü Cool down to 4 K ü Cavity level profile RF Loop and special device • ü Frequency shift vs. Pressure • let the LHe evaporate to low levels CRYO (below 30%) Frequency shift due to pressure RF VNA, frequency auto checking software CRYO ü Cool down to 2 K • • ü Static heat loads • ü Max. 2 K pumps capacity at • 2 K Effect of CV 105 in heat load Cavity's power limit: apply heat power until the level and/or the pressure in the cavity shows instabilities Effect of different FPC cooling temperatures in heat load Max. 2 K pumps capacity at 2 K (theoretically at 90 W) CRYO 6
Cold test detail (I) Process or check item Work Description Team • ü Coupler Cold conditioning • • ü Dressed cavity packet • cold conditioning • • ü Central frequency and HOM ü Loaded Q and Qe • • • Conditioning coupler with detuned cavity or with a frequency outside the cavity bandwidth Ramp up forward power to 1 MW during filling time Increase pulse width to 3. 6 ms Conditioning coupler and cavity at resonant frequency Ramp up forward power to 232 KW or less Increase pulse width to 3. 5 ms Get central cavity frequency and high order mode Loaded Q and -3 d. B bandwidth Qe Loop and special device SGD: RF CTRL Power High power RF station, FREIA software Data acquisition system Personal safty system RF CTRL SEL: RF VNA RF station FPGA, Interlock system, RF switch Data acquisition system Personal safty system Low power 7
Cold test detail (II) Process or check item Work Description Team • Runing pulse SEL from RF ü Q 0 low power with ü Dynamic heat load 3. 5 ms, 14 Hz forward CRYO ü Max gradient pulse ü Dynamic Lorentz • Get average Q 0 value as a function of force detuning average gradient • • ü Dynamic Lorentz force detuning • • Checking the radiation Increas the forward power until reaching the nominal gradient Measure dynamic heat load at different power level Use I/Q meadth to check the frequency shit during the pulse Use Lund system to generator step pulse input Use FPGA to check the frequency shit during the pulse RF Loop and special device Power SEL: High Power SEL, FPGA, RF station Interlock system, RF switch, Helium gas flowmeter, Data acquisition system, Personal safty system Lund system , FPGA, RF station Data acquisition system, Personal safty system 8
Cold test detail (III) Process or check item Work Description Team • ü Stabilization of the cavity field with LLRF using only RF compensation • ü Tuning range of the slow step tuner • ü Tuner related testing • • • Loop and special device Power High power Use Lund system to produce input pulse Ramp up power level from low power to 232 KW Stay at nomial gradient for a certain time to confirm the stabilization of the cavity field CRYO RF Lund system RF station Data acquisition system, Personal safty system Slow tuning control by lund system Slow tuning control by IPNO software ? CRYO RF Lund system Data acquisition system, Test that lund university are interested ? CTRL Lund university Low power 9
Warm up test detail Process or check item ü Frequency shift vs. Pressure Work Description • Frequency shift due to pressure Team Loop and special device RF VNA ü Warm up to 4 K CRYO • Frequency shift due to ü Frequency shift vs. T warm up RF ü Warm up to 300 K CRYO VNA 10
Current progress Ø 704 MHz SEL> • Hardware: SEL box is under design and will be finished at the end of Oct. ---key people: Tord, Tor and Han • Software: SEL Labview interface will be modified next week ---key people: Han and Tor Ø Temperature sensors • Temperature sensors location of interested. ---key people: Rocio, Magnus, Younguk and Han Ø Four wire heater for power calibration • Wiers extending of hearter; • One current meter is need to connect in the loop. ---key people: Rocio 11
FPC temperature sensors positions Cernox Pt 100 Minco Heater (thin film) Cavity-Antenna interface Cavity-FPC interface Inlet Sc. He (TT 303) TT 125 TT 117 EH 103 C (TT 143 C) Pt 100 (TT 147) FPC Midsection TT 115 EH 103 A (TT 143 A) Cooling (TT 104) Outlet Sc. He (TT 305)
To do list Ø 704 MHz Conditioning system • Hardware: Validation of Interlocks ---key people: Konrad and Kjell • Power limitation and interlock ---key people: Magnus, Konrad and Han • Software: SEL Labview interface will be modified next week ---key people: Han and Tor Ø Pressure gauge test Find out the reason of the step-wise reading and how ti improve it? ---key people: Rocio, Konrad and Han 13
questions 1. Do we need to consider quench or not ? Which signal should we use for Quech detection? What is the way to hook up this signal into interlock system? 14
Parameter for HB elliptical cavity Ø main parameter of ESS high Beta elliptical cavity 231 k. W at 19. 9 MV/m 189 k. W at 18 MV/m Ø Q 0 for SC cavity: ⪸ 10 e 9 Ø Q 0 for NC cavity: ≈ 10 e 4 15
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